Thursday, January 14, 2021

The Intersection of Old Film Photography And Modern Makers

Something completely different that I find insanely cool, although I have no particular desire to own one or get involved.  

First, a little Grandpa Simpson story to get you acquainted.  When I was first getting interested in photography, the only big name cameras I knew were 35mm.  Nikon.  Canon.  Pentax.  Still the big names in photography. It took me a few years to get one and by then I had learned the reality that if you want to enlarge a picture, the bigger the negatives the more you could enlarge it.  I learned about view cameras that took glass plates as big as 8x10.  I had seen that for trips to the moon, not just once in a lifetime, but once in human history photography, NASA had used Hasselblad cameras as they had been using for most of the space program.  For use on the moon, they couldn't bring a large format view camera, taking pictures was a sidelight to the other things the crew had to do, so they brought a medium format camera, generally 6 by 6cm, smaller than the impractical cameras but considerably larger than the 35mm film at 24 by 36mm.  The film format you can buy is called 120 or 220, depending on the number of shots it will allow.

The advantages of the bigger film led to medium format being a high end camera for the very serious photographers or those that could justify the expense.  That was the case in the 1970s and for as long as I kept track.  

Imagine my surprise when Digital Photography Review (DPR), the weekly photography newsletter I get, featured an article, "These open-source medium format cameras are 3D-printed."  The article links to the store and story of Dora Goodman in Budapest, Hungary.  Ms. Goodman's company gives away the plans to print the camera parts yourself, or will sell you a finished Goodman Zone camera body for as little as $113.40 while the holiday sale is still in effect.  The body appears patterned after a very popular medium format camera, the Mamiya RB67  (from Mamiya Sekor, another major Japanese camera maker).  It currently uses the Mamiya film backs, although they will be selling their own backs soon. 


Now this is simply a camera body; a light-tight box with ways to interface to a lens, a shutter, and not much else.  Especially not a lens.  You may know that in the 35mm world, a "standard" lens is around 50mm (its photographs match most closely to how we see real life than focal lengths much shorter or longer); in the 6 x 7 cm world the equivalent is around 80mm.  A quality 80mm lens is going to set you back much more than the cost of the body.  For several lenses, you might need to sell a kidney.

PetaPixel, a serious photography devotee's place, did a story on these cameras and has more depth and lots more pictures, and there's a ton of links on both DPR and PetaPixel.  Like I said, I think it's insanely cool although I don't have much interest in following into medium format photography again.  It's cool because it's part of the paradigm of the convergence, the new industrial revolution.  It's personal fabrication; the intersection of home CNC, 3D printing, continually more powerful digital electronics, into what's called the Maker movement, in which interested people out-innovate the big guys.  It's a drum I've been beating on for years.



Wednesday, January 13, 2021

A Remarkable Day at SpaceX Boca Chica

I've been watching the activities at Boca Chica for quite a while now, and today was probably the most remarkable day of testing I've seen.  Like many people, I started watching the Lab Padre feed around mid-day in hopes of a static fire test.  Last night, they had extended the 8A to 5P road closure and were working toward a static fire by 8PM (CST).  That attempt was aborted in the last minute, prompting concerns and belief that they'd be troubleshooting and trying to repair whatever it was.  After that I was expecting to see a static fire at some point, no matter how late in the day

I never expected to see three static fires in one afternoon.  They've never done three static fires in one day before.  I'm not sure they've ever done two within 24 hours before. 


As you can see from the text at the bottom, this firing happened at 12:28:51 local time.  Right away, it didn't look like last night's attempt.  Within seconds, certainly within a minute of last night's abort, the vehicle was venting large clouds and conventional wisdom was Starship was detanking.  That didn't happen after this firing.  Soon, someone posted that Elon said they were going to do multiple firings today. 


To be clear, that time tag is EST, so 1:06 at Boca Chica, roughly 40 minutes after that screen capture.  I'm not sure what he was referring to as "two starts completed," unless one was some other time. 

By the end of the day that doesn't add up because they went on to have two more static firings today; the three were at 12:28, 2:23 and 3:37 PM.  Musk later tweeted, "all three static fires completed & no RUDs!" (Rapid Unplanned Disassembly). 

The next big milestone is clearly their launch for their re-try to do the same hop that SN8 almost completed. They believe they've got a temporary fix for the pressurization issue in the small header tank that they experienced on SN8, although they're said to be trying to come up with a fix that doesn't depend on helium as this one does. That's one less thing to take to Mars and one that requires special handling.  That flight will probably be Friday, but I have a hard time keeping up with these guys.  I can see them going for it tomorrow if the situations allow.



While on the topic of space news, I went in search of when NASA intends to do a full up firing of their SLS core stage during its Green Run Testing.  According to the SLS website, NASA is now targeting this coming Saturday, Jan. 16 for the test. 
The Green Run test series is a comprehensive assessment of the rocket’s core stage prior to SLS launching Artemis missions to the Moon. The core stage includes the liquid hydrogen tank and liquid oxygen tank, four RS-25 engines, and the computers, electronics, and avionics that serve as the “brains” of the rocket. NASA has completed seven of the eight core stage Green Run tests, including loading and draining propellant for the first time during the most recent test, the wet dress rehearsal, on Dec. 20. During the upcoming hot fire test, all four engines will fire to simulate the stage’s operation during launch.
This will be a major milestone because the system has never been tested before and it will run for the full 8 minutes expected for a mission to orbit.  True, they're using space shuttle main engines (SSMEs) and those have an extensive and excellent life history, but the rest of the vehicle is nowhere near that mature.  The test will not be televised or video live streamed (at least this posting doesn't say so) but one may apply to listen to it by audio telecast on a conference call.  Details at that SLS Website link.



Tuesday, January 12, 2021

Welcome to Dystopia

If the last few days haven't seemed like complete dystopian life, I don't think you're watching.  Tech oligarchs ban speech they disagree with?  Parler getting dumped by Google, Apple and Amazon?  Dozens getting deplatformed everywhere from Twitter to Facebook?  AR-15.com gets dumped by their ISP with no warning?  

And then there's this, lifted mercilessly from Miguel at Gun Free Zone.


I don't think I've seen a more obvious or less clever trap in my life. The chances that this is real, constitutional conservative organization are right around the chances of winning Powerball - one in 250 million?  Is it Antifa, our government, Chinese government?  Harder to say. 

All of this just from the color scheme and general look.  It's so obviously communistic that I'd bet 80% of the parodies on The People's Cube look like this.  No US flag, no red white and blue, just red and yellow.  Are the three stars on Lady Liberty three of the four on the Chinese flags?  Since I mention the lady, notice that picture is swapped left to right - she holds the torch in her right hand not her left hand like this shows.  The only thing missing from a communist poster is the hand pointing the way to the glorious future. 

As Miguel points out, notice where it says "come armed at your personal discretion" while talking about going to the White House?  Unless you've just joined the world of concealed carry you should know that carry in DC is just about completely forbidden.  The only people who can carry in DC are approved LEOs, Military on duty or those who have adequately greased the palms of the local politicos.  If you open carry in DC, you're going to jail as soon as they see you. 

Suffice it to say, in the immortal words of Admiral Ackbar from the Star Wars universe, "it's a trap!"



Monday, January 11, 2021

So Why Should I Believe the FBI?

The headline said, "FBI warns 'armed protests' are being planned in all 50 states ahead of Inauguration Day" and caught my eye.  My first reaction was the post's title: so why should I believe the FBI?  Why should I trust them?  They've lost their credibility to me - speaking as an organization, of course.  I'm sure there are tons of employees there, agents to lab scientists, whom I could trust.  From the management side, the ones who would issue this sort of news?  Not so much. 

