NASA’s Giant SLS Rocket Rolled Back For Repairs

There’s little debate that the most exciting move in a rocket’s repertoire is when it launches itself skywards on a column of flame. But failing that, it’s still pretty interesting to see how these massive vehicles get juggled around down here on terra firma before getting fired off into the black. Which is great for anyone interested in NASA’s towering Space Launch System (SLS), as it’s been doing an awful lot of milling about on the ground for a vehicle designed to return humanity to the Moon.

Most recently, the SLS completed a trek from the iconic Vehicle Assembly Building (VAB) to launch pad 39B and back again aboard the same “crawler” that moved the Space Shuttle and Saturn V before it. While the nearly 60-year-old tracked vehicle has received some updates to carry the 98 meter (322 ft) tall booster, clearly the space agency subscribes to the “if it ain’t broke, don’t fix it” school of thought.

The ICPS being loaded onto the SLS

The SLS itself however is definitely in need of some work. The rocket was brought out to the pad for the first time on March 18th, where it was to conduct what’s known as a “wet dress rehearsal” — a test of the pre-flight operations, propellant loading, and countdown that includes everything except engine ignition. Unfortunately, the test was plagued with technical issues, and after three attempts, it was decided to bring the rocket back into the VAB to make the necessary repairs to both it and the ground support equipment.

One issue involves a valve in the Interim Cryogenic Propulsion Stage (ICPS), a propulsion module that’s being used on the early SLS flights to provide the trans-lunar injection (TLI) burn that will send the Orion spacecraft on a course towards the Moon. As the name implies, the ICPS is destined to be replaced with the larger Exploration Upper Stage on later missions. There’s also a leak on the launch tower itself that will need to be addressed. After the identified problems are repaired and some adjustments are made, the SLS will once again be rolled out to the pad to reattempt the launch rehearsal.

Now in development for over a decade, the Space Launch System has been plagued with technical issues and delays. At the same time, commercial launch providers like SpaceX have moved the state of the art forward considerably, leading many to wonder if the mind-bogglingly expensive rocket will be able to compete with in-development vehicles such as Starship and New Glenn. The fact that missions which were previously assigned to the SLS have started to get shifted over to commercial rockets would seem to indicate that even NASA is losing confidence in their flagship program.

33 thoughts on “NASA’s Giant SLS Rocket Rolled Back For Repairs

  1. I was around during the Mercury missions. Noone ever thought that private corporations could ever accomplish what NASA did. It was a truism that only a nation state could do it.

    And now here we are with NASA being left in the dust by SpaceX and others! To me it shows that it’s not so much a matter of technology available to NASA or even maybe the engineering skill. I think this shows how inefficient and ineffective management that NASA has shown since the STS days leads to either cost overruns, delays and disasters.

    1. SpaceX exists because of the technology NASA helped developed. Nasa is not a for profit corporation, it is mean to incubate technology. There is allot of consumer products that benefited by the technology developed by NASA.

    2. I’ve been albeit superficially but consistently following the situation for at least 5 years now and I’ve got quite different impression.

      First, SX at least since CRS program got active support from NASA and tapped into their knowledge and technical expertise. This even Elon himself, the man with a huge ego, has been consistently mentioning for years!

      Second, some part of NASA management somehow managed to fought off gargantuan bipartisan! pressure in both house and senate against giving absolutely any funding to COTS or whatever the commercial support program actually was back then. Porkmaster Shelby even called former Apollo astronaut before some commission or senate (lazy to search for the details now) to tell them how supporting SX and other aspiring private providers is pure BS.. which they unfortunately really did! ( Have you seen the interview with young teary Elon after this hearing with Apollo astronauts? )
      NASA finally *somehow* managed to get some spare change for COTS which was an absolute lifesaver for SX.

      This give me a huge impression that there is not just technical knowledge still at NASA but also skilled managers/politicians.

      1. I’d agree, they are being left behind in self made equipment because the politicians keep leading them around and janking on the chains to change direction, which makes for a massively inefficient system full of great but wasted efforts…

        Where all the companies have to do is be able to develop to the point SpaceX has, where it has a service it can sell profitably enough to run, all the efforts of the company are bent on just the tasks at hand, and abandoned only when that line of reasoning proves inferior to some other parallel option, rather than because X politican wants jobs in his area or some other such pointless to job at hand problem.

    3. In part, it has got to be about the government purchase/supplier problem. There’s jokes about it because it’s true, and the jokes don’t even exaggerate much or illustrate the depth and breadth of the problem. In short, SpaceX can buy a hammer for $15 and NASA can’t.

