Shop Update

It has been almost three weeks since I posted an update.  I ended up spending more time than usual in the ham shack instead of the metal shop last week.  The parts I'm working on are either small or fiddly or both.  Let me show you some of what I've been up to.

The top piece is the simplest, but still a fiddly bit.  It's a washer made from brass rod that's 1/4" OD with a 1/8" hole down the center.  It's easy to do this; the only touchy operation is cutting off a .015" thick sliver of a brass rod with a 1/8" hole down its center.  The cutoff tool usually leaves a nib that has to be trimmed off and then the whole thing needed to be lapped on sandpaper to bring the thickness down about .003".  I could make washers like this and sell them, but one of these would cost you the same as a box of 1000 stock washers.  It's kind of silly to make things like this.

The piece of bar at lower left is straightforward cut a piece of 1/4" drill rod to 0.938" long and then move it to the mill (or good drill press) to drill a 1/16" cross hole through it 0.844" from one end. 

The piece at the lower right is the blank for the cam pictured just to its left.  I've never made a cam like this and there's a couple of ways to make them.  The plans I'm using recommend using a method developed by a guy named Hamilton Upshur, which requires building a fixture to turn the cam eccentrically - that is, off the centerline of that big 3/8" reamed hole in the center.   I had no idea what that fixture needed to be until I found a video that's one of a series where this guy takes you through building an entire engine that Upshur published.  Late in the video, I got a good look at some prints he kept using, paused the video, screen captured the frame and improved its appearance. 

The fixture I'm making is at the upper right.  In the first picture, the 3/8" "peg" the designer calls out is lying on the top right edge of the print; the big 1" diameter cylinder that holds the peg is waiting to be drilled for it on the mill.  The peg is through-tapped, 8-32 instead of 6-32 because I prefer 8-32 screws.  Tomorrow, I should be able to complete the fixture and maybe make my first attempt at the cam.  A finished cam is in the middle of this screen capture, and it looks very much like the one I'm trying to make.  With this method, the cam is largely machined by hand; the fixture just makes it easier to hold the work for those odd cuts.

There's another method for cutting cams that has been shared by a home engine modeler named Chuck Fellows, and his video details how he got there.  It seems a bit fussier to set up than this, but probably gives a more controlled shape.  Fellow's method fixes the cam blank on a rotary table which then moves for all the cuts while Upshur's method uses a lot of hand work; tighten down the screw that holds the blank in place, make a cut, loosen the screw, change the blank's position, tighten the screw, make a cut, and repeat.  Over and over.  
 
The topic of making cams is of great importance for engine manufacturers, especially generating the curves mathematically.  I've read several things on this, including equations that can be plugged into an Excel-compatible spreadsheet.  Take this exercise:  the green circle is the starting blank; the big white circles cut the left and right flanks; the center points where the center of a boring head should sit while rotating to cut those big white circles are computed and displayed.  The boring head is cutting an inside diameter, not an outside diameter. 

This rabbit hole is as deep as you want to go and as techno-geeky as you want to get. 

DARPA is Reviving NERVA - What?

It's a rule of writing for others to never use acronyms without explaining them.  Fully spelled out (so that it would be a two-line title) the Defense Advanced Research Projects Agency (DARPA) is opening bidding for contracts to revive the Nuclear Engines for Rocket Vehicle Applications (NERVA) program from the early days of NASA.

The basic problem is that moving things around in space is slow, ultimately because every molecule of fuel has to be lifted with you (for now) so using small amounts of fuel and taking a long time to get anywhere is a reasonable trade.  The idea of nuclear powered propulsion goes back to the earliest days of NASA.  Wernher von Braun, the German engineer who defected to the United States after World War II, started a program to develop systems before the moon landings.  That program, NERVA, eventually got closed down to help pay for the Shuttles.  See here for a NASA review of the program (pdf) and here for a video of a test firing. 

But now, the US Department of Defense is getting interested in space-based propulsion. Last month, through a presolicitation, the US Defense Advanced Research Projects Agency announced its intent to have a flyable nuclear thermal propulsion system ready for a demonstration in 2025.

Through this Demonstration Rocket for Agile Cislunar Operations, or DRACO program, the defense agency seeks technology that will allow for more responsive control of spacecraft in Earth orbit, lunar orbit, and everywhere in between, giving the military greater operational freedom in these domains.

"Activity in cislunar space is expected to increase considerably in the coming years," Maj Nathan Greiner, manager of the DRACO Program, told Ars. "An agile nuclear thermal propulsion vehicle enables the DOD to maintain Space Domain Awareness of the burgeoning activity within this vast volume."

There are a few ways to achieve nuclear propulsion; the most accessible (and probably the most politically acceptable) is nuclear thermal power in which a reactor super heats a fuel (probably hydrogen gas) and it expands through a nozzle.

In "Phase 1" of its solicitation, DARPA has asked industry for the designs of both a nuclear thermal reactor and an operational spacecraft upon which to demonstrate it. This initial phase of the program will last 18 months. Subsequent phases will lead to detailed design, fabrication, ground tests, and an in-space demonstration. No contracts have yet been awarded, and award values will be determined by industry submissions.

With the DRACO program, the US Defense Department could potentially move large satellites quickly around cislunar space. For example, moving a 4-ton satellite from point A to point B might take about six months with solar electric propulsion, whereas it could be done in a few hours with nuclear thermal propulsion.

It's arguable that this DARPA action is being brought along by other trends going on.  First is the creation of Space Force and the recognition of the value of the High Frontier.  Second, critical enabling technologies are maturing at the right times, such as better refractory materials (able to handle extreme temperatures); in a nuclear thermal engine, Hydrogen is stored at 19 Kelvin, while "the other end" of the reactor has hydrogen heated to 2500 Kelvin - or higher.  Third, NASA is working with BWX Technologies, the company which makes most of the nuclear reactors found on US Navy submarines and aircraft carriers, on the design of a reactor for Mars missions.

1960s artist's concept of a nuclear thermal rocket arriving at Mars.  The circular structure on the left is an aerobrake. 

DARPA has a reputation for producing some of the leading edge technologies in the world.  It seems they've decided the time is right to push this one along. 

Probably The Weirdest Story You Haven't Seen

In 2020, it's saying something to refer to a news story as the weirdest thing you've seen.  This story is definitely among the weirdest things I've run across this year; Wuhan flu and plagues of locusts have nothing on this.  I first saw this picked up at Ars Technica, but have since seen it elsewhere.

The US Department of Justice and US Attorney's Office in Massachusetts together announced that they had charged six former eBay employees with “leading a cyberstalking campaign" against a newsletter editor and publisher, which "included sending the couple anonymous, threatening messages, disturbing deliveries—including a box of live cockroaches, a funeral wreath, and a bloody pig mask—and conducting covert surveillance of the victims."

James Baugh, 45, is eBay's former senior director of safety and security, and David Harville, 48, is eBay's former director of global resiliency—both were arrested today and charged with conspiracy to commit cyberstalking and conspiracy to tamper with witnesses. Each charge "carr[ies] a sentence of up to five years in prison, three years of supervised release, a fine of up to $250,000 and restitution," the DOJ said.

