Author Topic: How many flights for the SLS, ever? (Read 69991 times)

skybum · « **on:** 08/21/2014 09:37 am »

THIS IS A SINGLE POST WITH VOTE THREAD.

Chris' recent article on the flight rate dilemma raises an interesting question: how many times will the SLS fly in its lifetime?

The Article:
http://www.nasaspaceflight.com/2014/08/sls-missions-solve-flight-rate-dilemma/

SLS Articles:
http://www.nasaspaceflight.com/tag/sls/

Personally, I'm a pessimist: although I'm pretty sure that they'll manage to get a single test flight in 2017-2018, I expect the program to follow the Ares trajectory and be cancelled sometime before its second test flight. By 2021-2022, the facts on the ground -- whatever they might be -- will simply be too clear. In a pessimistic scenario for the development of space, there will simply be no missions which the SLS could feasibly fly; conversely, in an optimistic scenario for the development of space, there could be many such missions -- but that same optimistic scenario necessarily includes cheaper commercial launchers, in-space assembly capabilities, and fuel depots -- all of which would provide for cheaper and more robust missions architectures than the SLS could provide. I can't imagine a middle-ground scenario whereby there is genuine demand for SLS launch services, yet no commercial capabilities to fulfil that demand. But hey -- maybe I'm wrong! Anybody want to tell me why?

What would you vote for?

Hauerg · « **Reply #1 on:** 08/21/2014 09:45 am »

Try as I might I cannot see more than the first few flights with the legacy engines.
Do not know if those are enough for 2, 3 or 4 flights.
(And, yes, if it were my money I would choose other ways to spend it on HLV)

Lar · « **Reply #2 on:** 08/21/2014 11:00 am »

A poll has been added. I have not yet set an end date and probably won't.

Some discussion below has been trimmed...

Some ground rules: Let's not get into motivations, attacking other people's views and the like. Please keep commentary to why you think your vote is valid. Please also don't rehash... if you think another discussion or post is pithy and explains your vote, link to it rather than regurgitating. Please don't bash SLS, Congress, NASA, Commercial Crew, JWST, whether NSF should allow polls, or LEGO (threw that last one in to see if you're paying attention)

Polls have a tendency to go pearshaped so if the posts deviate... they may be axed. Or... the poll may be locked and the thread deleted.

Final caveat: One post rule in effect. You get one post to discuss your vote and that's it. No debating other people's choices, just explain yours and done.

Lar · « **Reply #3 on:** 08/21/2014 02:07 pm »

I voted 2.

I think the current schedule won't be accelerated much, so the second flight will be in 2020 or so and by that time I think (being a SpaceX fan boy) that SpaceX will have FH flying routinely. The MCT/BFR will be well in development and the need for SLS will lessen. Congress will come to its senses, and the need to save money and have robust missions will win over pork. Current SLS centers will be redirected to work on exploration hardware (landers and habs) so the pork will continue to flow.

Most of that has been stated ad nauseum on other threads and I know it's not a lock. It's rather optimistic, in fact. I also know that others may disagree. Which is why we have a poll.

jsgirald · « **Reply #4 on:** 08/21/2014 02:15 pm »

Quote from: skybum on 08/21/2014 09:37 am

Personally, I'm a pessimist: although I'm pretty sure that they'll manage to get a single test flight in 2017-2018, I expect the program to follow the Ares trajectory and be cancelled sometime before its second test flight. By 2021-2022, the facts on the ground -- whatever they might be -- will simply be too clear. In a pessimistic scenario for the development of space, there will simply be no missions which the SLS could feasibly fly; conversely, in an optimistic scenario for the development of space, there could be many such missions -- but that same optimistic scenario necessarily includes cheaper commercial launchers, in-space assembly capabilities, and fuel depots -- all of which would provide for cheaper and more robust missions architectures than the SLS could provide. I can't imagine a middle-ground scenario whereby there is genuine demand for SLS launch services, yet no commercial capabilities to fulfil that demand. But hey -- maybe I'm wrong! Anybody want to tell me why?

Agree with you, my vote is 1.

PahTo · « **Reply #5 on:** 08/21/2014 02:29 pm »

I realize this is something of a cop out, but instead of stating how many WILL fly, I'll go with no more than four (4 )for the obvious reason of propulsion hardware availability. It will be no more than two if SpX gets their BFR flying before/concurrent to SLS notional debut.

Coastal Ron · « **Reply #6 on:** 08/21/2014 02:33 pm »

I think political inertia allows for three test flights, even if cancelled before then. Although I could be wrong, and some of the centers make good cases for needing new hardware for display on their lawns...

edkyle99 · « **Reply #7 on:** 08/21/2014 02:39 pm »

Greater than 21. The U.S. is going to need SLS more than is now believed.

