Sunday, October 31, 2021

Post #4000

Over the course of the last week, some of you may have noticed a number at the bottom of every post.  I've put that there not so much for you but to remind me of the countdown to post 4000. 

This is it, and I don't have much to say except thank you to my regular readers and to everyone who stops by.  Since Blogger tells us the number of the post, I've known this has been coming for quite a while, and back over the summer I estimated it would be around now.  You regular readers will have noticed I tend to put up one post a day, so a thousand posts takes about three years.  By that, 4000 takes about 12 years, and my 12th blogiversary will be in February, so I'm ahead of schedule. 

Last Sunday, I said I thought I'd finish the crankshaft for my 1 by 1 engine.  I ended up finishing that today.  After slowly trimming both sides to their proper lengths, I had to make a single purpose tool to help stabilize it for the last operation, and that added a few hours.  That's a story for another day. 

For now...


Make that 

Yeah, that's trying to make it outrageous.

Saturday, October 30, 2021

It's Starting to Look Like More Testing Coming in Boca Chica

If you've been watching the daily or 24/7 feeds and news reports from SpaceX Starbase at Boca Chica, you'll have heard some of this.  Bottom line, like the headline, it's starting to look like the emphasis at Boca Chica is going to get back to testing their orbital Starship and Super Heavy.  It's looking like it could be starting this week.  

One of the bigger items in the news feeds this week is that the giant crane on lease for the last few months, the one the Lab Padre people nicknamed Kong, is apparently being decommissioned and returned to whomever they leased it from.  That's another signal that the major heavy lifting to complete the launch complex is over.  My first mention of Kong appears to have been May 21 of '21.

Teslarati's Eric Ralph talks about the various things that have been going on with both Booster 4 and Starship 20 while the work around the launch complex dominated the schedules.

B4 has had several Raptors removed and replaced.  Of course, we don't know why.  

Aside from removing around a third to half of Super Heavy’s 29 Raptors, SpaceX also began slowly but surely installing parts of a steel heatshield designed to protect those engines during ground testing, ascent, and reentry. Newer Raptors have also been trickling from Starbase’s build site to the launch pad for installation on the booster and more engines will likely be (re)installed as heatshield installation progresses.

Perhaps the most unusual part of recent Super Heavy B4 work is the apparent application of some kind of foam around several racks of pressure vessels (COPVs), hydraulic manifolds, and umbilical connections installed around the booster’s base. Those racks will eventually be enclosed inside steel ‘aerocovers’ already staged beside Super Heavy. A number of Twitter users believe that the foam being selectively applied is for acoustic deadening – meant to protect sensitive electronics, valves, and computers from the brutal environment Super Heavy itself will produce at liftoff and during ground testing.

The booster aerocovers are highlighted in the red rectangle at left.  For scale comparison, notice the two concrete mixer trucks just to the left of the top of B4 in this view looking down, from RGV Aerial Photography.

Starship S20 has had less going on than Booster B4; it appears that since the recent static fire tests, they've gone back to the full complement of three sea-level Raptor Center (RC) engines and three Raptor vacuum (Rvac) engines.  

Barely a full day after that successful back-to-back static fire test, SpaceX rolled two more sea-level Raptors to the suborbital pad and installed them on Ship 20. Another unusual week of downtime later and, on October 28th, SpaceX has rolled two more Raptor Vacuum engines from the build site to the launch pad and staged them beside Starship. Once installed, Starship S20 will, for the second time, be fully outfitted with six Raptors. Having already fired up two of those engines without needing either replaced, though, there’s a decent chance that all six will actually be used before Ship 20’s next bout of engine removal/installation deja vu.

Base of S20 back in August, the first time it had all six engines installed.  Elon Musk photo.

There are things to be tested here that have never been tested before.  For openers, no Starship has been tested with all six engines.  In real life, they aren't used together since the Rvacs are optimized for operation in a vacuum (or close) while the Rc engines are optimized for nearly sea level.  The Rvacs will be used when the booster drops away and the upper stage is working toward orbit; the Rc engines will be used for the Starship's landing.  They can test all six, though, since they're ensuring all the plumbing, valves and all that hardware is actually working.   

Beyond that, the booster will have 29 Rc engines.  They've never lit that many engines at one time.  SpaceX hasn't even performed a full Super Heavy wet dress rehearsal (WDR; filling the booster's tanks and performing a launch countdown) or fire up more than three Raptors on a booster or ship prototype. 

Right now, the only road closure scheduled on the Cameron County website is for most of the day Monday.  I think that's probably to move Kong the crane back to the shipyard area.  When they issue an over pressure notice, that's when there's a good chance it's going to get interesting. 



Friday, October 29, 2021

NASA: Cut SLS Costs by 50% and We'll Use It 'Till 2050

According to a document found by Ars Technica, NASA has asked the industry for ideas on how to go about "maximizing the long-term efficiency and sustainability" of the Space Launch System (SLS) - both the rocket and its ground systems.  This was not directed just at prime contractor Boeing, but at any company in the industry.

The request, which appears on the website in the form of a Request For Information (RFI), opens with the following explanation. 

The National Aeronautics and Space Administration (NASA) invites industry to submit responses to this Request for Information (RFI) to assist NASA in maximizing the long term efficiency and sustainability of the Exploration Systems Development (ESD) programs, including the Space Launch System (SLS),  Exploration Ground Systems (EGS) and Cross-Program Systems Integration (CSI) office by minimizing production, operations, and maintenance costs.  NASA will use the information received from this RFI on a non-attribution basis for informing future acquisition(s) to address this challenge.

NASA says it sees itself as the "anchor tenant" of the system, and says they see themselves procuring one manned flight per year, which doesn't strike me as much of a pace of operations.  They then say industry will "market" the large launch vehicle to other customers, including the science community and other government and non-government entities.  

NASA says it wants to transition ownership of rocket production and ground services to the private industry. In return, this private contractor should build and launch the SLS at a substantial savings of 50 percent or more off of the current industry "baseline per flight cost."

The problem for us observers is that NASA has never published what that baseline cost is.  We have seen some figures that imply that the cost would have to be over $1 billion per launch and possibly well over.  In May of 2020, we found out that the first stage engines would cost $146 million per engine, so nearly $600 million ($584 m) for just the four engines of the booster core.  That doesn't count the solid rocket boosters, the upper stage(s) or anything else.  I don't think they could put the rest together for under $1 billion.

Ars asked the NASA communications office on Tuesday for this figure, but as of Wednesday morning there has been no response. In 2019, the White House Office of Management and Budget estimated the cost of one SLS launch a year at "over $2 billion." Subsequently NASA did not deny that figure, but it has not been transparent with taxpayers about the rocket's expected costs.

There's an ironic story here.  The SLS was first started as a make-work program in 2011 for companies from the Shuttle era, partly architected and pushed by Florida Senator (at the time) Bill Nelson.  He proudly announced the SLS would be delivered on time and under budget.

“This rocket is coming in at the cost of... not only what we estimated in the NASA Authorization act, but less,” Nelson said at the time. “The cost of the rocket over a five- to six-year period in the NASA authorization bill was to be no more than $11.5 billion. This costs $10 billion for the rocket.” Later, he went further, saying, "If we can't do a rocket for $11.5 billion, we ought to close up shop."