The bloody pig mask was a Halloween mask and shipped via Amazon.com, a court document said. The mask arrived at the victims' home the same day one of the victims "received an email reporting that a 'Preserved Fetal Pig' had been ordered online to be sent to the Victims' house," the document said. A few days later, the victims "received a box of cockroaches" that was purchased from a roach breeder and seller.

The targets of the harassment were a couple from Natick, Massachusetts, who aren't named in the publicly released documents, but who run an online newsletter that covers e-commerce companies.  eBay managers felt the newsletter was unfair to the online auction giant.  One alleged victim is a reporter and editor for the newsletter, while her husband is the publisher.

"Members of the executive leadership team at eBay followed the newsletter's posts, often taking issue with its content and the anonymous comments underneath the editor's stories," the DOJ said.

You probably know the line from Shakespeare that goes, “Oh! What A Tangled Web We Weave When First We Practice To Deceive,” and this is quite a tangled web.  You should read the whole thing if you want the straight story.  Here's a snip. 

The alleged crimes took place in August and September 2019. Four other former eBay employees weren't arrested today but face the same charges. They are Stephanie Popp, 32, eBay's former senior manager of global intelligence; Stephanie Stockwell, 26, former manager of eBay's Global Intelligence Center (GIC); Veronica Zea, 26, a former eBay contractor who worked as an intelligence analyst in the GIC; and Brian Gilbert, 51, a former senior manager of special operations for eBay's Global Security Team. Harville is from New York City while the other five defendants are from California.

"It is alleged that in August 2019, after the newsletter published an article about litigation involving eBay, two members of eBay's executive leadership team sent or forwarded text messages suggesting that it was time to 'take down' the newsletter's editor," the DOJ announcement said. Another message from one unnamed eBay executive to another said "we are going to crush this lady," according to the charging document.

The "take down" message was followed by a three-part harassment campaign by the six defendants, the DOJ said. The first phase included anonymous deliveries such as "a bloody pig Halloween mask, a funeral wreath, a book on surviving the loss of a spouse, and pornography—the last of these addressed to the newsletter's publisher but sent to his neighbors' homes."

For their part, eBay said that as soon as they found out about this, everyone involved was fired.   That included the company's former Chief Communications Officer, fired last September.  It gets a little weirder: the CEO of eBay at the time of the incidents was Devin Wenig.  He was also let go of in September of  '19.  Being a CEO, there was a more public announcement than for the others let go last September.  The announcement said something intended not to scare investors, that "both Devin and the Board believe that a new CEO is best for the company at this time."  Was the ex-CEO the guy who said it was time to take down the newsletter?  Was his departure linked to this mess? 

The More That Covid-19 Gets Studied, The More It Looks Like a Paper Tiger

That's the conclusion of NPR, of all places, quoted in the Foundation for Economic Education (FEE) news mailing.  The conclusion is surprising for them, but not how they start - which is to discredit the W administration and the '03 war in Iraq.

The Iraq War WMD debacle is arguably the greatest expert “fail” in generations. The holy triumvirate—lawmakers, bureaucrats, and media—all failed to sniff out the truth. If any of them had, a war that cost trillions of dollars and claimed the lives of 100,000-200,000 people likely could have been avoided.

It would be difficult to surpass the Iraq blunder, but emerging evidence on COVID-19 suggests the experts—again: lawmakers, bureaucrats, and media—may have subjected us to a blunder of equally disastrous proportions.

They go on to say that mounting evidence says that the coronavirus is more common and less deadly than it first appeared.  Originally, the claims for the numbers who would die were wildly terrifying, and you probably know the many times those estimates were revised downwards.  Neil Ferguson, professor of mathematical biology at Imperial College London, predicted millions would die in the “best-case scenario.”  As FEE points out, Neil Ferguson said in 2005 that up to 200 million might die from bird flu worldwide.  About 100 did.  Not 100 Million; 100. A bit too much reliance on models that aren't too accurate.

Similarly, Infection Fatality Rates were pegged in the 3 to even 5% rate.  In reality, no study I see says it's over 1%.

"The current best estimates for the infection fatality risk are between 0.5% and 1%," says Caitlin Rivers, an epidemiologist at the Johns Hopkins Center for Health Security.

With all due respect to Dr. Rivers, Dr. John P. Ioannidis published work last week reporting:

Infection fatality rates ranged from 0.02% to 0.86% (median 0.26%) and corrected values ranged from 0.02% to 0.78% (median 0.25%). Among people under 70 years old, infection fatality rates ranged from 0.00% to 0.26% with median of 0.05% (corrected, 0.00-0.23% with median of 0.04%).

Among people under age 70, a median Infection Fatality Rate of 0.04%  The horrific death rates from New York Generalissimo Cuomo shoving patients with Covid-19 infections into nursing homes can really skew those numbers.

The main thrust of Dr. Ioannidis' paper is that the lockdowns were - at best - unnecessary, and could have done more harm than good.   This is a theme coming out of research all around the world and that I reported on a month ago (almost to the day).  Marko Kolanovic, a physicist and strategist for JP Morgan, pointed out that a majority of nations saw declines in infection rates after the lockdowns were lifted.

As I said in that post a month ago, early on when people first started talking about this virus, before the lockdowns, before much information was out, I pretty quickly concluded that eventually everyone other than the very few people living hundreds of miles from human contact will get the virus and develop antibodies to it.  Some people, obviously, will die and every death is a tragedy.  Thankfully, it looks like well over 99% will recover from it just fine.

Early on in the spread of the disease, it was pretty easy to come to the conclusion that eventually everyone on earth will be exposed to this.  It's a new virus, and new viruses jump from animals to humans pretty regularly; it's simply how the world works.  I don't have strong numbers to base this on, but I believe the nationwide downward trend in new infections will continue downward, this numbers guy says the worst of the epidemic is over, but the virus will be back next fall.  It's my understanding that coronaviruses, as a group, are hard to create vaccines for.  The common cold is one of many such viruses that we're always exposed to, for example, and there's no good vaccine for the common cold, right?

EDIT: 6/17/20 7:38 AM - I left out a link to my old post, which has a very worthwhile graphic as well as background info.

SpaceX Changes Direction and Pops a New Tank

It seems like long ago - 17 whole days ago! - when we talked about SpaceX's SN4 "RUD" (Rapid Unscheduled Disassembly).  At the time I said SN5 was built and I had said, "There will be a few days work and SN5, which has been ready for weeks, will be transported to the test area."

It didn't turn out that way.  First, there was a lot of demolition and then expansion of the area where testing is done.  A new test stand was designed and built.  Concrete was poured for a new Vertical Assembly Building at the Boca Chica facility.  There were road closures and the implication SN5 or 6 would be taken to the test stand last week.  Around the first of the month, though someone had spotted an unaccounted-for tank dome outside the existing High Bay buildings.  Then the dome was identified as being made of a new alloy steel being considered for the fuel and oxidizer tanks on Starship.