It turns out that linked story at The Blaze relies on ABC.  ABC?  Strike two against believability. 
Starting this week and running through at least Inauguration Day, armed protests are being planned at all 50 state capitols and at the U.S. Capitol, according to an internal FBI bulletin obtained by ABC News.

The FBI has also received information in recent days on a group calling for “storming” state, local and federal government courthouses and administrative buildings in the event President Donald Trump is removed from office prior to Inauguration Day. The group is also planning to “storm” government offices in every state the day President-elect Joe Biden will be inaugurated, regardless of whether the states certified electoral votes for Biden or Trump.

"The FBI received information about an identified armed group intending to travel to Washington, DC on 16 January," the bulletin read. "They have warned that if Congress attempts to remove POTUS via the 25th Amendment, a huge uprising will occur."
Riiiigghhht.  "Received information?"  Was that information supplied by the Southern Poverty Law Center, also called the Southern Preposterous Lie Center, by any chance?  Their motto, "attacking non-liberal groups for profit since 1984."

Peter @ Bayou Renaissance Man ran a piece today with extensive long quotes from Larry Correia and Tom Kratman summarizing how they see things today.  I strongly identify with this paragraph I pulled from Larry Correia.
People are confused and constantly bombarded by conflicting information, some correct, some bull****, and nobody knows what to believe because nobody trusts the people we are supposed to be able to trust. Then we have a super powerful global media complex that straight up gas lights everyone, and we're shocked the people have lost trust in information sources.
Yeah, that's where I am.  No trust in anything from the swamp. 





Sunday, January 10, 2021

The Major Pieces Are in Place

The big lifting/moving in the shop seems to be done with.  There will be lots of smaller things moving around, and maybe some of the bigger things making smaller moves, like a few inches here or there.  I can't get you a view like the overhead views from the drawings, but I can do photographs.

Looking toward the left.


Looking toward the right.


There were some surprises and gotchas, which always seems to be the case in any project.  For one thing, the distances I expected from the model didn't show up in real life.  I wanted enough distance between the table with the two small lathes and the big lathe to the right to get that chair (front left) between them to sit while working at the lathes.  According to the CAD drawing from the left wall to the base of the lathe should have been 11 feet.  I laid a tape measure on the floor and found it to be 10 feet.  Everything seemed to be where it should be and the right size, how could they be a foot different?  I've been around enough construction to know that sometimes dimensions on a drawing are viewed more as suggestions than requirements, but the distance from the left wall to the right edge of the back window was within a couple of inches of what the drawing said. 

I eventually just shoved the lathe and the new shelves toward the right. They may still need to move another few inches.

Compared to yesterday, you'll note that the computer was moved down to the right side of the bench along the back wall compared to the drawing that had it on the left.  My thought was that putting the computer between the small mill and small lathes would allow me to see either machine from the computer equally well, while working on the lathe before was much harder than working on the mill. 

It leaves me in a little bind because I had to use a special cable for the CNC control box I built for the big mill and needed to use an arrangement of cables and lengths for the three machines that was different from before.  Another example from the "you can't get something for nothing" file.  I need to get a short parallel port cable: DB-25 M-F.  Both the big and small mill work properly under computer control.  The compressor, visible along the back wall below the blinds, is hooked up to the Fogbuster cooling system.  The only thing I couldn't do tomorrow that I could do before this all started would be to use the CNC lathe. 

The next couple of days will be less strenuous, but I've moved some of the small tools I want in the machine shop over to the new shelves, freeing up room on the shelves in the woodworking area of sandpapers and odds and ends that are on workbenches. 

I need the space because I've decided to take the plunge into the world of 3D printing and I'll need a place for the printer.  I've ordered a Creality Ender 3 V2 (not from these guys, they're out of stock).  I've been diving into the world of getting started with one and the process is very similar to what I've been doing all along.  Parts are designed in CAD and then go through a different kind of CAM (Computer Assisted Manufacturing) program, called a slicer.  When presented with a solid model, all the CAM or Slicer knows is the outside.  You tell the slicer how thick the walls should be and how much fill-in is between the outside lines and it turns those into slices that the printer makes.  The printer puts down thin lines of heat-softened plastic. 

A machine tool CAM program outputs the path of a cutter that takes everything away except the shape.  A Slicer program outputs the path of the filament extruder that lays down the thin lines of the walls of that shape and the reinforcing plastic filled in between the walls.  Both use G-code, a language I already work with. 



Saturday, January 9, 2021

Things Are Moving - Part ii

I didn't finish the rearrangements today, but I didn't think that was sure.  Maybe a 75% chance I could, if everything went well and painlessly.  

I thought I'd step back and show some 3D models of the starting point and envisioned end point, along with explanation. Like pretty much all the 3D modeling I do, this was done in Rhino3D. It started out in '14, and has been updated and modified several times since. The main part of what I've been doing so far is in the metal shop area.  That's the top left corner in this model, which shows the way the shop has been laid out pretty much since '16 when the big mill CNC conversion was finished.


I've labelled the major parts.  The computer along the wall on the left (west) controls the Grizzly mill via that small white box to its right with some parts visible inside it, the CNC Micro mill (a combination of Sherline and A2ZCNC parts) and the CNC lathe (Sherline).  Both of those have small white boxes that don't show any parts inside (that link does).  There's also a manual (non-CNC) Sherline lathe on the bench aligned long axis perpendicular to the west wall.  It's a bit difficult to work on the CNC Sherline and look at the computer if I need to see the display, so that was a minor thing to correct.

There were two motivations for doing this; the big one is what I mentioned yesterday about walking around the shop to get a drill bit or a screw to check threads.  The light green rectangle marked "small shelves" is a bit over 2' long, 18" wide and 2' tall.  I needed more room there.  The other motivation is to clear out the area directly in front of and below the mini-split air conditioner, that beige rectangle running along the west wall (and 7' off the ground).  We clean the filter a few times a year, and it requires climbing on something to get to it.  Besides that, it's going on 7 years old (installed in May of '14) and that means chances of it needing repair are greater than zero and growing. The harder it is to work on, the more expensive the service call.

My first thought and model was to push the the two benches along the west wall over toward the top, getting closer to the big mill's enclosure.  To keep it from going into the enclosure, I had to move that to the right and that just moved lots more.  I eventually thought of swapping the mill enclosure with the two other benches, and arranging them differently.


The new shelves are visible just below the big lathe and were the first thing added on Thursday.  The two blocks to the right of them are a set of rolling drawers for that area (brown top) and the shop crane (red, black).  They've been pushed right about two feet.  That wretched light green thing that moved from right of the benches to sitting in front of the air conditioner is a stationary exercise bike that can be moved across the room should we need to let an A/C repair guy get to the unit on the wall.

Today we pulled out the bench with the computer and micro mill and swapped it with the big mill.  Then we pushed it farther toward the top of the pic and rotated it to get that bench in place along the north wall.  It's closer to both walls than this shows.  The bench with the two lathes still remains to be moved.  The compressor (the blue block, top center) will stay where it is and it's hookup to the Fogbuster cooling system on the back of the mill will be modified. The only machine currently hooked up is the micro mill, and I tested it.  It moves normally. 

I should be able to get the other table with its two lathes into position tomorrow and work toward making the shop fully functional again.  There's more cool stuff that should be happening to go over in the next couple of days. 



Friday, January 8, 2021

Things Are Moving

I just don't have any decent pictures to show what I'm doing.  Let me back up a minute.  

We started down the road of my building a dream shop for retirement in 2013 and broke ground on it in early 2014. As always, no one can predict the future with absolute accuracy so we had no idea that an early retirement offer would change my plans and have me retire after the addition was put on the house but long before the shop was done.  In '14, we had the addition put on the house, with the construction being finished in May and by the end of the year adding the big machines.  Long time readers might remember stories I posted as I converted my milling machine to CNC.