As most of you know, a decade latter Bill Nelson is the NASA administrator, he's still pushing the SLS, the rocket still hasn't flown, its first flight has slipped yet again to 2022, and while they've gotten farther in the last year than at any time before now, the cost is over $30 billion so far.  If not being able to "do a rocket for $11.5 billion" is a clue for being time to close up shop, not being able to do it for $30 billion should lead to the doors being nailed shut and the shop razed.

It's arguable that the SLS is a relic of the Apollo age; put it all up in one giant stack.  It makes me wonder about the prospects of using SLS until 2050 as parts go obsolete and impossible to get.  Virtually all of the new space companies are moving in the direction of reusability.  SpaceX has obviously led this effort, but other launch companies, including Blue Origin, United Launch Alliance, Rocket Lab, Relativity Space, and others, are all working on reusable hardware. The European, Chinese, Japanese, and Russian space industries are as well. After reusable boosters come refuelable upper stages, tug "boats" in space, and in-space assembly.  All of those can be launched into orbit on smaller and more affordable rockets.  

NASA Artist's Concept of SLS.

NASA will hold a virtual "industry day" on its SLS request on November 10 and desires responses from industry by January 27, 2022.


Wednesday, October 27, 2021

The New Competitors in the Private Space Station Sector

Over the course of this blog, I've run a few pieces on a small company with big dreams.  The company is Axiom Space and their dream is a privately funded and operated space station.  The plans to get to that goal include sending private crews to the ISS as part of training, with the launch services provided and vehicles under contract from SpaceX.   That mission, Axiom 1 or AX-1, is currently "penciled in" on the Spaceflight Now Launch Schedule for February 21, 2022.  That's less than four months from now.

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.  

This week, the competitive field grew with an announcement from Blue Origin about an effort in cooperation with a group of other companies and academic experts to put up a private space station for business and travel, research and tourism, with a goal of starting operation in the second half of this decade.  

Blue Origin and Sierra Space today announced plans for Orbital Reef, a commercially developed, owned, and operated space station to be built in low Earth orbit. The station will open the next chapter of human space exploration and development by facilitating the growth of a vibrant ecosystem and business model for the future. Orbital Reef is backed by space industry leaders and teammates including Boeing, Redwire Space, Genesis Engineering Solutions, and Arizona State University.

Designed to open multiple new markets in space, Orbital Reef will provide anyone with the opportunity to establish their own address on orbit. This unique destination will offer research, industrial, international, and commercial customers the cost competitive end-to-end services they need including space transportation and logistics, space habitation, equipment accommodation, and operations including onboard crew. The station will start operating in the second half of this decade.

Sierra Space is an offshoot of Sierra Nevada Corporation, one of the companies vying for the Human Landing System contract, but not then partnered with Blue Origin.  Redwire Space is a bit tough to summarize.  Officially, they're a young company; according to that source, they were formed in June of '20, and they just went public with a stock Initial Public Offering in September, but their website shows they've already worked on the recently-launched probe to the Jovian Lagrange points, Lucy, and a wide variety of other important satellites that required that work as much as nearly 30 years ago.  Genesis Engineering Solutions appears to be a solid player in the satellite contract engineering area.  Boeing is ... unfortunately, at this point in time ... Boeing, the company that can't get a much simpler space capsule than this space station running properly.

Blue Origin's Concept Sketch of the Orbital Reef Space Station. 

I have to say when I first heard of this, I thought, "Yeah. Right - the rocket company that can't make orbit is going to build a space station." That was before I looked up the web page for the project and Blue's announcement.  Blue Origin and Boeing getting together and agreeing to put up a private space station means the company that can't get a rocket (New Glenn) into orbit and the company that can't get a capsule working right (Starfire) or a different rocket into orbit (SLS) are working together.  

Blue and Boeing together saying they're going to do something like this isn't much more of an indicator of future success than any dozen of us blog readers getting together and saying that we'll put up a space station.  Except for their billions of dollars of funding, fresh from between the sofa cushions in Jeff Bezos' house.

Is that harsh?  Sorry.  Space is a harsh place.  Boeing used to know how to do this stuff.  The justification used to be, "yeah, Boeing will charge more than some others, but their stuff will work."  I think it's possible to get that back, but they need to really step up their game.   




Tuesday, October 26, 2021

Early Halloween Morning Launch Coming

Early Halloween morning for the Eastern and Central time zones, Saturday night for points west, SpaceX will launch the next manned Crew Dragon capsule for NASA.   

Known as Crew-3, the mission – SpaceX and NASA’s third operational astronaut launch and second ‘crew rotation’ – is scheduled to launch as early as 2:21 am EDT (06:21 UTC) on Halloween (Sunday, October 31st) after a minor one-day delay.

The capsule will be carrying a crew of four: Thomas Marshburn (NASA), Raja Chari (NASA), Kayla Barron (NASA), and Matthias Maurer (ESA).  The Crew-3 mission astronauts will relieve the Crew-2 astronauts Shane Kimbrough, Megan McArthur, Akihiko Hoshide, and Thomas Pesquet, allowing them to return to Earth after some six and a half months in orbit.  After some time together on the ISS.  

Their Crew Dragon capsule, named Endurance for this mission by the crew, arrived at launch complex 39A on the Kennedy Space Center on the 24th and a Flight Readiness Review was held Monday the 25th. 

In a media briefing following a successful October 25th flight readiness review (FRR), SpaceX and NASA officials revealed that the only ‘open item’ (the only issue left unsolved) for Crew-3 was the qualification of a change… to Crew Dragon’s toilet. During SpaceX’s highly successful Inspiration4 mission in September 2021, Dragon performed flawlessly except for a small issue discovered with its last-resort toilet. According to the briefing, in less than a month and incurring what amounts to zero delays to Crew-3, SpaceX analyzed the Inspiration4 spacecraft, determined the fault (a leaky storage tank), redesigned said tank, and replaced the new spacecraft’s faulty toilet with the fixed design.

It's considered an open item because SpaceX and NASA are still finalizing the studies and documentation needed to qualify the design change.  Anyone who has worked in this industry is probably wincing at the idea.  Neither of the two seems to think it's anything that would delay the mission. 

The capsule at the Pad 39A test area.

SpaceX photo. 

There are lots of tests to be done before the launch, and one of the first steps will be to roll the vehicle to the launch pad; something that's done with the vehicle horizontal on the transporter, like this photo of the Crew-2 mission's capsule last April. That will probably happen tomorrow.  They will do a dress rehearsal countdown with a firing of the first stage engines, and many tests that can't be seen from a distance.

Photo credit: NASA/Aubrey Gemignani

An interesting little aspect of this mission is that Crew-3 will be Falcon 9 booster B1067’s second Dragon launch and second launch overall after a successful Cargo Dragon launch debut in June 2021.  I don't think it's a reach to say this is the only booster to fly both manned and unmanned spacecraft to the ISS. 




Monday, October 25, 2021


Yeah.  Me, too.  