The mystery dome.  Photo @bocachicagal for NasaSpaceflight. 

Then the mystery dome was assembled into a new test tank called SN7.  Eric Ralph, SpaceX correspondent at Teslarati, wrote today,

Just like its three predecessors, the newest test tank’s purpose is relatively simple: demonstrate – at full scale – the efficacy of SpaceX’s current manufacturing processes. Back when SpaceX built and tested the first two tank prototypes in January 2020, the company was in the midst of making big changes throughout its coastal Boca Chica, Texas Starship factory – a major leap forward compared to the methods used to build Starship Mk1. While the first tank made it to 7.1 bar (~103 psi) before failing, a second tank survived all the way up to 8.5 bar (~125 psi), as did a third separate test tank built about a month later. According to CEO Elon Musk, 8.5 bar is more than satisfactory for Starship pressure vessels to safely launch humans into orbit, offering a safety margin of more than 40%.

This weekend the tank was taken to the test stand.  It was talked about that this was a major revision to the tank, being built of a different steel grade than before, because it's considered better for cryogenic temperatures than the grade stainless steel they had been using.

The most obvious reason to build a new test tank after the success of full-scale Starship prototype SN4 is a substantial change in the steel alloy SpaceX is building rockets out of in South Texas. CEO Elon Musk has teased such a shift for almost a full year and it appears to have happened right on time – if not ahead of schedule. SpaceX currently uses 301 stainless steel for Starship production, while the new material – discussed earlier by Musk and confirmed by inscriptions on the exterior of what would later become the fourth test tank – is a slightly different 304 steel “with higher ductility” (malleability). 

I recall seeing the mystery dome marked 304L (I've just spent 20 minutes looking for the picture), and I looked it up on the Materials Web: 304L gets that improved ductility by using a lower percentage of carbon in the steel.

Today the tank was tested.  The comments are saying it was intended to be a test to failure and they succeeded at failing.



A commenter on YouTube quotes Elon Musk.  I'll have to go with his report since there's nothing on any of the spaceflight news sites I comb saying one way or another.

From Elon's twitter: "Tank didn’t burst, but leaked at 7.6 bar. This is a good result & supports idea of 304L stainless being better than 301. We’re developing our own alloy to take this even further. Leak before burst is highly desirable."

Note: the action starts about 30 seconds in to this 2:15 video.  Before that you'll see a set of straps over the tank, apparently to hold it to the stand and keep it from flying away in pieces should it fail like some previous tanks have failed. 

We Were Treated to a Spectacular Launch This Morning

This morning at 5:21 AM EDT, the 8th bundle of SpaceX Starlink satellites launched into the night sky and we went out to watch from the side yard as usual.  The launch was the most visually spectacular launch either one of us could recall, and as Teslrati author Eric Ralph suggested, probably led to reports of UFOs and strange lights in the sky all along the east coast.  

Through a confluence of orbital dynamics and luck, SpaceX’s seventh Starlink launch of 2020 may have created one of the most spectacular light shows visible across the US East Coast in recent memory.

Likely to incur a massive wave of ‘UFO spottings’ across the Eastern seaboard, Falcon 9 lifted off from a Cape Canaveral, Florida launch pad at 5:21 am EDT (09:21 UTC), a bit less than a half an hour before dawn. Heading east (and up), the 70m (230 ft) tall SpaceX rocket took just three minutes to escape Earth’s shadow and meet the rising sun a bit ahead of the East Coast’s schedule – the light from which instantly backlit the plume created by Falcon 9’s second (upper) stage. Effectively replicating – in reverse – a similar phenomenon often seen after SpaceX West Coast launches shortly after sunset, this is the first time in quite awhile that the stars have (somewhat literally) aligned for a similar light show in Florida.

Mrs. Graybeard and I have lived near the Cape Canaveral/Kennedy Space Center complex since 1982.  Years ago, we concluded the prettiest launches are when it's dark on the ground and the rocket goes into sunlight as it climbs. 

Local sunrise is 6:26, and we're in the week of the earliest sunrise of the year.  The rocket appeared to go northeast, but stayed visible through the end of the second stage burn making it into orbit.  During daytime launches that's never visible.  Visually, when it got to first stage cutoff and dropping the booster, it was still a bright spot in the dark.  Moments after the staging occurred, the second stage moved into sunlight and the exhaust plume started to light up.  For the next several minutes, we watched this glowing, bluish circle enlarge around the bright rocket, and we could see the first stage brightly illuminated by the sun basically tracking along the same path but below it, clearly dropping away from the second stage and payload.  At this point in the flight, the rocket is traveling on a gentle slope into orbit, moving mostly straight away from us, so it's approaching the horizon and getting lower in the sky as we watch. The peak height in the sky from our vantage point is probably around where the first stage cuts off and gets dropped. The glowing bluish exhaust cloud eventually got to around 30 degrees diameter when the second stage cutoff. 

Teslarati published a long exposure of the launch, but because it collects several minutes worth of light, it doesn't really capture what it looked like.

After the second stage cutoff (SECO), we came back into the house, went to SpaceX on YouTube  and replayed the launch through first stage recovery on their drone ship, then stayed with it through the satellite deployments.   

It's worth noting that this launch was different than other Starlink Launches.  SpaceX has started a Ride-Sharing service for small satellites, sending three ~110 kg (242 lb) Planet SkySat imaging satellites on the way to their final orbits, “for a price so low that the company initially didn’t believe it could be real.”  The cost to SpaceX was to reduce their usual load of 60 satellites down to 58.  

Next launch of a Starlink mission is currently No Earlier Than the 22nd, a week from Monday.  That's a late afternoon mission, 6:20 PM, so no chance of a repeat of the light show. 

A Ham Radio Series 4 - Antennas, Tuners, and Analyzers

The whole field of antennas and how to get them to do what you want comes up regularly.  There's dozens of books on the topic and an article or two isn't going to get you expertise.  Things that I think might be important may not be relevant to how you want to operate.  I've written lots on this from a more or less "how do they work" perspective.

• A general introduction:  Ham Radio - Antennas
• A more technical series:  part 1,  part 2,  part 3 

Lately, I've been playing with something like The Three Laws of Antennas, patterned after Asimov's Three Laws of Robotics.

First Law: anything you can put up works better than nothing at something.
Second Law: nothing is best at everything.
Third Law: whatever you can put up won't be as good as you'd like.  Unless you have a Jeff Bezos-level budget including the property to match. 

A friend once told me that “Engineering is the art of compromise” and antennas are a perfect example.  The three laws emphasize that, each in their own way. 

It's my experience that most hams don't go out and put up some sort of megabucks antenna installation as they're starting out, going instead for something that's a bit more of a compromise, so let's consider a compromise antenna.  This is a length of wire that can only be resonant at one frequency and unless that frequency happens to be in a ham band, you won't be able to use it.   It doesn't matter what antenna you pick in terms of this discussion: a G5RV multiband antenna; an Off Center Fed Dipole (OCFD) or just a random length of wire, end fed. 