We've been adding household stuff into the room as well as adding tools and accessories all over the shop, but living with the original layout of the shop since the completion of the CNC conversion in 2016. 

As I'm wrapping up the project that has sucked so much time in the last 18 months (!?!), my little IC engine, I've noticed some things I did wrong in the shop layout that have started to annoy me.  I finally decided I wanted to change the layout in the shop, increase storage around the metal shop area, and eventually decided that it needed to be pretty seriously changed.  I had silly little issues like having to walk from the mill halfway through the shop to get a drill bit or a screw.  While I think that stuff about walking 10,000 steps a day is a meaningless number not based on anything, I especially don't want to do it in a couple of hours in the shop. 

The vision when I started was there were to be three shop areas.  One would be machine tools - lathes and mills (there are three and two respectively).  The second area would be for woodworking with a pair of woodworking benches, table saw, router table and hand tools.  The third area would be for reloading, cleaning and working on guns, plus working on fishing tackle, making lures and the very occasional fishing rod.  By necessity, it has morphed into the area where I do much of my battery testing.  (The necessity is that I have nowhere else to set up a computer and monitor.)

In intervening years, the limited woodworking I've done is to build a few sets of shelves that went into the reloading area, and the enclosure for the big milling machine.  There have been a couple of other things, but nothing major. 


The mill in its enclosure when I declared the CNC conversion done and started trying to make things with it.  In the bottom left corner of the picture you see a wooden bench top with a mouse pad on it. 

In the next day or so, the mill enclosure and that work bench, which is paired in an "L" with another bench just like it, will swap places.

Oh, and there's more geekiness to come.



Thursday, January 7, 2021

Eileen Lights Up

Yesterday afternoon, the Starship prototype Eileen had an apparently successful static fire of all three Raptor engines as it moves closer to its first hop.  Potentially this weekend or Monday.


As I say, though, apparently successful.  Teslarati summarized it this way:
SN9 ignited all three of its Raptors in quick succession and shut the engines down over the course of 1.5-2 seconds – extremely short relative to all previous nominal Starhopper or Starship-mounted Raptor static fires. Long-time followers immediately noted that small discrepancy, speculating that it could either have been a post-ignition abort or intentionally shortened to avoid damaging the pad’s concrete surface (an incident that’s occurred several times during recent tests).
It seemed a little short by counting out seconds, which is approximate when I do it, and the test had some unusual aspects to it.  The most unusual thing is that unlike other static fires I've seen, they didn't empty the vehicle and give an "all clear" within an hour or so after the test.  As you can see in the picture, the test was at 4:07 CST (5:07 here).  I went over to the Webcam two hours later to see if anything was going on and saw signs that they might be setting up to do a second static firing.  That never happened and the author at Teslarati implies it might have been because of rain.  They also make clear that none of us know anything official unless SpaceX releases information, typically in a tweet or two from Elon Musk. 

That means the unusual conclusion to this test might have been from troubleshooting some oddity they saw, or a shift to another cryogenic pressure test or something else entirely.  Another piece of evidence arguing something went wrong was that they canceled the road closures for today. 

Two days ago, SpaceX was granted TFRs for flights to unlimited altitude on the 8th - 10th.  From where I sit, I don't think it will launch tomorrow, and if anything was wrong in yesterday's tests I think that lowers the odds that it can launch this weekend at all.



Wednesday, January 6, 2021

The Devil Went Down to Georgia

I'll be honest; I'm having a hard time processing the day.  I could see there being people converging on DC for the Stop The Steal protest, but it went a lot farther than I would think.  If I've heard one person call into one of the talk shows saying they're going to DC, I've heard over half a dozen.  None of them sounded like Antifa.  The stuff captured on the TV news did.  I find Irish collecting lots of things that make it seem like a false flag operation, specifically by Lefties working to make conservatives look bad.


Two months old, same concept. 

A couple of hours ago I'm saying "this smells like a false flag" to Mrs. Graybeard.  While she was watching a video of protesters breaking glass in the capital building she's saying (in concept) the contents of this Tweet that Irish posted.

The situation after Georgia is horrible.  After the enormous fraud in November, why should I believe that this isn't fraud?  After all, Georgia cheated last time, too. 

The chances of getting election reform passed, especially in the Ho Jo administration is zero.  After all, the places that cheated worked very hard to cheat.  They want to keep cheating because cheating = winning.  Anything lawmakers do will be like putting a "Cheat Free Zone" sign over the vote counting offices. 




Tuesday, January 5, 2021

A Set of Predictions for the Year in Space - 2021

A preview of the year to come in space exploration is an annual feature at Ars Technica, and Eric Berger posted this year's version this morning.  He titled it, “There are an insane amount of cool space things happening in 2021” and that's as good a summary as I could hope to do.  As I usually do when I say to go RTWT, I'll excerpt some pieces, starting with what I was thinking of this morning: when are those Mars probes that launched for the opposition going to arrive?
The United Arab Emirates' first mission to the red planet, Mars Hope, is due to arrive on February 9. At this time, the spacecraft will make a challenging maneuver to slow down and enter orbit around Mars with an altitude above the planet as low as 1,000km. If all goes well, the spacecraft will spend a Martian year—687 Earth days—studying the planet's atmosphere and better understanding its weather.

China has not said when, exactly, that its ambitious Tianwen-1 mission will arrive at Mars, but it's expected in mid-February. After the spacecraft enters orbit, it will spend a couple of months preparing to descend to the surface, assessing the planned landing site in the Utopia Planitia region. Then, China will attempt to become only the second country to soft-land a spacecraft on Mars that survives for more than a handful of seconds. It will be a huge moment for the country's space program.

NASA's Mars Perseverance will likely be the last of three missions to arrive at Mars, reaching the red planet in mid-February and attempting a landing in Jezero Crater on February 18. This entry, descent, and landing phase—much like with the Curiosity lander in 2012—will be must-see TV.

History suggests at least one of these three missions will not make it, but we'll hope to defy those odds.
They go on to mention that many Starship tests will take place.  Eileen, on the new test pad over in Boca Chica is up now, with the usual "every date changes" course of action we see.  Today's updates are that residents have been given an over pressure warning for tomorrow.  That implies a minimum of the Wet Dress Rehearsal, and probably static firing.  The FAA granted an unlimited Temporary Flight Restriction for the area, Friday through Sunday, which could be Eileen's flight to 15 km - or higher.

A test flight of the first Super Heavy booster in the first six months of the year is likely, making it almost a sure bet for the whole year.  Berger predicts that's not the only totally unprecedented mission the year will see.  He predicts we'll see one of the most anticipated and most-delayed missions:
Snarking about the delays in the launch schedule of the ultra-ambitious James Webb Space Telescope have become commonplace in the space community, and indeed this flagship astrophysics mission is far behind schedule and over budget.

However, it seems like NASA's current science leadership has addressed a number of the technical and management issues that had been plaguing the telescope program and causing delay after delay. Now, there seems to be quiet confidence that NASA's space telescope will stick to its Oct. 31, 2021 launch date on a European Ariane V rocket.
In addition to Super Heavy, we're likely to see the launch of United Launch Alliance's Vulcan rocket, carrying Astrobotic's Peregrine lander to the Moon.  This one doesn't look good to me; the Vulcan is based on Blue Origin's BE-4 Methane-Oxygen engine, which technically doesn't exist.  Delivery is expected in the summer and launch in the 4th quarter, which is tight considering the amount of newness there.  Other big rockets are possible as well: Japan's H3 booster and Europe's Ariane 6 rocket.  Finally, not a new rocket, but SpaceX has three Falcon Heavy flights on the manifest this year.  Their main emphasis will be recovering all three boosters.  Only one center rocket has landed, and that one later tipped over and fell due to rough seas combined with the lack of hardware to hold it on deck (the Octagrabber on both recovery drone ships now).

