What do you think of the SLS?

[NSEP]

Its a modern Saturn 5! Thats it!

[Kerbal01]

Its a piece of govt pork supported only by Sen Richard Shelby. Should be cancelled and funds diverted to BFS/BFR development.

[tater]

5 hours ago, DarthVader said:

Its a piece of govt pork supported only by Sen Richard Shelby. Should be cancelled and funds diverted to BFS/BFR development.

While I am certainly not an SLS fan (as anyone who has read my posts on the subject in other threads knows), BFR is even less real than SLS, and has an identical problem. It's a launch vehicle without a mission. If someone comes up with a bazillion dollars of private money to watch people die on Mars, then it has a mission, otherwise it's a huge rocket with nothing to lift. That's the problem with SLS, not that it exists, but that the annual fixed cost of maintaining the capability (once it actually exists) is so high that it needs a lot of launches to look reasonable, and there are not enough huge payloads for it---and if there were, they would also be incredibly expensive themselves.

[Emperor of the Titan Squid]

NASA needs to listen to buzz aldrin. Translunar cyclers. Deep space vehicle, l1 gateport, asteroid missions. There would be plenty to do with SLS.

[Bill Phil]

42 minutes ago, Emperor of the Titan Squid said:

NASA needs to listen to buzz aldrin. Translunar cyclers. Deep space vehicle, l1 gateport, asteroid missions. There would be plenty to do with SLS.

They would love to. Thing is, NASA has no actual control over what they can and cannot do.

[Nibb31]

22 hours ago, DarthVader said:

Its a piece of govt pork supported only by Sen Richard Shelby. Should be cancelled and funds diverted to BFS/BFR development.

You can't just divert government funds to a private corporation legally.

[KSK]

21 minutes ago, Nibb31 said:

You can't just divert government funds to a private corporation legally.

Sure you can. Just set your tendering requirements such that your launch vehicle, for example, must use five segment SRB's of a type and specification that - entirely coincidentally - only a single company manufacture.

Snark aside, from my extremely limited knowledge of government procurement, I'm prepared to believe that you're technically correct. However there also seem to be no shortage of ways to make sure that government funds get spent on contracts with the 'right' companies anyway.

 

[Gaarst]

Haven't read the 10 pages of discussion but here's my 2 cents:

SLS is the only super-heavy lifter there is (there's also that Chinese rocket maybe, CZ9 I think). Having a heavy lifter is nice, but being willing to spend money on missions that will use and require its power is another thing. Unless the US govt decides to suddenly increase NASA's budget (not going to happen unless the Chinese start to shoot people towards the Moon/Mars, and even then...) and collaborations with other space agencies, SLS will be a waste of money.

[tater]

1 hour ago, Nibb31 said:

You can't just divert government funds to a private corporation legally.

 

1 hour ago, KSK said:

Sure you can. Just set your tendering requirements such that your launch vehicle, for example, must use five segment SRB's of a type and specification that - entirely coincidentally - only a single company manufacture.

Snark aside, from my extremely limited knowledge of government procurement, I'm prepared to believe that you're technically correct. However there also seem to be no shortage of ways to make sure that government funds get spent on contracts with the 'right' companies anyway.

 

While a specific contract can certainly be steered one way or another, something of the magnitude of the SLS program, including any similarly expensive and huge payloads required to make it have any use at all, would certainly in fact be spread over numerous contractors as it has always been done since the initial order of Frigates during the Washington Administration. That's the way the horse trading gets done, and to expect otherwise is delusional.

On top of that, see my other post above---what is the purpose of SLS or BFR? What payloads exist, or might exist to utilize this capability? Short of a full manifest of possible payloads, it's building a huge, expensive program for nothing other than what it really is, a Federal jobs program for space workers.