As a general rule, transmitters are fussier about the exact impedance of the antenna than receivers are and you'll find that your transmitter might not put out power at all - especially if it's a solid state (transistor of some kind) final.  What you need here is an antenna tuner.  I prefer automatic tuners (autotuners) because I like pushing a button and letting it do the work.  There are many on the market; the first I owned was by LDG and I still have a couple of them. 

What's inside an antenna tuner?  An impedance matching network called an L network.  It's simply two parts in a configuration that looks like the letter L, if you lie on your side.   The two components can be a series L/shunt C, a series C/shunt L, both can be inductors or both can be capacitors.  There are eight possible configurations; four to match to higher impedance, four to match to lower.   It helps to visualize the direction of impedance change, to higher or lower impedance, if you draw it almost like a little ladder.  The shunt component is on the higher impedance side.  In this example, we're climbing up to a higher impedance load.  If the load was lower impedance, the shunt component would on the source side - still the higher impedance side.  Another thing I like about an autotuner is that I don't have to think about this.  I push a button and it finds a good solution. 

The autotuner is an L-network with a bunch of coils and capacitors with relays to switch the series and shunt components of the L-network end to end and change their values rapidly; series adding inductors or parallel adding capacitors.  The tuner tries a combination, measures VSWR, compares it to the starting value and goes through an optimization process to find the lowest VSWR it can get.  In the end though, it’s electrically two components.

If you shop for radios, you'll find that a number of models feature an internal autotuner; everyone I've seen is limited in the range it can tune to 3:1 VSWR or less.  By comparison, the external autotuners tune a much wider range of impedance, 10:1 or more.  There are also external tuners that are more than just a two component L network; they can tune even wider ranges.  I've had older model radios that tuned well beyond the 3:1 range, which is a fairly minor adjustment.  Newer radios have software that does that first measurement, sees that it's starting above the limit, and won't try to tune at all. 

Do you need an antenna analyzer?  What is an antenna analyzer, anyway?  An antenna analyzer measures the impedance of the antenna.  Some are manual, like the popular MFJ-259D, you set them on frequency and read off the Resistance and Reactance.  You need to tune the frequency and see how the reactance (X) varies to see if it's inductive or capacitive - if the reactance goes up with frequency, it's inductive and if reactance goes down, it's capacitive. 

The manually tuned analyzers like the MFJ are lacking in a lot of features, but you can trim an antenna for lowest VSWR with one.  There are many antenna analyzers that do a frequency sweep for you and save the impedance values, both resistance and reactance with sign, save plots, or even export files of your antenna data for use in antenna design (or redesign for new purposes). 

“In the old days,” we used to tune an antenna to resonance by turning down the transmitter power, keying it up, measuring SWR with an SWR meter, and keeping track of how it changes.  If you're putting together a station, you should consider an external autotuner if you have a radio that limits tuning to 3:1, and especially if your radio doesn't have a built in tuner.  An analyzer is a purchase that makes most sense if you plan to experiment with antennas or want to build more.  They make keeping track of changes in your antennas easier, too.  I have an analyzer (not made anymore or I'd show you a picture) and since I make little odds and ends around the shack, I use it to measure components as well as measuring antennas.  They're useful tools.

Tales From the Seattle Communist Enclave

Or You Just Can't Make This Shit Up.

According to PJ media, Seattle's breakaway communist enclave called CHAZ (Capital Hill Autonomous Zone) has encountered troubles with their independence.  The only assets they have are stolen, and people who steal other people's assets (that is, the people of CHAZ) will steal anything that isn't permanently attached.

As Divemedic pointed out on Confessions of a Street Pharmacist, the communists behind CHAZ are incredible hypocrites.  One of the first things they did was build a border wall.  I assume it was with stolen materials, like the road barricades they stole from America when they formed their little empire.  And then their border wall was stolen right back.  

Bryan Preston, writing over at PJ Media puts the thoughts together like this:

The CHAZ collective thanked the mayor for her gift of a six-block area of America the mayor does not personally own (and which includes about 500 homes of actual Americans) by storming city hall and demanding that she resign unless she disbands the police.
...
Call the police!

Right — CHAZ wants to disband the police. The police are over in America anyway, and American police have no obligation to help secessionist CHAZ.

CHAZ has no farms or orchards. CHAZ is paved over with streets and buildings. CHAZ cannot feed itself.
...
It’s a pity CHAZ has no indigenous lumber supply.

Or electricity. Or water supply.

There has been talk about putting an embargo around the CHAZ and starving them out.  Note that they report there are 500 homes in the area they've taken over.  That's got to be somewhere between 700  and a thousand innocent people that are hostages in the CHAZ.  Since that's Antifa, and they're a designated terrorist organization I believe there are protocols for situations in which terrorists hold hostages.  We assume the citizens are opposed to losing their property to Antifa, so free the hostages and if all the Antifa loons happen to not survive, those are the breaks.   


 

A Lot of Sanity in 15 Minutes

I'm a long time subscriber to Glenn Beck's internet streams, first signing up right around the time of the legendary “wardrobe malfunction” Super Bowl half time show.  Beck's right hand man for the life of the program has been Stu Burguiere and they talk about having worked together since the first days of the show in Tampa, Florida.  In my early days listening to them on the radio at work, I thought Stu was really the brains of the outfit and Glenn, who described himself as a rodeo clown, was essentially just that.  In the years since, I've come to regard them as a really good team that comes at problems from some very different directions.  Glenn is driven by his emotions while Stu is a much more logical thinker.  On his own shows and on the Blaze TV network he has done a segment called Stu-tistics, in which he takes a decidedly analytical approach to things.  The Glenn Beck show is another example of a situation where the sum is greater than the parts.

We've all seen some of the statistics thrown around about the riots and urban unrest going on.  We've seen Instagram remove the 2013 FBI crime stats because it violates their narrative standards.

Larger version at the above link (90 Miles From Tyranny).

Stu takes a look at some of these stats with a different take than I've heard anywhere else.  I thought the fact of the day Stu quotes is that 144 people a year die from constipation.  If the number we've seen elsewhere is correct that 10 black men were killed by the police last year, then they're over 14 times more likely to die of constipation than from being killed by a cop.  I've heard a lot of demands, but none for free Ex Lax. 


Over 60 people died from an unfortunate lawnmower incident but almost 700 people a year die falling out of bed.

Stu's point, and it's a good one, is that in a population of over 300 Million, something that affects 10 or 20 people is awfully hard do anything about.  All the data we can find that's from real academics and not race hustlers says the rate of these police killings has been declining for years.  If next year's statistics said it was 12 instead of 10, was that a horrible relapse or random variation?  What are the error bands? 

So the cities are going to de-fund police because some radical activists say so? 
  

As The Crew Dragon Test Flight and Work on Starship Continue

As the Bob & Doug Show continues, more formally the Demo 2 Test Flight of the Crew Dragon spacecraft, an interesting little modification to the existing NASA contract has gone through and is pointed out by a comment on the Teslarati news site.  You might have heard that NASA only wanted brand new Falcon 9 boosters for manned flights.  This contract modification, on the Federal Government's SAM.gov beta website says that they will allow reused Falcon 9s. 

