SLS is a stunningly overpriced rocket that Congress is forcing NASA to build to keep former shuttle contractors and NASA centers employed. Congress is sending ~ $1.8 billion every year to states including Alabama, Florida, Utah, and Louisiana to develop it. There are very few payloads manifested for it. Launching the Europa missions on it would be a tremendous waste of money—the benefits would not warrant the cost.
It would be worth exploring the lobbying performed by SLS contractors including Boeing and Orbital ATK, as well as that of people close to the main NASA centers involved with SLS, the Marshall Space Flight Center in Alabama and the Kennedy Space Center in Florida.
> SLS is a stunningly overpriced rocket that Congress is forcing NASA to build to keep former shuttle contractors and NASA centers employed.
Understanding this is key to understanding a key constraint on how NASA operates. 10 separate field centers that work together, but are just as likely to try and stab each other in the back using their local congresspersons to get work earmarked.
I work in support both NASA aeronautics and space. Generally speaking, I appreciate the aero side more because, despite the small fraction of the overall agency budget, I feel like it has a much healthier and better-defined relationship with industry and academia at large (e.g. no one in NASA aero has any illusion about being an airline or airframe production company, we work and deliver on fundamental R&D). Which makes sense as largely a direct continuation of our precursor agency, NACA.
I remember there being a feeling that, post STS, the space side could make a similar transition - a developer of in-space fundamental research technology, and mission design/management with launch systems being treated as a "solved" technology to be purchased from vendors. But I think that senators in AL, FL, and TX will make sure that nevers happens, because it would likely gut the workforces of MSFC, KSC, and JSC.
"The mission concept review board in September concluded the SLS launch option was 'far superior' to other alternatives because it would allow the probe to fly directly to Jupiter in less than two years. Launching on a smaller rocket would require gravity assist flybys of Venus and Earth, adding three-and-a-half years to the voyage."
I think SLS makes a lot of sense for outer planet missions - at least until commercial super heavy lift options are available.
If you look closely in that article, you'll see the price that review board assumed for the SLS was $500 million. That's a number that SLS people like to throw around, but it is far, far less than many outsiders expect it will cost. The SLS is only expected to fly once every couple of years in the mid-2020's, so one or two years of the full cost of the program needs to be booked against each launch. Each will have an effective cost of $2 to 4 billion, and that doesn't even include any fraction of the enormous development cost.
It could easily be worthwhile to spend $500 million to cut a few years off of a $2 billion mission. It's much less likely to pay off when the cost is $2 to 4 billion. That's the equivalent of three to eight extra entire Discovery-class missions, or two to four New Frontier missions.
This is how things get approved since states want funding and jobs.
That said the SLS has a lift capability twice the size of a Falcon heavy which hasn't been launched yet, so no I'm not sure that it's a waste since if we want to get to Europa quickly it's probably the best rocket we got atm.
SLS is also our best current candidate for serious human space flight past LEO, SLS brings up back to Energia and Saturn V launch capacity and while it is the usual cross state designed by a committee project it's good to have it since we do need it.
It's hard to know what's "best" when you're looking at a development program being run by an agency which has a not-so-good record of designing and building rockets.
An alternative would be to use multiple, much-cheaper launches, and rendezvous in orbit. Even though the spacecraft needs to be more complicated, the rocket tech will be much more proven. And on-orbit refuel is an active area of R&D in the commercial sector.
Never attempted? No, done many times: ISS assembly and resupply. And the commercial satellite rendezvous and refueling market will probably be well on its way by 2020.
p.s. I'm confused by your mention of ULA vs Falcon reliability -- given that I didn't mention either! Did you read something into my comment?
The ISS was assembled when we had the shuttle, we never had reassembly and relaunch in orbit.
Commercial satellite refueling market won't be viable by 2020, we might have a handful of attempts.
And I didn't read anything into your comment since there isn't much beyond ULA (Delta, Atlas) and Falcon to launch the damn thing to begin with.
And I'm sorry that I don't want to bet on technology that isn't there yet in any shape and form to start planning for a mission that is supposed to launch in 7-8 years with a limited launch window and a failure that would set you back a decade + and not insurance payout + 18 months like if it was a commercial launch to LEO.
And again you are missing the point we need big rockets it's not even a question, and SLS is the only big rocket anyone is currently building, if Space X comes up with a Falcon Heavy Plus capable of competing against the SLS on both payload mass and reliability there would be a room to talk.
We need NASA, and the US need cross state national projects because they are industry incubators, yes they are inefficient at times but you get plenty for them. If going to Europa also means that the US is back at building Saturn V class rockets it's a huge plus regardless the costs.
Oh, so the modules launched by the Russians, and all of the supply vehicles, somehow don't count? I'm afraid that you're coming at this argument with a very different and impossible-to-understand worldview.
Depending on the design, the craft could be assembled at off one of the docks for the ISS. Assembly would be little different than the actual construction of the ISS and could be launched with cheaper and less bureaucratically constricted launch systems.
Again no one currently does this atm, and there are no "cheaper and less bureaucratically constricted launch systems" atm to launch these things.
SpaceX isn't ready for these kinds of launches it's not proven enough.
ULA is just a " bureaucratically constricted" as the SLS.
I don't understand why people are proposing to play around with projects that are already insanely risky and hard to approve, we get to send a probe to Europa, which on it's own is complicated enough and now you want to build a whole orbital launch platform around it? Let the industry do it, blow up some stuff in orbit till they make it work, blow up some more stuff in transit till they get things sorted and then lets use it to launch billion dollar probes to Jupiter.
Isn't trying something we've never done before the whole point of research funding? I am much more interested in advances in space technology than whatever we'll find on Europa.
SLS is a stunningly overpriced rocket that Congress is forcing NASA to build to keep former shuttle contractors and NASA centers employed. Congress is sending ~ $1.8 billion every year to states including Alabama, Florida, Utah, and Louisiana to develop it. There are very few payloads manifested for it. Launching the Europa missions on it would be a tremendous waste of money—the benefits would not warrant the cost.
It would be worth exploring the lobbying performed by SLS contractors including Boeing and Orbital ATK, as well as that of people close to the main NASA centers involved with SLS, the Marshall Space Flight Center in Alabama and the Kennedy Space Center in Florida.