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The Apollo heat shield was "hex-gunned Avcoat", and that's no secret, not today. It exists in multiple variations. This Apollo hex-gunned Avcoat was also what flew on the Orion in its very first unmanned flight test, before the unmanned Artemis-I flight test.
The phenolic-impregnated fiberglass honeycomb is attached to the capsule base with the hex cells facing into the wind blast direction during entry. Humans wielding powered "caulking guns" inject the ablative manually into those hex cells. There were almost 300,000 of them on Apollo, almost 400,000 of the larger Orion. The ablative is cured in place, and resurfaced by the equivalent to coarse sanding to smoothe the shape.
The ablative was a silicone polymer (not sure which one right off the top of my head, but I think that it is listed in the Wikipedia article on Avcoat), loaded with small micro-balloons to reduce its density. Lower density is lower heat shield mass, but also a faster ablation rate. The density you want to use is a trade-off, set by the mission to be accomplished. That heat shield material and construction information might once have been militarily classified long ago, although I don't really think so. More likely it was a company trade secret that NASA tried to protect for a while.
This technology grew from very similar materials tried experimentally on Mercury and Gemini, both built by McDonnell (before it merged with Douglas). Some of the early Mercury suborbital tests were made with a metal beryllium heat shield, but they quickly went to ablatives as the better-performing and lighter-weight deal. What flew on Gemini was a very close precursor to what flew on Apollo. Apollo was built by North American Rockwell. NASA had to be the technology source and guardian for this heat shield information, since this was used by two different competing companies for NASA. A lot of the development tests in arc jet facilities were done by NASA.
NASA management did not like two things about the Apollo-style hex-gunned Avcoat: (1) the enormous manual labor cost, and (2) the inherent variability in manually-loading hex cells. It takes a skilled and well-practiced operator to get consistent results, and you have to pay those skilled operators more.
So what they did for the Orion that flew in Artemis-I was delete the hex attached to the capsule base, and instead just bond down cast tiles made of the Avcoat balloon-loaded polymer, but without any hex cell reinforcing material embedded in it. And they built the Orion for the manned Artemis-II test flight the same way as they built the one for Artemis-I, BEFORE Artemis-I actually flew! They really thought it was going to work based on computer simulations and some arc jet data to set the density.
But it did not work right on the Artemis-I test! Unreinforced char is a lot easier to strip away with fluid surface shear forces. You don't get a lot laterally-directed surface shear in a straight-on arc jet test, which is the way those are usually done. And you only can get what you know to program-in, in computer simulations! GIGO! I am guessing they never ran any angled arc jet tests, because they never did before, with the hex-reinforced Avcoat samples.
The original real management mistake was building the Artemis-II heat shield before getting the flight test results from the Artemis-I flight test. They did that to save schedule time, betting that it would work fine. But it didn't.
The follow-up mistake was not switching heat shields back to the hex-gunned method on that Artemis-II Orion, when Artemis-I showed bad results. There's been enough other delays to completely cover the time needed to do that, but they did not, because that would require publicly admitting a top management mistake!
And as we have already seen since Challenger, they NEVER want to admit top management mistakes! That culture never changed, or there would not have been a Columbia disaster. Or two stranded Starliner astronauts aboard ISS.
The track record indeed shows that money, schedule, and management reputation are all valued more than human lives. At NASA, and even at the "old space" big corporate contractors.
As far as NASA goes, that bad, still-unfixed, management culture is a separate problem from the Congressional (incompetent) micromanagement of NASA projects, just to support high-$ Congressional pork-barrel politics.
However, be that as it may, until BOTH those fatal problems are fixed, NASA will not successfully send anybody back to the lunar surface, much less to Mars!
GW
The co-op came out and set a new meter on the house. The display shows when the meter is running backwards, like the over at my shop.
I went and looked: it was a bright sunny morning with the sun about halfway up to zenith. With the air conditioner running, the meter was stull moving backward, just very slowly. With it not running, the meter was moving very fast backwards. I don't think the hot water heater was running (it's an all-electric house out in the country). No lights on, just a couple of computers and maybe the TV. The house system uses 21 panels, feeding DC to one inverter that feeds phased AC at that meter.