    4. What was required from the nation state (US, USSR) to fund a space program, and act as the overall program manager.

      As for Mercury, McDonnell Aircraft Co (prior to its merger with Douglas) designed and built the Mercury Spacecraft, as served as the prime contractor. Chrysler built the Redstone booster, and Convair built the Atlas.

      That said, you were not going to have McDonnell fling their own missions like SpaceX now does.

    5. Every government program is a _jobs_ program.

      SLS has to have components made in every congressional district in the nation. That costs money.

      Bonus: Every company making a SLS component ‘gets’ to hire air thief politician relatives. How much damage do you think the likes of Chelsea Clinton (w. Authoritai) does to a company?

      At least the ‘military industrial complex’ builds something. Better than the ‘homeless industrial complex’, by far.

  2. there is no “SLS”,at best we could call it what it is,a space shuttle
    hack of 40 year old components that has somehow cost more
    than the entire original program,good question is what is the
    worse case blast radius for this thing?sad watching the tertiary
    use of the nasa brand

      1. Man, that reference point is nuts. The shuttle was derided by critics as an overly-complex and -expensive boondoggle, and here we are with a less flexible vehicle that will be launched far less and it’ll end up being more expensive both by development and launch.

        Gotta love the Senate Launch System.

      2. I’ve never seen an accurate accounting of Shuttle costs. Just lies and more lies.

        Where did you get the 1.5G$ number?

        How can we trust any numbers from NASA after all the bullshit?

  3. Do they not turn a TV on at NASA any more and see the commercials??? Obviously their leak problems would have been handled in seconds if they just had some Flex Seal. ;-)

      1. Heh, yeah if somehow I had got volunteered for a Shuttle mission in it’s last decade, when they asked what personal items I was taking I would have been like.. “Baling wire, JB weld, tire repair kit, leatherman…”

  4. The Senate Launch System is a complete and total waste of our money.

    Just think of all the useful science missions that $20 billion could have funded, launched on top of a Falcon 9! Instead of using reusable engines once and dumping them in the ocean.

    Cancel SLS now!

    1. Yeah, its porksters love pointing to all the good-paying jobs the program generates, but all that money could have been funding good-paying jobs that actually do something useful or interesting, in space or not.

    2. On the contrary. The SLS is very successful, as long as measure it according to the real purpose, which is moving federal money into friendly hands. Space flight is just a distraction.

  5. Around 20 years ago, I was called in as part of a team to review a proposal being written for the SLS program by a division of a company that had just moved into a new building that is now a server farm in El Segundo, CA.

    It was the worst proposal I had ever seen. At that time, half-way into my career, I had worked on a a LOT of proposals. I also built and managed a lot of space electronics hardware and I knew the REAL costs for the requirements being levied on us, especially for man-rated hardware.

    The team writing the proposal was green and had no clue what they were bidding on or the repercussions of their attempts to cut cost. The original bidding team was trying to build on a previous company employee’s dream of “faster, better cheaper” that he took to NASA as their administrator several years prior. We were also working with a major industry partner that, later, had problems keeping certain commercial aircraft in the sky. We were bidding the engineering and development and they wanted the lucrative production part of the contract.

    The team I was on fixed a majority of the bidding problems, corrected errors in the interpretation of requirements and put in realistic costs to cover the development of the hardware. At least the design would have been good.

    To this day, despite our hard work and long hours fixing that proposal, I am thankful that we lost the bid.

    The bulk of the problems with the current SLS, IMHO, are due to the lack of retained knowledge of ancestral systems and hardware. Years prior while at the NASA Apollo/Saturn V Center, standing under the second stage of the Saturn V with a propulsion engineer that had been part of the 2nd stage engine design team, I heard words that chilled me – “We [the company and the United States] had lost the knowledge to design that hardware again”. I specifically remember asking for the definition of “we” and was shocked it was all encompassing.

    Anyone that doubts that “we” lost that knowledge needs to recall that “we”, until recently due to a war, still bought propulsion hardware from Russia.

    As for the “faster, better, cheaper” mantra that came from NASA. Hogwash. “faster, better, cheaper pick any two” was the employee insider’s response to that mantra. And after 40 years in the industry, I still believe that is true. That NASA administrator may have had the right idea (to cut cost), but the implementation in the industry was all wrong – leading eventually to blindly embracing “COTS” parts and opening the industry to a storm of counterfeit parts and materials that has not yet climaxed.

    The phrases “high reliability” and “Commercial Off the Shelf” should never be used in the same contract. Unless, of course, someone believes that man-rated and defense hardware does not need to be reliable. “Gee, was that an A-Bomb or a really big boom at a mine? Never mind, where are the launch codes?”

