Monday, November 30, 2020

The Next Big Thing - A Private Space Station

Yes, it has been talked about for ages, but now with the reusable orbital class boosters SpaceX has developed, along with the reusable capsules to ride to destinations in orbit, the dream of private sector space station development looks closer than ever to becoming reality.  

Allow me to reintroduce you to Axiom Space, a private company that intends to start launching private missions to the International Space Station in late 2021 or early '22.  We talked about them earlier in the year (March).  They will sell training for private astronauts to make the trip and help them do whatever mission they want to carry out.  In the longer term, they intend to build a private replacement for the ISS starting in early '24.  Which is necessary because the ISS has been inhabited continually for 20 years and is reaching end of life in some areas.  Back in that piece last March, I noted: 
It's worth noting that the ISS is only planned to be in service through 2024 and there are already plans to decommission and deorbit the $100 Billion dollar habitat. NASA officials are hoping to maintain funding through 2028; that would be 30 years after the first modules were placed on orbit. That pretty much guarantees that the annual maintenance costs for the ISS are going up (I have a 40 year old house - DAMHIK).
SpaceX news site Teslarati reports that the first Axiom flight will reuse the Demo-1 capsule flown last May through August.  Tentative launch date is the fourth quarter of '21.  The mission to the ISS will be commanded by former NASA astronaut Mike Lopez-Algeria and will carry three other private astronauts, including Israeli multimillionaire Eytan Stibbe. 
Thanks to the relentless innovation that SpaceX does, we're in a period unlike the previous ten or twenty years and more like the early days of the space program.  The current first regular mission (i.e., not a demo) to the ISS on a SpaceX capsule, Crew-1, is slated to return in six months, or May of 2021.   Until the 63-day Demo-2 mission, only one US manned spacecraft had ever stayed in space that long; the US record for a crewed spacecraft is 84 days.  Crew-1 will easily double that record - it will be in space around 180 days.  Several Russian spacecraft have decades of experience spending at least several months at a time in orbit.  As the first US crewed spacecraft to spend that much time on orbit, you can be sure Crew-1 will be examined closer than any other spacecraft in ages.

But wait, it gets better.
The Demo-2 Crew Dragon capsule is currently scheduled to fly a second time as early as March 31st, 2021 on SpaceX’s Crew-2 mission, ferrying another four astronauts to the ISS. If successful, Crew-2 will represent the first commercial astronaut launch ever to reuse both an orbital-class rocket booster and an orbital spacecraft, and the NASA-overseen process of refurbishment and re-flight will thus pave the way for future flight-proven astronaut launches. That includes private company Axiom Space’s first private AX-1 astronaut launch, which is currently scheduled to launch as early as Q4 2021. [Bold added - SiG]
In that bolded sentence, strike the word "commercial."  It will be the first launch by anyone to reuse both an orbital-class booster and an orbital spacecraft.

Axiom's vision of their own space station.  Older articles talk about them launching a lab that can be docked to the ISS and provide facilities for the private astronauts they want to put up there.  The current website implies that "Axiom Hub One" (crew quarters, + research and manufacturing capability) appears to be what they want to launch first to get their own station started. 

Sunday, November 29, 2020

A Ham Radio Series 19 – What is Phase Noise?

If I get a chance to talk with other hams about receivers, the questions often come down to why some receivers are so much more expensive than others.  Someone might say something like, “an RTL-SDR costs $30, while a professional grade receiver like an IC-R8600 covers a bit more frequency but costs $2300.  It’s way bigger, too.  What’s the difference?”  That’s a question with many answers, often deep in details.  It’s hard to read much about the details in product reviews without coming across references to transmitter and receiver noise performance and the mention of phase noise.  What is phase noise and why does less of it cost so much more?
This is one of those topics that can fill a book, so let me try to break this down to some simple ideas.  Consider an oscillator that you build to produce one single frequency; perhaps a crystal oscillator, perhaps LC; the technology doesn’t matter.  Ideally, the oscillator would produce just that one frequency you’ve designed it to produce.  It would output a voltage, V(t) = A * sin(2*pi*f*t) where A is the amplitude, f is the frequency, t the time the voltage occurs. 

As I harp on all the time, nature is a bitch and the reality we get is not that ideal value.  What we get is something like V(t) = [A+E(t)] * sin(2*pi*f*t+p(t)).  That’s a fancy way of saying that in addition to the desired output we get fluctuations in amplitude E(t) in time, and fluctuations in phase p(t).  As a general rule, the effects of the phase fluctuations dominate the amplitude noise.  Perhaps you’ve seen a signal on an oscilloscope where you can see the signal width (time) varying slightly, perhaps an edge of the square wave is jumping around slightly on the screen.  That’s called jitter and jitter is just another way of describing phase noise (you can convert jitter in time to phase noise and vice versa).  If this signal is listened to on a good receiver, or observed on a spectrum analyzer, it goes from being the ideal situation in which all the power appears on one frequency to a signal with a noise around it that drops off as the frequency offset increases.  This is called a noise pedestal.  The higher the phase noise from the oscillator, the higher that pedestal is.

This is frequency in the WiFi band, and shows noise in a 10 MHz span.  I’ll get back to some descriptions of what you’re seeing after some additional points.

One of the most important things to know about noise is that the way we see it depends on how we look at it.  (Hmm… almost sounds like a zen saying)  By that I mean that if it’s truly random noise, the power goes up as the measurement bandwidth goes up.  Because of that relationship and the ease of converting the effects in different bandwidths, noise is usually specified as a power in decibels below the desired signal in a 1 Hz bandwidth, or dBc/Hz.  To convert the levels seen, simply use 10*log(bandwidth ratio).  If we double the bandwidth, the noise power is 3 dB higher; if we use 100 times the bandwidth, the noise power is 20 dB higher and so on.  This allows easy, direct calculation of the effects of the noise on our system.

In that scope picture, it says along the bottom left that the “resolution bandwidth” (RBW) is 100 kHz; 10*log(100,000) is 50, so the noise in 1 Hz is 50 dB lower or -50dBc.  Look at the point 2 MHz above the signal that I circled.  That noise is about 50 dB below the desired signal, so -50dBc -50 dB says it’s -100dBc/Hz.  By the way, if you’re intending to measure noise, it’s good practice to make the video bandwidth (VBW) 1/10 of the RBW all the way down to 1/100 of the RBW.  This makes for long sweep times, but video averages out much of the variation in the noise level. 

What difference does this make?  First off, let’s look at the transmitter side.  Say you’re operating ham radio field day and you’re at a club station that wants one station on CW and another on phone on some band at all times.  Consider 20 meters, and say the CW guy is at 14.025 MHz while the phone guys are 14.225.  A good transmitter could have the phase noise down 145 dB 200 kHz away, right on the CW guy’s frequency.  You’re putting out 100W, which is +50 dBm.  Noise 145 below that is -95 dBm.  In the 500 Hz bandwidth the CW guy is using that adds back up to -68 dBm.  Sure that’s a tiny fraction of a billionth of a watt (1nW = -60 dBm), but it’s a very big signal to a receiver.  It’s 89 microvolts in 50 ohms when the radio can copy under 1 microvolt easily – less than ¼ of a microvolt.  

In reality, that -68 dBm only exists at the transmitter output and what the receiver hears depends on how much loss there is between the transmit and receive antenna.  The only thing that can help here is having their antennas as far apart as possible to add path loss that would lower the noise. 