The one over at the shop was running backwards pretty fast, even with my renter's air conditioner running. Hs domicile is much smaller and better shaded and insulated than my house. The shop system uses 8 panels feeding DC to one inverter that feeds phased AC at that shop meter.
How's that for a performance report? We were selling electricity back to grid from both systems, even with air conditioners running in a serious heat wave. The high that day, about 4 hours later, was about 105F. It was already 95F when watched the meters that morning.
The system went operational August 13. The bills for August show up in September. I expect to see lower bills for August, half of which the meters ran backwards significantly. I expect dramatically lower bills for the month of September, which will show up in October.
GW
Titanium dioxide is THE most common white pigment used in every sort of paint made anywhere on the planet! It's a fine white powder. Yes, the meltpoint is high, but how does one go about turning a white dust into a real structural material? A heat shield must withstand high temperatures, but also must stay intact and in place in the face of high fluid pressures and shearing forces.
GW
PS: the movie reruns not only include the fatal shuttle Challenger and Columbia disasters (two dead crews of 7, twice), but now two stranded Starliner astronauts.
I could not quickly find the right thread for this, so I put it here. This is from today's AIAA "Daily Launch", referring to a longer article in something called Ars Technica.
Ars Technica
NASA wants clarity on Orion heat shield issue before stacking Artemis II rocket
NASA would like to start stacking the Space Launch System rocket for the Artemis II mission—the first human flight around the Moon since 1972—sometime next month, but the agency's exploration chief says the milestone could be delayed as engineers continue studying the readiness of the Orion spacecraft's heat shield.
My take on it:
NASA still clearly does NOT (officially) understand why the Artemis I unmanned flight test heat shield experienced irregular spalling and material loss when the first (before Artemis) Orion flight test heat shield did not! You can bet the actual engineers understand, but that answer was (and still is) not what upper NASA management wanted to hear!
The difference between the two unmanned test flight heat shields is as plain as he nose on my face: the first heat shield ablative was reinforced by the hex cell structure into which it was gunned, cell-by-cell, which is effectively a fiber-reinforced composite as it ablates. There was no hex cell structure in the Artemis I heat shield, and it experienced excessive and erratically distributed material loss.
No fiber-reinforced composite effect in the second test, and it performed badly. Surprise, surprise! Experiment trumps computer modeling results, EVERY SINGLE TIME!
The trouble is, as managed, the project built and installed the heat shield on the Artemis II Orion before they understood what happened to Artemis I during that test, and they built it the same way they built Artemis I. Problem: the Artemis I result so very clearly said "go back to the Apollo-style gunned-in-hex-cell construction technique".
That would mean removing the already-installed heat shield from the Artemis II capsule (or just replacing the entire capsule), and replacing that heat shield with a new one made with the old Apollo technique. They did NOT want to spend the $ to do that! Nor did they want to admit a program management error, and a rather egregious one, at that!
They've had the time to replace the heat shield with one that would perform properly, but they didn't do that work, instead hoping the engineers could find some excuse to fly anyway. And now, FINALLY, somebody in a responsible position somewhere is starting to worry about killing the Artemis II crew with a faulty heat shield design, just as they are ready to stack the SLS rocket and go fly!
$ vs lives! $ vs management reputations! Where have we seen this movie before?
GW
The value of G and the masses of the celestial bodies that I have been using came from the same 1973-vintage edition of the CRC Handbook. Those go together in the gravity equations as the GM product, sometimes given the symbol mu. The values they were using back then gave results for orbit sizes and speeds that generally matched observations.
I suspect the mass values today are also slightly different, and in such a way that the GM product values today and back then, are just about the same. Whether you are using older or newer values is very likely less important than getting your G and M values from the same source. The stuff published in the more reputable sources was checked to see if predictions using it matched observations. Mixing and matching data from different sources is the way to make the small changes in accepted values over the years to show up as errors in predictions.
GW
The value I have been using for estimating orbits (quite accurately I might add) is G = 6.6732 x 10^-11. It came from a 1973-vintage edition of the CRC Handbook for Chemistry and Physics.
GW
The spacecraft hull is some protection from Van Allen Belt radiation, but not generally enough. They will get exposed a bit, as did the Gemini crew that flew to a similar apogee altitude long ago. Not too seriously, but certainly measurable with a dosimeter.