This is just a look at a few things that caught my eye.  If you like to follow space exploration, go read


James Webb Space Telescope, rendering for NASA.  The diameter across those 18 hexagonal mirror "tiles" is 6.5 meters or 256 inches.  Intended for Infrared observation, it has nearly three times the aperture of the Hubble Space Telescope.  Lots of details here.



Monday, January 4, 2021

In Other Space News

Virgin Orbit appears to be readying a test flight of their LauncherOne, an air-dropped small satellite lifter.  The tentative launch date is January 10th and the launch is likely to take place out of west coast facilities as did their previous attempt.  The one which ended with the launch vehicle apparently disintegrating soon after release.
LauncherOne is a rare air-launched rocket and is designed to be dropped from a modified Boeing 747 passenger jet (named “Cosmic Girl”).  For a cost of $12 million, LauncherOne will be able to place up to 600 kg (~1300 lb) into low Earth orbit.

Virgin Orbit also wants to develop a tiny third stage that would enable the small rocket to send payloads of 25-50 kg or more to the Moon and beyond.
The mission has bumped into this year after delays from Covid - they're in California - and going through periods when they didn't have enough people to get things done.

After that last loss of vehicle and mission, Peter Beck (Rocket Lab) and Elon Musk (SpaceX) tweeted moral support to the Virgin Orbit team.  "Orbit is hard."



Similarly, startup Firefly Space, has been steadily moving toward the first test of their orbital class rocket, Alpha.  The last time we talked about Firefly Space, last March, they were talking about testing it "this summer" - as in summer of '20.  As you might expect, that was too ambitious.
Firefly's first Alpha booster arrived at its Vandenberg Air Force Base (VAFB) launch pad in November, while Alpha's orbital upper stage wrapped up a qualification static fire in December - shipment to Firefly's California launch pad TBD.

The cause of the delay is unclear but it's not exactly surprising for a new rocket's first launch campaign and a startup's first launch attempt.
Firefly Alpha.



Blue Origin made a show of christening a used cargo ship currently being modified into a seagoing landing platform for the New Glenn's massive boosters.  Since Blue Origin took possession of the ship - formerly known as Stena Freighter - more than two years ago, almost nothing has visibly changed.  The visible changes are the removal of two aft exhaust stacks and renaming the ship Jacklyn after Bezos' mother.  It appears to be nowhere close to ready for New Glenn booster landings. 

Which may not be a problem because the New Glenn appears to be nowhere close to ready to fly.  Aside from two aluminum rings, maybe a fifth of a tank dome, and two "pathfinder" BE-4 engines that are (1) not meant for New Glenn and (2) not meant for flight, Blue Origin has yet to reveal New Glenn flight hardware of any kind. The last real official announcement of the first launch date ("2021") came almost two years ago in January 2019 and is now comically ludicrous with just ~12 months left and zero flight hardware in work.



Meanwhile, the last time we talked about the SLS static firing test, word was they hoped to resume testing this month.  They're close-mouthed about it and no news is available.  I'm trying. 




Sunday, January 3, 2021

About That Small Engine I'm Building

Small?  Tiny?  How does 3/4 cubic inch strike you?  To me, that's closer to tiny than small, but definitely in the range.  3/4 cubic inch is bigger than the tiny model plane engines and smaller than any lawnmower I've owned.  

The short update is that it still doesn't run. A longer update is I haven't tried to run it since finding the fuel bottle destroyed back a bit over two weeks ago.  The parts I need to fix the tank were here by the day after Christmas, much sooner than I expected, but I haven't tried to put gas in the tank and start it yet.

I've been doing other things.  I noted in that linked post that it was time to take that valve stack apart. For openers, it didn't look like the intake valve spring was moving right, so I did something I should have done all along and tapered the valve guide per print.  First the intake and then the exhaust.  Because I didn't think it possible to remove the valve guide from the intake block without ruining the guide, I set up my four jaw chuck on my manual Sherline lathe and used their compound to cut the taper.  


Then I lapped the valves against their valve guides again. This time with the valve stem in the three jaw chuck on the lathe and pulling the block with the valve guide (pictured) against the valve.  I've done more troubleshooting steps trying to convince myself the engine is OK.  

I wanted to make sure the valves would drop freely through the valve guides.  Intake fell, exhaust would bind sometimes.  I made a little valve holder to hold it in lathe chuck, then held 240 followed by 500 sandpaper against as it spun in the lathe.  After this, it fell freely through the valve guide as well. It was time to put it all back together and see if it looked any better qualitatively.

When I ran the flywheel with my starter drill, I didn't see any motion of the intake valve.  I want to see it opening and closing, but I've been told by a couple of guys who have made this engine that it might not be perceptible.  On the other hand, I've seen videos where the intake valve's movement is very obvious.  There's a potential problem with the intake valve spring in that I made it from music wire I had on hand (.015" dia) not what the plans called for (.013" dia). If there are two identical springs made with those wire sizes, the one made with bigger wires is stiffer than the one made with the smaller.  Springs are complicated. The strength comes from the wire diameter, the pitch (turns per inch) and the diameter of the spring. I could have used the wrong wire but made up for it by making too many turns.

Strangely, I have around three feet of .013" wire in the house. It's called the second string in a set of Ernie Ball Slinky guitar strings.  Even stranger, it's cheaper to sacrifice a set of those strings than buy a few more feet of .013" music wire from the usual sources.

I'm just about at an impasse where I don't know what to do.  One possibility is to rewind the intake valve spring.  I have considered sending the whole engine to Hydraulic Press channel on YouTube to let him crush it into a round slab of mixed metals.  A better idea is to back away for a few days.  I could use to clean up and organize a bit better in the shop anyway.




Saturday, January 2, 2021

When Landing Orbital Class Boosters Gets Too Routine...

You can accuse Elon Musk of a lot of things, but something you can't accuse him of is having no vision for the future.  As recently as 2014, NASA dismissed SpaceX's plans to recover Falcon 9 boosters.  Now, SpaceX has recovered so many boosters that they dropped their production rate; they simply don't need as many boosters, even with their launch cadence that's many times anyone else in the business.  As far as NASA and other Fed.gov agencies are concerned, they've dropped their policy of never flying on a recovered booster - even for manned flights.  While I'm still not tired of watching them do it, landing a booster on a drone ship hundreds of miles from any landmark has become routine.

As reported by Teslarati on Thursday, last Wednesday, Musk revealed that their plans for Super Heavy are changing.  Super Heavy, of course, is the booster for the Starships they've been protoyping.  They're considering not putting landing gear on Super Heavy and landing them as we're used to with Falcon 9 and instead catching them with the launch tower.


It's important not to lose track of what we're talking about here.  Super Heavy will be the largest rocket stage ever built – and by a large margin.  It will lift a ~300,000 lb Starship around 25% of the way to orbit, with a liftoff thrust of ~16.2 Million Pounds.  The booster alone will be 70 meters, around 230 feet, tall.  The Apollo Saturn V booster had a liftoff thrust of ~7.5 million pounds.  I don't have any references for what the Super Heavy should weigh when it's ready to be recovered, but the idea is to modify the launch umbilical tower to allow it to catch Super Heavy by its titanium grid fins. 
Launch mount recovery would require unprecedented precision and accuracy and add a new element of risk or a need for extraordinarily sturdy pad hardware. However, the benefits would be equally significant, entirely eliminating the need for expensive recovery assets, time-consuming transport, and even the time it would take to crane Super Heavy boosters back onto the launch mount from a pad-adjacent landing zone.
In a way, Super Heavy has an advantage over the Falcon 9.  When the Falcon is returning to land, at the very last moments, a single Merlin engine can't be throttled back far enough to allow the booster to hover.  They have to adjust the engine to reach zero velocity at zero height, which requires amazingly accurate knowledge of the booster's position in the real world.  The Super Heavy is so much heavier than a Falcon 9 that it can hover. 