Mrs. Graybeard and I went to see the new version of Dune today at the local 10-plex.  As is usually the case, it was a Monday matinee and there were six of us in the theater.  The movie essentially set the hook in me within the first few minutes.  Visually stunning, excellent CGI and sets; it's getting so hard to know where one stops and the other starts these days.  I don't throw around the word masterpiece everyday, and I hesitate to use it here, but the book's story arc is epic and the screen does it justice.

Let me stop for a minute to talk about the books.  I read the first three-book series around 1979 to '80, so an early to mid-20s guy learning about working for a living.  A friend recommended them as an allegory for the middle east, with oil being replaced by the spice melange, "the most valuable substance in the galaxy," and the Fremen on Dune replacing the problems with militant Islamists starting to show up for the first time.  I read the second three books a bit later and I'm hazier on the dates.  I think it was around 1990 or the early '90s. To better understand the second three, I reread the first three as well.  To some degree.  I simply don't remember enough of the details. 

I also saw the 1984 version of the movie, with Kyle MacLachlan as Paul Atreides, Sean Young as Chani the Fremen girl, Patrick Stewart and Sting.  I thought it did a reasonably good portrayal of the book story arc, but it's such a big arc. 

Because of how long it has been since I've read the books, I can't tell you much about how faithfully this new version follows the story arc; all I can tell you is I recognized virtually every scene in the movie from the book and knew what the scene was about.  All of the characters that are mentioned I can recall from the books, even those that have minor roles in the books.

This version is the mental offspring of director Denis Villeneuve, and while he has a long list of work there on IMDB, the only one I'm sure I've seen was Blade Runner 2049, from back in '17, and I find I wrote about that possibly being the most visually stunning movie I'd ever seen.  The movie includes many familiar faces from other movies I've seen and it was fun to see them play different roles.  Chani is played by actress Zendaya, who I've seen in the Marvel Universe in the most recent Spiderman movies; The Beast Rabban Harkonnan is played by Dave Bautista of the Guardians of the Galaxy movies; Duncan Idaho (one of my favorite characters in the books) is played by Jason Mamoa of the Aquaman movies; Duke Leto Atreides is played by Oscar Issac from the last three Star Wars movies; and finally Baron Vladimir Harkonnen is played by Stellan Skarsgård from the first three Thor movies.  I shouldn't say "finally" - there are more.

The title screen said, "part one" and IMDB is telling me that part two is in "pre-production."  Unless they did lots more shooting while they had everyone on location, I read that to think the theatrical release would have to be more than a year out.  

Left to right, Duncan Idaho (Jason Mamoa), Gurney Halleck (Josh Brolin), Duke Leto Atreides (Oscar Issac), Paul Atreides (Timothe'e Chalamet), Lady Jessica Atreides (Rebecca Ferguson), Stilgar (Javier Bardem), and Chani (Zendaya). 

It's a two and half hour movie, and that's setup for at least one more movie, possibly two. 


Sunday, October 24, 2021

Weekly Update on the 1 by 1 - Part 11

I really told myself not to post this until I was sure the crankshaft was done, but since I want to be an Alec Baldwin-free zone and I'm not aware of any space news today, writing about the crankshaft is about all I've got.  

The biggest milestone is that I'm through with turning between centers, the lathe dog and all that.  The final sizes for the sides of the counterweight holders are done.  The remaining operations are to cut the keyway on the long shaft side, cut both sides to finished length, and drill and tap holes for the mounting screws that hold the crankshaft counterweights in place. 

I probably was too zealous in editing out dimensions in this graphic from a few weeks ago.  But the long side (left) is 2.73" and the short side is 2.27".  The keyway (side view on the left) is 3/32 wide and 1.25 long.  The screw holes are visible at the top middle of each side as hidden line.  The print calls out #5-40 screws, but since I don't have any of those while I have a parts cabinet drawer full of #4-40, chances are that's what they'll get. 

I started here:

(Ackchyually ... I started from a 1-1/4 in diameter round bar and threw away more weight in chips than I kept.  This was after cutting it into a slightly oversized rectangular bar).

Today, it looks like this.

The smaller diameter ends on both sides going to get cut away - they're way beyond the amount that ends up in the part.  They were put on to help position the lathe cutters better than when the bar is constant diameter along the whole length. 

As always, I expect to be able to finish it real soon. 


Saturday, October 23, 2021

Senate Tells NASA to Choose Another Lunar Lander

Remember Blue Origin's attempt to sue NASA to get selected for the next Human Landing System contract, after NASA selected just SpaceX instead of two companies?  

This week, the Senate Appropriations Committee wants NASA to select a second company for its HLS program.  The kicker is that they gave the NASA about $1.50 to pay for it.  Well, $1.50 in DC, which is a lot more to you and me.  

That bill offers $24.83 billion for NASA overall, slightly above the administration’s request of $24.8 billion but less than the $25.04 billion in a House bill.

I mean, DC couldn't blow their nose for less than a million, and the $24.83 billion vs $24.8 implies $30 million for HLS.  Then the article says this:

The committee increased funding for HLS by $100 million, to $1.295 billion. “The Committee believes having at least two teams providing services using the Gateway should be the end goal of the current development program,” it stated in the report. “Using this funding, NASA is expected to ensure redundancy and competition, including robust support for research, development, testing, and evaluation for no fewer than two HLS teams.”

The 30 vs. 100 million difference is apparently that they allocated $100 m for HLS and budget cuts to other things reduce the total budget number so that it looks like $30 million.

For perspective on the costs, the total contract to SpaceX was $2.9 billion and Blue asked for $5.9 b.  In July, Jeff Bezos offered to pay part of that out of his own pocket.  Or, as most of us would say, Blue submitted a lower bid after they lost and the contract was already awarded. 

Jeff Bezos published an open letter to NASA Administrator Bill Nelson on Monday morning and offered to pay more than $2 billion to get the agency's Human Landing System program "back on track." In effect, the founder of Blue Origin and world's richest person says he will self-invest in a lunar lander because NASA does not have the money to do so.

Even with all that, the committee is offering $100 million to pay for a program that still costs $3.9 billion after Bezos' $2 billion "instant rebate."  If you're like me, you're probably wondering why.

Appropriators rejected claims that the [HLS] program is underfunded, noting that last year, the agency predicted that it would need nearly $4.4 billion for the program in fiscal year 2022 but only requested $1.195 billion. “Given that request, NASA’s rhetoric of blaming Congress and this Committee for the lack of resources needed to support two HLS teams rings hollow,” the report states.

I should point out that this is the Senate's appropriations committee, and there's another bill that's probably equally messed up coming from the House.  After both bills are finalized, the sausage making process goes into overdrive, and they're combined into one budget.  Since Congress hasn't passed an actual budget since 2008, the reconciled agency budget then gets worked into those continuing resolutions congress uses to avoid responsibility.  

Oh, and if that one makes you confused, the Senate Appropriations bill also includes $579 million this year for Boeing's Space Launch System's Exploration Upper Stage, which has been unfunded.  It specifically says that money is for "engine development and associated stage adapter work." The engine in question is Aerojet Rocketdyne's RL-10.

The RL-10 has been flying since, oh, 1963, and is generally very well-respected from everything I can find.  How could it really need nearly $600 million worth of work?  

Artists' renderings of SpaceX's Starship HLS (left) and Blue Origin's lander.