THE PURPOSE OF THIS BILATERAL MODIFICATION IS TO EXTEND THE DEMO-2 FLIGHT TEST FROM TWO WEEKS TO UP TO 119 DAYS AND ADD THE REQUIREMENT FOR 45TH OPERATIONS GROUP DETACHMENT 3 (DET-3) JOINT TEST TRAINING FOR PCM-1 THROUGH PCM-6 IN EXCHANGE FOR ALLOWING REUSE OF THE FALCON 9 LAUNCH VEHICLE AND CREW DRAGON SPACECRAFT BEGINNING WITH PCM-2. [BOLD added - SiG]

My own view, worth nothing, is that a once-flown booster is probably the peak of reliability; everything has been thoroughly tested, then thoroughly reinspected afterward.  Obviously, the Demo 2 test mission isn't over until the capsule reenters the atmosphere, splashes down in the Atlantic, and the crew is safe and sound on board the recovery ship.  That should be the weekend of September 26th, if the Days From Date Calculator isn't mistaken.  The crew for the next Crew Dragon mission is already in training and undoubtedly has been in training for quite a while; Doug Hurley and Bob Behnken were assigned to this mission and worked with SpaceX for five years before this flight. 

Jim Bridenstine, explained during a pre-launch briefing that the next flight of the Crew Dragon could fly as soon as August 30. That flight, called Crew-1, would see the Dragon carry four astronauts to the space station for a six-month stay. On board will be three NASA astronauts — Mike Hopkins, Victor Glover, and Shannon Walker — who will be joined by Japanese astronaut Soichi Noguchi. 

Meanwhile, work on preparing to resume testing the Starship prototypes continues.  The debris from SN4's RUD was largely cleared away the next day and the work of rebuilding all the damaged hardware has been underway.  The cause of the explosion was quickly isolated to Ground Support Equipment, a Quick Disconnect panel that's supposed to ease connecting and disconnecting fuel lines.  It's an assembly like this one, although this particular QD is on the Starhopper that flew last summer. 

Shortly after a post-launch briefing celebrating and discussing SpaceX’s inaugural astronaut launch on May 30th, Reuters reporter Joey Roulette was able to ask Musk about Starship SN4’s spectacular demise the day prior. The SpaceX CEO was quoted saying that “what we thought was going to be a minor test of a quick disconnect ended up being a big problem”, confirming suspicions based on careful analysis of public views of the explosion that it was caused by issues with Starship’s ground support equipment (GSE).

Reading the LabPadre video sidebar, it seems there was hope of moving SN5 to the test stand today but those plans were scuttled and the road closure postponed until Thursday, June 11, at 6AM to 2PM CDT.

Meanwhile, in addition to the Starship testing in Texas, SpaceX has their first four-launch month scheduled.  Four in a month isn't a huge improvement; their previous busiest was four launches in 32 days, but it's indicative of a continuing emphasis on getting better at what they do and improving their launch tempo.  Those are:

(the first launch was Wednesday night, June 3rd)
June 12 – 9th Starlink launch
June 24 – 10th Starlink launch
June 30 – GPS-III-SV03 launch 

With a June 30th launch - as usual, a “No Earlier Than” date - it doesn't take much of a delay to push that into July, but July 3rd is 30 days later, just not a calendar month.  It's interesting to watch, not so much for the milestone of four launches in a calendar month but seeing the cadence they're attempting to hold.  SpaceX has 14 commercial launches scheduled in the second half of 2020, while an additional 20-24 Starlink launches were talked about at the start of the year.  So far, they're off their stated goals, with it looking more likely they'll get 18 Starlink launches.  

SpaceX's Boca Chica, Texas, production and test facility.  From Elon Musk.  There's talk of building something the size of NASA's Vehicle Assembly Building to accommodate the Starship Heavy that is in development now. 

A Ham Radio Series 3 - HF Propagation Practicalities

As I start writing this, I’m going back and forth between typing and working across the southern tier of the US by Sporadic E skip on 6 meters.  East Central Florida to eastern California and Arizona.  While not impossible this time of year, it’s also not to be dismissed as trivially common. 

Of course, I don’t know more than a few of you well enough to know your interests in radio, but let’s resume where we were last time. 

The practical question comes down to this: how do you know that the band you’ve set your radio to is going to go to the F2 layer and come back down far away?  It's common for the ionosphere to allow, for example, 21 MHz signals to propagate over a path, but not 24 MHz, and certainly not 28 or 29.  Which frequency escapes into space and which refracts back down depends how densely ionized the ionosphere is where the signal hits it.
 
The density of the ionization depends on how much high energy radiation is coming from the sun and that varies with the (roughly) 11 year long solar cycles.  Around World War II, a relationship between propagation and observable radio emissions from the sun was realized and the world standardized on monitoring solar radio emissions, called the Solar Flux, at a wavelength of 10.7 cm, or 2.800 GHz.  That’s just above the 2.4 GHz WiFi band.  Note to people who think being exposed to microwave or WiFi frequencies is new to humanity; 2.8 GHz radio has been coming along with sunlight for as long as we’ve been on the planet! 

The 10.7cm Solar Flux Index (SFI), is one of the longest running records of solar activity but only goes back to 1946, while sunspot observations go back hundreds of years.  The measured solar flux correlates well with the sunspot number as well as a number of UltraViolet (UV) and visible solar irradiance records.

The strongest solar cycle on record occurred in the 1950s.  Cycle 19, as it’s called, is still remembered fondly as the source of 24 hour openings on 10meters and openings on 6 meters.  Observations of sunspot numbers exist back to the time of Galileo, and those cycles show that the 20th century was remarkably active.  We appear to be settling back to more typical amounts of activity.  The consensus of groups trying to predict the next cycle, 25, are saying it’s going to be much like the past cycle, which was said to be the weakest in over a hundred years.  That’s going to put a premium on operating with denser crowds of signals in the bands, receivers that handle big (nearby) signals well, and better ways to extract hard to copy signals.

(Source) Two things about this plot; first, note the highest peak, that's 19 in the late 50s/early 60s; second, note it doesn't include the cycle just completing; that one is very similar to the peak around 1910. 

You might say, “that's cool but it still doesn’t answer how you can tell if your signal will be propagated to that location you want to contact.”  A simple answer is you can listen.  If you’re trying to hear a country with a large ham population, if you can hear them, chances are someone can hear you.  But what if you want to contact a country with a small population?  What if everyone is listening? 

There are propagation prediction programs widely available to the amateur.  Some, like VOACAP (Voice of America Coverage Analysis Program) are the result of big government studies and expenditures.  Others are the result of different analyses and there are many websites and programs available.  As mentioned in the preface, the ARRL produces graphics like this one, which shows predicted propagation from the East Coast of the US to the areas described and a graph with a few colored lines. This plot is for last month, May, 2020 and assumes an average Solar Flux of 66 which is Quiet Sun or no solar enhancement. 