Phase noise is also a problem for receivers, but in other ways than just hearing another transmitter.  The main issue is that phase noise on the receiver local oscillator can mix with undesired signals out of band and translate noise or spurious onto the desired channel as interfering signals.  For reasons I’ve never quite grasped, this is referred to as “reciprocal mixing” – it seems like straight up, normal mixing to me.  In effect, your receiver’s local oscillator becomes self-jamming.

This drawing depicts the LO with noise dropping off in the adjacent channel, mixing noise into desired IF.  In ham radio, where most services are not channelized, the offset can be tiny.  They’re attempting to show that the noise mixed onto the undesired signal is degrading the signal to noise ratio of the desired signal.  If there are spurious signals on the LO, they'll mix into the channel, too.  If the desired signal is weaker than pictured, you can imagine it completely under the noise pedestal mixed on top of it. 

Exactly how to design a low phase noise local oscillator is so far beyond the scope of what I can do here that I can barely address it.  In a PLL, the phase noise of the voltage controlled oscillator (VCO) affects the noise more farther from the carrier, and a VCO with bigger components, higher Q, will be lower noise (rule of engineering: Q comes by the cubic yard).  The amount of division in the frequency synthesizer affects the noise closer to the carrier than the VCO.  Direct digital synthesizers are typically lower phase noise than a synthesizer, but much richer in spurious output signals.  Those spurs also mix in to the IF by reciprocal mixing. 

The newer, higher-end ham radios on the market have eliminated the receiver LO by doing RF direct sampling; they bandpass filter the signals being received and then convert them to digital without mixing in the analog world.  Likewise, the transmit LO can be produced by a Direct Digital Synthesizer and the modulation performed in digital signal processing, before converting the modulated signals to RF to amplify and transmit.

Saturday, November 28, 2020

I Prefer a Different Name

SpaceX booster 1049, designated as B1049-7 to denote having flown seven times,returned to Port Canaveral today to come ashore for its journey to the booster refurbishment facility and then back to another flight.  NASA Spaceflight has a camera set up at the port now to catch the return of all boosters and fairings that come back.  They're calling it SpaceX's sootiest booster yet, and that's the name I propose changing.  That video is an hour and a half video, by the way.  It's unedited, just the camera stream as it happened, but you can skip around in it and look at anything you'd like.  You should look around the video for a recovered faring on a truck - around 1:11:00.  I was startled by the size perspective.  

This screen capture was right before the moment where Lando Calrissian and Han Solo stumble out of the base of the booster, obviously hung over and each blaming the other for getting caught.  NASA Spaceflight calls it SpaceX's sootiest booster, but that's not really soot.  The black is scorch marks from its trips.  The straight lines are cleaned areas to allow inspection of weld lines - part of the inspection between flights.  It's just a used spaceship.

Since it's not really soot, I think I'd call it the Millennium Falcon, probably the best-known used spaceship.  A nation of Star Wars freaks would be in awe.

The rumor out of Lab Padre is the launch to 15 km is still scheduled for Monday, but the Temporary Flight Restriction notice (TFR) has not gone through, and the weather isn't looking good for Monday either.  I checked the National Weather Service Weather Prediction Center since we're getting our strongest cold front of the season Monday and I thought perhaps they're getting it too.  That would be unusual, and it doesn't seem to be the case.  Tuesday and Wednesday have road closures scheduled as back up to Monday.  I'll be checking in on the channel to see if the overview changes or the schedule gets confirmed. 

EDIT 11/29 @ 10:00 PM EST:  Lab Padre is saying the 15km flight is No Earlier Than 12/2.  Monday, 11/30 will be a static firing test. 

Friday, November 27, 2020

I Think It's Becoming My Annual Black Friday Post

Looking back on the phrase "Black Friday," it seems I've done a post about this unofficial national holiday every year.  I think sometimes more than once.  You might say, I'm a little curmudgeonly about the whole thing.  
Back when I was a production test technician (between iterations of college) I worked for an electronics manufacturer that shipped on a quarterly system, meaning that orders were booked and the company's financial results were tracked by the quarter.  Since I was in the group doing the final system tests, by the time products got to us, every delay that could have possibly happened had pretty much all happened and things were running late.  To stretch a metaphor, they were pushing the product to get shipped so hard that if you got between the product and the shipping door you'd be crushed to death.  Our shipping department had metal garage doors tall enough to let a semi-trailer back up to the dock so we could roll things in on fork lifts or dollies.  So much product was pushed so hard through those metal doors that the morning after the last day of the quarter there were literally metallic hemorrhoids glistening in the morning sun around the frame of the garage doors.  OK, so maybe I was the only person who could see them.

In the weeks before that, the production expediters would go through the work orders coming into my department and mark which of them were “hot” and should be worked on first.  In the last week or two, pretty much everything was marked that way.  You've probably been wondering where I'm going with this: it's that I told a production coordinator at one time, “when everything's hot, nothing's hot.”  To his befuddled and exasperated expression I calmly explained that nobody can work on everything first, I can only work on one thing first.  Only one thing can be most important.

And now that we're over the target, by extension, when every day is Black Friday, no day can be Black Friday - in the usual sense of a special day that kicks off the Christmas shopping season. 

I don't know about you, but I'm sure I started seeing black Friday ads in July.  For sure, for the last month, I must have been getting 50 to 75 emails a day with black Friday in the subject.

When did this become a national thing?  It seems it must have been within the last five or ten years. 

Black Friday was supposedly called that because it was the day where businesses turned their annual ledgers from red ink to black ink, but in the last few years it seems to have morphed into something else.  It has been reported for years that the big deals aren't necessarily really deals at all, or that some companies raise their prices in the weeks (months?) before the day so that what would have been a normal, small discount from MSRP suddenly seems like a deal.  It's being reported that more and more people are carrying their smartphone into the stores to price check things, compare price and availability at other stores, or get coupons.  I confess: I've done it and not just this time of year. 

Once there started to be a perception that good deals came on Black Friday, it was only a matter of time until it became just another way of saying “BIG SALE!”  But shoppers like to think they're getting big deals, and there are stores that put one or two items on a massive discount to get some people to line up the night before.  Maybe they can get some buzz on the news.  Of course, now that stores are opening on Thanksgiving itself, Friday seems like it loses some drawing power.  Regardless, every year there's some incident where people get violent over something stupid.

It always pays to know what going prices are.  I've heard that generally speaking, the best time for deals is closer to Christmas, especially right before Christmas.  You'll get better prices than this week, but it's a gamble.  You're betting that the stores will be stuck with something you want and would rather discount it than not sell it.  If they sell out first you lose.  If they don't sell out but still won't or can't cut the price, again you lose.  That said, it has worked out for me in the past.  It's sort of like calling a bluff in poker. 

Retail is a rough way to make a living. I'm sure you've heard how airline reservation systems base the seat price on the apparent interest in a flight.  If you go back and check on the price of that seat every week, the system says there must be more demand for that flight and raises the price.  What if stores could measure real time demand and adjust the price.  Say you're looking for a new tool or other gadget; what if they see someone checking the web site regularly and interpret that as several people interested in that item and raised its price?  Would you be upset or offended?  What if they dropped the price to see at what level you can't resist pushing the Glistening, Candy-like, "BUY IT" button?  I don't have any hard evidence that anyone does that, but it seems trivial for an online store to track interest in something.  The biggest risk is scaring away customers.