    The only reason “faster, better, cheaper” and “COTS can work on a program is because of the vast knowledge and experience of the team managing, designing and building the hardware. That is the ONLY way it will work, and I have seen it in action. I have had the honor to have worked with some of the world’s most brilliant and talented managers, engineers, technicians and production and support staff, so I have first-hand experience here.

    Now we have managers right out of school that can’t manage their way out of a paper bag, let alone manage a highly technical design or manufacturing team. Engineers designing hardware that are appalled that they can’t use Digi-Key parts in their high-reliability designs (nothing wrong with Digi-Key, BTW, it is that fact the parts do NOT meet contractual requirements that is the issue). Then there is the sociopolitical invasion into engineering. I’ll not even go into that even though it is probably worse than the flagrant unskilled use of COTS parts on man-rated space or defense hardware.

    The fact that programs like the SLS are having problems needs to be thoughtfully considered and “we” need to learn from the advances and mistakes made in these programs. And, “we” need to remember and respect the knowledge and lessons learned from ancestral programs and retain similar knowledge from current programs.

    That is the foundation for our technological future. Without it, “we” are bound to repeat mistakes made by those before us.

    1. Perhaps you could comment on what I read was the main reason why we can’t build a Saturn V nowadays using the original plans. It’s because in those days before CNC etc everything was essentially custom built. So only the engineers and construction staff who worked on them and learned from experience were capable. When the projects was over and they retired the unique knowledge was lost.

      1. Which way to do it though if you had a time machine… go back to 1960 for some fresh engineers, or go back to 1940 for mechanics/machinists that can rebuild any worn part so you can fly the original hardware again.

      2. No. Knowledge lost is an issue, but.

        Opposite in fact. Before CNC things were more designed around standard parts.

        They can’t get the parts used, or the tooling, or the tools.
        Available tubing diameters are different etc.

        They would have to reengineer to utilize modern alloys etc.

        Might as well move forward.

      3. I can’t completely address Michael’s question because I was not as involved on the mechanical manufacturing side as much as the electronics side. I can say this: when I first hired into the company in which I worked for over half my life, the mechanical fab area was loaded with many manual and some semi-automated metal working machines. There were a LOT of VERY skilled machinists there. The smell of oil-based cutting fluid still permeated the building many years after the equipment was replaced with state of the art machinery that used “non-toxic” water based coolants and cutting fluids. Now there are a lot of VERY skilled OPERATORS; however, I question their old-school machinists knowledge.

        There WAS a lot of unwritten knowledge in the old designs; this was definitely a problem of the past. I saw it first hand while trying to bring a subcontractor up to speed on “building to print” some older space hardware. as the hardware technical subcontracts manager I received calls weekly from their configuration data manager asking for clarifications to our drawings and schematics. Many times the answer was something to the effect “the drawing was wrong, but we (the prime) just knew how to build it”. The Sub was then given permission to “fix” the drawings or schematics.

        Working to poorly documented drawings and processes was definitely wrong, even if the “fixes” were correct, and the attempts to fix this past weakness was half-hearted and were quickly replaced by the new-school management’s latest “cause du jour” like 6-sigma, design to cost and many others industry endured. The new-world management’s “cause du jour” mentality is worse today than it ever was. There is a total lack of respect for past knowledge. Now some of that knowledge is gone forever, buried with the people that carried the knowledge to their graves.

        There were also a lot of “on the floor” corrections to design mistakes that were not always faithfully communicated back to the designers. Again, that was a problem with the old system. We unwittingly relied on the experience of others in the manufacturing chain to fix “design for manufacturing problems” that designers should have thought of and corrected. But the degree to which this was the case, is, alas, a limited knowledge set for me. I know it happened, but I can’s say for sure how often on all but one program’s limited hardware.

        But back to Michael’s question, I can say for electronics at least, in the conversion process from old drawings (many of which were blue-lines when I first started) into the new electronic cad systems, there were definitely translation problems. That has, however, been mostly corrected with the many new electronic tools that allow talented product designers to lay out boards that would have been nearly impossible 40 years ago if done by hand.

        I will pass along a story that may help show one of the issues at hand. It happened on a special program involving a small defensive missile. An experienced mechanical designer interrupted a status meeting bringing in several E size prints he just created for a pin and clevis design. He was very proud of his mastering of the new CAD system and wanted to show off his work.