The different colors represent the frequencies expected to be open to those locations to different probability levels.  The red curve is always highest; it's the Highest Possible Frequency that will be available on 10% of the days in the month (that's 3 days out of the month; which 3?  good question).  The green curve represents the 50% of days curve or that half the time, the best frequency will be that high.  That used to be called the Maximum Usable Frequency or MUF.  Finally, the light blue curve represents the Lowest Usable Frequency for a 1500 Watt transmitter using CW (Morse code).  For lower powers or other modes, that frequency may be higher; between the shown light blue curve and the green curve.  The horizontal lines seem to represent amateur HF bands.

The "East Coast" is a big area and it would help to know where this data is centered, but assume for the moment it applies to us in Florida.  Let me pick the East Coast to Australia chart.  0000 hours UTC is on the left, which is 8PM EDT.   Three days of the month, the 12 meter (24.9 MHz) band should be open to Australia, but 50% of the time, the 15 meter (21 MHz) band will be open.  By 0400 UTC, or midnight local that has closed down to 20 meters (14 MHz) and it's going away fast.  From then until dawn (around 1000 UTC), the most reliable band looks to be 30 meters, even going down to 40m.  After sunrise, the curves show the opening returning to 20 meters, and finally to 15 then possibly 12m again from 2000 to midnight UTC, or 5 to 8PM EDT. 

Should you go for the 50% chance, green curve or try for those 3 days a month that it goes to the red?  The advantage of going to the Highest Possible Frequency is that absorption in the ionosphere is lower closer to it, so a weak signal might do better.  The drawback is the other 90% of the month you sit around listening to nothing.

One of the issues of charts like these is that they don't address any of the real world effects; a guy with an 80 foot tall tower and high gain antennas experiences this differently than someone operating portable with backpack antenna and QRP power.  The good propagation programs attempt to use that sort of information to make predictions more accurate and reliable.

No matter what the propagation forecasts or predictions say, sometimes you've just got to listen.  There is no substitute for listening.  Even if you're not listening, but a piece of software is. 

A Ham Radio Series 2 - Radio Propagation Preface

It seems that one of the most popular things people wanted to read about was propagation.  That's a tall order for a couple of reasons: the first is that it's a very broad field; so broad that many books have been written about it.  So broad that none of it is applicable to every amateur radio band, but that some aspects can blend for different bands.  So broad that experts in one area can study nothing but that area and still not predict it perfectly. 

Propagation is concerned with getting radio signals from one user to another.  It's not all ionospheric; I'm not even sure I'd say it's all atmospheric, but most is.  At low frequencies, say below HF (defined as 3-30 MHz), much signal propagation is by conduction along the ground - the ground wave.  There's a ground wave at HF too, but it's much less prominent than the AM broadcast band and lower in frequency.  HF is where the ionospheric propagation is most influential.  In the entire electromagnetic spectrum, there is one piece of spectrum that allows worldwide communication without man-made infrastructure; that place is the HF spectrum. 

Most hams have probably seen a diagram somewhat like this one at some time:

It shows that as the signal leaves the transmit antenna, it splits into two components, the ground wave and the sky wave.  If the ionosphere is dense enough, from a variety of factors, the sky wave can be refracted by the electrically charged ions in the ionosphere, and come back down hundreds or thousands of miles away.  That signal coming back down can reflect off the earth, or especially the ocean, and go back into the ionosphere again - called multi-hop. Underneath that area where the signal is depicted going into the ionosphere and refracted back down, nothing can be heard.  This is called the skip zone; the signal skips over the vast path under that curve. 

A problem with this depiction is that it gives the impression that if we could be above that radio path and look down on it, it would be straight on some compass heading.  That's not always true.  The signal path can bend.  Narrow beam width HF antennas are extremely big and expensive (for most of the spectrum) so there's little experience with it. 

The radiation angle from the transmitter matters a great deal; if the angle is too high, above a critical angle for the ionosphere, the signal path will get refracted by the ionosphere, but not refracted far enough to come back down to the ground, so it travels off into space.  This graphic was published in Electronics World for April, 1969 and posted by RFCafe.  Signal paths above the critical angle are seen on the left. 

The radiation angle is a property of the antenna, including how it's mounted and the area around it.  People trying to work stations the farthest away always emphasize getting a low angle of radiation, pointed pretty much at the horizon.  Look at the bottom ray leaving the transmitter on the left.  Because it's so low, it reaches the ionosphere the farthest point from the transmitter and while we can see it coming back down, that's so far to the right we don't see it.

This is not to say that the ionosphere is the only way we have of getting signals from Here to There.  F layer skip pretty much disappears above 6 meters (50-54 MHz) - and isn't that high often.   Sporadic E, talked about last time, is regularly heard on 6 and occasionally as high as 2 meters.  Most of the time, signal propagation on 2 meters is in the lowest layer of the atmosphere, the troposphere.  Weather conditions cause the possibility of ducts to form in the air that keep the signals from going straight (and out of the atmosphere) by bending them down toward the Earth as they travel.  There are attempts to predict this based on weather modeling that post plots of the chances of tropospheric ducts.

Tropo ducting is the dominant way of propagating VHF and UHF, up into the microwave spectrum.  A friend of mine once experimented on the 10 GHz amateur microwave band and used to tell the story of testing his small (3 feet diameter) microwave dishes on the beach, from near Cape Canaveral talking with another guy down near Ft. Pierce, Florida (around 70 miles).  He'd say when there was no duct it was very hard to get the dishes pointed precisely and hear the other guy, but when a duct formed, it was very easy.  Sometimes it almost didn't matter where the dish was pointed.   

The troposphere has another trick called Scatter.  Think of blasting a high power VHF signal into the sky and listening to what bounces back, as if it were some sort of radar.  Troposcatter has been used by the military.  There are such things as rain scatter, and aircraft scatter, where signals bounce off airplanes traveling in heavily traveled corridors.  Meteor scatter is a routine mode of communications, especially now with fast digital modes like MSK144 to take advantage of meteor trails that aren't very long lived.  I'm sure there are others I haven't thought of. 

The ARRL has a propagation prediction site that has color graphics to download of HF (ionospheric) propagation predictions and some articles that help explain what you're looking at.

Tiananmen Square - The End of Limited Freedoms in China

Thirty one years ago today, June 5th, 1989, the symbolic resistance of the so-called Tank Man took place in Tiananmen Square in the People's Republic of China.  Ironically, this event that was taken as the symbol of the protests in the West took place after the protests were largely over and the protesters largely massacred. 

The resistance of this never-identified man was celebrated widely by the west as a successful resistance to the power of the column of tanks but was preceded by the Chinese Government massacring an estimated 10,000 of their citizens for the Tiananmen Square protests on the night of June 3-4 in Beijing.  The folks at Ammo.com, have written a worthwhile piece on the event, the history leading up to it and since then.  It deserves reading. 

The lead tank tried to maneuver past the man, but was met with nonviolent resistance. The man repeatedly shuffled in front of the tank to obstruct the tank’s path. After a while, the lead tank stopped in its tracks and the armored tanks behind it stopped as well. From there, a short pause began with the man and tanks remaining in a standstill.