To me the Golden Rule is the willing seller/willing buyer.  My inner engineer drives me to optimize things, but if people are happy with what they paid, regardless of whether or not it really is "the best price of the year", and the seller is happy with the price they got for it, that's definition of a fair price.  I'm sure not gonna poop in anyone's corn flakes by telling them they didn't get the best price.

Yesterday we took our traditional trip to my brother's house in South Florida, a bit short of 300 miles round trip.  It was a big get-together, with 16 people together.  Since we're not under lockdowns here in Florida, traffic seemed normal. Maybe a little light, but nothing really obvious. I have no idea what the stores will be like, but probably worse if you're in a blue state or city under lockdown. There will be no crowds and no people fighting over the one or two items that had the big discount.  An article on Breitbart shows this Black Friday scene, this morning. 

Jeenah Moon/Getty Images, Macey's Department Store in New York City, this morning.

Wednesday, November 25, 2020

Tuesday Was a Make Up Day

On Sunday I posted that SpaceX had scheduled a static fire test of Starship Prototype SN8 for Monday the 23rd, but Sunday night itself there would be a Falcon 9 launch "up the road" at 9:56 PM.  The launch was scrubbed Sunday night and Monday they never achieved the static firing.  

As you might gather from the post title, Tuesday was the day to make up for the missed milestones and there was both a successful and uneventful static firing of number 8 and a successful launch of 60 more Starlink satellites, marking the seventh successful flight (and recovery) of B1049.  If you want to watch it in lots of detail, a video of the SN8 static firing from NASA Spaceflight (.com) is available.  Elon Musk says the static firing was nominal and the vehicle is cleared for the 15km test flight on Monday. 

The mission video from the Starlink launch is here, queued up to start at T-1 minute before launch.  I've grabbed a screen capture from the video a few seconds after the booster landed; long enough for the camera to recover from its shock of going from photographing the ocean at night with a few lights on to a rocket's plume 90 million f-stops brighter, and then a few seconds for the smoke to clear so you can see the booster standing there.

The only bad aspect to me was that at launch time for the Starlink mission, it had clouded over badly and we saw absolutely nothing.  Maybe the clouds in the direction of the mission got a little brighter. 

Getting back to Texas and the Starships, a quote from the Teslarati article linked earlier is worthwhile.
Having now spent more than a month at the launch pad, it’s increasingly unlikely that SpaceX will continue to choose caution first for upcoming Starship SN8 tests. As Musk recently noted and easily visible from public roads, SpaceX’s Boca Chica factory is developing an extraordinary backlog of giant steel rockets. Just today, November 25th, Starship SN9 (featuring “small improvements”) was officially reached its full 50-meter (~165 ft) height after SpaceX kicked off nose section installation. In simpler terms, if SN8 is destroyed during testing, Starship SN9 will likely be ready to roll to the launch site almost as soon as the pad is clear.

Meanwhile, Starship SN10 is likely just 7-10 days away from a similar nosecone stacking milestone and Starship SN11’s tank section is just one stack away from completion, likely putting it less than two weeks behind SN10. In other words, insofar as speed is a priority and each prototype is anywhere close to as cheap as Starship’s majority-steel bill of materials, SpaceX is building the rockets so quickly that it almost doesn’t make sense to spend more than a few weeks working through any given ship’s bugs.  Bold added: SiG
It doesn’t come as a huge surprise, then, that Musk has given SN8 – warts and all – a 33% chance of successfully launching, ‘skydiving’ back to Earth, reigniting one or more Raptors, and landing in one piece. The only real certainty is that regardless of the outcome, Starship’s high-altitude launch debut is guaranteed to be spectacular.
My mind is officially blown. 

Most of you will read this on Thanksgiving, which is tomorrow at the time I'm posting this.  Let me take a moment to wish you and yours a happy and blessed Thanksgiving!  I'll be taking the day off and be back on Friday. 

Tuesday, November 24, 2020

My Little Engine is Pointless

I should make that, "despite my best efforts, my engine is pointsless?"  The engine is designed for an old-fashioned points, ignition coil and capacitor (condenser, if you must) ignition.  I decided to upgrade it to a capacitive discharge ignition (CDI) for model engines, from a guy who sells to the hobby engine makers.  At that point I had a choice between using a hall effect sensor or the points and decided to stay with points. 

The plans say to use points from, "1969 DODGE CHARGER, 383, 4BL, W/SINGLE POINT DIST" but the only place where that matters is in the mounting dimensions. I could have adjusted the piece of metal that the points mount to, if I had understood that back when I was getting started (this is one of the first pieces I made for the engine).  Let's say I had a set of points from some really old car I used to have; I could have redesigned the mounting support and used those.  I eventually searched for points on AutoZone and Advance Auto Parts; the two national chains are within a block or two of each other and a couple of miles from home. I had to pay for the points at AutoZone on Saturday and have them delivered to my local store from their regional warehouse in Orlando.  I got them this afternoon and had them installed quickly, once I found the two screws I needed.

Something's missing.  These are actually the wrong points in AutoZone's cross reference.  You can see a sheet metal spring hanging off to the lower right around the black SHCS, and to the lower left of that screw is the moving contact on its plastic mount.  The plans for the engine show a bent up piece of metal on the bottom of the arm between the two mounting screws (flat blade/slot screws shown), and a stud with hardware on it (circled in red) between the screws connecting the points to the capacitor. 

A little more research took me to their competitor, Advance Auto Parts, and they have the points I need.  Tomorrow I'll call or drop by to see if they stock them or I have to order from Orlando again. 

Until I get the points, I have more stuff to do.  I need to cut a little gasket material to go between the cylinder and cylinder head.  In the last couple of days, I put together a little fuel tank holder to keep the tank in the right relationship to the carburetor input.  Hopefully.

That's two U shaped aluminum uprights on a 3/8" thick aluminum plate.  The plate needs some finishing work done on it to make it look nicer.  Actually, everything could use some "prettying up," it's just too late for most of the engine.  I've seen people run these electronic ignitions spread across their workbench, and I need to take a look at making a little box for that.  I will assume attention should be paid to whether it's metal and all ground or maybe made of wood.

I have no idea how long it will take to get this running.  It took me several tries to get my flame eater to run OK, and I'm sure there's a lot here I'll need to do.  OTOH, I've bought or made everything I think I need - and I don't think another problem like the wrong points is possible.  I sure would like to have this running soon, though. 

Monday, November 23, 2020

NASA Has an Anti-Exploration Group Fighting to Keep the US Earthbound

I'd heard rumors of this, but didn't pay it much attention.  This morning's email brought a link from Bill Whittle and an absolute Must See video.  
NASA’s Equity Diversity and Inclusion Working Group (EDIWG) publishes an anti-capitalist, anti-colonialist manifesto which, if followed, would effectively ban the USA from exploration of Mars, our Moon and other planetary bodies. After all, our “extractive capitalism” approach could interfere with evolution of microbes on lifeless worlds. How shall we meet the EDIWG invasion of NASA?

The video makes some points I've never heard of, including that the Viking missions in 1976 was the last Mars mission with experiments on it to search for life because of the actions of this group under the name of the Planetary Protection Office.  A strange name because it implies protection of this planet and they apparently have nothing to do with that.  Exobiologists are not allowed to search for life on another planet until they can prove there is no life there.  Excuse me?   How is that even remotely logical?

