A detailed review of SLS’s present launch status
Link here. The article provides a detailed look at the engine controllers in the former shuttle engines that SLS is using on its core first stage, including some details about the failed unit and the issues involved in replacing it.
I found this historical data in the article most interesting:
The first attempt to launch Orbiter Atlantis and the STS-43 Shuttle vehicle was scrubbed before dawn on July 24, 1991, when the primary computer, DCU A, failed while propellants were being used loaded into the External Tank. … As a result, the launch was scrubbed to allow replacement of the controller, and the launch was rescheduled for August 1, 1991. The failure analysis of the controller revealed a broken blind lap solder joint connection of the bit jumper to the half stack, which is not a generic design problem.”
According to contemporaneous Shuttle Status Reports issued by NASA Public Affairs at KSC in late July, 1991, after the launch was scrubbed and the External Tank was drained and inerted, access to the engine area for maintenance was established on July 26. The broken engine controller was removed, and a new one was installed on July 27, followed by testing to verify the new controller on July 28; the three-day countdown was started over from the top on July 29 for the next launch attempt on the morning of August 1.
It took NASA less than a week to replace an engine controller in 1991. Now, it appears it might take NASA several months, including testing, to do the same thing on SLS. Moreover, the article suggests that there are other subcontractors and organizations (such as the range safety) that are also having trouble being ready for the presently scheduled mid-February launch.
All in all, this report suggests that SLS will not launch in February, will be delayed until April, with a strong chance that even that April date might not be met.
The report also illustrates the sluggish manner in which NASA operates today. Nothing is done with any speed. No task is done in one day if it can take a week. This is bad management, and also a very dangerous way to operate, as it actually encourages sloppiness because no one is under any pressure to work hard. The result has been endless niggling failures, each of which delays things interminably.
On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.
The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.
The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.
"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News
Link here. The article provides a detailed look at the engine controllers in the former shuttle engines that SLS is using on its core first stage, including some details about the failed unit and the issues involved in replacing it.
I found this historical data in the article most interesting:
The first attempt to launch Orbiter Atlantis and the STS-43 Shuttle vehicle was scrubbed before dawn on July 24, 1991, when the primary computer, DCU A, failed while propellants were being used loaded into the External Tank. … As a result, the launch was scrubbed to allow replacement of the controller, and the launch was rescheduled for August 1, 1991. The failure analysis of the controller revealed a broken blind lap solder joint connection of the bit jumper to the half stack, which is not a generic design problem.”
According to contemporaneous Shuttle Status Reports issued by NASA Public Affairs at KSC in late July, 1991, after the launch was scrubbed and the External Tank was drained and inerted, access to the engine area for maintenance was established on July 26. The broken engine controller was removed, and a new one was installed on July 27, followed by testing to verify the new controller on July 28; the three-day countdown was started over from the top on July 29 for the next launch attempt on the morning of August 1.
It took NASA less than a week to replace an engine controller in 1991. Now, it appears it might take NASA several months, including testing, to do the same thing on SLS. Moreover, the article suggests that there are other subcontractors and organizations (such as the range safety) that are also having trouble being ready for the presently scheduled mid-February launch.
All in all, this report suggests that SLS will not launch in February, will be delayed until April, with a strong chance that even that April date might not be met.
The report also illustrates the sluggish manner in which NASA operates today. Nothing is done with any speed. No task is done in one day if it can take a week. This is bad management, and also a very dangerous way to operate, as it actually encourages sloppiness because no one is under any pressure to work hard. The result has been endless niggling failures, each of which delays things interminably.
On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.
The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.
The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.
"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News
If NASA is just a jobs program then these delays make perfect sense.
It is amazing how they parallel the difficulties SpaceX is having getting a launch license for Starship.
This may be the final straw to get NASA out of the trucking business, finally. Let Elon do it! Otherwise, they will keep wasting money to little or no result. Let them do science, which they still do very well indeed.
My prediction: Once Starship is fully up and running and proven, NASA will eventually scrap the SLS entirely. However, it is politically impossible (ie: career suicide) for them to make this decision so until Starship is fully operational and proven and human-rated. Until then, they will continue to pour billions down the drain into SLS. But once Starship is charging 10s of millions of dollars to do the same missions that SLS will request 10s of BILLLIONS to accomplish, how long do you think SLS will last? Just a matter of time now.
Hey Carl, long time no hear. I hope your Christmas and New Years are wonderful.
The argument I usually get for this sort of thing in the SLS NSF forums and subreddit goes like this: The Shuttle had been flying for 10 years in 1991. They had a lot of operational experience with not just the controllers but the whole launch system. With SLS, they’re still trying to establish procedures and experience for the very first launch.
Never mind that the point of reusing so much heritage Shuttle hardware was to cut down both the development timeline and the learning curves. NASA’s management of Orion and SLS strikes me as an agency which has no sense of urgency, an abundance of internal rules, and a paucity of experienced human technical capital, all to operate a launch system which is designed for a very low launch cadence anyway.
How long do you think it would take SpaceX or RocketLab to switch out an engine controller? Certainly not two weeks. I doubt it would have taken SpaceX that long even in 2010.
