Major Review Completed for New SLS Exploration Upper Stage

Space Launch System in flight. (Credit: NASA)

HUNTSVILLE, Ala. (NASA PR) — NASA has successfully completed the exploration upper stage (EUS) preliminary design review for the powerful Space Launch System rocket. The detailed assessment is a big step forward in being ready for more capable human and robotic missions to deep space, including the first crewed flight of SLS and NASA’s Orion spacecraft in 2021.

“To send humans and even more cargo farther away from Earth than ever before, NASA decided to add a more powerful upper stage — the upper part of the rocket that continues to operate after launch and ascent,” said Kent Chojnacki, EUS team lead and preliminary design review manager.

“With the completion of this review, our teams will start developing components and materials for the EUS, and build up tooling,” he added. “Full-scale manufacturing will begin after the critical design phase is completed.” Critical design review is the next programmatic milestone that will provide a final look at the design and development of the EUS before beginning full-scale fabrication.

An expanded view of the next configuration of NASA’s Space Launch System rocket, including the four RL10 engines. (Credit: NASA)

Starting with that first crewed mission, future configurations of SLS will include the larger exploration upper stage and use four RL10C-3 engines. The EUS will replace the interim cryogenic propulsion stage that will be used on the initial configuration of SLS for the first, uncrewed flight with Orion. The EUS will use an 8.4-meter diameter liquid hydrogen tank and a 5.5-meter diameter liquid oxygen tank. A new universal stage adapter will connect the EUS to the Orion spacecraft, and be capable of carrying large co-manifested payloads, such as a habitat.

The preliminary design review kicked off Nov. 30, 2016, with approximately 500 experts from across NASA and industry assessing more than 320 items on the EUS, including documents and data. This review had a new “techie” touch to it with the incorporation of virtual reality glasses, which gave teams enhanced visuals of how the EUS is put together and a broader perspective on the size of the hardware. The preliminary design review board was completed Jan. 19, with the board voting unanimously that the EUS is ready to move to the critical design phase.

“I couldn’t be prouder of the SLS Stages team completing this review,” said SLS Program Manager John Honeycutt. “We continue to make progress on hardware for SLS’s first flight, while also working on the next-generation rocket that will take astronauts to deep-space destinations, like Mars.”

The powerful stage will be built at NASA’s Michoud Assembly Facility in New Orleans. Massive welding machines, like the Vertical Assembly Center, currently building the SLS core stage, also will help build the EUS liquid hydrogen tank. New tooling and assembly areas will be put in place to manufacture the liquid oxygen tank.

Once built, the EUS structural test article will undergo qualification testing at NASA’s Marshall Space Flight Center in Huntsville, Alabama, to ensure the hardware can withstand the incredible stresses of launch. “Green run” testing on the first flight article will be done at NASA’s Stennis Space Center near Bay St. Louis, Mississippi. For the test, the EUS and RL10 engines will fire up together for the first time before being sent to Kennedy Space Center in Florida for the 2021 launch.

  • Henry Vanderbilt

    Does *anyone* think this will ever actually be built and flown?

    Bueller? Anyone?

    Assuming SLS ever actually does get that far, they should just contract ULA for a stretch ACES stage and have done with it.

  • Well they have 12 years at $3 billion a year invested in it.

    Not counting all those decades of the NLS.

    What could go wrong?

    It’s a heckava job, but somebody has to do it for several more decades.

    And our NASA astronaut heroes are depending on this thing for a couple of joyrides.

  • Richard Malcolm

    EM-1 will almost certainly fly.

    After that? All bets are off.

  • therealdmt

    It’s got a lot of political momentum and vested interests.

    Ultimately, it’s going to be too expensive to operate in an era of shrinking non-defense discretionary spending — an era with no end in sight. But until that is proven by the money simply not being there, or a much cheaper clear alternative is in regular operation, the money funnel is likely to continue. The SLS continues to serve a political purpose (albeit one only tangentially related to spaceflight), so it is likely to continue to receive political funding.

    However, SLS does look like the kind of bloated government aerospace contract that Trump would love to Tweet-target and triumphally destroy (or at least renegotiate the cost of). And he and Musk are now fast friends… Still, Trump appears to be swinging at so many targets right now, creating so much controversy and starting to reinvigorate his opponents within his own party, that by the time he gets around to NASA (which can’t be all that high on his priority list), he may find himself in sore need of congressional allies. And there’s a number of congresspeople from certain great states that would love to support their president — for a price.

  • Henry Vanderbilt

    All true enough, in the short term. But you’re not factoring in one thing – time.

    This news item is about how they just finished PDR. It’s 2017. Do you really think current NASA can get from PDR to a human-rated flight-ready copy of this by 2021, in just four years? Absent radical organizational reform (which would likely involve ditching the whole project) it’ll take longer. Years longer.

    And the longer it drags on, the more chance either a (by then) existing ACES variant will be substituted, or (more likely) the whole project will have collapsed of its own weight.

  • John_The_Duke_Wayne

    “Do you really think current NASA can get from PDR to a human-rated flight-ready copy of this by 2021,”

    Hasn’t that been the trend of the entire SLS program? Always stay 4 years away and when you get close move to the right, increase the budget, rinse and repeat.

    You’re looking at this program as if it is intended to accomplish a goal and be innovative or progressive. It’s not intended for any of those things it’s an extended jobs and congressional district funding program. The purpose has always been funnel money not build a rocket, if the goal was to build a rocket they could have launched by now considering every major element was already built and just needed testing and qualification.