No missions to planets that might have microbes on them - think Mars because it might harm microbial life on the planet.  What about a sterile body like Earth's moon?  Can't go there either because it might harm microbes that could eventually evolve!  (I'm not making this up)  Can't mine asteroids, also sterile bodies, because that's extractive capitalism.  Can't do anything.

It should go without saying that this is aimed at destroying American efforts in space because you can bet your butt the Chinese aren't going listen to NASA's EDIWG.  Watch if you have a high stupidity tolerance, read the PDF.  Paging Elon Musk: you may need to relocate to outside the US, if you can find any place that will grant you the freedom to launch to Mars.

Sunday, November 22, 2020

Back to Normal at SpaceX Boca Chica

It was back on Friday the 13th that I posted an update on SpaceX's testing program at Boca Chica, after a meltdown during the static engine firing test on the preceding Tuesday.  After ten days without any road closures or other tests scheduled, yesterday they announced road closure for tomorrow, 11/23, from 7a-6p CST, 1300-0000 UTC, with Tuesday and Wednesday as backups.  Expect more cryogenic proof testing and another static fire test, possibly more than one.    

The bigger news from them is the long anticipated test flight to 15 km (~50,000 feet) has been scheduled for Monday November 30th, with the same 7a-6p CST hours.  It has never had a committed launch date before.   Tuesday and Wednesday 12/1 and 12/2 are backup dates, same hours.  Elon Musk has committed to live streaming this launch saying it might be really ugly but we'll see it in real time the same time he does. 

Let's see... the SN8 meltdown was Tuesday the 10th; the Do Over is Monday the 23rd.  Considering the talk about redesign of the Starship and changes to the launch facilities, a delay of less than two weeks seems astounding. 

View of the "flying sparklies" from the night of Tuesday the 10th, from the NASA Spaceflight (.com) video posted Wednesday the 11th. 

Meanwhile, here within viewing distance of the Kennedy Space Center/Cape Canaveral Space Force Station, we're counting down to the 9:56 PM launch of another Starlink mission (Starlink-15).  Yesterday's Falcon 9 launch from Vandenburg Air Force Base set a record for launches by SpaceX in one year at 22.  This makes tonight's launch doubly special; in addition to setting a new record for number of launches in a year (and any more launches will do the same) it will be the seventh launch of booster B1049.  That will be the most launches of any reusable rocket and one more step toward their long-time goal of 10 launches 'without a major refurbishment.' 

With tonight's launch #23, SpaceX is looking towards a year of 25 launches (possibly more - Spaceflight Now has four launches before the end of the year)), but a couple of times, CEO Elon Musk has revealed that the company is pushing to achieve as many as 48 launches in 2021. 

Saturday, November 21, 2020

Test Post and Infobleg

 First, the test post.  Ever seen square gears?  

I think it's one thing to visualize that motion and another to design the shapes.

This is animated gif that I made from an .mp4 video I found at Homemade Tools.  This is the first time I've done an .mp4 to .gif conversion, using the free versions of a video editor I've trying out. 

Which gets me to the info bleg.  I'm looking for a video editor for my YouTube channel.  This video editor (VSDC) isn't expensive to upgrade, but it has far more features than I care about.  For my purposes, the screens are way cluttered with things I just don't want.  I don't have much in mind that I want to do, but consider a running engine or a machining operation.  I can see running those videos at twice normal speed, doing a voice over of and perhaps adding a text screen.

Think of things more like documentaries and less like what kids do with their phones. 

So of those of you who do videos for yourself or friends or have YouTube channels, what's a good, video editor without too much bloating in it?     

Friday, November 20, 2020

Rocket Lab Recovers First Mission Flown Booster

We've been covering the advancements of Rocket Lab (or one word: RocketLab) since they started picking up international headlines three years ago and have watched their success in the small payload market.  If they haven't cornered the market, they're close.  In August of '19 they announced that they were going to move toward recovering boosters and last December they conducted a test flight to take data and ensure they understood the issues.    

This week they did it “for real” with a mission for paying customers and recovered the Electron booster.  Unlike the better-known SpaceX Falcon 9, the electron booster is too small, and too close to its limits on any given flight to retain fuel for a powered landing back either on land or on an autonomous drone ship.  Instead, they planned to come down under a gliding wing parachute, and get caught out of the air by a heavy lift helicopter.  Which doesn't seem to be quite how the booster in this released photo got there.  Parachute?  Yes.  Helicopter?  Must have missed the catch. 

Rocket Lab ordinarily names every mission, sometimes with a cheeky reference to the mission itself.  This flight was called "Return to Sender" and the booster is doing just that.  I'm being mildly facetious myself.  Ars Technica reports Rocket Lab saying they didn't attempt the helicopter snag of the parachute this time. 
Return to Sender didn't test the full process, but it was the first in which RocketLab would attempt to deploy the parachute to facilitate a gentle splashdown and recovery. This would allow the company to get detailed readings of the stresses and temperatures that the Electron experienced during reentry.

While the livestream of the mission cut out before the splashdown took place, the company released a statement indicating that the rocket had been successfully recovered and posted posted photographic evidence to its Twitter feed.
This little addition to the post seems too good not to add:
But one final bit of payload won't be remaining in orbit. RocketLab is terming it a "mass simulator," but it's a 3D-printed titanium garden gnome named Gnome Chompski, modeled on an item from the Half-Life game series. In the game, the goal was to sneak the gnome onto a rocket and send it to space. Supposedly, it was being sent to test the performance of 3D printed hardware during the rigors of launch. But in reality it was an excuse for Valve’s Gabe Newell to donate money to charity—one dollar to anyone who watched the livestream within the first day. So far, Gnome Chompski's launch has raised over $80,000 for the Paediatric Intensive Care Unit at Starship Children’s Hospital in Auckland.

Gnome Chompski in space.  Echoes of Starman.

Thursday, November 19, 2020

Bottom-Feeder Lawyer Frenzy Over Roundup Seems to be Ending

Every now and then, I surprise myself by searching for something I'm absolutely sure I've written about before and don't find it.  Sometimes it has shown up when searching for totally off-the-wall search terms (can't think of an example) but ordinarily I search for the topic and find something I'm sure I've written. 

Not this time. I can find no evidence of having written about the bottom-feeding lawyer race to the bottom that has been going on over the weed killer Roundup.

Yesterday at Townhall, occasional columnist Angela Logomasini passed on the news that the bottom feeders seem to be moving on to something else to sue over.  It's an interesting story, if you know the background that no carefully controlled study has ever concluded that Roundup (glyphosate) causes cancer, nor has any country declared it a carcinogen.  Even the EPA hasn't ruled Roundup to be dangerous and you've got to know the EPA would love to regulate as much as they possibly can.  Ms. Logomasini put it this way:
All these cases are built on a single, discredited hazard assessment produced by a United Nations outfit known as the International Agency for Research on Cancer or IARC. IARC classified Roundup’s active ingredient—glyphosate—as a known carcinogen despite contrary findings by most governmental and nongovernmental entities around the world.

Yet IARC does not even attempt to determine if real-world exposures pose risks, they just consider the theoretical possibility of risk at some unspecified level.
I'm sure you know what's referred to as the First Law of Toxicology, which is "the dose makes the poison," right?  IARC totally ignores that.  If you look into IARC rulings, it's even more bizarre.  IARC places plutonium in their Group 1, the same cancer category as Chinese-style salty fish, leather and wood dusts.  I think everyone considers plutonium a carcinogen; the salty fish and sawdust, not so much.  They're hard to take seriously. 