Friday, October 22, 2021

A Little More About Last Night's Starship Tests

Toward the end of writing last night's post, SpaceX did a second test fire of Starship S20, marking the first time for multiple static fires on one vehicle in one day since SN9 back at the end of January.  

SpaceX Tweeted on their official account that this was the first firing of a Raptor vacuum engine integrated onto a Starship, and posted a nice video loop.  This is a screen cap from it in full screen mode. 

While previous static fires seemed to last three to four seconds, this one lasted closer to six or seven.  This static fire was the Raptor vacuum version, but the second static firing was more interesting; it tested both sea level and vacuum engines at the same time.

Finally, after perhaps the windiest road yet for a Starship from cryoproof to static fire, Starship S20 sailed through a static fire test flow on October 21st and ultimately fired up for the first time ever at 7:16 pm CDT (00:16 UTC). In perfect opposition to weeks of unprecedentedly slow testing, Starship S20 not only completed its first true static fire early in the test window, but it completed the first on-vehicle static fire of a Raptor Vacuum engine and then, just over an hour later, performed a second static fire – this time simultaneously igniting both a Raptor Vacuum and Raptor Center (sea-level-optimized) engine. Aside from also marking the first time that two Raptor variants have been simultaneously fired on the same vehicle, Starship S20’s two-test surprise was technically the fastest back-to-back static fire SpaceX has ever completed, beating Starship SN9 by about 15 minutes.

Back in January, SN9 completed three static fires; the three were at 12:28, 2:23 and 3:37 PM, according to my notes.  First to second firing was five minutes short of two hours, or 115 minutes.  The second to third was much faster, 1 hour 14 minutes or 74 minutes, setting an impressive company turnaround record. Starship S20, however, achieved two static fires in 62 minutes yesterday, October 21st.  

Completing the two firings in 62 minutes versus 74 probably doesn't mean much, but Musk's vision for Starship is unlike any other rocket ever.  He views it more as an extremely high powered commercial jet.  Maybe even an ultra fast, ultra long range car.  When you get off your jet at Atlanta Hartsfield or someplace similar it's probably going to be taking off again in a time similar to 62 to 74 minutes (60 to 90 or 120). 

For your amusement, Lab Padre put up a video of both static firings with views from several cameras.


Thursday, October 21, 2021

Another Space News Roundup

As usual a few stories I think of being interesting enough to talk about, but that aren't big stories.

Starliner Put Off Into '22

It's hardly news, but the last time I ran a dedicated piece on Starliner, I dropped the opinion that it wasn't likely Starliner would fly its unmanned Orbital Flight Test-2 (OFT-2) mission to the ISS until January 3rd to February 22nd.  This Tuesday, NASA and Boeing announced that they were going into deeper failure analysis of some of the failed valves, with a most likely date being before the end of the 2nd quarter of next year.  One source interviewed for that article said the "No Earlier Than" date for OFT-2 is May. 

NASA and Boeing officials said Tuesday that they have successfully removed two valves from the Starliner spacecraft and have shipped them to Marshall Space Flight Center in Alabama for further analysis.

The forensic examination—the two valves will be inspected with a variety of techniques, including a CT scan—is part of Boeing's ongoing effort to diagnose the "stuck" valve issue that caused an abort of Starliner's uncrewed test flight on August 3. With less than five hours remaining in the countdown to launch, during a routine procedure, 13 of the 24 valves that control the flow of dinitrogen tetroxide oxidizer through the service module of the spacecraft would not cycle between closed and open.

The funniest part of this to me is the failure was attributed to humidity.  Who would have guessed there would be humidity in Florida in August?  Listen, Boeing, humidity is one of Florida's main exports.  And they say this capsule is designed to be launched from Florida.  

Boeing's chief engineer for space and launch, Michelle Parker, said during a news conference with reporters Tuesday that the company has a pretty solid hypothesis for what went wrong. At some point during the 46-day period when the vehicle was fueled—and when the valves were found to be stuck—humidity must have gotten into the spacecraft. This moisture combined with the oxidizer and created nitric acid, beginning the process of corrosion.

The First SLS Flight Vehicle is Fully Stacked

Early Wednesday, the Orion capsule was lifted by cranes inside the Vehicle Assembly Building at the Kennedy Space Center and placed on top of the SLS in preparation for the first Artemis unmanned flight.  Technicians inside the VAB worked overnight to tighten 360 bolts connecting Orion to the first Space Launch System heavy-lift rocket.

Cliff Lanham, NASA’s Artemis 1 flow director, said late Wednesday that the Orion spacecraft was “soft mated” to the rocket with an initial set of five bolts in each quadrant. The spacecraft sits on top of the Orion Stage Adapter, the uppermost element of the Space Launch System that sits atop the rocket’s cryogenic upper stage.

The rest of the process of “hard mating” the two was expected to last through today.  A launch date will be set after the completion of a wet dress rehearsal currently scheduled for December.  February '22 is likely to be the earliest the SLS could launch.

SpaceX Successfully Static Fires Starship S20

The test late Monday night Boca Chica time seemingly was a pre-burner test for the Raptor Vacuum engine.  Quite a bit earlier this evening, 7:16 PM CDT, they had a successful static fire of S20.  SpaceX's Twitter account says it was the static firing of the Raptor Vac, and the first such test ever.  A second static fire occurred at 8:18:25.  This one looked rather different from the first, and lasted over five seconds.

Not that you can see anything except overexposure.  There should be videos of this on YouTube by the morning.



Wednesday, October 20, 2021

The Major Buildout At Boca Chica is Wrapping Up

It seems like the build out at Boca Chica has been consuming virtually all of the time being spent on Starship Development for the last couple of months.  In the last week, since about Oct 14, virtually all of the major parts have been put into place, culminating today in putting the full Mechazilla Chopsticks onto the Orbital Launch Integration Tower or OLIT.  A few days ago, the last tank and tank insulating cover for the cryogenic fuel farm were transported to the Launch Complex.  This picture captures the major changes, although due to the distance of the camera and focal length chosen, they might not be immediately obvious. 

The eight large tanks for liquid oxygen and methane are just to the left of the launch pad and behind the yellow crane.  A few days ago, one of those tanks was gleaming stainless until the last insulating cryoshell (white insulating cover) was transported to the Launch Complex and lifted into place over the stainless steel tank.  There was a large horizontal tank taken to the pad complex at the same time as that last insulator which was said to be a liquid methane tank.  I don't see it in this view. 

Right above the launch pad, the Chopsticks are being put into place today.  Early this morning, they were still on the assembly fixture.  A few hours later they were in virtually the same place they are in these pictures from this afternoon as the work of attaching them goes on (and they appear to be in the same place at the time of this writing, four hours after this photo). 

The Chopsticks are integrated with the OLIT and will go up and down depending on the task they're doing.  They can lift Starship onto the top of a booster, or will eventually catch the returning boosters and lower it onto the launch pad. 

Meanwhile, Starship S20 underwent some sort of test Monday night/Tuesday morning.  It was either an irregular static firing or a preburner test.  Probably the latter.  Why the question?  In the early days of Starship testing, they did preburner tests regularly, but as the sea-level optimized Raptor Boost engines matured, that part of the testing was done less often.  S20, however, has the first Raptor Vacuum engines (RVac) to be installed on a Starship and it wouldn't be out of the question for them to go back to the preburner testing for a little while.  In that case, a full static fire is still probably necessary.  