Scott Manley does a great presentation on this.


This idea is wild, and full of risk, but could bring a lot of improvements to the Starship. Not having the landing legs will save weight, which moves into the payload. They are, after all, planning on building hundreds of these.


A few weeks ago, Musk tweeted that we should see Super Heavy fly "in a few months."  I don't see any infrastructure in the Boca Chica area that could catch the booster out of the air; I guess they have a few months to build that, too.

This has the potential of being a lot of fun to watch.  Word is they think they've fixed the issue that caused SN8 to crash, so considering how close to total success that was, Eileen's flight should be fun to watch.  I expect that next week (11th to 15th).  




Thursday, December 31, 2020

Happy New Year

So it turns out that the year that I thought would known for optometrist jokes will be known as one of the worst years in recent memory.  I think about the only people for whom 2020 will have turned out as they hoped would be the people who rigged the election.  Their years of preparation and work to destroy election integrity came to fruition.  Can the complete collapse of the country be far behind?  Some of those same people have been working at that far longer than merely destroying elections.  

In light of just how big a crapfest 2020 has been, I raise my standard argument.  There are plenty of ways to delineate time and it's only New Year's Eve 2021 on the calendar the Western world generally follows.  It's like the end of the first quarter of 5781 in the Jewish calendar.  I'm going to pretend that opening a new year's calendar really does fundamentally change things in a way that flipping a one-page-per-day calendar doesn't.  Tomorrow will be a fresh start.

2020 was my fifth year of retirement and for the second consecutive year, our planned trips were cancelled.  Thankfully the reason wasn't personal injury as it was in '19, it was the reaction to the pandemic that shut down the events we were considering going to.  One of our annual events in the area, February's Orlando Hamcation, has been cancelled, as well as one we might travel to, the Cabin Fever home machinist's show.  From my view, '21 isn't off to a good start. 

Frankly, that's all the year-end review I have the stomach for.   

So Happy New Year, y'all.  Let's hope for better, while we prepare for whatever may come.  Meanwhile, I'll just paste an image I got from Daily Timewaster.





Wednesday, December 30, 2020

The Two Days of Testing Eileen (SN9) Went By With No Problems

SpaceX Boca Chica had arranged road closures alongside the test pad for a series of tests this week, with closures Monday through Wednesday.  After the tests Monday and Tuesday, today's road closure was cancelled.  That indicates the tests probably went as expected and they're ready for more testing after the holiday weekend. You'll recall that back on December 13th, Serial Number 9 was standing in the high bay building when its support structure collapsed, causing the prototype to lean into a corner of the high bay, damaging its aero surfaces and earning the name Eileen.  Last week, on the 22nd, after replacing the damaged flap, Eileen was loaded onto a transporter and rolled to the test pad, where Bluto the giant crane lifted the ~165 foot tall, 200,000 pound spaceship onto the test stand.  

Honestly, it's remarkable to be able to repair a rocket subjected to loads it wasn't designed for.  If you're keeping track, record this as a minor miracle. 

On Monday, the 28th, they performed pressurization tests using ambient temperature nitrogen.  This is a first check for leaks, to ensure everything can be pressurized, verify basic vehicle valve and plumbing performance, and generally ensure a basic level of structural integrity.  Eileen appeared to pass her ambient temperature pressurization tests with no concerns.

Tuesday's tests focused on cryogenic tests.  The exterior of Starship SN9 began to develop a coating of frost after SpaceX started loading its oxygen and methane tanks with liquid nitrogen around 2:30 pm CST. While used similarly to verify structural integrity like an ambient pressure test, a ‘cryo proof’ adds the challenge of thermal stresses to ensure that Starship can safely load, hold, and offload supercold liquids.  Observers reported not seeing evidence of frost at the small header tank in Starship's nose.  Since the last second troubles in SN8's flight was insufficient pressure in that tank, that raises questions of why it didn't appear to be tested. 

It leaves us in an interesting place. 
According to NASASpaceflight’s managing editor, if Monday and Tuesday’s ambient and cryo proof tests were as uneventful and successful as they seemed, SpaceX may move directly on to triple-Raptor static fire preparations. In a first, Starship SN9 was transported to the launch pad last week with two of three central Raptor engines already installed and had that missing third engine installed within a few days of arrival. SN9 is also the first Starship to attempt its first proof tests with any Raptor – let alone three – installed.

If SpaceX does move directly from cryo proof testing to a three-engine static fire, that will mark another first for the Starship program and signal growing confidence and a desire for speedier preflight tests – both of which will help accelerate flight testing. As of now, SpaceX has yet to cancel a road closure scheduled on Wednesday, December 30th [Note: clearly written before this morning when today's closure was cancelled - SiG] but it’s far more likely that a trio of 8 am to 5 pm CST closures requested on January 4th, 5th, and 6th will host Starship SN9’s first static fire attempt(s). According to NASA Spaceflight (.com), Starship SN9 is expected to attempt a 12.5 km (~7.8 mi) launch similar or identical to SN8’s as early as a few days after that static fire. Stay tuned for updates!

Another great photo from Mary, @bocachicagal.  On the left is the remains of SN8's nosecone, middle shows Eileen and Bluto the crane on the right. 

In slight contrast to the quoted text above, they don't mention the Wet Dress Rehearsal test in which every step of a countdown down to liftoff is carried out except for lighting the main engines.  I expect to see that at some point next week.  I'm not so sure about a static firing, but wouldn't be terribly surprised to see them do one.  If they clear those hurdles, the hop to 12.5km could be the following week.



Tuesday, December 29, 2020

Primum non nocere

Among the few latin phrases that a large number of people have heard is that one: primum non nocere, which translates as "first, do no harm." Like most quotes, it's probably not from the source most of us think it's from - in this case it's not from the Hippocratic oath, which was in Greek.  Far from strictly being a Medical Doctor's oath, which is a person to person interaction, primum non nocere applies to group interactions as well.  When you contemplate doing things with a potentially large population that might be affected by something you do, it's good to remember this.

In this case the population is the entire world, and the issue is Bill Gates is throwing his spare change into an effort to cool the earth by dimming the sun.  Gates is one of the main funders of Harvard University's Stratospheric Controlled Perturbation Experiment (SCoPEx).
According to Reuters, a Harvard University project plans to test out a controversial theory that global warming can be stopped by spraying particles into the atmosphere that would reflect the sun’s rays.

The project represents one of the most controversial aspects of what’s known as “geoengineering” — the idea that, to tackle issues like climate change, massive aspects of our ecosystem can be played with or changed. In this case, it would involve reflecting some of the sun’s rays to stop them from reaching Earth.

“Open-air research into spraying tiny, sun-reflecting particles into the stratosphere, to offset global warming, has been stalled for years by controversies – including that it could discourage needed cuts in greenhouse gas emissions,” Reuters reported.
Since every single joule of energy that the earth gets comes from the sun, and every single living thing on earth, from the simplest virus to the most complex mammals, depends on the sun for its life,  this is one area of research where the ground rules need to be the most stringent that can be applied.  It needs to be verified with no doubt in a large number of experiments and every last little thing that doesn't seem to be exactly as predicted needs to be cleared. 

The article on Western Journal goes into some of the issues, but mostly from the standpoint that the objections to this project have come from people saying it will distract from getting the world to cut CO2 emissions. 
There are several problems with this plan, not the least of which is that we don’t know what the unintended consequences might be. But to environmentalists, the problem is that it doesn’t solve global warming the way they want to do it.