The video footage then shows the man climbing on top of the tank’s turret and chatting with a crew member and the tank’s commander. After having a conversation, the man jumps back down and gets in front of the tank again. The standoff between the man and tank continued until two figures in blue came out and pulled the man to the side. To this day, witnesses at this event are unsure about who pulled the “Tank Man” to the side. Furthermore, the identity and fate of the man is still unknown, although there has been speculation that he was either executed or fled the country shortly thereafter.

I don't think “executed or fled the country” are mutually exclusive.  If he fled the country, he could well have been tracked down and executed.  If he survived that, he's probably smart enough to never tell anyone that he was that man.  I doubt we'll ever know the story.   

Milton Friedman once observed that economic freedom generally is a precondition for political freedom, but that's hardly a law of nature.  People who have had a taste of genuine economic freedom may develop hunger for political freedom, but the Chicom technocratic dictatorship is not likely to do anything for that hunger.  Tiananmen Square itself was the result of protests for more freedom and against the emerging class of insiders who made enormous profits through connections with the Chinese Communist Party, a problem to this day.

In the years since the Tiananmen  Square massacre, the Chinese Communists have created one of the most monitored and tracked societies on the planet.  Facial recognition systems feed into their Social Credit Score system made in the US by Google and Facebook; it is, after all, based on what those companies are doing to conservatives here in the US.  The Chicoms, of course, have gone beyond that to putting Muslim Uighurs in re-education camps, to widespread condemnation from international human rights observers.  There are reports of organs being harvested from living, healthy, people to sell on the transplant market.  

The Tiananmen Square protests were disastrous for the Chinese people.  A protest for increasing liberties led to the elimination of most freedoms and the introduction of the world's worst surveillance state.  (well... maybe)   It led to the massacre of whoever was in that square the night of June 3rd and 4th.  The only argument for the protests is that it might have wound up this way regardless.

The SpaceX Falcon 9 at 10 Years Old

 Last night, we got the chance to watch SpaceX launch their Starlink 8 mission on top of booster B1049; the booster and rocket performed flawlessly and the booster successfully landed on their drone ship Just Read The Instructions (JRTI).  This marked the first time a booster has been recovered after flying five times and brings them another notch farther in their life testing of the Block 5 boosters, designed to fly ten times.  SpaceX President and COO Gwynne Shotwell says that they may be able to fly more than ten missions without massive refurbishment.

B1049 moments after landing - screen capture from SpaceX webcast, June 3, 2020.

At the end of the Webcast, the Engineer doing the commentary casually mentioned that today is the tenth anniversary of the first Falcon 9 launch.  I recalled doing a story on the 10 year anniversary of the Falcon, but that was the first flight of the Falcon 1.  That 10 year anniversary was less than 2 years ago, September of 2018, so in less than two years, SpaceX went from a booster powered by one Merlin engine to the nine of the Falcon 9.  From that itty bitty booster on the left of the family tree to the second one.

As in that first article, I'm basing this on a piece by Eric Berger on Ars Technica.  Eric says, “Forget Dragon, the Falcon 9 rocket is the secret sauce of SpaceX’s success.”  His point is good; in the last week, the Crew Dragon capsule has gotten the attention of millions of people, but what has made SpaceX into the competitor they are is the outlandish engineering of the Falcon 9.

The article isn't long and is definitely worth going to read, but I usually excerpt a few things to whet your appetite in pieces like this, so this will be no exception.  Berger starts with a story that sums up some of the things behind that success.  He begins on June 3, 2010; as often happens, thunderstorms had come across the cape that day, the day after the vehicle had been moved to the launch pad and gotten clearance from the Air Force to launch on the 4th.  This was a humongously huge moment for the startup company, looked down on by old line NASA for being "cowboys". 

Four tall lightning towers protected the rocket from strikes during the rains, but post-storm checkouts revealed a weak telemetry signal coming from antennas on the Falcon 9 rocket's second stage. Water from the day’s downpour must have gotten into the electronics. This was a potential showstopper for the next day’s launch attempt; it had to be fixed. To do so, the launch director, Tim Buzza, drove out to the launch pad with the company’s founder, Elon Musk, and a senior director of avionics, Bulent Altan.

They arrived at the launch pad well after dark, and the Falcon 9 rocket had already been lowered from its vertical launch position back into a horizontal configuration.

Altan, who knew the avionics system as well as anyone, climbed a ladder to where the antennas were located on the second stage. He removed a cover to assess the damage, confirming that rain from that day's storms had gotten into the rocket's electronics. Overhead, bright lights shone down. Below, dozens of eyes stared up at Altan.

So now what?  Do they roll the booster back into the hanger and give up their launch position?  Swap out the electronics?  Nobody liked those ideas, so they tried a decidedly lower tech solution.  Someone got a hot air gun, virtually a blow dryer.  Altan went back up the ladder and blew hot air onto the electronics until it seemed dry.  Then he applied silicone sealant (RTV) onto the seams to keep moisture out.  What was that about cowboys?

At 2:45pm local time on June 4, 2010, the first Falcon 9 rocket blasted off from the Cape Canaveral Air Force Station.  When questioned about flying the rocket after drying out the electronics with a hot air gun, Musk replied, “I've done crazier things than dry out a radio antenna.”

The booster has etched a number of superlative firsts, from vertical landing and subsequent reuse, to flying into orbit with a record nine first-stage engines. And then there is its cost. At the time of its debut a decade ago, SpaceX offered a basic launch on the Falcon 9 rocket for $50 million. After a few incremental increases, since 2016, SpaceX has listed the base Falcon 9 price at $62 million. This put tremendous pressure on competitors in the satellite launch industry.

On the figurative shoulders of the Falcon 9, the US has gone from having virtually none of the world's commercial launch business to having about 70%, according to NASA administrator, Jim Bridenstine.  I've reported it here a few times; the world can't keep up with the US - largely SpaceX. Last year, Arianespace announced development of a booster copied from remarkably similar in appearance to the Falcon 9, after saying there was no sense in making a reusable booster because it would put people out of work.  China has been working on recovering boosters - so that they don't drop them on small villages anymore.  It has been noted their boosters feature grid fins like the Falcon 9 boosters do. 

Imitation is the most sincere form of flattery. 

The engineering behind landing boosters on a ship at sea is worth studying on its own.  I've run across one video on the subject from a channel called Real Engineering.  Between 2013 and 2017, SpaceX improved their landing accuracy by a factor of 1000x.  The video describes how they perform landings.

 

Shop Update

Seems I haven't done an update for a while because most of what I've been doing doesn't lend itself to this thread, but I still get some stuff done in the shop regularly.  This part took longer than it should have because of a "comedy of errors" (where the important word is errors, not comedy).  I wasted a couple of pieces of steel before I smacked myself upside the head about not paying enough attention! 