I think you are all off the mark. I think the reason is that NASA has zero confidence that SLS is actually going to work and they are absolutely terrified to even try as a launch failure will doom them completely vs just make them look foolish.
I know SLS is based on proven hardware and SHOULD work OK, but that doesn’t change the fact that ANY rocket is incredibly complex and requires real skill and expertise to operate. And sadly NASA has lost their mojo and have absolutely no operational competence any more. They are simply a shell of what they once were, drawing the same paychecks, but no longer able to actually do the job.
My humble opinion anyway.
They need to get the mojo back-not get their throats cut? Super Heavy may also face problems. I think Space Force funding should support that. Elon can’t go to the Tesla well too often. Rockets are national assets and need support. Contrary to Robert-I do want NASA in rocketry of different kinds.
Pretendian Warren in the Senate should have went after Bezos-who has hurt Old and New Space alike with his antics. Musk needs Space Force investment to avoid burn out. He too is a national treasure.
Man, you are truly desperate to keep Marshall going. If they aren’t designing or building anything, what use are they? Fire ’em all so they have to find productive jobs that contribute to the economy (Thank you, Dr Hayek) and give the land back to the Creeks or Cherokees or whatever so they can build a casino to fleece the white man (aka Geronimo’s Revenge)
The casino needed to be in Birmingham…but the preachers and the Poarch kept thwarting things. The old blue hairs vote against gambling but get on Thrasher brothers buses to gamble and buy lotto tickets out of state! That’s another issue that gets me steamed! Errr…
Richard M wrote: “The argument I usually get for this sort of thing in the SLS NSF forums and subreddit goes like this: …”
The usual and expected analyses apply. NASA was similarly careful before the first Space Shuttle launch. Any new system requires careful thought before messing with it in repairs, even if the individual components have a lot of experience. In this case, the existing components are integrated differently.
Comparing SLS’s current phase with Starships current phase is comparing apples and coconuts. The only existing SLS rocket cannot be treated lightly, as it must work correctly on its first launch. It is the only one they have, and it is in its final verification phase before becoming operational. Reliability is a high priority at this phase, so when something goes wrong they have to be careful about finding the root cause and be careful to do no further harm. Starship is in development, and the upcoming launch is only to test the current engineering thinking; it isn’t even going to work in an operational way. Several more test articles are to be built and tested before attempting an operational launch. Reliability is not expected at this phase; it is acceptable to fly a risky repair. SpaceX can afford to lose a few Starship test units, NASA cannot afford to lose any SLS rockets.
You can blame the management, and they deserve some discredit, but this philosophy is built into the expendable rocket paradigm. The expense of the launch vehicle reduces the number of launch opportunities and thus a necessarily slower learning curve. As we have seen with the rapid cadence of Falcon 9, SpaceX had a steep learning curve, making changes to the Falcon rocket and creating a Heavy version. SpaceX was launching Falcon less than a decade after its founding, SLS was conceived eleven years ago, and we are still waiting for first launch.
There is no urgency in the SLS project, because unlike Project Apollo the U.S. is not trying to beat a competitor nation nor is there any longer a “complete by” date. Is NASA a jobs program, these days? Congress treated SLS as one, setting design requirements that kept Shuttle contractors employed. Is SLS useful? Five years ago, NASA announced a request for proposals for science probes to launch on SLS, and the result was chirping crickets.
SLS was designed as a throwaway (expendable), so maintenance was not a priority in the design. Starship is being designed with reusability in mind, so maintenance is a high priority in the design — even with these test units. NASA made a terrible mistake with the Space Shuttle when it didn’t make it easily maintainable, a lesson that SpaceX and Rocket Lab can learn. Especially since Boeing and Lockheed Martin did not learn this lesson with SLS or Orion.
There is great incentive for commercial space to do better than NASA is doing, these days. Commercial space does not have the same constraints with Congress as NASA has. Commercial space is freer than NASA, and this explains the tremendous advantage to NASA for converting its purchasing paradigm to a commercial “rental” plan.
SLS was not designed with a high manufacturing rate in mind, since the manufacturing cadence is intended to increase to only about one per year. Blue Origin seems to be having growing pains in ramping up its BE4 engine manufacturing cadence to a couple dozen or so per year. This year, SpaceX manufactured three dozen or so Raptor engines, and a recent note from Elon Musk suggests that they are having difficulty ramping up to a manufacturing cadence of maybe thirty dozen next year.
Jeff Wright may be disappointed that Marshall Space Flight Center is not better utilized, but it is also subject to Congressional whim. Marshall and some other NASA centers need to adapt to the new paradigm and find new niches in the new market. Being an important resource for the commercial rocket engine companies is a good start. It brings NASA back toward the goal of the old National Advisory Committee for Aeronautics (NACA). NASA focused on space and let Britain get ahead of us in commercial aviation, and it would be a shame if they made the same failure in commercial space.
Carl asked: “But once Starship is charging 10s of millions of dollars to do the same missions that SLS will request 10s of BILLLIONS to accomplish, how long do you think SLS will last?”
I suspect that Starship will be closer to two orders of magnitude less expensive than SLS rather than three, but either way, Starship will look like a free ride when compared to SLS. When we let government do it, we only get what government wants, but when we do it ourselves, we get what we want.