I can’t even start to describe how insane this is.
How do they propose to do two SLS launches for a mission when they are only planning one every couple years? And why in the world would they need one to launch crew?
15 thoughts on “SLS, And ARM”
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They need one for crew since NASA won’t let the Orion team build one that would fly on a ULA or SpaceX heavy launcher. It’s doable, but it’s nearly a firing offense to bring it up with NASA.
Using SLS to launch both ARM mission spacecraft is preposterous on many levels, BUT, the need to launch 2 SLS close together is not one of them. The reason is that the robotic ARM spacecraft that will move pebble (tiny asteroid) into lunar orbit for the manned “exploration” mission will need to launch many years before the manned mission (at least 4, maybe as much as 10).
They’d need one of the SLS to launch crew, because nothing commercial currently flying can loft the bloated Orion plus Orion’s service module through TLI.
Of course, there’s the niggling little issue that Falcon Heavy could do it, but, Falcon Heavy, though likely to fly this year, doesn’t yet exist, while SLS, which is still largely a powerpoint rocket and unlikely to fly before 2020, does exist (So sayeth NASA and congress…). 🙂
It’s also important to note that contra Keith Cowing, NASA hasn’t settled on the launcher for the ARM spacecraft. They haven’t even finalized the approach or the destination or the timing. Now, I’m sure that SLS huggers in NASA would prefer to have SLS fly both missions, but from a physics standpoint, it’s possible to launch a useful ARM spacecraft on even a non-heavy EELV or Falcon, and getting a capsule to and from a lunar DRO is feasible with at worst Falcon or Delta-IV Heavy.
I think the SLS launch for Orion is non-negotiable for NASA/Congress, but I haven’t heard anything about SLS being settled on for the robotic spacecraft launch–the presentation Keith linked to even specifically said that Delta was still actively being traded against SLS for the spacecraft launch.
~Jon
Jon, what was the weight of the payload of the EFT-1 test compared to the planned capsule launch for the ARM? EFT-1 had a structural representation of the service module, but I’ve not heard if it was ballasted to represent the actual weight of an operations service module. In any case, did they use the Delta IV Heavy for all it was worth to loft the capsule to its 5,800 apogee, or were they holding back? Unless they were holding way back, I don’t see how it could send a functioning Orion & service module to Lunar DRO.
Kirk,
I wasn’t suggesting sending Orion out to DRO. That would be more than Delta-IV Heavy could handle. If NASA wasn’t doing SLS/Orion, they could easily still do this mission with existing LVs and in-development commercial crew vehicles (with light mods).
~Jon
From a physics viewpoint, it isn’t even necessary to *do* the retrieval part of the mission. Orbital mechanics shows that there should be at least in asteroid in temporary Earth orbit at any given time. Why not visit one (or more) of them?
Astronomers have not yet located those “temporary moons,” but what would it cost do a systematic search to find them? Probably much less than a billion dollars.
NASA is not driven by physics, however. It’s driven by politics. There has to be a big deep-space robotic mission to get support from JPL and the “unmanned space” side of NASA.
At a higher level, a majority of the relevant politicians hate ARM and love SLS. Surely, NASA realizes that the only way to get Congressional support for ARM is to tie it to a more popular program.
Ed,
Totally agree there are a wide range of other missions possible. It would be cool if the theory suggesting we get occasional temporary moons is true. As you point out though, we don’t actually have evidence proving that theory correct.
Also, I think there’s a real benefit in having repeatable access to a location. If you just want a stunt exploration mission, picking a temporary moon or a free-range asteroid makes a lot of sense. If you want to learn how to mine and extract useful materials from asteroids, bringing one home so you can visit it regularly makes a lot of sense.
All that said, I agree with you that because this is a NASA-run program, that it’s not going to turn out anywhere near optimal, even if it does actually fly. But if I were a Planetary Resources or a DSI, I’d want to do an ARM-like mission at some point in the process–they’d just do it in a far more sensible way.
~Jon
It’s a requirement that the ARM flight system interface with either SLS or D4 heavy because the target asteroid has not been identified. If they choose to go after a bigger rather than smaller one then the xenon load might go as high 10 or 12Mg. There are scenarios where either D4 heavy or SLS will work but the D4 would leave it up to the more efficient propulsion system on the ARM vehicle to finish escaping earth by spiraling out and then using a lunar gravity assist rather than a direct earth escape via the more powerful SLS. And yes, the ARM and Orion SLS launches would be years apart.
If we have the technology to capture an asteroid and bring it back, we must surely have the technology to stabilize one that’s already in Earth orbit and keep it around.
There would also be the advantage of having humans on site to supervise the process, which is a big help when you’re trying something for the first time. Right now, NASA merely *assumes* that the asteroid capture will go better than the comet landing.
A solar powered tug might be useful some day. The rest is just criminal.
It’s just perfect. The more flights, the more pork. And it makes the Obama asteroid mission become a good lapdog to the SLS crowd on the Hill.
You just gotta see this from the right perspective. Any relation to advancing spaceflight is purely incidental and meant for the rubes.
The SLS, like the Shuttle and ISS before it, is a vehicle in search of a mission. NASA wants to build SLS in the worst way, and it looks like they will.
Gerstenmaier only has lemons to work with, so he’s making the best lemonade he can. It won’t taste very good (if it gets made at all). Sad.
There’s also the question of whether NASA really wants to do the ARM, or whether it’s just marking time until a new President comes in and it gets a “real” mission (i.e., going to Mars).
If it’s the latter, well, then, it doesn’t matter whether they baseline SLS, Delta IV, or the USS Enterprise, since they never intend to fly.
As BlueMoon said, ARM is the best lemonade NASA can make with SLS+Orion. But it still looks like… well, you know. If the ARM actually comes off before 2030, if at all, I’ll be surprised. I predict about 4 flights, until SLS gets the “mission accomplished” treatment and is retired after an Apollo 8 redo around 2025.
Of course, that might be optimistic.