This is the rocker arm for the Webster.  You're basically viewing it in same (top) view as that drawing but because it's a real object and not just one view, you see part of the front of it.  I put a 4-40 Socket Head Cap Screw in the tapped 4-40 hole on the right just because.  Although that does make it look a little wonky. 

The notes you see that are handwritten are derived dimensions, usually to tell me where to place my cutter for different features. You'll see they're all 0.250" from a feature - a sure sign I was using a 1/2" diameter end mill and had to specify start and end points for tool movements. 

Getting Things Into Orbit is Hard

With the big guys doing it regularly, it's easy to lose sight of the fact that space flight is hard to do.  Everybody who thinks of it understands that safety margins are slim and launch vehicles are controlled barely-controlled explosions.  Most companies that develop a new rocket fail to reach orbit on their first attempts, even after exhaustive testing on the ground.

Last weekend Virgin Orbit proved that once again, losing their air-launched, two-stage, LauncherOne in its first test flight.

“LauncherOne maintained stability after release, and we ignited our first stage engine, NewtonThree,” Virgin Orbit said. “An anomaly then occurred early in first stage flight. We’ll learn more as our engineers analyze the mountain of data we collected today.”

The rocket was carried aloft from Mojave Air and Space Port in California by the Boeing 747 mothership, named “Cosmic Girl.”

The article doesn't say when the 747 took off, just that the release was at 2:50 PM PDT, and the anomaly occurred within the first three minutes of flight.  The aircraft landed at 4:26 PM, so about 1hr 35 minutes later.  That implies a takeoff around 1:25 PM. 

Chief pilot Kelly Latimer, a veteran test pilot, flew the the 747 through the rocket’s drop box, then entered a race track pattern to loop back around line up for launch on a southeasterly heading.

In the final moments before release, she maneuvered the airplane to pull up at an angle of about 27.5 degrees. The launch team aboard the plane then commanded release of the 70-foot-long (21-meter) rocket from a pylon under the aircraft’s left wing at 2:50 p.m. EDT (11:50 a.m. PDT; 1850 GMT).

Virgin Orbit did not livestream Monday’s launch attempt, but the company provided near real-time updates on Twitter. After confirming release of the LauncherOne rocket, Virgin Orbit followed up three minutes later with a tweet saying the “mission terminated shortly into the flight.”

Cosmic Girl with LauncherOne on the release pod - Virgin Orbit photo.

Imagery from National Weather Service radar in Los Angeles appeared to show a debris cloud in the vicinity of the LauncherOne drop zone at the time of the rocket’s release.  Those two words (debris cloud) are probably the last descriptors you ever want applied to a rocket launch you're working on.

Virgin Orbit is in tough competition to get into the small satellite launch business before it fills up.  Currently, Rocket Lab is the most successful of the newcomers in the smallsat business.  Firefly Aerospace aims to fly its new Alpha rocket into orbit before the end of this year.  SpaceX has come up with an arrangement they call Ride Sharing.  SpaceX says it charges as little as $1 million to share a launch as a piggyback payload of up to 440 pounds, or 200 kilograms, with a primary payload on a Falcon 9 rocket.  I've seen the cost of a Falcon 9 listed as $50 million, but I've also heard costs can vary and experienced boosters are cheaper than new ones. 

I thought it showed camaraderie in the business for the CEOs of Rocket Lab and SpaceX to tweet encouragement to the Virgin Orbit team. 

Virgin Orbit says the main test objectives were to launch the vehicle and start the engine, perhaps observing stable flight, making it a successful test flight but you've got to know they really hoped they'd make it all the way to orbit. 

So congratulations to everyone at Virgin Orbit, and here's hoping for more successful, longer missions soon.

Another Day, Another Falcon 9 Launch. Almost

It seems that way but it's not a daily occurrence.  Not yet.  Sunday, we were in the after-buzz of the successful return of manned space flight to the US, with a mission that though still underway seems nearly flawless, when we read that the long delayed Starlink 8 mission to put up the eighth batch of 60 Starlink satellites has been set for Wednesday night, June 3rd, No Earlier Than 9:25 PM EDT.  

The mission – deemed Starlink-8 – will be SpaceX’s eighth Starlink launch overall and the seventh launch of upgraded v1.0 satellites, pushing the company a mission past the halfway point towards its first internet beta test. If successful, it will raise SpaceX’s ever-growing constellation to some ~475 satellites strong, approximately 400 spacecraft shy of the ~840 COO and President Gwynne Shotwell believes are necessary to begin rolling out Starlink internet service.

The Demo 2 mission launched from Pad 39A; Starlink 8 will launch from Launch Complex 40, about 3-1/2 miles down the Cape from 39A, so they don't have to turn around 39A and get it ready for this launch.  I find no indications that the Falcon 9 and payload has or has not been standing on LC40 since we started talking about this mission in mid-May. 

This morning's forecast calls for an 80% chance of good weather for the launch. 

Despite the fact that this doesn't require a fast turnaround of 39A, it still pushes on SpaceX's capabilities.  Drone ship OCISLY (Of Course I Still Love You) is carrying the booster from the Demo 2 mission back to Port Canaveral, with an expected arrival time of Tuesday afternoon to evening.  There isn't enough time to get back out to the recovery zone even without any time spent working on the booster, so this mission will feature the Return to Service of their second drone recovery ship, JRTI (Just Read The Instructions).  On Saturday, the day of the Demo 2 astronaut launch, drone ship Just Read The Instructions (JRTI) was seen heading out into the Atlantic Ocean, deck cleared for the first time in the better part of a year.

JRTI at the Port of Los Angeles with booster B1049 aboard.  Pauline Acalin photo.

SpaceX intends to perform its limited manifest of future Californian launches while relying entirely on return-to-launch-site (RTLS) rocket booster recoveries back onshore, freeing up drone ship JRTI to head to Florida to support the company’s far busier East Coast manifest. After transiting the Panama Canal in August 2019 and undergoing several months of refits in Louisiana, JRTI arrived in Florida in December 2019 and has been gradually upgraded at Port Canaveral over the last few months. Now, outfitted with a new Octagrabber robot and thrusters and power supplies that dwarf those on SpaceX’s other drone ship, SpaceX has apparently given JRTI the go-ahead to attempt its first booster recovery in almost a year and a half.

The Octagrabber is a new addition to the fleet, but I don't know if this is a first use or not.  This is a low profile robot that maneuvers under the booster and grabs it to keep it from sliding around on deck.  

The unmentioned highlight here is that photo shows JRTI with B1049 aboard, the same booster it will attempt to recover on Wednesday night.  Plus, B1049 is going for its fifth flight and recovery.  You might remember that the last booster going for its fifth flight had an engine malfunction due to some alcohol left in the system by a test error.  That was B1048 two and a half months ago. 

If B1049 can successfully launch and land for the fifth time on June 3rd, it will become the pack leader of SpaceX’s fleet of reusable rockets. With a safe landing, B1049 can prepare to become the first booster to launch six times, hopefully proving that Falcon 9 can safely fly six, seven, eight, or more times – perhaps one day cresting 10 launches to achieve Falcon 9 Block 5’s design goal.