They will be inside the spacecraft penetrating the radiation belt at the apogee of an elliptical orbit. The article says the apogee is 870 miles (1400 km), which is definitely getting into the belt, but that boundary is neither sharp nor precise.
The article also says they will lower the apogee (but no number given) for the spacewalk. I suspect they will lower it a little bit below about 600 miles (1000 km), where the belts are nominally said to begin. The suits would be very little protection against radiation. There's no point exposing the spacewalkers needlessly.
Bear in mind that the bottom of the Van Allen radiation belt is not at a fixed altitude. There is a persistent low spot over the South Atlantic, called the South Atlantic Anomaly, through which the ISS actually flies, every several orbits. That is the largest factor in the exposure that ISS astronauts receive.
GW
In a different topic, I hear that SpaceX has re-opened the tower test stand at McGregor, after it was damaged by some kind of fire incident. Literally, I hear it.
GW
There's no routine reports coming from this. The tale will be told by the monthly bills, over the course of a year from this point.
I can get a subjective impression by watching meters run backward. But that's not data. And in a sunny August day in Texas, making lots of solar electricity is to be expected.
GW
From “Daily Launch” for 8-15-2024:
NEW YORK TIMES
NASA Is Still Deciding How to Bring Boeing Starliner Astronauts Home
A week ago, NASA officials said they would most likely need to decide by mid-August on how to safely bring home two astronauts who had traveled to the International Space Station on Boeing’s troubled Starliner spacecraft. But on Wednesday, NASA said a decision remained at least a week away.
My take:
NASA management is still pressing its engineers hard for some way to get them off the hook, for making a decision that they do not want to make: that Starliner is unsafe. Problem is, there is nothing to get them off the hook for that, another week will almost certainly make no difference, and the danger is now exposed to the public, so that it cannot be swept under the rug anymore.
GW
Here's an astronomical funny for y'all. How much implied fun depends upon where you put the hyphen and who you are with. Consider: (1) naked-eye astronomy, or (2) naked eye-astronomy.
GW
Solar installation is completed and operational. There are two systems hooked to two separate electric meters from Heart of Texas Electric Cooperative. One is on the house (some 21 panels), and one is on my shop, a separate meter, some 8 panels. Each has its own inverter to make AC phased to the grid, and its own cutoff switch and breaker. The panels themselves are roughly 2-something feet by 4-something ft, probably about a square meter each.
The reason these things do not supply power during a grid outage is that the inverter controls require AC from the grid to function at all. When the grid is down, the solar is down. There is no way around that, as long as the house current is AC. The electricians showed me where to hook in the back up generators for grid outages, and they tell me such generators are a better deal than battery backups. I need to save up, and have a back up generator installed on the house. My renter (on the shop meter) already has a small one. We'll probably hook him up first.
My renter is paying rent, but doesn't use much electricity. I don't charge him for that directly, just an allowance in the rent. He built his own home out of shipping containers, which is very well insulated and located in the shade under a metal roof. It has a very efficient heat pump for heating and air conditioning.
Those 8 panels on the shop are designed to average about 100% of the electricity use on the shop meter. Those on the house about 70-75% of the electricity use on the house meter (we have about 2200 sq.ft under air conditioning). On a hot sunny afternoon like this, both meters are running rapidly backwards. We are generating more than we use, and selling the excess back to the co-op. We are part of the distributed generating system they are trying to add to their system.
This system cost a tad over $49K to install. We expect a tad over $14K as the tax rebate for it. That makes its effective cost about $35K. It should effectively zero the shop electricity bill except for the meter fee. It should effectively reduce the house electricity bill to the meter fee plus a little bit of usage, on average. It is warrantied for 25 years, with an expected lifetime in excess of 40 years. The inverters communicate by wifi with the company; if something goes wrong, they send the technicians right out.
It's nearly 4:30 in the afternoon here as I type, and if you go outside, the sun beating down still feels like a hammer blow, unless you wear a broad-brimmed hat. That's just central-to-west Texas in the summertime. About 80 F at dawn, about 100-105 F near 4 to 5 PM. Typical August conditions.
GW
I sold and delivered my 15th ramjet book yesterday.
