SLS Core Stage Passes Preliminary Design Review

HUNTSVILLE, Ala. (NASA PR) — The team designing America’s new flagship rocket has completed successfully a major technical review of the vehicle’s core stage. NASA’s Space Launch System (SLS) will take the agency’s Orion spacecraft and other payloads beyond low-Earth orbit, providing a new capability for human exploration.

The core stage preliminary design review (PDR) was held Thursday at NASA’s Marshall Space Flight Center in Huntsville, Ala., and included representatives from the agency and The Boeing Co. Boeing’s Exploration Launch Systems in Huntsville is the prime contractor for the core stage and its avionics. Marshall manages the SLS Program.

“Passing a preliminary design review within 12 months of bringing Boeing on contract shows we are on track toward meeting a 2017 launch date,” said Tony Lavoie, manager of the SLS Stages Element at Marshall. “We can now allow those time-critical areas of design to move forward with initial fabrication and proceed toward the final design phase — culminating in a critical design review in 2014 — with confidence.”

The first flight test of the SLS, which will feature a configuration for a 70-metric ton lift capacity and carry an uncrewed Orion spacecraft beyond the moon, is scheduled for 2017. As the SLS evolves, a two-stage launch vehicle using the core stage will provide a lift capability of 130-metric tons to enable missions beyond low-Earth orbit and to support deep space exploration.

The purpose of the PDR was to ensure the design met system requirements within acceptable risk and fell within schedule and budget constraints. An important part of the PDR was to prove the core stage could integrate safely with other elements of the rocket’s main engines and solid rocket boosters, the crew capsule and the launch facilities at NASA’s Kennedy Space Center in Florida. Core stage designers provided an in-depth assessment to a board of engineers comprised of propulsion and design experts from across the agency and the aerospace industry.

“Each individual element of this program has to be at the same level of maturity before we can move the program as a whole to the next step,” SLS Program Manager Todd May said. “The core stage is the rocket’s central propulsion element and will be an optimized blend of new and existing hardware design. We’re building it with longer tanks, longer feed lines and advanced manufacturing processes. We are running ahead of schedule and will leverage that schedule margin to ensure a safe and affordable rocket for our first flight in 2017.”

The core stage will be built at NASA’s Michoud Assembly Facility in New Orleans using state-of-the-art manufacturing equipment. The plant continues modifying its facilities and ordering materials for construction of the rocket. Michoud has built components for NASA’s spacecraft for decades, most recently, the space shuttle’s external tanks.

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  • safe and affordable‘.

    It numbs my mind that that many people can be this clueless.

  • Paul451

    Can’t go to the moon by 2017 if they have no lander and no possibility for funding a lander.

    Can’t go to the moon by 2017 if they have no lander and no possibility for funding a lander.

    Can’t go to the moon by 2017 if they have no lander and no possibility for funding a lander.

  • Doug, that last comment of mine got garbled. Could you delete that one.? Thanks.

    SLS for Return to the Moon by the 50th Anniversary of Apollo 11, page 2: Orion + SEV design.

    Argues the first version of the SLS will actually have a 95+ mT payload capacity, not just 70 mT, enough to do a manned lunar landing by its first launch in 2017. And moreover addition of a small propulsive stage a fraction of the size of the upper stage on an EELV can raise the payload to 130 mT at minimal additional cost.

    It’s mystifying why NASA continues to cite the 70 mT payload capability of a Block 0 SLS, when all logic says the payload capability should be increased in accordance with the more powerful SRB’s and core stage to be used on the Block 1 version. It is important to acknowledge what the true capabilities are because what it means is that we can mount a manned, lunar landing mission by the first launch of the SLS in 2017.
    You would think also NASA would prefer the solution to get the full size 130 mT SLS of just adding a minor upper stage to the SLS. To put in perspective how small this stage can be, it could also be accomplished by the upper stage of the Falcon 1 with the addition of a second Kestrel. This is the upper stage of a rocket whose payload to orbit is only 0.42 mT.

    Bob Clark

  • Can’t go to the moon by 2017 if they have no lander and no possibility for funding a lander.

    I really don’t want to delve too deep into my own pet crackpot ideas here, but I should point out that Grasshopper has demonstrated landing abilities of large core stages already, and that should extrapolate even better to the moon. I just can’t help but notice the SLS core stage is pretty overpowered already, and doesn’t even have any funding for payloads let alone a GIANT HEAVY payload fairing or a mission.

    But the rocket itself is well funded. I have drawn my conclusions on this already. Mostly I’m interested when others will also drawn the conclusion that I have.

  • Paul451

    [Well now, don’t I look stupid. Gee thanks Doug.]