Whatever it was, it didn't look at all like the previous static fires I've seen.  Lab Padre has a short video with a few views of the test.

Tuesday, October 19, 2021

Just-Launched Satellite Lucy's Solar Panels Have a Problem

NASA's Lucy mission to the Trojan asteroids of Jupiter launched successfully early this past Saturday morning, but after deployment of its two enormous solar panels, one has not reported successfully latching into place.  

Combined, the two solar arrays have a collecting area of 51 square meters. Such large arrays are necessary because the spacecraft will spend much of its 12-year journey about five times the distance of the Earth from the Sun. Lucy's solar panels can only generate about 3 percent of the energy at a Jovian distance than they can at Earth's orbit around the Sun.

A rule of thumb number to remember is that the sun delivers around 1300 Watts per square meter to the top of Earth's atmosphere.  The 3% value they quote is 39 W/sq.m., and the 51 square meter array would give the spacecraft 1990 Watts every hour at those distances.  Lucy is traveling farther from the sun for a longer mission than any previous satellite that was completely solar powered.  Earlier satellites commonly used Radioisotope Thermal Generators, RTGs.  

The other way to think about this issue is that if it's designed to run on 3% of what's available in Earth orbit, it's got 33.3 times that right now while they troubleshoot the issue.  On Lucy's NASA project website to watch, they note:

Lucy’s two solar arrays have deployed, and both are producing power and the battery is charging. While one of the arrays has latched, indications are that the second array may not be fully latched. All other subsystems are normal. In the current spacecraft attitude, Lucy can continue to operate with no threat to its health and safety. The team is analyzing spacecraft data to understand the situation and determine next steps to achieve full deployment of the solar array.

This is yet another example of the saying that "space is hard."  Lucy is in an escape orbit and beyond the reach of any other spacecraft to help out.  The mission controllers are on their own.  I should point out that they said, "indications are that the second array may not be fully latched."  They still need to determine it's actually a problem with the latching and not the circuit that measures whether or not the latch is properly set.  If the sensor or circuit is bad, it's annoying but not a show stopper. 

Lucy is an interesting mission that seems totally academic.  The mission is to the Trojan asteroids, orbiting at the LaGrange points of Jupiter, ahead of and behind Jupiter itself.  

The $981 million mission will fly an extremely complex trajectory over the span of a dozen years. The spacecraft will swing by Earth a total of three times for gravitational assists as it visits a main-belt asteroid, 52246 Donaldjohanson, and subsequently flies by eight Trojan asteroids that share Jupiter's orbit around the Sun.
Lucy will fly by its first asteroid target in April 2025, a main-belt asteroid named after Donald Johanson, the American anthropologist who co-discovered the famed "Lucy" fossil in 1974. The fossil, of a female hominin species that lived about 3.2 million years ago, supported the evolutionary idea that bipedalism preceded an increase in brain size.

The mission itself is named after that fossil Lucy as well.  It's a fanciful name, but these asteroids themselves are considered to be old fossils from the formation of the solar system. 

This is Lucy's trajectory over the next 12 years.  It looks complex but it's really more complex than this shows.  This perspective is created by fixing Jupiter's position, so during the 12 years of the mission that this is showing, Jupiter and both groups of Trojan asteroids will complete a little more than one full orbit around the sun, making this a more complex plot.  Plot from the Southwest Research Institute, the scientists behind the mission.  

I'll end this with a mind-blower.

Somewhat ironically, although Lucy is visiting the "Jupiter trojans," it will never be closer to Jupiter than when it is on Earth. This is because the Trojans trail Jupiter at a greater distance than the distance that lies between Earth and the Solar System's largest planet.



Monday, October 18, 2021

No, It Doesn't Appear That SpaceX's First Orbital Flight Has Slipped to March

A buzz has been going on in active space and SpaceX watcher communities that a NASA document shows that SpaceX's "first orbital flight" has slipped to late March.  It apparently started on Reddit's /r/SpaceXLounge and then was picked up by Teslarati's Eric Ralph.  As of late today, Reddit's readers and Eric Ralph both seem to have converged on the actual message; saying that not necessarily the first orbital flight, but that an orbital flight will be in used in March '22 for a project NASA is working on.  

The story focuses on a program NASA is going to do the monitor the surface tile temperatures of the Starship during reentry.  The whole story focuses around these two graphics, which appear to be the kind of slides that get presented during a design review, from a program called the NASA Scientifically Calibrated In Flight Imagery or SCIFLI.  Click em to embiggen em, as usual.

As you can see, the plan is to use a set of infrared imaging cameras that they're currently developing to monitor the "entire lower surface of the Starship spacecraft during hypersonic reentry."  The cameras will be flown on a NASA WB-57F research aircraft which will have to be tracking the vehicle from a high altitude in a parallel course.  The very last sentence on the top graphic says, "Targeting Starship reentry observation opportunity near March 2022."  That clearly doesn't say "Targeting the first Starship reentry ..." and if anything, it can be read as the March suggestion saying that's the target date for their equipment to be ready.

If you'll pardon the expression, the exact date of the first orbital flight is still up in the air.  The FAA has yet to announce either an approval for them to continue or a disapproval.  SpaceX has needed to put a lot of effort into completing the ground infrastructure for Starship/Super Heavy operations, or "Stage Zero" as Elon Musk refers to it.  As we've talked about many times, in the last several months there has been a constant effort to move every little bit of infrastructure possible from the vehicles to the ground.  This time hasn't been wasted, although we all would like to see them trying to fly these ships.

As launch facility work has been going on, they continue to produce more Starships and more boosters.  Currently at the launch facility they have Starship S20 and booster B4.  Booster B5 and S21 are said to be nearly ready.  It's conceivable that B4/S20 might do some testing before attempting a true orbital flight.  Since everything published so far on them says both will end up being tossed into the Gulf of Mexico (B4) or the Pacific near Hawaii (S20), it might well be that B5/S21 will attempt the first orbital flight.  

The sooner any of this kicks off, the better.  Oh, and if you want to see a cool video that just might show what a Starship reentry would look like, check out this one.

Fixed It For Ya

With apologies to whomever posted this and that I got it from over the weekend. This is the problem.

This the fix. 

From everything I've read about this ***hole funding state's attorneys general and then prosecutors, I never cease to be amazed that he's not behind bars somewhere.  He's wanted in several countries, but apparently none that have police competent enough to take him in. 

Saturday, October 16, 2021

This Week's Update on the 1 by 1 - Part 10

I concluded the last report by saying I was going to sand the journal to get it down to the final size, using the plastic sticks I had made to hold the sandpaper.  It had been filed down to a bit oversized and I used the plastic sticks with 220, 400 and 1000 grit to finish.  The final size of the journal varied from 0.3751 to 0.3752", or within 1/10,000 of an inch over its length.  Since I make the other side of that matching pair, the piston, that should end up being easy to live with.  

I didn't get as far as I wanted to because I continued to dump hours into troubleshooting the odd printer problems I spent days on last week, but I was able to make progress on the crankshaft. 