GW
Construction began this morning on our solar PV installation.
GW
I still stand by what I wrote in post #4, about Starliner, the test flight, and Boeing.
I would only add that 2020 hindsight says NASA was rather dumb to remove the 3 lower seats from crew Dragon. You do not have to fill them for a given mission. But if those seats are NOT there, you cannot do the rescues that you would like to do, without reducing crew size ahead of time. And THAT is a very stupid place to be in, NASA!
GW
It may be too late to do this for the Crew 9 launch, now September. But the crew Dragon originally had 7 seats (4 above, 3 below, per the picture in the earlier post). Just put them back in it. You don't always have to fill them, but if they are there, any such similar rescue is a lot easier. You cannot do the rescue if the seats are not there! Simple as that. Common sense, too.
Having that seating capability is now so very clearly evident to be much more important than any concerns over how hard it might be to get into and out of the 3 lower seats. If NASA was any damned good anymore, every Dragon henceforth would fly with all 7 seats. Period. But I'll only believe it when I see it! Boeing is not the only screw-up here!
Butch Wilmore and Suni Williams are experienced Navy test pilots, experienced NASA astronauts, and were specifically recruited by NASA to do this job test-flying Boeing's capsule. They are definitely NOT inexperienced civilians! And it certainly is NOT their fault that this test flight did not go well. I suspect they would be the first to volunteer to fly the thing back, despite the risks and unknowns.
GW
Be careful trying to re-use pallet lumber. Some is "ordinary" lumber, some is not. Quite a few pallets are made of Bois d'Arc wood (also known as "ironwood"), which is so dense (and hard) that it sinks in water. It also routinely breaks drill bits and saw blades. There's just not a lot you can do with it, unless you are tooled-up to deal with harsh properties like that.
Pallets made of Bois d'Arc last a whole lot longer than the rest, out in the weather. And they take bigger load forces than any other sort of lumber in pallets. But eventually, they rot, too.
Been there and done that. Since I was a teenager, now very long ago, indeed.
GW
All I would add to what Bob just said is that when you divide total program cost by the number of missions that program actually flew, you are amortizing all the development costs into that per-mission figure. Different projects have different development costs and development difficulties, so that simple procedure might not be "quite fair", in some very arguable ways.
As for Apollo, there was hardware built to support missions all the way through Apollo 22, not just through the Apollo 17 mission that actually flew. Apollo got terminated by presidential fiat early, which inherently drives up per-mission cost, when figured that way. Some of that hardware got used later on the Skylab project, and on the Apollo-Soyuz Test project, so how do you account for that? That value is NOT zero! The rest is on display at various sites around the country. So, how do you account for that? That value is NOT zero!
I think the "trigger figure" numbers for what is "sustainable" and what is not, are very severely compromised by those unincluded considerations. Inflation is a huge effect, yes, but so also is the lack of accounting for all the eventual end uses. And don't ask me how to correct for those eventual end uses, because I honestly do not know. I'm an old engineer, NOT an accountant! I hire my accounting done!
Just remember this: "figures lie and liars figure" is a real truism.
GW
Kbd512:
Actually, I quite agree with you about China. I would only add that communism just made those same faults even worse, pretty much the same way it did in Russia. Naziism and fascism did the very same things in Germany and Italy. Supposedly, those ideologies are polar opposites. My thesis: no they are not! Not really, in any observable objective way!
Far left, far right, I see no real objectively-observable difference! They both end up with leader-cult dictators held in place with military force, oppressing all under their sway, and neighbors, too. Their words don't matter! Only their actions do!
The political spectrum is NOT linear (as everybody conceives), it is in fact a circle, with 2 "different" ways to end up on the dictatorship side (one using far-left words, the other using far-right words). Which is EXACTLY why the words they spout do NOT matter, while their ACTIONS mean everything! The evil that starts the process around the circle to the dictatorship side, by either way, is extremism. Pure and simple. Extremism, be it political or religious or both, is the true evil that Satan has let loose in this world.
As for US politicians, throughout our history, you can easily tell when they lie: their lips are moving! Left, right, doesn't matter. Politicians are like diapers, they need changing often, and for exactly the same reason. So said Mark Twain. And he was quite right! Do NOT listen to the words! Look at the actions!