- Ed Kyle

mheney · « **Reply #8 on:** 08/21/2014 02:49 pm »

I voted 4 - I think there'll be a mission or two beyond the currently manifested flights before political inertia is overcome and the program is cancelled. But I hope Ed is right, and we evolve to a place where we actually NEED a lot of BFR flights. And a mixed manifest of SLS and Raptors would suit me just fine. (And maybe an Ariane 9 in the mix as well ....)

M129K · « **Reply #9 on:** 08/21/2014 03:25 pm »

I voted 6-10. I think that SLS will have made its first flight by 2018, and will have flown thrice by 2022, but after that, things get a little less certain. I expect maybe one or two mission campaigns using SLS after that; a manned mission to an asteroid, or a manned lunar return a la Apollo. However, after that, I expect funding for the exploration program to go down the drain after interest is gone and possibly because another cheaper vehicle with similar capacity will be flying by then. SLS will need to either get a significant redesign to cut costs, or it will be the first item canceled, as it's the most expensive yet most replaceable item of any exploration program.

Of course, if it flies 21+ times and makes itself useful, it would be amazing. I just don't see it happening.

Jim · « **Reply #10 on:** 08/21/2014 03:37 pm »

I said 2. The USG doesn't have a need for it.

butters · « **Reply #11 on:** 08/21/2014 03:40 pm »

Voted 4. There are a number of missions NASA could do with SLS, but let's be honest, few if any of them can happen before the SLS industrial complex sits around too long and exceeds its sustainable shelf life. I'm skeptical about the ARRM mission actually happening, let alone Europa or Mars Sample Return. The lead times on NASA programs like these are approaching 10 years at this point. Nothing will get done until the SLS program is ready for mothballing. A few Orion joyrides and that's it.

EE Scott · « **Reply #12 on:** 08/21/2014 03:57 pm »

I voted 1. The SLS teams seem to be making decent progress, and inertia can be a powerful force. However what may sink SLS as it is currently planned are the multiple versions of the rocket, which make it many times more expensive and complicated to design, test, and build than it had to be. I am not sure that Congress realizes just how convoluted the 2010 Authorization Act has made SLS, and when the cost of designing and building this rocket starts to become more obvious there is a good chance of outright cancellation. That said, SpaceX will most likely have plenty of challenges (funding and technical) and delays over the next several years, so I am not sure they will be as compelling an alternative as some people expect. Stating the obvious, there are many possible ways this could play out.

cro-magnon gramps · « **Reply #13 on:** 08/21/2014 04:36 pm »

3 missions from 2018-2022... because Shelby and co. won't want to give up the pork too soon... the inertia syndrome...

I am in agreement that SpaceX and others (Bigelow,etal) will be moving handily along on their own separate trajectory towards a viable 2018-2024 Cis-Lunar Space Architecture, (with an agenda to eventually go to Mars)

But don't see it as impacting SLS (aside from making Gov't efforts look weak) as much as the cost factor of 1-2 launches a year, with payload development costs rising steeply... squeezing an already thin budget even thinner...the American people will rebel at the slow rate, unexceptional missions, and waste of money, forcing the Gov't to hack the program...

mike robel · « **Reply #14 on:** 08/21/2014 04:43 pm »

I voted for 3 flights, but if, and only if, the 2nd flight goes and retrieves an asteroid. If it doesn't, then it may be only 1, given the 3 year gap from the 1st flight to the 2nd flight and the lack of any actual achievement with Humans.

Davp99 · « **Reply #15 on:** 08/21/2014 04:49 pm »

3 and out...Punt

FinalFrontier · « **Reply #16 on:** 08/21/2014 04:55 pm »

0 as orion does not count as SLS hardware and I have serious doubt about whether this program exists after November 2016.

German Space Fan · « **Reply #17 on:** 08/21/2014 04:59 pm »

11-20. In my opinion its unrealistic a comparable vehicle will be operational before 2030, so SLS will make several flights. By the way: I don't think its fair to reduce a vehicles achievement on the number of flights it has carried out. Saturn V only made about 14 flights and you cant tell me it wasnt a successful launcher.

newpylong · « **Reply #18 on:** 08/21/2014 05:20 pm »

4-5, but I hope more. A SpaceX BFR will not exist before the mid 2020's and Falcon Heavy doesn't cut it.

Oli · « **Reply #19 on:** 08/21/2014 05:24 pm »

21+

I think the chance for politicians to cancel SLS and thus human spaceflight BEO is less than 50%.

Poll

How many times will SLS hardware be flown/launched?

Author Topic: How many flights for the SLS, ever? (Read 69991 times)