Once I had let it sit for a day, and measured it another few times, the next task is to take off the extra metal around that journal and prepare it for turning the rest of the bar down to its final size (also 0.375").  I did that on my bandsaw and didn't take any pictures until it was done and put back on the lathe.  Which is when I realized I had problems with the tooling.  

The problem?  Look at the top left of the picture where you'll see a kludge of a bolt, a wingnut, two washers (to increase diameter) and a hex nut.  That was because the system I bought from Little Machine Shop offered a bolt for that radial slot in the plate, but the bolt was at least 1/4 inch above the end of the rod it needed to be pushing.  I replaced that M8 (metric) bolt with a 5/16-18 bolt from my stash, going through a couple of lengths before I found one that work for the job.

While that worked, and I skinned back the side of the "cheek" holding the journal, I thought it felt flimsy enough that it was worth making a replacement tool.  My first thought was an L-shaped bar that would replace the hex nut and stick down far enough to push on that steel bar (the lathe dog's tail?) and be more secure.  

I had two rectangular (steel) bars that used to be the other half of that crankshaft blank, and cut down one to make the reinforcing piece in the middle of the shaft (visible just above the rounded journal above).  I tried to think of how that leftover piece could work and couldn't see a way.  So I took an inch off the end of a 3/4 x 1" wide steel bar I had and made the tool from that.  (The reinforcing block is there to keep the pressure on the ends of the crankshaft bar from bending it around the journal - it's epoxied in place while I work.)

There's not much adjustment range, you can see the adjustment slot just above the nut and washer, but it's about 1/2 or 5/8" long.  It feels more secure than the stacked washers.

So with that in place, it was time to start turning down the rectangular steel bar and making it round.  It's far from done, but I took this picture at a convenient stopping point yesterday. 

The top side of the bar here is flat from the saw cut.  I think the numbers tell me that it ends up circular before it reaches final size, but I have to admit I'm sweating it a little.  

Both ends are too long and will be cut to final size.  Both sides should have had enough extra material coming off the (manual) cut on the bandsaw.

Operations left to do:

  1. Turn this side, the long side, to final size and shape.  That will reduce the width of the rectangular block and put a raised ring on the left end of the bar ( .025" tall by 0.440" diameter).
  2. Cut length to final size
  3. Flip the shaft end for end and turn the other side to final diameter with the same detail ring on it.
  4. Cut other side to length. 
  5. Move to the mill and cut a 3/32 wide keyway on the short side. 
  6. Reduce the thickness and length of the rectangular side blocks to final sizes (currently .025" over)
  7. Drill and tap a 5-40 hole in the centers of both side blocks.

Friday, October 15, 2021

Astra Explains Their August Sidways Launch, Sets Date for Next Try

Some of you will remember from the end of August when California rocket company Astra launched a rocket that flew sideways for a while before starting to fly vertically and eventually going to its second stage.  

Early this week, the company announced a launch date of October 27th, the last Wednesday of the month, and will be flying from their mini spaceport on Kodiak Island, Alaska.  The rocket, this time called LV0007 (LV for Launch Vehicle) rather than Rocket 3.2 or 3.3 as the last two were called, will be carrying a small payload weighing a few dozen kilograms for the US Space Force.  The diminutive size of the payload belies the importance of this launch to the company, which has yet to achieve orbit. 

As its name implies, this is the seventh rocket Astra has built. The first two models were strictly for suborbital tests. The third rocket was lost during a launch pad fire. The fourth rocket—the company's first actual attempt at an orbital launch—failed after about 30 seconds due to a guidance error. That flight took place in September 2020. During a subsequent attempt in December 2020, LV0005 reached space but did not have enough propellant to reach orbit.

That attempt last December led to a small redesign of the vehicle to add about five feet of length to the first stage for slightly larger fuel and oxidizer tanks.  The December flight got high enough to be in space, but wasn't fast enough to attain orbit, falling about 500 meters/second (about 1100 miles/hour) short.  The redesigned vehicle was the one tested on August 28th and went sideways for a while until it burned off enough fuel to have a thrust to weight ratio greater than 1:1. 

What happened?  

In a blog post published Tuesday morning, Astra chief engineer Benjamin Lyon provided more information about this failure and steps the company has taken to ensure it does not happen again.

"The issue we encountered was something we hadn’t seen before," Lyon wrote. "Leading up to liftoff, the first stage propellant distribution system provides the rocket with fuel and oxidizer. We designed the system to quickly disconnect and seal when the rocket lifts off. On this launch, propellants leaked from the system, mixed, and became trapped in an enclosed space beneath the interface between the rocket and the launcher."

At this point, exhaust from the rocket's five engines ignited the propellant, which in turn cut the connection to the fuel pump electronics. This led to a shutdown of one of the rocket's engines a fraction of a second after the booster lifted off. This caused the rocket to effectively hover before its on-board flight software compensated, allowing the rocket to fly more upward. The four remaining engines, however, did not have enough thrust to boost the rocket into orbit.

Lyon said Astra has modified the design of the rocket's fueling system so that the kerosene fuel and liquid oxygen oxidizer can no longer mix. It has also been modified to further reduce the risk of leakage during the fueling process. "We believe these changes significantly reduce the likelihood of seeing a similar event in the future," Lyon said.

Again, this is a very important launch for Astra.  They need to demonstrate they can get to orbit and safely deliver paying customers' payloads if they're to be taken seriously in an increasingly crowded and competitive market.  This past July, Astra became a publicly traded company and between the stock sales and some NASA contracts, I noted they could keep working after August's mishap.  The company's stock has fallen by nearly 50 percent compared to July's stock price.  Nothing would help that situation as much as some success at their core business: getting into orbit and delivering payloads to required orbits. 

Astra's launch facility in Kodiak, Alaska.  (Photo by John Kraus for Astra)

Wednesday, October 13, 2021

On The Big Story of the Day

Today singer/songwriter Paul Simon, Rhymin' Simon his self, is 80 years old.  Happy Birthday, Paul!  

Accredited as one of the best singer/songwriters of his generation, Simon might be best known as half of the iconic duo of Simon & Garfunkel formed in 1965, although his solo career was longer and arguably more productive.  His popular songs are too numerous to list.  The guy has 12 Grammy Awards, a Grammy Lifetime Achievement Award, a Songwriters Hall of Fame induction, a Johnny Mercer Award, and not one but two Rock ‘n’ Roll Hall of fame inductions, one for Simon and Garfunkel and one as a solo artist.

Just kidding.  Well, I mean it really is his birthday and all of that is true, but to most of the news of the world the big story of the day is William Shatner's trip to space on Blue Origin's New Shepard rocket.  

There's a 39 second video from their time in weightlessness in a couple of places.  This screen capture is from the C/Net Highlights channel at about the 23 second mark, where you can see Shatner visibly saying "oh, wow!"  

Eric Berger at Ars Technica (and @SciSpaceGuy on Twitter) pointed out: 

Finally, there can be no question that inviting Shatner to fly as a guest on just the second human flight of New Shepard is a marketing ploy. This mission lacks the novelty of the first crewed flight—carrying Bezos—and interest would otherwise have been low for sending two millionaires (Chris Boshuizen and Glen de Vries) and Blue Origin employee Audrey Powers into space for a few minutes.