Engineering-wise: there needs to be an objective assessment of what a project is really all about: excellence or profit? If profit, what are the legal and ethical constraints that you MUST observe? If excellence, how much can we currently do, and still profit in some way? THOSE are the questions nobody asks or answers anymore! And it is really beginning to show! Not just at Boeing!
GW
Not sure where to put all this stuff:
From AIAA’s “Daily Launch” for 8-9-2024:
ARS TECHNICA
A new report finds Boeing’s rockets are built with an unqualified work force
The NASA program to develop a new upper stage for the Space Launch System rocket is seven years behind schedule and significantly over budget, a new report from the space agency's inspector general finds. There is also some information about the project's prime contractor, Boeing, and its quality control practices. "We found an array of issues that could hinder SLS Block 1B’s readiness for Artemis IV including Boeing’s inadequate quality management system, escalating costs and schedules, and inadequate visibility into the Block 1B’s projected costs," states the report, signed by NASA's deputy inspector general, George A. Scott.
My take: why is that a surprise to anyone? At this rate, there never will be an SLS Block 1B or a Block 2.
SPACENEWS
Chinese megaconstellation launch creates field of space debris
A Chinese launch to deploy a first batch of communications satellites has created more than 50 pieces of debris which could threaten spacecraft in low Earth orbit. The Long March 6A launched Aug. 6, from a specifically constructed launch pad at Taiyuan spaceport. The rocket’s upper stage, modified for restarts and deploying numerous satellites, deployed 18 flat panel Qianfan (“Thousand Sails”), or G60, satellites into roughly 800-kilometer-altitude polar orbit for Shanghai Spacecom Satellite Technology (SSST).
My take: a cultural attitude developed over millennia is showing through. They behave irresponsibly unless forced to behave responsibly. It’s just part of the bullying hierarchy thing.
I pretty much agree with Kbd512's analysis of what's required for a sustainable off-Earth space effort. There are multiple mission-killing technology lacks, of which propulsion is still perceived to be one (although it really is not, not so much anymore). And it's not an on-off switch effect with any of them. It's a matter of spending enough development money to make stuff work well enough so that the overall program is affordable. These things perform better the more you spend developing them. THAT has been the history of it.
As for a "real chief engineer" at SpaceX, while Musk is quite knowledgeable of what is being done, he has also long-proven to be a serious under-estimator of how much prep work must be done, and of how long it will take. He has no formal training as an engineer (I looked up his academic records), and he has no professional engineer's ticket in any state of the union that I know of.
He might get away with calling himself SpaceX's "chief engineer" in other states (laws vary), but if he moves SpaceX's headquarters to Texas as he says he will do, then him continuing to use that title in Texas is a VERY DEFINITE violation of the Texas Engineering Practice Act! People get prosecuted for that, here.
He does have a demonstrated history of scoffing at regulators and then getting into trouble with them by violating the terms of his licenses. That is EXACTLY why it has taken this long to get Starship/Superheavy actually flying experimentally at all!
Everybody does both bad and good. The "trick" for being regarded as "good generally" is to do much more good than bad. With Musk you do get a lot of bad with the inarguable good that he does. Why? He's so rich (with the power that confers) that most people in his organizations will not tell him "no" when he is wrong. And like all of us, he is often wrong.
GW
I could not look at the site with my adblocker on, and I am not about to visit such sites with it off.
But, I know the trends that TH spoke of, in the previous post, and his interpretation is exactly right.
To that I would only add that when Boeing management went to money-grubbing instead of excellence, they bragged in public about converting Boeing from an organization focused on excellence, to an organization that maximized shareholder value. That is almost a direct quote! It is also the "nail in the coffin" for making this management attitude point.
All that being said, please do not get me wrong. Capitalism when properly constrained by appropriate regulations has proven to be the most powerful engine of creation yet devised by mankind. Unconstrained or improperly constrained by regulation, it has also proven to be a very powerful and rapid path to rich piracy for the few, and abject slavery for the many. That's just history, you cannot argue real facts.
The problem in recent decades here in the US has been a political mania to deregulate capitalism, on the theory that the "rising tide" for the rich pirates at the top "floats everybody else's boats". It quite demonstrably does not, and it never has, not in our entire history going back to the beginnings of the colonial days. And it never did in any of the other societies before us.