The reason there's a feeding frenzy over suing Bayer AgroSciences, parent company of Monsanto, is that in some jury case a suit was successful and thus became a legal precedent.  In an attempt at self-preservation, Bayer established a policy of just paying out on these claims, but that sent the message to the lawyers that the gravy train had arrived. All they had to do was file and Bayer would pay out.

As the money has been paying out and the number of new cases is going down, the sharks are looking for a new place to feed.  They've found one.  Again, to Ms. Logomasini:
As Roundup cases hopefully winds down, there are a growing number of lawsuits focused on ethylene oxide (EO) on the horizon. EO is a chemical used to sterilize more than 50 percent of the nation’s medical supplies—including masks, bandages, ventilators, and more. The U.S. Environmental Protection Agency aided and abetted the trial lawyers on this one in 2016 by producing an absurd assessment on the chemical’s risk.
I've long considered the EPA to be the High Priests of Junk Science, and this time it's Junk Science in the extreme.  The EPA has a program called the Integrated Risk Information System or (IRIS) (pdf warning on the link), and IRIS assigned a safe exposure limit of 0.1 parts per trillion for EO.  For perspective, the American Chemistry Council (ACC) says this is the equivalent of taking one drop of water and spreading it into 200 Olympic-sized swimming pools.  Must be powerful stuff, right? 

Here's where the EPA really screwed the pooch on this subject.  See, your body produces EO at levels 19,000 times greater than the EPA's 0.1 ppt.  All day, everyday.  Further, since this is part of the intricately regulated biochemistry of our bodies, the body clears EO quickly, with a half life (that is, levels falling by 50%) of 42 minutes.  If the EPA was right, people would be dropping like flies from the EO in their own bodies, inhaling it in the air, and more. 

Since the EPA declared it such a ridiculously potent poison, the lawyers have followed. 
Despite these realities, EPA’s air quality office used the IRIS number in a 2018 report that suggested people in communities near medical sterilization plants might face elevated cancer risks. Sensationalist news headlines followed, whipping up panic in several communities leading local and state governments to shut down several plants during 2019 and into 2020.

These closures exacerbated medical supply shortages  (pdf warning) just when the novel corona virus crisis started. Fortunately, in March and April of 2020, the Food and Drug Administration was able to get states and localities to open all but one of the facilities to help address shortages, but this issue is far from over.
The problem, I'm sure you can see, is that if the EPA doesn't reclassify EO, the lawyers may get lucky and get into a court with a dumb enough jury to award money, which will trigger a Roundup-like feeding frenzy that could shut down all the medical production that relies on it.  Instead of hurting one corporation (and the millions that depend on Bayer), they'll hurt everyone dependent on the medical facilities that sterilize with EO.  Which hurts everyone, especially in the days of the Rona. 

Typical lawyer attempt at trolling. 

Wednesday, November 18, 2020

An Ariane Launch Failure and a Post Mortem on SN8 from SpaceX

Arianespace, the European space consortium, had a launch at 8:52 PM Monday night (EST) of one of their Vega rockets that failed to achieve orbit.  It was the second failure of a Vega in two years, after a spotless six years of service.  The vehicle was carrying earth observing satellites for both France and Spain; both satellites were lost. 
The Vega is designed for relatively small satellites, typically handling total weights in the area of about 1,000 kilograms (2200 lbs), though it can lift heavier items into lower orbits or take lighter ones higher. The trip to space is powered by a stack of three solid rocket stages; once in space, a reignitable liquid-fueled rocket can perform multiple burns that take payloads to specific orbits.
Although the solid rocket stages operated normally, when the liquid-fueled stage ignited to push the satellites into their desired polar orbits, something went wrong.  According to Roland Lagier, chief technical officer of Arianespace, the problem started the moment the stage ignited.
However, “straightaway after ignition” of the upper stage, he said, the vehicle started to tumble out of control. “This loss of control was permanent, inducing significant tumbling behavior, and then the trajectory started to deviate rapidly from the nominal one, leading to the loss of the mission.”

Analysis of the telemetry from the mission, along with data from the production of the vehicle, led them to conclude that cables to two thrust vector control actuators were inverted. Commands intended to go to one actuator went instead to the other, triggering the loss of control.
Ouch.  That kind of human error is always exasperating and especially when it takes out a mission.  The entire infrastructure around launches is aimed at catching operator error like this.  Everything: quality inspections, the workers performing the connection signing off on every operation, stamping the work to verify it agrees with the requirements, everything.  Picture two cables marked  1 and 2, or something, that are supposed to go to connectors marked the same way.  Instead of seeing 1 connected to 1 and 2 to 2, it was 1 to 2 and 2 to 1.  And it got by. 

One of the satellites that was lost, while being readied for launch. Arianespace photo.

Yesterday, Elon Musk announced in his Twitter feed what the failure analysis showed as the root cause of the problem with SN8 that led to dripping molten metal and the other things I talked about last Friday.
About 2 secs after starting engines, martyte covering concrete below shattered, sending blades of hardened rock into engine bay. One rock blade severed avionics cable, causing bad shutdown of Raptor.
As I understand it, martyte is a ceramic filled epoxy intended to help fireproof and protect the area under the test launch pad. Moments after this tweet, he added that avionics cables would be moved to steel pipe shields and they would be adding water-cooled steel pipes to the test pad.  He also stated that an overview of the Starship development program will be delayed to account for some “notable” design changes.  While we're all looking forward to seeing Starship and SN8 flying and proceeding in development, this all seems like things that must be done.  After all, the Raptors are producing up to 200 metric tons (~450,000 lbf) of thrust each and an exhaust stream traveling some 3.3 kilometers per second (2 mi/s, Mach ~10).  Don't leave anything loose under the vehicle that you ever expect to see again.

It originally seemed to me that this is the opposite kind of problem that Ariane had with their Vega. It's not a human error like swapping two cables, it's more a design error of picking the wrong materials for the launch pad (the martyte) or not anticipating what can go wrong. On second thought, I don't think it's that simple. It could be the martyte wasn't the right choice of material, but perhaps it would have been fine if it was mixed or applied differently.

Teslarati author Eric Ralph is optimistic that we may see testing resume before the end of the year. From the information I've seen, including the chatter by the full-time (or nearly so) observers on the Lab Padre cameras, the vehicle has already been fixed, with the one damaged engine replaced already. If any design changes are known to be coming, especially to the vehicle itself, it would seem to be best to incorporate those before any more attempts.

Tuesday, November 17, 2020

I Heard Something That Made My Jaw Hit the Floor

I frequently listen to Rush Limbaugh in the afternoons if I sit here at the computer doing stuff.  I regularly mute commercials, but today heard a commercial that was so astonishingly wrong that my jaw hit the floor.  For a few minutes I wondered if I'd had an aneurysm or a stroke, but I could speak and move so I realized it was just the shock of the idea they were selling. 

It wasn't exactly a commercial, and it wasn't exactly a public service announcement; the closest I can come is that it was propaganda broadcast.  I've got to say that because of how astonishingly wrong it was, I've thought for hours about whether or not I should link to them.  The announcement was intended to scare people about global warming and there's a video that's very much like it, except that the announcer in the video is a dude and the radio spot was a dudette.  The script is very much like this:
What is the main difference between the Sun and the Moon? Earth has two trillion tons of CO2 that provides a 60-degree temperature difference and a stable environment for life. However, we currently have three trillion tons of CO2 in our atmosphere. This is causing consistent warming and an increase in natural disasters that we are seeing year-after-year.
The group behind the commercial is a place called VoLo Foundation that's here in Florida.  They don't ask for contributions.  They don't tell you buy or not buy anything.  They apparently just want to scare people and get that fear to raise their issue in the polls. 