I asked Twitter followers on Tuesday whether they thought the spectacle of flying Shatner to space was more "marketing" or more "marvelous," and by a three-to-one margin they voted for "marketing."

As someone who has written about space for decades and watched most episodes of most Star Trek series, I would say that flying Shatner into space is marvelous marketing. This flight does not solve any of the problems at Blue Origin, which are substantial. Due to poor management, the company has under-delivered. But Captain Kirk is finally going to space, and it's thanks to Blue Origin and Jeff Bezos.

There are a lot of things to be upset about in the world today, but sending Shatner to space, after he's delivered so much joy to so many for so many years, is not one of them.

Note that Berger said Shatner flew "as a guest" today; I take that to mean that he didn't pay but was given the flight by Blue.  I've read that Jeff Bezos is a big fan of the Star Trek worlds and especially Captain Kirk.  

On the scale from utter contempt to unrequited love for William Shatner, I come down kind of neutral.  He's clearly no Lawrence Olivier, but he played fun roles and was entertaining.  The only thing I want from the dancing monkeys I hire is to dance better than I can.  It's not a high bar to get over.  I'm happy for Bill.  Qapla', Kirk!  chay' jura'?

Tuesday, October 12, 2021

The Trillion Dollar Coin Scam

By now, I'm sure everyone has heard the story about the way to fund the growing federal debt.  Some one said simply mint a coin in platinum and declare it to be worth $1 Trillion dollars, then deposit the coin with the Federal Reserve.  Then the Fed could add the stated value of the coin to their balance sheet and buy the trillion dollars worth of bonds.  Since a trillion is nothing in the face of the current debt levels, they'll have to mint a lot of them.  The recognized national debt is closing in on $29 trillion with other payments due in the future (most places call those unfunded liabilities) of nearly $158 trillion.  They'd have to mint 187 of them.  

Since there's nothing backing it and nothing to distinguish the value other than "the coin is worth what we say it's worth," I suggest they go buy some silver dollars, some paint, and create something like this.  

Maybe get some first graders to do the lettering.  Give it more personality than my edit in "Paint".  And add that pesky "s" that needs to go on the end of "dollar."

Saying the coin is worth a trillion dollars is the essence of Modern Monetary Theory.  The fact that someone would seriously consider minting such a coin shows economic ignorance of epic levels, but the whole country is running on MMT now, which is nothing but ignorance of economic history.  Nobody stops to think how other countries would react to us doing that, and how it would affect their confidence in our bonds or anything else.  (Much like their confidence in our leadership after Afghanistan).  Nobody stops to ask the question that if we can create trillions like that, why do we tax anybody in the country anyway.  It's a nonstop train to no longer being the world's reserve currency. Honestly, though, that train left the station long ago and the death of the dollar in that role is a matter of when, not if.  I wouldn't be surprised to see it happen almost any day, now.

It's kind of fun in a macabre sort of way to watch MMT failing all around them yet they seem incapable of seeing that's why things are falling apart now.  A common failing in all sorts of endeavors is to be so in love with your theories that you can't see that other ideas might work better.

Treasury Secretary and long term Deep State Hack Janet Yellen is still saying the inflation is only transitory, and oh by the way, let's get rid of that pesky debt ceiling so we can just create and spend whatever we want whenever we want.  Money is just medium of exchange, right, peons?  What's that about store of value?  Don't be silly.  We want a constant 2% inflation so that the prices of everything will double at least twice in your wretched lives.  That's not storing value, it's planned destruction of value. 

Even John Maynard Keynes didn't envision his Keynesian brand of economics creating money perpetually; he thought it would be done in times of crisis, and then stopped.  The excess dollars could be wrung out of circulation. 

Monday, October 11, 2021

Just A Couple of Images From Boca Chica

I was going to have more to say, but our evening was interrupted by our water leak alarm under the kitchen sink.  It appears to have been a "replace the battery" alert;  some checks for water came up negative but it took up time.  

Meanwhile, the first ever Raptor Vacuum engine was installed in S20 this morning.  This is before it was lifted into place, and may have nothing at all connected.

Photo credit to Nic Ansuini via Twitter.

Later in the day, the second "Chopstick" of the pair being installed on the Orbital Launch Integration Tower (OLIT) was lifted into place.  It's the one on the left in this picture.  

Screen capture from Lab Padre, with a little photo contrast enhancement.

The red structure visible around the big crane (Kong) is an assembly fixture; the smaller red structure is farther from the camera than the taller one.  Although it only shows one of the chopsticks, this 14 second animated video shows what that assembly fixture looks like.   The two giant arms in the back (unrecognizable in this view) with wrap around ends, wrap around the OLIT and the straighter chopsticks open and close. 

Cameron County's road closure website says a "primary" closure for tomorrow, 5PM to Midnight has been cancelled, but the back up dates of Wednesday the 13th and Thursday the 14th, same times, are still open.  If the road closures are to static fire S20, it will mark the first time the Raptor Vacuum engine has been fired in a Starship.  If S20 is fully configured for flight with six engines, three sea level and three vacuum, that will be a first.  I don't know of scenarios in which all six will be used simultaneously, but all six need to be tested.  

A road closure shouldn't be necessary to put the Mechazilla Chopsticks in place so that could happen as soon as it's ready to lift. 


Sunday, October 10, 2021

Meanwhile at Boca Chica - Someone is Playing Chopsticks

Well, someone is playing with chopsticks.  That's the term for the massive steel arms that are supposed to catch the Super Heavy booster out of the air at the launch site.  Instead of having it land on a barge at sea or landing pad near the launch pad, which is apparently too easy now.  Yesterday and today have marked the slow motion movement of the first of the chopsticks onto what appears to be a fixture that will be used to assemble the pair before they're mounted on the Orbital Launch Integration Tower.  

These things have an odd shape and I don't know what they're going to look like in use.  This is a screen capture from very late in this NASA video that shows it horizontally oriented, suspended in the air by the big crane.   

Yes, it's rather asymmetrical with that big section on the left end that extends vertically downward to large piece that looks like a pipe flange.  I watched that around some other things I was doing yesterday and they had some problems getting the cables to the crane over the chopstick's center of gravity.  Eventually, it was positioned near that red structure along the left edge of this picture.  There's a rendering of that on Twitter if you want a better look.

While it isn't as glamorous as watching the actual launches, this is extremely important work going on at Boca Chica Starbase.  Teslarati's Eric Ralph has a summary posted today

SpaceX has begun preparing its Starbase ‘launch tower’ for the installation of a pair of giant arms designed to lift, stack, and even catch Starships and Super Heavy boosters out of mid-air.

Deemed ‘Mechazilla’ by CEO Elon Musk, assembly of first of the structure’s three main arms only began in earnest in June 2021. That ‘quick disconnect’ (QD) arm – designed to fuel Starship and stabilize Super Heavy during Starship stacking – was installed on August 29th and followed by the addition of a claw-like appendage meant to grab onto boosters about a month later. Now, all that’s missing from Mechazilla’s first arm is the actual ‘quick-disconnect’ device that will connect to Starship’s umbilical panel to supply propellant, power, and communications links.