Lots of US corporate giants have figured out how to game the system and get around what regulations there are. The most notable recent example is Boeing, but there have been many. Despite that, we as a people never seem to learn the lessons of history. Unless fenced properly, the cows always eat the seed corn. They always have. They always will.
GW
Well, today's news stories indicate disagreement within NASA over whether Starliner can bring its crew home safely. They haven't reached a decision yet, but one spokesman indicated the SpaceX option is more likely than it was a couple of days ago. If they go that way, Crew 9 launches in late September with only 2 aboard instead of the planned 4, and Butch and Suni return in those 2 seats, next February.
Personally, I think Oldfart1939 is right, we are seeing the beginnings of Boeing withdrawing from the crew program and cancelling Starliner to cut its losses. Which are somewhere near $1.6B on that one program now. We will soon see (yet once again) if reputation carries any weight, or if only money is the focus of Boeing corporate management.
NASA has to s**t or get off the pot with this Starliner crew return issue, and they know it. The reports of disagreement within NASA more than likely represent the managers vs the engineers, and we already know much of NASA management sides with Boeing, which explains the optimistic press releases up to this point. We've seen that before, with Columbia and Challenger. Today's NASA is most definitely NOT the NASA that figured out how to land people on the moon, and then actually do it, in the 1958-1972 interval.
I've posted before about airplanes and other projects that have not turned out very well since Boeing's corporate management turned into only money grubbers not long after merging with McDonnel-Douglas, moving far away from the engineers in Seattle, first to Chicago, and then to DC the better to lobby Congress.
The public is well aware of the 737 MAX problem that killed 2 planeloads before they got caught violating the FAR's with it. Not so well known are very severe certification problems with the 777X, and severe manufacturing defect problems holding back deliveries of the 787. Add to that an SLS that is over a decade late and multiple $billions over budget, that cannot reprise even Apollo 8 pushing Lockheed-Martin's Orion, and which is costing over $4B per flight. Now add in Starliner. And I just looked up the KC-46 variant of the old B-767 airliner. It still cannot do its design job for USAF, despite being "operational" for a couple of years now.
Anyone else see a pattern with all that?
It sure as hell ain't the Boeing that brought you the B-17, the B-29, the B-47, the B-52, the B-707/720 airliners, the B-727 and early-model B-737 airliners. It sure as hell isn't the Boeing that brought you the B-747, B-757, or B-767 airliners. All those predate the corporate management shift. But after that shift, everything has turned out to be crap! Expensive crap, but crap nonetheless!
I know some corporate managers that really, really, really need to be criminally tried, and quite properly sent to jail! At least, that's my considered opinion! (And THAT opinion ought to keep me off any juries. And rightly so.)
GW
Here below is what I found today from CNBC. The real story is finally starting to peek out. They still do not have a definitive answer for what went wrong approaching ISS, even after weeks of testing. NASA is now weighing the risk to astronauts coming home in a suspect craft, vs the risk that Boeing will cancel Starliner and leave the crew taxi program. Once again, it's money vs lives. I note the 8-2-24 date and wonder why I had not found this 4 days ago. -- GW
----
Aug. 2, 2024, 11:13 AM CDT / Source: CNBC
By Michael Sheetz, CNBC
NASA management has been in deep discussion this week about whether to return the agency’s astronauts on board Boeing’s misfiring Starliner capsule or to go with the alternative of using a SpaceX craft to rescue the crew.
The agency’s concern with Starliner — which flew NASA astronauts Butch Wilmore and Suni Williams to the International Space Station in early June — comes from not having identified a root cause for why some of the spacecraft’s thrusters failed during docking, a person familiar with the situation told CNBC.
NASA this week has been discussing the possibility of returning Starliner empty and instead using SpaceX’s Crew Dragon spacecraft to return its astronauts. There is no consensus among those responsible for making the decision, that person said, calling the outcome of NASA’s ongoing discussions unpredictable given the variety of factors involved.
The Starliner capsule “Calypso” has now been in space 59 days and counting. The mission is intended to serve as the final step toward proving Boeing’s long-delayed spacecraft is safe to fly lengthy crew missions to-and-from the ISS.