“There is no merit in this test except to enable the next step. You can’t test the trigger of a bomb and say ‘This can’t possibly do any harm,'” said Niclas Hällström, director of the Sweden-based environmentalist think-tank WhatNext?
I don't see how something of this magnitude could be done without unintended consequences; changes to weather patterns, changes to ocean circulation patterns, changes to plant growth with the potential of mass famine, changes to the amount of Vitamin D that people make from sunlight exposure with concomitant changes to wellness in the world's populations. Further, the extent of all of these things won't be known - at best - until exhaustive tests are run. 

It doesn't even have to work to cause trouble. Imagine if a country, say China (since they've expressed interest in weather control) runs some experiments that ultimately do nothing.  Two years later, the monsoons fail in India causing mass starvation and deaths.  Can you see Indians not being convinced China told the truth and starting a war over a failed experiment?  Similarly, what if the experiment works and the climate change makes someplace like China or the US' Midwest grain belt have better weather while people somewhere else have worse weather problems, even if it's not directly from the experiment.  Can you see the people with worse weather striking out against the people who they perceive made their weather worse? 

In August of '19, the Daily Mail (UK) did a good summary of the story and potential problems. I've barely scratched the surface.


Solar Geoengineering ideas, to reduce solar power reaching the Earth.  From the Daily Mail.

Ya know, it's awfully hard not to think of Gates as Mr. Burns in this classic clip from the Simpsons.



Monday, December 28, 2020

Clap For The Covid

Sung to the tune of Clap For the Wolfman because it has the same rhythm.  Now that I've implanted that ear worm...

In the most bizarre news story of at least the last 15 minutes (hey, it's still 2020 after all) we find that Covid-19 is being blamed for a particularly nasty strain of "the clap:" gonorrhea.  The New York Post covers the story, H/T to Twitchy by way of PJ Media.
The unnecessary overuse of antibiotics during the coronavirus pandemic has created a rise in drug-resistant strains of super gonorrhea, according to a new report.

Azithromycin, a common antibiotic used to treat chest and sinus infections, has been used during the pandemic to prevent co-infection of hospitalized coronavirus patients and to treat inflammatory symptoms of severe infections.
...
“Overuse of antibiotics in the community can fuel the emergence of antimicrobial resistance in gonorrhea,” a WHO spokesman told the outlet, noting that azithromycin was used for COVID-19 treatment earlier in the pandemic.
Covid-19: is there nothing it can't do? 

I have lots of issues with this story.  The big summary is that it's just more fear mongering.  There is not one study cited to justify the claim, not even the associational "he who" studies that are the bulk of all the junk science in the press.  They didn't say anything like Covid patients treated with azithromycin were more likely to have antibiotic-resistant gonorrhea, and at least that makes some sense.  They presented no data whatsoever, except that there's more of this "super gonorrhea."  So frickin' what?  There could be reasons not even remotely related to using antibiotics to treat Covid-19.  Don't forget, there's this thing called coincidence, too.  

Besides, think of a Venn diagram of the sets of people who are fooling around with anyone they can find regardless of how sick they are and the set of people who are being treated for Covid.  How big do you think the intersection of those sets is? Who do you think comprises that intersection?  As a rough guess I'd say there aren't many 80 year old nymphomaniacs in nursing homes.  I can't say for sure, but I bet if an ICU nurse walked in on a patient hooked up to a ventilator having sex with anyone, that would be the stuff of legends in that hospital. 


(iStockphoto of a petri dish culture of something or other, used by the NY Post.  You know they meant to use a scary looking picture for their scary junk article.  Judging by the accuracy of the rest of the article, this is probably a cell culture of cucumbers)

There.  I saved you the time of reading this so I could make fun of the study.  Just doing my part to be a full service blog.



Sunday, December 27, 2020

We Had a Covid-19 Vaccine Just Under A Year Ago

But first a B-i-i-ig R-o-o-und number.  This is post number 3,700 in the life of this blog with my 11th blogiversary just under two months away.  For quite a while I've been averaging just under a post a day; maybe missing one or two a month.  At this rate, I'll reach post number 4,000 around mid-July.

Self-congratulations aside, it has been slow news week as I'm sure you've noticed.  An interesting thing I came across earlier in the week is an article on the Foundation for Economic Education (FEE's) website and daily email that said the Moderna vaccine was actually developed last January.  It could theoretically have been allowed to enter testing last January and might have been available months earlier than when it entered use a couple of weeks ago.  All except for one big thing: the Food and Drug Administration. 
The vaccine, a triumph of medical science known as mRNA-1273, was designed in a single weekend, just two days after Chinese researchers published the virus's genetic code on January 11, 2020.

For the entire duration of the pandemic, while hundreds of thousands died and the world economy was decimated by lockdowns, this highly effective vaccine has been available.
Why?  The FDA prohibited rapid "challenge trials"—where volunteers take the vaccine and then expose themselves to the virus in a lab, rather than waiting agonizing months to see how many catch the virus "in the wild."  The challenge trials could have proved the effectiveness of the vaccine in weeks or a month or two.  The FDA considered the risk to the volunteers to be too high.

The easiest word for a bureaucrat to say is "No" and that's what the FDA did here.  Now, I can understand the FDA's desire to make sure the volunteers don't get killed by the virus, but following blanket policies that apply at all times and in all circumstances doesn't make allowances for unusual circumstances.  As the author at FEE points out, somewhere close to the first 200,000 people to die of Covid-19 in the US died after this vaccine could have been available.  During a raging pandemic, might the balance of risk that's allowed be a little different? After all, the potential deaths of volunteers is not the only cost.  The monster cost is the death toll on the world's population from the virus.  The Godzilla: King of the Monsters cost is the suffering caused by lockdowns, especially the economic suffering.

There can be no other conclusion than the acronym CYA - Cover Your Ass.  The FDA was covering their collective asses rather than trying to help the population.  It's a tragic truth that they're a cowardly medical bureaucracy that would rather allow hundreds of thousands of people to die than face any potential criticism for allowing an accelerated vaccine trial.  CYA, unlike "no", is not a word that bureaucrats say.  It's just how they live their lives. 

The author at FEE suggests that based on what we know about how quickly the vaccines are produced and how quickly they could have been tested, that the Moderna vaccine could have been available last March or April.  Instead of the first wave of COVID deaths and lockdowns in the United States, we could have seen a wide vaccine rollout, leading to rapid herd immunity, and the pandemic being curtailed before it really got started. 


The Moderna vaccine being administered.  Photo from FEE.

The answer is more freedom and less Tyranny of Experts



Saturday, December 26, 2020

Holiday Recovery Odds and Ends

We had subdued holiday around the house, did a video phone call with Precious Grand Daughter, Son and Dear Daughter In Law in the evening, and generally didn't do much else, besides arm wrestle Windoze 10.  It just refuses to let me control my own computer.  I cooked some spare ribs in the Masterbuilt Electric Smoker because it's insulated while the Weber Kettle isn't.  I've seen videos of people cooking in the MES with outdoor temperatures around 30, so our 48 to 54 was easy for it.  


Oh, yeah, we had a lot of spare ribs.  This is after three people ate as much as they cared.  Probably about 2/3 left.



While there has been some activity visible at SpaceX Boca Chica around Eileen, the last three days have seemed slow, with no work yesterday as you'd expect.  It's hard for me to imagine they can keep fully staffed and going full speed this time of year.  It seems to be a nationwide thing that the high-tech sector facilities tend to shut down between Christmas and New Year because so many people working there come from other cities and travel home for the holidays.  I never looked into it from any statistical sense, just my experience both at companies I worked for and companies I had to talk business with.

Despite that general lull in activity, Elon Musk surprised a lot of people on Christmas Eve when he tweeted the first hop of the Super Heavy booster would be in "a few months".  It's no secret they've been working on Serial Number 1 Super Heavy in the shipyard at Boca Chica (which sometimes seems to be called BN1, perhaps Booster Number 1?).  Within a month or two would be "soon" for something that epic.