    Heck they designed built and flew the first shuttle in less time than it will have taken to get the SLS/Ares V design to first manned flight and none of the Shuttle hardware existed before STS-1

  • windbourne

    Assuming that we are going to the moon by 2022, SLS as built will be used. Not much, but still, it will fly.
    If for no other reason than to serve initially as backup for FH.
    Once ula and BO get their own SHLV, than SLS dies.
    But for us to go to the moon without redundancy built in is stupid.

  • Henry Vanderbilt

    An “always 4 years away” jobs program? Of course. But they must nevertheless pretend they will actually fly at some point (and have an actual mission at some point) or they’ll lose support in the majority of Congress that doesn’t have an SLS contractor in-district.

    “Make the enemy live up to its own book of rules.” Heh.

  • Henry Vanderbilt

    That’s a pretty big assumption, NASA going (back) to the Moon by 2022. Let’s look at the details.

    SLS core stage and solids should be tested and flown by then. Should.

    A big hydrogen upper stage to get to Lunar orbit? That’s what we’re debating here. 5 years from PDR to critical mission? 1963 NASA, sure. 2017 NASA? Riiiiiggght…

    And a lander to get from Lunar orbit to the surface and back by 2022, when it’s still an unfunded cocktail-napkin sketch? I’ve got the toll rights to the Brooklyn Bridge to sell you once you’re done believing in that.

    Mind, the lander could be done in five years – IF it were contracted out to a Masten-ULA team, and they were given a spec, funding, and NO gratuitous intrusive-supervisory “help” from the HSF bureaucracy. Don’t hold your breath.

    (Just out of curiousity, which notional plan did you have in mind? I lose track, there have been so many such.)

  • Paul451

    Windbourne is clearly referring to EM-2 by 2022, not a lunar landing.

  • windbourne

    Nope, Bigelow still wants to make the moon by 2022.
    If NASA money is not cut, and perhaps increased, private space with NASA help can make it. I hope.

  • windbourne

    Oh come on.
    NASA going by self would take 10 years or more.
    But, NASA continuing to help private space should enable us to head there in 6-8 years.

  • Henry, I thought ULA already proposed a dual-use ACES that NASA turned down…

    I do think SLS could be turned into an effective program, but there’s a bigness IF involved. IF the next administrator comes in and really wants SLS to become operational during his/her tenure, they could get it done. I was reading a biography of George Mueller (Doing the Impossible) and it was interesting to see Webb, Phillips and Mueller got the 3 centers (MSFC, JSC, KSC) working together, let people go that weren’t performing, shorten the schedule and contained the budget overruns.

    IF an administrator got the right people (could even be current people) with the right mandate (this isn’t a jobs program, get it done by X or your fired) in place at the top of the program (Constellation?), I bet they could cut through the crap and get the system flying. It probably wouldn’t even cost anything more beyond a few bruised egos and hurt pride.

  • Henry Vanderbilt

    ULA undoubtedly did try to sell NASA on an ACES variant instead. They’d be remiss in their fiduciary duties if they didn’t, however bureaucratically unlikely that sale might have been.

    Given that the sole major repository of actual current operational hydrogen upper-stage experience in the US seems to be at ULA, obviously NASA ought to reconsider this plan to roll their own – write up a one-page spec and put EUS out for commercial bid.

    (Nobody should hold their breath waiting for this to happen, of course.)

    That aside, RE “IF an administrator got the right people (could even be current people) with the right mandate (this isn’t a jobs program, get it done by X or your fired) in place at the top of the program (Constellation?), I bet they could cut through the crap and get the system flying.”

    Mike Griffin could make the trains run on time – this time for sure? Color me deeply skeptical. Whatever the mandate, it’d still be modern NASA – a VERY different beast than the one Webb, Mueller et al had. The bureaucracy has had fifty years to “mature.”

    Any such program inevitably would still be treated by the bureaucracy as a jobs program, and he couldn’t force them to make the rockets fly on time on the last such last attempt in Constellation. What fundamentally would have changed?

  • All good points Henry.

    I think a dual-use ACES is still a good idea, even if no one bites.

    I think that Webb, Mueller and Phillips showed that the key was to get outside people to do the program. So I do NOT think Mike Griffin is the right guy to lead something like this. (And he was administrator anyway, not the program manager.)

    The problem for NASA today is actually similar to that of Apollo: how do you attract proven performers from outside to take on a low-paying, thankless, government job? At the time “patriotic duty” carried a lot of weight, but how could you attract people today from other mega projects? People from Ford or Apple or Boeing or whatever REALLY like their jobs and their perks. Even a government space guy like Gen. Schriever turned down the top NASA job!

    I think the NACA bureaucracy is not substantially different from the NASA bureaucracy today. I think the main issue is a lack of people who have successfully lead mega projects, and that’s something NASA doesn’t have. ISS was their last mega project and it dragged on for decades. The science community does one-offs that are just payloads, NOT mega projects. The lack of mega project experience kills NASA when it comes time to replace a launch system.

  • Henry Vanderbilt

    My suspicion is that any ACES variant NASA might ever buy for SLS would in no way be dual-use – it’d be customized for SLS to a fare-thee-well. NASA just rolls that way. (But it’d still be a better, faster, cheaper stage than what they’re on now.)

    And I think the current NASA bureaucracy is hugely different than that of NACA. NASA has had 59 years of survival-of-the-bureaucratic-fittest selection pressures since it was in part NACA. There are still competent people scattered through the system, but whatever the relevant critical mass is, the relevant bits of NASA long ago fell far below it.

    Agreed on a lack of successful mega-project leaders, but my belief is that even if you could attract such, you’d find that even the second coming of Wernher Von Braun himself couldn’t kick this organizational dead whale very far down the beach.

    YMMV, of course.

  • publiusr

    I can see ACES and SLS used together

  • Arthur Hamilton

    Yes it will fly.