    There’s also the dual-thrust-axis lander, such as Masten’s Xeus. Solves the problem of having your crew sitting at the top of the vertical rocket. But NASA ain’t funding an actual vehicle. No funding for missions, no missions. SLS is eating all the funding on its own. And it is not as if funding for NASA is going to increase over the next 5 years.

  • The trick is NOT to have any crew. With my proposal – there isn’t even any conventional payload, just fuel, and thus an ovoid stress free O2 tank suffices. That completely eliminates the suddenly glaring payload fairing problem as well.

    With long SSME burns and sequential engine (pair) shutdown it’s straight thru TLI. Everything else after that is pretty easy and the landing gear can be stowed between boosters and even on the moon – over engineering the landing gear isn’t required. You just find a clear flat level place, and land. Problem solved. The only thing I see that is needed is help from SpaceX with the Dracos and the boosters, and some kind of deployable sun shield to manage the boiloff. Those are the kind of things NASA should be doing anyways. The key problem is propulsion and integration of the numerous vehicle and engine relationships. All I’ve done is propose moving TLI to the core stage and integrating landing, which then almost immediately solves the glaring missing upper stage problem.

    Thank (Blame) Newt Gingrich, not me. He was the one who issued the challenge.

  • Paul451

    With the change to Robert’s comment it now looks like I was replying to you or the main article. My original comment was directed at Robert’s plan for a manned lunar landing, with the first launch of SLS by 2017. (Along with a tease about his now-deleted triple posting.)

  • A human lunar landing by 2017 (five years!) is not going to happen without a presidential directive, a huge infusion of cash, and SpaceX’s and Musk’s direct assistance. Robert needs to come to grips with that, Orion isn’t even going to fly on the SLS, rather the Delta IV Heavy. They won’t even get an expendable test flight of the SLS done by 2017 by the looks of it. I’m just saying that an uncrewed SLS landing by 2017 is more technically feasible in the initial test flight than any human rated nonsense, especially since the cost of the upper stage, the payload fairing, payload and their structural loads, and the mission more or less goes away, and the unmanned continuous station operations are the thing that NASA excels at anyways. Another thing that goes away is RISK since they are intending to do expendable uncrewed test flights anyways. Win win.

    When you sim this out – liquids (LRBs) and super powerful SSMEs doing direct TLI are really good things, and either five RL-10s or a single J-2S are capable of doing the lunar orbit injections and landings. This is physics, not politics.

  • Paul451

    That said, the plan that Robert is referring to uses a very modular lander based on the SEV, and keep it at L2 for 18months before the crew arrive. (The other proposal is, I believe, a single launch.)

    But given that it’s a modular design, and given how light the SEV is, it should be possible to use medium-heavy lift launchers like Delta IV (and particularly Falcon Heavy) to launch the components and assemble them in LEO. Each major part should be within the lifting capacity of DIVH or FH. Then the crew capsule (whether Orion or a private player). By keeping the assembled lander/TLI-stage in LEO, you can launch a refueller just before to manned launch, in order to top off the tanks to offset boil-off.

    So, compare, say 130 tonnes for the best case SLS, with the 25 tonnes via DIVH, you are looking at 5-6 launches. At $250m per launch, that’s $1.5b for the launches. That’s comparable with the estimated launch price for a single SLS… but without the $2.7b/yr development price for SLS, if you cancel it now. SpaceX wants to price FH below $100m, but even if it cost the same $250m, double the payload halves the price to $750m.

    Either way, without SLS, you are left with $2.7b funding each year to develop and built the actual mission hardware.

    SLS is just a failed concept at every level.

  • SLS is just a failed concept at every level.

    Indeed it is, but it is a legislated and funded concept just like Ares I was, with tens of billions of dollars invested thus far. What Robert is talking about is just another ‘Golden Spike’ scenario, and nothing will be gained by funding it at the national level because the concept is messy and premature.

    On the other hand, everything can be gained by salvaging the SLS just like everything could have been gained by salvaging Constellation. Ares I was nonsense pure and simple, and the only possible salvage was an entirely new rocket. Ares V was not the launch vehicle I envisioned as salvaging the Ares I. But we got two nice launchers and a capsule out of that salvage operation, so I am hopeful that we can get an actual lunar base out of this salvage situation. Something that a ‘Golden Spike’ operation could visit and obtain water from. Not lunar water, but good old fashioned fuel cell water, delivered directly.

    That’s the deal, right? Lunar water? Easily deliverable to the lunar surface in large quantities by the large lunar launch vehicle designed to deliver it? I posit the SLS could be that launch vehicle with some rational design changes that were not available until I had the time to start thinking about this. You get a lot more benefits than a bunch of residual fuel water with this setup. Certainly it beats a all up flight to destruction reminiscent of the Ares 1X.