There's so much wrong with this that it's hard to know where the start, but the easiest place is that Earth has a large complex atmosphere, not just CO2.  That 2 trillion tons of CO2 they mention is a tiny percent of the 5.5 quadrillion (5,500 trillion) tons of atmosphere we have.  Most elementary school science books say CO2 is 0.4% of the atmosphere which is close to the 2 trillion tons they quote, so at least that's right.  The latest numbers on concentration of CO2 are right around that 2 trillion ton mark, so their line about us currently having three trillion tons is nonsense.  The moon has a tiny trace of an atmosphere that isn't at all comparable to the Earth's.  The most complex part of the atmosphere is clouds, water vapor, which none of the climate models seem to get right. 

The next easiest thing to mention is that Earth has oceans and the moon doesn't.  Hardly news, right?  I mean you've probably heard that 70% of the Earth's surface is water all your life and the folks at VoLo have to know we have oceans.  Water is important to global temperature regulation because the specific heat of water is around five times that of air; again, anyone who lives near the ocean or a large lake knows this.  There's 1.332 billion cubic kilometers of water in the oceans and surface water; I get 320 million cubic miles of water and have seen estimates of 332 million cubic miles.  Tiny compared to the Earth but a big influence.

Earth also absorbs more sunlight than the moon does because of its larger size.  The surface area of the Earth facing the sun is 13.5 times that of the moon.  Do you think the earth might absorb more heat than the moon with 13.5 times the absorbing area and 81 times the mass?  Now you get into differences in reflectivity (what the astronomers call albedo); like that we have high reflectivity ice around the poles because of all that water, while the moon doesn't.  It's a small percentage of the surface area, though.  

Moon facts from NASA.

With this many huge considerations they didn't consider, it's hard to consider that VoLo ever intended to be right.  They got close to the average distance of the earth/moon orbit to the sun, they got close to the amount of CO2 in our atmosphere but the rest is nonsense.  It's a meaningless comparison and they're just trying to scare people.

Monday, November 16, 2020

NASA Commercial Crew Officially Flying

I guess that's kind of an odd headline; the Demo-1 mission back on May 30th was “officially flying,” it was just considered experimental.  With last week's approval of the SpaceX Crew Dragon for operational use by NASA, the Crew-1 mission currently on the way to dock with the International Space Station (ISS) isn't a special mission.  It's the first regular mission of the now-standard ride that NASA astronauts will be taking to space; at least until Boeing straightens out their Starliner capsule to take crews to the ISS and adds another way to get crews into space. 

Being a night launch, we were treated to another beautiful sight, just not this beautiful:

As the lower right says, Richard Angle photograph from Teslarati.  If you extend the arc of the trajectory down toward the horizon, it lines up with an unusually bright streak just above the buildings on the horizon.  That's the first burn of the first stage returning to land on their drone ship Just Read the Instructions.  We didn't see that from here, but the trajectory was toward the Northeast, so it's lower in the sky here 40-ish miles south of where that was taken. Additionally, we had some clouds that were low in the sky, blocking the NE.

Teslarati updates the mission as of this late this morning.  There were apparently some issues from software limits and a couple of glitches as the mission made orbit. 
Crew Dragon’s fault detection software was tripped sometime after reaching orbit. Both thermal control system (TCS) “loop” pumps – likely referring to pumps used to circulate a liquid-based radiator system to maintain capsule temperature – experienced off-nominal pressure spikes, causing the spacecraft computer to switch to the second pump (“Loop B”).
SpaceX was able to resolve that issue, effectively restarting the pumps and confirming healthy operation. Several hours later, the backup pump (“Loop B”) suffered another minor issue but was again returned to healthy operations. Simultaneously, Crew-1 astronauts found themselves stuck at an (admittedly comfortable) cabin temperature of 23C (~73F).

More pressingly, three of four heaters used to warm the propellant fed to Crew Dragon’s small Draco maneuvering and attitude control thrusters were automatically disabled a few hours after liftoff. Essential for most operations in orbit and necessary for Dragon to be allowed to remain docked with the ISS, restoring the functionality of at least one of the three heaters was essential, and SpaceX was thankfully able to restore function to all three by relaxing excessively conservative limits in the spacecraft’s flight software. Thanks to SpaceX’s fast work, Dragon is now in perfect health and ready for two crucial Draco burns at 11:20 am and 12 pm EST (UTC-5) on Monday, November 16th and is still scheduled to arrive at the ISS around 11 pm EST.
Sigh... I call that "Universal Software Fix:" turn it off and back on (restarting the pumps) and I'm sorry to hear it.

An interesting little fact about this mission is that the 24 hour delay from Saturday to Sunday due to high winds in the area has made their climb to the ISS take over three times longer.  Had they launched Saturday, the cruise phase would have been just 8-1/2 hours.  The hour delay gets them around 28 hours.  From last night at 7:27 PM until tonight at around 11 PM. 

Sunday, November 15, 2020

On Masks

As with pretty much everything about the Covid disaster, the mask stuff is hard to decipher.  It's not like people haven't been studying the effectiveness of masks against respiratory viruses for a hundred years, and pretty much concluded they don't do much.  Even though there might have been absolutely fine studies that have been guidance for that time, everything had to be treated like it was a New Thing, with studies saying masks help alternating with studies saying they don't.  Recently a study in the news that said masks worked had to be retracted by the authors.  The masks didn't actually help. 

It was pretty obvious in the early days they didn't want people to have N95 masks because a shortage was happening and the professionals said they needed them more than we do (which I don't dispute).

Let me pass on a saying I picked up when I was a student: one study doesn't prove anything.  Two don't either, but two are stronger than one.  Several studies might well mean something, but they all might have the same fatal flaw big mistake in their setups.  Fourteen studies might well prove something, with the caution that they may have made the same mistakes over and over again.  (The fourteen includes both hand washing and mask studies, not just masks).  

(Original article at CDC - I've lost track of where this screen capture came from)

Note this doesn't say masks are totally useless, just that any benefit is indistinguishable from random differences between groups of people.  A worthwhile observation from redneck statistics is that if you have a handful of studies of something, with one pile saying there's an effect and another pile saying there isn't, it could be that there is an effect, it's just very weak.  Maybe a mask could reduce the spread of the virus by 1%; maybe the mask makes the spread worse by 1%.  

Personally, I come down to thinking they are less about protecting people than the politicians saying they're doing something.  Some of them, of course, are just tyrants who want to control people regardless of whether it's helpful or not.  I think it's an undeniable observation that a lot of people aren't really adults, regardless of their age, and want to be protected by big government.  These are the people you see in video reports where they verbally and sometimes physically attack someone for not wearing a mask around them.    

A politician is someone who never wants to be thought of as being wrong.  As an engineer, I wrestled with nature full time, so I'm quite used to being wrong.  I always used to tell the new grads I would mentor that I reserve the right to be wrong.  I try not to be, but that just doesn't mean much.  This might all be wrong, too.

Saturday, November 14, 2020

A Ham Radio Series 18 – Is There a Transmit Equivalent of the RTL-SDR?