The Boeing crew flight was initially planned to last a minimum of nine days. But it has been extended several times while the company and NASA conduct testing both back on the ground and in space in an attempt to understand the thruster problem.
While NASA and Boeing leadership have publicly characterized the extensions as a data-gathering exercise, the concerns raised in recent days reveal that there is less confidence internally on whether Starliner is safe to return the astronauts than the agency has disclosed.
Ars Technica first reported NASA’s mixed opinion on Starliner’s situation. NASA previously noted that SpaceX serves as a backup but has sought to deemphasize that possibility, calling Boeing’s spacecraft the “primary option” for return.
For its part, Boeing says it has the “flight rationale” to return Starliner with the astronauts on board, meaning the company believes the spacecraft can return without too much risk.
“We remain confident in the Starliner spacecraft and its ability to return safely with crew. We are supporting NASA’s requests for additional data, analysis and data reviews to affirm the spacecraft’s safe undocking and landing capabilities,” a Boeing spokesperson said in a statement to CNBC on Friday.
If Starliner returns empty, the most likely alternative would be to bring the astronauts back using SpaceX’s Crew Dragon by removing two astronauts from the Crew-9 mission — currently planned to launch four people in the coming weeks. That would open up two seats for Wilmore and Williams.
NASA did not respond to CNBC’s request for comment on the ongoing Starliner discussions, but told Ars Technica in a statement that the agency “is evaluating all options for the return.”
“No decisions have been made and the agency will continue to provide updates on its planning,” NASA said.
Trusting the thrust
After testing this past weekend, NASA noted that 27 of Starliner’s 28 thrusters appear to be healthy. The thrusters, also known as its reaction control system, or RCS, engines, help the spacecraft move in orbit.
But from an engineering perspective, not having a root cause for why five of the thrusters failed on the flight to the ISS means that risk remains for more thrusters to malfunction during the return flight.
Boeing’s Mark Nappi, vice president of the Starliner program, said during a press conference on July 25 that testing of the thrusters has resulted in “very significant” findings that “are likely the root cause.” But despite that, the company has not identified the root cause yet.
“We’re going to continue to take that hardware apart so that we can finally prove this,” Nappi said at the time.
NASA now needs to decide if it’s willing to trust that the unknown issue with Starliner’s thrusters does not arise again, or even potentially cascade into other problems.
An unpredictable outcome
NASA’s lack of consensus arose when the Commercial Crew Program Control Board met earlier this week to discuss Starliner’s return. PCBs are a standard part of NASA’s decision-making process, dating back to the Space Shuttle era, and are an effort to make sure any risks can be elevated to the highest levels of the agency’s authority.
The PCB, chaired by Commercial Crew program manager Steve Stich, did not come to a decision on whether to move forward with a flight readiness review, the next major agency step toward establishing a date for Starliner to return. The next PCB meeting is expected in the coming days, with NASA noting in a blog post on Thursday that return planning will continue into next week.
If any members of the PCB dissent on the decision to return Starliner with crew, the decision would go up the chain of command until the dissent is addressed. As it stands, the discussions within the PCB do not have a predictable outcome as NASA personnel discuss the level of risk involved on returning crew with Starliner.
Making a choice
NASA often emphasizes that “astronaut safety remains the top priority” for the agency in making decisions about human spaceflight, an inherently risky endeavor.
But the choice NASA faces has further ramifications, which threaten Boeing’s involvement in the agency’s Commercial Crew Program. Already, Boeing’s Starliner losses total more than $1.5 billion due to repeated setbacks and years of delays in developing the spacecraft.
If NASA backs Boeing and returns Wilmore and Williams on Starliner, the agency is accepting a currently unquantifiable amount of risk. A major failure during the return, with the astronauts’ lives at stake, would put NASA leadership under pressure to end Boeing’s contract and involvement in the program.
If NASA decides to send Starliner back empty, it’s a vote of no confidence in Boeing that may lead the company to cut its losses and withdraw from the program.
Additionally, if NASA takes the SpaceX alternative and Starliner returns home without incident, the agency faces blowback from being seen as overreacting to a situation that it publicly declared for weeks was not a significant risk.
I looked at the gal Kbd512 came up with. Impressive for one so young.
GW