Speaking of soon there are road closures at Boca Chica Monday through Wednesday, with commenters expecting from hypergolic testing to Wet Dress Rehearsal and even to a Static Fire test before Friday. We'll have to see.


Prototype SN9, also called Eileen, at sunrise on Christmas morning. Photo credit Boca Chica Mary.



Teslarati posted a link to a processed video of number 8's test flight, in 4k video.  I'd embed it here, but go watch it in full screen mode.  



Thursday, December 24, 2020

Christmas Eve. Roswell, New Mexico. 1949

The true story.


Found linked on Pinterest.  No true source credited.  Original URL from when I ran across the picture is dead.  

Let me wish each and every one of you who stop by here a very Merry Christmas.  Hold close the ones you love.  Spend time with family or friends or both.  Remember the good service members deployed far from home.  If you're Military, LEO, or fire; EMT, Nurse or MD, and are one who must work while the rest of us celebrate, thank you. 

 


Wednesday, December 23, 2020

Good Grief - Christmas is Friday!

I love Christmas.  I've known people in my life who decorate for Christmas way more than I do, and I've known people who plan their Christmas six months in advance, way before I do.  I know a guy whose house decorations for Christmas put the local shopping centers to shame, and focused his whole year around decorating for Christmas.  Maybe if you saw me, or saw my barely decorated little house, you wouldn't think so, but I do love Christmas.

Christmas is unique among holidays in America.  It has a very strong Christian tradition (well, duh!) as well as very strong secular traditions, and I love them both.  I love giving gifts to loved ones - and even total strangers.  I love the old favorite songs and the whole feeling of this time.  People in retail will tell you that Christmas often determines whether or not they stay in business.  I'm sure you've noticed that news outlets report sales from the Friday after Thanksgiving (Black Friday) as if they're reporting scores from a bowl game.  Another part of the holiday is the annual struggle to "keep Christ in Christmas" and not overlook the spiritual side of the holiday.  I like to remind everyone there's actually a court ruling that says how many reindeer (three) a holiday display must have to remain "sufficiently secular" to be legal to display on public property.  If I'm putting on a public display and among all other other Winter Holiday symbols I have three reindeer on display, it's secular; if everything else is the same but it's only two reindeer and package of reindeer sausage, I'm obviously trying to convert you!  Does it get more stupid than that?  On second thought, don't answer that. 

Other than the perpetually aggrieved people who protest everything, who's offended by someone wishing them happiness?  For years, I used to run this video by Jackie Mason saying as "The Ultimate Jew" he wasn't remotely offended by people wishing him a Merry Christmas.  Now I could choose one from Dennis Prager, except this is half an hour.

A couple of weeks ago, in an email I just spent an hour looking for, the author said that all our lives there's been a secret hidden right in front of our eyes in the Charlie Brown Christmas Special from 55 years ago.  If you know the show, you know the scene where Charlie Brown in exasperation says he doesn't know what Christmas is all about and questions out loud if anybody does. 

When Linus recites the passage from Luke chapter 2 about the birth of Christ, he drops his security blanket right at the point where he quotes the angels saying, "Fear not." He drops his security blanket and doesn't pick it up until he's done reciting the passage.  When he finishes, he picks up his blanket to walk off stage.


For those of us who read Peanuts every day while growing up, I'd bet no image is as well-associated as Linus and his security blanket, yet he drops it on that cue.   A kid carries a security blanket because they're afraid.  He knows he doesn't need to be.  

As we plunge through the last days before Christmas, take time to enjoy it and your loved ones.  If you feel a need to get some perfunctory gift for someone you'd really rather not give to, I say don't.  That's some sort of bizarre social ritual, not Christmas.  Don't put yourself in debt for Christmas; even if it means the kids get a "meager" holiday.  It won't hurt them and may just help them.  If you're one of the 45% who recently said they'd just as soon skip the whole thing - I say skip it.  It's still a federal holiday, so you have that going for you.




Tuesday, December 22, 2020

A Study in Contrasts

I have to say I was surprised to see this but today, SpaceX put Eileen on a rolling transport to the test area.  Bluto (the crane) had been put in place yesterday.  Bluto lifted Eileen onto the new test stand around sunset this evening.  


Back when they moved SN8's nose cone to the pad it took days to get to the milestone of lifting the nose cone onto the existing prototype. 

Toward the left side of the picture, the test stand used for every launch to date is visible, yellow because of the flood lights on it (note the local time on the bottom - it's after sunset).  Visible in the distance between Bluto and Eileen, you can see the nose cone of SN8.  I've read the rest of the wreckage has been removed and many observers thought Bluto was only there to put that nose cone on some vehicle for transport back to the ship yard.

So now what? Eileen will undergo less testing than previous versions. More was known about how to build her than was known when SN8 was built on the test stand. Pretty much everything that allowed them to finish Eileen in the High Bay came from SN9. There's another road closure all day tomorrow, and I wouldn't be surprised if they did some pressurization tests, maybe cryogenic tests.



Meanwhile, at the Stennis Spaceflight Center, NASA's Space Launch System, SLS, had a "mostly successful" wet dress rehearsal (which they call a Green Run) as they prepare for a full static firing of that system.  I say "mostly successful" because of the last sentence in this paragraph.
Engineers working in the Test Control Center monitored all core stage systems during the test as propellant flowed from six barges into the core stage in the B-2 Test Stand at NASA’s Stennis Space Center near Bay St. Louis, Mississippi. First looks at the data indicate the stage performed well during the propellant loading and replenish process. Part of the test was to simulate the countdown with the tanks loaded, leading up to 33 seconds prior to the engines firing. However, the test ended a few minutes short of the planned countdown duration.
The article goes on to say that it appears to have been a software flake. That's my interpretation of this statement.  (Don't worry, probably just some uncounted Biden ballots got into their system)
The core stage and the B-2 test stand are in excellent condition, and it does not appear to be an issue with the hardware. The team is evaluating data to pinpoint the exact cause of the early shutdown. Then they will decide if they are ready to move forward with the final test, a hot fire when all four engines will be fired simultaneously.
It looks like they might be ready to static fire the SLS early in the new year. 


SLS on the test stand at Stennis Space Center - NASA Photo.

While on the topic of the SLS, back at the start of the month, I passed on a report that the White House was pushing Congress to allow the Europa Clipper mission to choose another heavy lift vehicle if SLS was not looking to be available.   According to Ars Technica's Rocket Report this week, Congress appears to have gone along with that.
In the final text of the appropriations bill for fiscal year 2021, Congress may finally allow this. Some conditions to be met ... Congress said NASA should launch the Clipper on the SLS if a rocket is available, and if a "torsional loading analysis" determines that SLS is safe to launch the expensive spacecraft. However, if these conditions cannot be met, the authorization bill allows NASA to conduct "a full and open competition" for a commercial launch vehicle. It is likely SpaceX's Falcon Heavy rocket would win this competition, but not certain.
One of the most unsettled areas of the SLS program and Artemis missions is the Exploration Upper Stage. This is just about as far from the level of the rest of the SLS as one can be: NASA and Boeing just completed the Critical Design Review for the programThis is a larger, more powerful upper stage that will be used on the Block 1B variant of the SLS rocket, and enable the carrying of 10 tons of cargo and a crewed Orion spacecraft in a single launch.

Unfortunately ... neither NASA or Boeing have provided a cost estimate or timeline for development of the upper stage, which may take 5 years and cost perhaps $10 billion based upon past projects.