Do you have an RTL-SDR, or another version of those very broadband, very cheap Software Defined Radios?  I’ve talked about the architecture and how these radios work in some depth, including block diagrams and a fair amount of detail.  It begets the question that with these cheap and very broadband receivers, why aren’t there any matching transmitters.

I don’t mean to be dismissive of the question, but it’s mainly because transmitting is harder than receiving.  To begin with, the RTL-SDR is based on an integrated circuit that’s intended for watching HDTV over the air.  The market for broadband HDTV receivers is enormously bigger than the market for amateur transmitters, and justified the cost of developing receivers.  Custom or Application Specific Integrated Circuit (ASIC) development generally runs into hundreds of thousands of dollars, perhaps half a million (and that’s if it’s right the first time).  Plus, the chip designers thought of what the future features might be wanted in the HDTV receivers in the future and added digital data streams; called I/Q data (In-phase and Quadrature-phase) signals, which is what allowed the software developers (hackers) to use the chip as a broadband receiver.  On top of all that, to be brutally honest, the receivers just aren't that good (toward the bottom of this post).

Then there’s the nature of transmitting itself. I know I’ve talked about this before, but transmitters (like all circuits) have an output impedance and antennas have an input impedance.  A circuit theorem called “Optimum Power Transfer Theorem” says that for that to happen, they must be the same impedance.  A convenient way to approximate the output impedance of a transmitter is the voltage squared over 2 times the power output ((Vcc^2)/(2*Po)), which then gets matched to the output of the amplifier circuit, which is generally 50 ohms.  The higher the transmitter power, the lower the output impedance, which makes matching it harder, which means more parts, which leads to less bandwidth.  The transmitter connects by transmission line to the antenna, often specified to 50 ohms as well.  The antenna, in turn, can be thought of as an impedance transformation from the 50 ohms at its input to the 377 ohms impedance of free space.

The broader the bandwidth of the antenna (i.e., the frequency range over which the antenna presents a 50 ohm load), and the broader the transmitter output impedance match, the more broadband a transmitter can be. 

If you’ve played with an RTL-SDR for any length of time, you have probably noticed that it seems more sensitive on some bands than others.  That’s because the chances are you’re using a non-resonant antenna, like a rubber duckie or a short wire.  These are intended to match around their electrical length (remember for a quarter wave monopole, 234/f gives the antenna length in feet when f is MHz) and the match gets worse as you tune further away.  The RTL-SDR folks sell an upgraded version of the receiver with a collection of antennas, but they’re best from around the FM broadcast band up to around 1.5 GHz, although you’ll have to swap antennas and change their lengths while trying to listen to something.

You can do better.  There are antenna designs that are much broader bandwidth than simple monopole “rabbit ears” antennas like the ones that RTL-SDR sells, but those designs cost more than the “rabbit ears.”  The two that come to mind first are one called a discone; these tend to be operated in vertical polarization, and a log-periodic dipole array (LPDA), which has the advantage over the discone of offering antenna gain (directionality), and can be mounted in either vertical or horizontal polarization.

The antenna, then is less of an issue.  A log periodic with a bandwidth of 10:1 (say 50 to 500 MHz) isn’t exactly bleeding edge technology and a 144 to 1300 MHz (9:1 frequency) transmitting Discone is under $50 from Amazon.  If we can put a transmitter on the antenna that’s a broadband output, is that our transmit equivalent of the RTL-SDR?  Nope.  The SDR linked to above will receive 500 kHz to 1500 MHz, and the broadband antenna is over two orders of magnitude away from 500 kHz (288 times 500 kHz). 

Do broadband 50 ohm output transmitter systems exist?  Yes, but with two problems.  First, you don’t want to pay for one that delivers power of as little as 25 Watts.  These things go for thousands of dollars.   How about a 1W (in FM) or 100mW SSB amplifier from 10 to 4200 MHz; that’s only $1500?

The second problem is transmitters have an inherent need for filters.  While the receiver side will benefit from filters, the only one who suffers is you; the user.  When transmitting, your signal can carry harmonics and spurious signals that interfere with other spectrum users.  Interfering with other services can bring enforcement and big fines.  In the US, we’re generally able to receive anything we can build hardware and software to receive, but this isn’t the case in other countries.

When I started thinking about this problem, I thought the enabling technology might be a DDS with a modulator on its output.  Analog Devices has a line of products they call TXDACs (Transmit Digital to Analog Converters) that can generate the signal and produce a low power output (as in milliwatts).  These signals need to be software generated but give two or four tones tests that are exceptionally clean.  As soon as you amplify that to a watt or so, you’ll need to check the spectrum carefully.  The drawback is they’re just not broadband enough, I see nothing that will match a 500kHz to 1500 MHz RTL-SDR.  The closest thing I can find to that 144 to 1300 MHz discone as a TXDAC is the AD9122, a 1200 MHz TXDAC, DigiKey has at $68 in single piece quantities.  This part still requires an external modulator.

Since the market for transmitters is always smaller than for receivers, I don’t see a prospect for a transmitter as broadband as the RTL-SDR.  Virtually every service that can transmit requires a license which cuts down on the number of people who will want to get licensed, and every service that transmits is only allowed to use certain restricted pieces of spectrum.  The places people can transmit without a license are things like the WiFi bands, the Family Radio Service, and the old Citizen's Band.  All of these are small slices of frequencies, tiny pieces compared to the RTL-SDR bandwidth.  Any place where a license holder can transmit wouldn't be allowed to use a "casual" transmitter like I'm describing; they'll have industry requirements their transmitter will have to meet, and they won't be authorized to make their own radios.  Only hams can do that.

Many ham band only transmitters include very broad receivers; my Yaesu HT, an old VX-6R, includes the ability to receive from 500 kHz to 1 GHz (well, 998.990 MHz).  I think we'll have to be happy with these.  I don’t see a reasonably convenient way of putting together a transmitter to match the RTL-SDRs, and nothing even remotely capable of matching the cost/benefit ratio. 

Friday, November 13, 2020

ULA Flies, SpaceX Starship Melts Down on Pad

ULA's Atlas V launch carrying the NROL-110 payload lifted off tonight after using almost 20 minutes of slack in the launch window.  Scheduled for several days to lift off at 5:13 PM EST, they used built-in hold opportunities to eventually launch at 5:32 PM.   

The launch appeared completely nominal and was close enough to our local sunset to give a rather pretty contrail. It started out below the sun's horizon, so dark, then was illuminated by sunset colors that turned to white as the vehicle climbed out. Sunrise and sunset always give pretty launches when the weather allows.  I have to say the most surprising thing in the ULA video coverage was a short recruiting video to come work for NRO.  In my day, they were like the MIB. 

Due to the mission being classified, ULA stopped providing updates fairly early.  Apparently, the booster succeeded, but this flight has a Centaur upper stage to put the satellite in its required orbit.  It's possible they can issue a statement saying the performance of all systems was nominal or something but nothing I can find. 

Things did not go nominally for the SpaceX Static Fire last night. There are some people saying the static firing lit fewer than all three Raptor engines.  What seems to be the only solid information is (as usual) in a few tweets from Elon Musk almost in real time.  Read from the bottom up.