However, ever since Musk first hinted at the possibility of catching Super Heavy and Starship, the star of the Mechazilla show has always been its ‘chopsticks’ – SpaceX’s internal colloquialism for the pair of giant, moving arms meant to lift and catch rockets.

Super Heavy boosters are enormous: 225 feet tall and 29.5 feet in diameter.  The thought of its landing system knowing its position accurately and precisely enough to catch the booster without flying it into one of the chopsticks is a bit mind-bending.  Then there's thinking of the load those arms will have to bear to catch the booster, yet be delicate enough to not crush it.  

During the two hour and 20 minute walk around of Starbase with Elon Musk that Everyday Astronaut conducted, Elon said something that stuck in my mind like a sand spur in a wool sock.  He said when the Super Heavy returns to the launch tower to be caught in the air, its density (pounds per cubic inch) is close to that of an empty beer can.  A very, very big beer can. Beer cans can be crushed in your hand.  How rugged are they if you scale the beer can up to 225 feet by 30 feet diameter? 

Saturday, October 9, 2021

A Little Shop Update

This is not an update to the 1 by 1 engine I've been tracking, at least not exactly.  I didn't do much to the cam shaft at all this week.  Last Saturday, I concluded my update by saying it should be done "tomorrow" - meaning last Sunday.  Nope.  

I did some more reading and decided the cylinder I'd been turning (more precisely called a journal bearing) needed to be not only reduced to the right diameter but almost left with a polish.  That means sandpaper.  I did some research and found that the most common way of getting sand paper into a place like that and minimize the chance of repeating my finger injury (or worse) is by gluing sandpaper to a Popsicle stick.  Well, there's two of us in this house and neither of us eats Popsicles so it became a question of how I got one.  

While sitting in the shop, I almost put my arm on my 3D printer when my brain said, "it's a plastic Popsicle stick maker."  And so began a week of misadventures.  A comedy of errors that, like most of them, wasn't funny at all.  

If I'm going to print anything, I need G-code file and to get that, I need a 3D solid model of a Popsicle stick.  This didn't take long, and I quickly made a version 1 of what I started calling the Fat Popsicle Stick - because I wanted to put a nice handle on it.  

The dimensions aren't there, but it's 5 inches long, the thick part of the handle is 1/2" tall, and the stick portion is 0.4" wide by 1/16" thick. That number was completely pulled from thin air.  I mean, I have had Popsicles, just not in the last 35 years or so.  They seemed about that thick.

So Tuesday it was time to print it.  The print failed.  I watched it for the first few minutes and came in to do other stuff during the remaining hour the print would take.  Just as I was about to go check on it Mrs. Graybeard came in to tell me the thin, stick part was off the table.  I went out to check it out and figure out what to do.  I thought about putting a spot of glue under that end and pushed on it to see how flexible it was.  When I did that, I popped the whole stick off the print bed.  No choice left but to kill the job.  

Except that it was about 3/4 done and probably usable.  So I gave it a try and found two problems.  First, it was too wide.  The design was 0.40, but it came out a little wider.  When I wrapped sandpaper on it, it was too close to the .438 of the journal.  The second problem was that it felt too flimsy.  

Within a few minutes, I had a redesigned "Ver. 2" stick ready to print.  I doubled the thickness of the stick portion to 1/8" thick.  Stiffness in bending here is proportional to the fourth power of the thickness, so doubling the thickness should make it 16 times stiffer.  The minor change was to drop  the width to 3/8".  

Except that I noticed before I left the first time that it looked like the right front corner of the print didn't look as opaque as it did farther away from that corner.  I ran one of these bed level tests like I did when I was getting set up to use the printer and it came out that the right front corner didn't print.  Time to re-level the printer bed.  Except I realized I didn't remember how to go through the process of leveling the bed, so I gave up for the day. 

Of the various channels I found on YouTube, the one I think I got the most from was CHEP, so I went to his channel, searched on bed leveling, and found a video that was dated a month ago. Obviously not the one I watched back last January, but I watched it and thought it was a big improvement over the way I did it. The main difference is that the previous video is based on sliding a piece of paper out from under the print head while this one is based on a feeler gauge.  The 3D printed gun guys stress doing a better layer thickness calibration and I think they talked about using a feeler gauge. 

To do this calibration, I needed to load some new firmware onto my printer, which required that I verify which processor board revision I have.  I'd been meaning to do both of those things anyway.  

With the new firmware and the bed leveled, it was time to print the revised design.  Except that I hadn't put the Rev. 2 model's G-code on my memory card and printed Rev. 1. OK, time to really print Rev 2 and very quickly found a problem.  The G-code was having it print the 1/8" thick part but left it the original 1/16" in the back.  Then it went back to print the handle on top of that thinner area and it didn't even attach to it.  A real mess.  I ended up with two parts not really attached to each other. 

Between the first layers looking thin, and the layers not bonding well when I printed the squares to check the bed level, I started to doubt this brand new yellow filament.  So I removed it and put in the other new spool of PLA+ filament I have, this one white.  I started printing with that and then broke for dinner.  After eating I went to check it and found it had printed the bottom half of the 1/8" thick part and then got lost.  The extruder went the width of the stick up in Y and some random offset to the right in X.  Totally FUBAR.  It left me puzzling over which piece of software screwed up or if it was the printer hardware.  There's three possible sources of software errors: the new firmware in the printer, the slicer software that creates the G-code, or it could be that my CAD model had defects I can't see.  

I decided to start everything over from scratch, except for leveling the bed.  I redrew the model and sliced it with the other slicer software I have but switched away from, Cura.  That required me to convert the model to metric in Rhino.  That's not hard, just more to do and not having to do that is one reason I switched to the newer (to me) slicer software, Prusa.  Then I started printing it again.  This one worked fine and was done in an hour.   

If you lost count, I had to print it three times to get one to come out right.  The one that came out in two pieces is usable, I had to cut off the loose filament and glue that one together.  I now have two of the sticks that I think will work and that's all I need.  One will get 400 grit glued to it and the other will be more like 1000.  Maybe.  Probably?

The Fat Popsicle Stick family.  In the back is the Rev. 1 stick that popped off the bed before it was done, but was usable - except for being too wide. It has 220 sand paper glued to it and I actually ran that on the journal for a little while.  The one on the left is the second Rev. 1 that I printed accidentally.  Second from left is the first Rev. 2 that printed in two pieces.  I shaved all the loops of filament off the bottom of the back's top piece and glued it to the bottom.  The odd looking white mess is what came out of the printer losing its X and Y coordinates.   The last one on the right is the finished Rev. 2 stick that printed properly.  

Back in March of '17, I quoted an article from Machine Design magazine, "Are 3D Printers Overrated?" in a post for those of us who don't have one.  The author's point was that you can buy a 2D printer (better known as an inkjet or laser printer) set it up and get great results instantly.  Go buy a 2D printer at your local office supply store and you'll be printing out grandma's recipes in less than an hour.  3D printing is still a much, much less established technology.  

I've had several prints that went without a hitch, but days like this week remind me of this guy's article.  Yet another thing I've been thinking of doing is building an enclosure for my printer, which is his first recommendation.