Monday, December 21, 2020

My Annual Christmas Song Post - Expanded

Regulars here know that I'm somewhat of a blues fan.  I've introduced the outrageously talented Joanne Shaw Taylor, and the late country blues master (and songwriting partner to Eric Clapton) JJ Cale.  More appropriate to Christmas, every year around this time I comment on my favorite bluesy Christmas song, “Have Yourself A Merry Little Christmas.”

The song dates from 1944, is credited to Hugh Martin and Ralph Blaine for Judy Garland's 1944 movie, Meet Me in St. Louis, but it's generally acknowledged to be Hugh Martin's writing.  The somber tone is understandable; Christmas of 1944 was three years into World War II, and many people had undergone the hardship of long separations from or the loss of family members. The war was wearing on the national psyche; the death toll was the highest seen since the Civil War.  They were dark days.  It's interesting, then, that Martin has said he wasn’t consciously writing about wartime separations.


You'll note that at the end of the song, the line isn't “hang a shining star upon the highest bough,” it's the more subdued “until then, we'll have to muddle through somehow.” Much more fitting to a more somber song written during WWII. The change to “...highest bough” (which seems to be the last) was prompted by Frank Sinatra in 1957. According to Entertainment Weekly in 2007:
Then, in 1957, Frank Sinatra — who'd already cut a lovely version with the movie's bittersweet lyrics in 1947 — came to Martin with a request for yet another pick-me-up. “He called to ask if I would rewrite the 'muddle through somehow' line,” says the songwriter. “He said, 'The name of my album is A Jolly Christmas. Do you think you could jolly up that line for me?' ”
That request led to the line we hear most often, although Martin says he thinks the original line is more “down-to-earth.”  “Have Yourself a Merry Little Christmas” has become one of the most popular songs year after year.  EW says it's second only to the song Nat King Cole popularized: “The Christmas Song (Chestnuts Roasting on an Open Fire).”  It has been covered by a gamut of artists from Sinatra to Connie Stephens, to James Taylor (who sings something closer to the '40s, Judy Garland version) to '80s metal band Twisted Sister, and many, many more.

I'm not so one-dimensional that this is the only song I can live with for the month, though.  When I play them myself, I tend to start by playing “O Holy Night” although I can't hope to get within a light year of the ability or the vocal range of Kerrie Roberts under any circumstances.


Still, a fingerstyle guitar can approach the sound of the piano in the mix here.  I can't really link to a video that sounds like what I attempt to play because I sit with a piano song book and work from that sheet music. 

And there are more.  If asked to pick my one most favorite Christmas song, as if I could, I'd probably pick one of these two.   There are lots that are fun to listen to once or twice a year, even the cliche' “Jingle Bell Rock” is fun a few times. There are fewer that I could listen to over and over throughout this month.

What are yours?



Sunday, December 20, 2020

A Ham Radio Series 20 – Modulation, Constellations and Bandwidth, Oh My!

The previous series on radio that I put together, back in the winter and spring of ‘19, included a very wide-ranging post on modulation.  It’s a worthwhile refresher to go back to read to get a feel for the whole process of modulation, if some of this seems like it comes out of the blue.  Nevertheless, there were some important concepts that I dropped in the effort to keep the post length a bit more reasonable. 

The most important part of the posting is the idea of a “universal modulator.”  A universal modulator is nothing more than a multiplier circuit that takes an RF input to be modulated splits the signal in two paths which then go to two mixers.  One side of the split is shifted in phase by 90 degrees.  The modulating signals, shown here as i and q (both as time-varying functions), are applied to the low frequency ports of those mixers. 


Let’s start with this concept.  Any characteristic of the radio signal can be modulated.  Amplitude can be modulated (AM or SSB); the simplest Amplitude Modulation is presence or absence of the transmit signal, On-Off Keying.  Frequency can be modulated (FM, FSK).  Phase can be modulated (analog PM, BPSK, QPSK, 8PSK, 16PSK).  There are even types of modulation that combine more than one kind; the most common of those being Quadrature AM, like 64 or 128QAM (pronounced “kw-ahm”).  Quadrature AM modulates both the amplitude and phase of the signal to transfer data. 

The only difference between generating AM, or SSB or 64 QAM is the way the i(t) and q(t) signals are created and processed.  If they’re kept identical in phase and a DC offset added, full-carrier AM is generated.  If they’re left in quadrature, single sideband is produced.  If Q is left constant and I varies 180 degrees for modulation, BPSK is generated.  Everything is produced by the way those i and q signals are created.

Because of the concept of modulation by applying I and Q signals, Q can be plotted versus I, producing what’s referred to as constellation.  BPSK, or Bi-Phase Shift Keying is simply shifting the phase of the carrier from no shift to 180 degree shift for each symbol.  The signal shifts from +1 to -1 constantly to transfer the information.  QPSK is Quadri-Phase Shift Keying, shown here as varying I and Q at the same time, giving constellation values at (1,1), (-1,1), (-1,-1) and (1,-1), or simply changing one axis at a time (1,0), (0,1), (-1,0), (0,-1).  8PSK and 16PSK are what the names imply: 8 and 16 values of amplitude and phase.


This isn’t the only interpretation.  16QAM is modulating both amplitude and phase.  There is 16 phase shift keying (16PSK), where the amplitude remains constant and the constellation points are all on a circle of constant amplitude but with (360 / 16 or) 22.5 degrees between the symbols. 


This is 64QAM as it would be seen on a piece of test equipment.  Each of those dots represents a transmission and their random looking appearance (spread out and not just a dot) is from the introduction of noise in the channel.  If it were pure phase noise each of those would be short arc centered on the origin (0,0) in the graph with the points farthest into the corners being the longest arcs.  These look to be amplitude noise and not phase noise. 

There are subtle changes to the constellations that affect not just the number of constellation points but also the trajectories that the signal takes to get between them.  Below is a math simulation of a differential 8-phase shift keying (D8PSK), which has become widely adopted in the aviation world.  In one application, data at 31.5 KBPS is used in a 16 kHz wide AM channel previously used for voice, which has a 6 kHz bandwidth.


As I’ve been saying in almost every post, physics doesn’t allow something for nothing.  Perhaps in your wanderings around the ‘net you’ve come across the concept that information is proportional to bandwidth.  Simply, the more information you’re sending in the same amount of time, the more bandwidth the signal takes.  I bet you know this even if you’ve never seen it stated online.  Voice channels take up more bandwidth than on-off keying; video takes up more bandwidth than voice.  Lower data rates take less bandwidth than higher data rates. 

The trade between the modulation types is that they convey more information in the same bandwidth, but require higher amplitudes for the same bit error rate.  That means more signal power at the receiver, so transmit powers may have to be higher and marginal signal strength might not work.  The complexity (read that as cost) of the transmitter and receiver go up.  For that cost, the D8PSK signal provides more digital data in the transmit bandwidth than plain AM voice.


These curves are generically referred to as “waterfall curves.”  It’s not quite as vivid in this graph but for some of these modes, as the signal to noise ratio (horizontal axis) goes up, the bit error rate (BER) falls off like going over a waterfall.  The signal to noise ratio is expressed as Eb/N0energy per bit to noise power spectral density ratio”  It’s calculated from the signal to noise ratio (SNR). 

This is read by choosing an error rate you’re comfortable with; I’ll choose 10-4 because all three curves are on the chart.  That means 1 bit in 10,000 is wrong.  For BPSK, you’ll see where the blue curve intersects that line, go down to the X axis and see it’s a little over 8 dB; I’ll call it 8.5.  For the 16-PSK curve, you see it’s just over 16 dB.  You get a higher data rate but it costs you 7.5 dB more in the hardware complexity.  Adding 7-1/2 dB transmit power is expensive in the ham world, depending on the frequency and other requirements.  On the other hand, if the receiver is reasonably well-designed, it's physically impossible to make one 7-1/2 dB more sensitive.