They lost control of the vehicle.  Sitting there on the test stand with a load of cryogenic propellants, especially the liquid oxygen (LOX) everyone knows the oxygen will boil as it warms and that will increase the pressure in the tank.  We've seen these tanks tested to bursting pressures before, and we've seen the tanks reduced to strips of scrap metal when the pressure exceeds the strength of the steel.  The system is designed with low-strength, burst disks in key places, so that in the event of a failure like this, the vehicle doesn't get blown apart.  An obvious analogy is the freeze plugs in your car's engine that are designed to pop when water in the engine cooling channels freezes and expands.  This is "similar in concept, different in detail."  The burst disk worked as intended. 

The entire sequence happened while we were out of the house, so I didn't see this until a couple of hours later, but there was a test firing at 7:15:18 on the Lab Padre camera.  It lasted a few seconds, and then everything quieted down for another minute and 20 to 7:16:38 when something showed up as glowing red ribbon from the bottom of SN8.  It quickly became evident it was something molten when we saw the stream get lumpy; it was presumably metal.

It appears that at least one engine needs to be replaced.  I peeked in at the Lab Padre Nerdle camera several times today, and saw some work being done under SN8 but it didn't look like engine change tools. 

One of the more popular space channels on YouTube, Scott Manley covers this test without being too tedious.  The image clip above is from his video, using (of course) NASA material.

I suppose that it's asking too much but back on October 15th, I included a picture looking up SN8's skirt, showing all three raptors and more hardware than I can name.  I'd love to see a repeat of that picture before they start replacing things.  

Thursday, November 12, 2020

Space News Ketchup

The last few posts have been more or less Space News free, although several important things have gone on.  Time for a brief review of what will be mostly SpaceX news.  

On Tuesday, November 10th, NASA completed certification of the SpaceX Falcon 9 and Crew Dragon system, removing the last barriers to Saturday's launch of the first operational mission to the ISS, which will carry a crew of four for a regular rotation to the Space Station, twice the crew size of the demo flight over the summer.  Saturday's 7:49 PM launch will carry NASA astronauts Victor Glover, Mike Hopkins, Shannon Walker, and Soichi Noguchi of the Japanese Aerospace Exploration Agency.

The vehicle is on Pad 39A right now, having had a test static fire yesterday, among the last tests before the mission.  Today, the crew boarded the vehicle for a dress rehearsal. 

Meanwhile, over in Boca Chica, Texas, Tuesday also featured a second static fire of SN8's three raptor engines. 

You may want to fast forward to about 1:45 on the slider.  The engine firing is at about 1:50.  The editing and work on this NASA Spaceflight (.com) video is better, and there's lots more in this video, too, including a second, half-speed replay with the audio shifted in time so that it's more like being there, followed by a third replay at quarter-speed.   

You will notice a shower of white hot something or other flying off to the right of the vehicle when the engines are fully on.  They spent a day investigating the engines and report no problems found, saying it was probably some sort of debris left under the test stand.  At the moment, the crew is preparing for a repeat of that static firing test today, which should prove the engines were not the cause.  The road closure is in effect until 9:00PM Central, although I have seen them extend the closure at night.  It's a beach road; not much traffic toward the beach at night. 

My favorite explanation for the white hot sparks is that a family of armadillos were flash frozen as the system started venting liquid oxygen onto them, and then were flash fried when the engines started.  Not that it's a true story, just that it's a good story.

The Super Heavy booster is in the process of being stacked, in which the stainless steel rings are welded on top of each other.  I haven't seen an estimate of how close it is to completion. 

The highly anticipated test flight of SN8 has not been firmly scheduled but is now looking like it might be toward the end of next week, the last full work week in November. 

Finally, the ULA Atlas V launch of a National Reconnaissance Office satellite which has been delayed for months and scrubbed around nine times, is scheduled for tomorrow at 5:13 PM EST from the Cape. That's right, most delayed and scrubbed launch in recent memory is scheduled for Friday the 13th at 5:13 PM. They're showing they aren't superstitious in the slightest.

November 12, 1970 - The Oregon Exploding Whale Turns 50

You should pardon me, but given the story which will emerge I have to do this story in Dave Barry mode.  You see, 50 years ago, on November 12, 1970 a beached whale in Oregon became a legend in broadcasting.  For people there, it became somewhat of a horror story.  For most of us, it became a comedy legend.  Either way, the video is one of the highlights of human history.

I swear I'm not making any of this up.

Exactly how Dave Barry became involved in this story is a story of its own.  In the early days of the Internet, we're talking 1990, Dave heard about the story, saw the 20 year old video, and wrote a piece for his humor column in the Miami Herald's Tropic magazine section.  For details, we have to go to a website called The Exploding Whale.  The existence of a website with that name speaks volumes about the story's appeal. They reprint Dave's story in its entirety (it's shorter than I remember).
The following article was written by syndicated humor columnist Dave Barry of the Miami Herald newspaper. Even though the exploding whale event took place in 1970, Dave Barry didn’t actually hear about it until 1990, after which the incident began to receive much broader attention. The story was considered an urban legend by most people, though. By 1994 the exploding whale had worked its way onto the Internet in the form of an uncredited version of Dave Barry’s article. Amazingly, many news bureaus actually reported the incident as though it had just happened.
The TV station that broadcast the activities, KVAL in Eugene, also has a website devoted to the whale story.  Paul Linnman, who thought he was getting only the biggest stories in the Portland/Eugene area was assigned to the story. 
"It had to be said the Oregon State Highway Department not only had a whale of a problem on its hands," Paul Linnman reported for KATU a half century ago. "It had a stinking whale of a problem."
"I was getting good assignments and so when they asked me to go to Florence to cover the disposal of a whale, I went 'whoa, wait a minute - I'm boy wonder here. I do bigger stories. Send somebody else,' " he said. "Then they said they were going to use dynamite and I said 'OK, let's go.'

The plan was to obliterate the whale into tiny pieces that seagulls would eat.

But as Linnman and former KATU Photojournalist Doug Brazil found out, the pieces were not exactly bite-sized.

The two had to run to escape the flying blubber.

One chunk of airborne blubber proved so big it flattened a car.

"It came down as this oil rain on your jacket," Brazil said in 2010. "It was horrible and the smell - it was just sickening."

"If I think about it, I can still smell that smell," said Linnman.

The smell was only part of it.

John Linnman in 1970, with the soon to be "parted out" whale in the distance behind him.  KVAL photo.

Dave Barry tells the story this way:
So they moved the spectators back up the beach, put a half-ton of dynamite next to the whale and set it off. I am probably not guilty of understatement when I say that what follows, on the videotape, is the most wonderful event in the history of the universe. First you see the whale carcass disappear in a huge blast of smoke and flame. Then you hear the happy spectators shouting “Yayy!” and “Whee!” Then, suddenly, the crowd’s tone changes. You hear a new sound like “splud.” You hear a woman’s voice shouting “Here come pieces of… MY GOD!” Something smears the camera lens.

Later, the reporter explains: “The humor of the entire situation suddenly gave way to a run for survival as huge chunks of whale blubber fell everywhere.” One piece caved in the roof of a car parked more than a quarter of a mile away. Remaining on the beach were several rotting whale sectors the size of condominium units. There was no sign of the sea gulls, who had no doubt permanently relocated in Brazil. This is a very sobering videotape. Here at the institute we watch it often, especially at parties. But this is no time for gaiety. This is a time to get hold of the folks at the Oregon State Highway division and ask them, when they get done cleaning up the beaches, to give us an estimate on the US Capitol.
Unfortunately, the video Dave describes can't be embedded, but go to KVAL and watch it.  Story © 1990 Miami Herald.