        The program manager, an old-school mechanical engineer with vast experience, looked at the drawings and said: “Very nice work, beautiful drawings. But the design will not work – it is too weak.” The designer was more than PO’d and stormed away to check his work after being rather embarrased in front of the team. He later returned with a new set of drawings – addressing the strength issue. The program manager was right, and in less than five minutes he eyeballed the problem on the prints. His staff all learned a valuable lesson that day. Respect for old-school knowledge was on the top of the lessons list.

        The issue at hand exists for mechanical CAD as well as electronics CAD. The best CAD tool is no replacement for a designer’s working knowledge. This goes for PSPICE on the electronics side as well. In my early years, I was fooled into believing a PSPICE run showing an op-amp integrator I was re-analyzing for another company’s design would go unstable. My program manager, who had more than a lot of “in-the-trench” experience laughed and said I was wrong. In the application, he said, the integrator was inherently stable. I made a mistake in the PSPICE model, and believed it, even though I should have known better.

        Prior to PSPICE, we wrote all the node equations for our designs (I am an analog dinosaur). Those equations were entered into a matrix solver written in BASIC. The outputs were ALWAYS checked by at least the section manager, and often by another designer as well. But “faster better, cheaper” cut out knowledgeable section managers and secondary and tertiary reviews.

        Now inexperienced designers rely more on their tools now than they rely on their knowledge or past knowledge.

        Hence a lot of little problems found in dry runs.

        1. Thanks so much for sharing! So it sounds like there is some truth in what I heard.

          The issue of believing digital computer models without having any physical experience is certainly a problem. At least with the analog computers you could get a feel for the system under study and how it would react.

          In my Electrical Engineering undergrad studies in the ’70s I majored in Power Systems. The department had a power system simulated on a wallboard using op amps and various other analog techniques. By tripping power lines or cranking up generation beyond stability limits you can see what happens right in front of you- the generators go out of sync and the angle meters widely spin around. You could reset it and try something slightly different and see the results. In this way you got a feel for the system.

          Later when doing my Masters we wrote FORTRAN programs to simulate the differential equations and plot responses over time. But you really didn’t get the same feel for the system that way.

    2. Probably most of the problems you describe came about because those in power were doing things to benefit themselves or their own interests, instead of benefiting their own country as a whole, to paraphrase Kennedy. It’s a normal rot that takes hold when democracy doesn’t properly function anymore. Luckily, SpaceX is showing the good American spirit again. And other smaller companies.

      1. The only thing _any_ Kennedy ever did to benefit the ‘country as a whole’ was bootleg in quality European booze.

        Thanks Joe! You were one of the good ones.

        That said. Leaving Teddy alive was right out of ‘Gorrilla warfare’: Kill the popular, leave the corrupt idiots.

      2. “Probably”?

        No. Several of the people I worked with in my career escaped from what were communist block or socialist countries, and one barely escaped the Hungarian revolution of 1956 alive. They left those systems, at a minimum, because they were repressive.

        In fact, the gentleman that escaped from Hungary had a “Soviet Socialist Worker’s Award” received while building houses after WWII. But he also worked on some of the most sensitive defense hardware the United States has.

        The issue was and is that new staff brings their new ideas to fruition as they ignore the past. It is ignorance. Sophomoric ignorance. A “fix it even if it is not broken” mentality.

        There is little respect for the past, because every new employee has a “better idea”. Like “democracy doesn’t properly function anymore”.

        SpaceX could not exist in any non-democratic society.

        1. I’d not go quite as far as to say SpaceX could not exist (though obviously it would be somewhat different), if your dictator in chief, monarch, whatever they call themselves or one of the higher ups in whatever system governs the creation of infrastructure and wealth wanted to develop a SpaceX they could – all it takes is one of the powerful enough to pull it off to want it to happen and it can be made to happen.

          The USSR for all its flaws did produce some decent equipment and technologies, even while nutters like Stalin were in power, and the Chinese proved for a while at least how far you can come with communism, seems they are starting to seriously lean into the Stalin/PolPot mindset of stamp out anybody and any idea I feel like now though…

          Does the freedom to do and think things more freely, that democracy generally creates aid in engineering, technical, reasoning, science related fields? IMO absolutely, but it isn’t required, very smart folk exist inside other regime, and some of them are lucky/unfortunate enough to be tasked with ambitious project like SpaceX’s, though the price for failure to keep the boss happy is…

  6. When so many “little problems” pop up in the rehearsal, what are the chances of such a “little problem” popping up just after launch? And such “little problems” tend to become “big problems” in an actual launching rocket.

  7. Look guys. It’s far more important to get the thing right than to smugly go on in a dangerous craft.
    Killing astronauts by ignoring risks and embarrassment would be criminal. It would also set this endeavour back by a generation.

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