Edited August 25, 2016 by tater

[FishInferno]

23 hours ago, tater said:

While I am certainly not an SLS fan (as anyone who has read my posts on the subject in other threads knows), BFR is even less real than SLS, and has an identical problem. It's a launch vehicle without a mission. If someone comes up with a bazillion dollars of private money to watch people die on Mars, then it has a mission, otherwise it's a huge rocket with nothing to lift. That's the problem with SLS, not that it exists, but that the annual fixed cost of maintaining the capability (once it actually exists) is so high that it needs a lot of launches to look reasonable, and there are not enough huge payloads for it---and if there were, they would also be incredibly expensive themselves.

I would disagree with you on that point.  For one thing, BFR/MCT annd the Mars colonization plans have not been released yet, so it is unreliable to make a judgment off of speculation.  But if I were to guess, Elon seems to know lots of the specifics of this Mars base based on the way he talks about it.  Not to mention, BFR could easily be used to launch 30+ GSO satellites at once, a market that already exists.

[tater]

3 minutes ago, FishInferno said:

I would disagree with you on that point.  For one thing, BFR/MCT annd the Mars colonization plans have not been released yet, so it is unreliable to make a judgment off of speculation.  But if I were to guess, Elon seems to know lots of the specifics of this Mars base based on the way he talks about it.  Not to mention, BFR could easily be used to launch 30+ GSO satellites at once, a market that already exists.

SLS is actually under construction and hitting milestones, and you can watch videos of testing and assembly. BFR doesn't exist.

There is a finite market for satellite to GEO, and thecae of 30+ at once is pretty unlikely, volume starts to dominate over mass.

[cantab]

It occurs to me that SLS's unmatched capacity, in payload diameter as much as total mass, could be used for spy satellites. Obviously it's all sekrit stuff, but is there any evidence a new generation of mega spy sats are planned? If SLS is used for such payloads, then it becomes in a sense military spending and from the USA's point of view "waste of money" doesn't apply on the same level to that - not least because the SLS project is small beans compared to things like fighter jets and aircraft carriers.

Edited August 26, 2016 by cantab

[Bill Phil]

13 minutes ago, cantab said:

It occurs to me that SLS's unmatched capacity, in payload diameter as much as total mass, could be used for spy satellites. Obviously it's all sekrit stuff, but is there any evidence a new generation of mega spy sats are planned? If SLS is used for such payloads, then it becomes in a sense military spending and from the USA's point of view "waste of money" doesn't apply on the same level to that - not least because the SLS project is small beans compared to things like fighter jets and aircraft carriers.

Spy sats of that size went obsolete in the 70s. Why do you think they wanted a bigger shuttle?

[Nibb31]

Actually, size does matter when it comes to optics. There's no substitute for a big lense or a big mirror and these things are hard to fold.

A couple of years ago, I wouldn't have be surprised if there was a hidden CIA/NRO agenda behind the SLS program, because it doesn't make any sense to develop such a vehicle with no real purpose, and Congress seemed to have a weird fixation on the 130mt payload capacity. However, you can't keep an SLS launch secret and we would probably be seeing a military payload in the manifest at this stage. After all, never attribute to malice what can be explained by stupidity.

(I also wouldn't be surprised if Stratolaunch is a modern-day equivalent of the Glomar Explorer...)

Edited August 26, 2016 by Nibb31

[tater]

Yeah, big glass is certainly a legit payload.

[regex]

What do I think? Having the capability is strategic, in the sense that both China and Russia are making overtures towards exploitation of the moon, however silly (or realistic) their plans may be. Other than that, I can't imagine any currently realistic payloads for it beyond human exploration.

[tater]

Yeah, it's not that I have an issue with having the capability, I just don;t think we have a reasonable plan for using that capability, and unfortunately the capability has annual, fixed costs in perpetuity as long as it exists. To keep the lights on with zero launches is a couple billion a year. Should NASA decide to devote the bulk of their un-earmarked budget to SLS missions, then maybe it gets used.

[magnemoe]

18 minutes ago, Nibb31 said:

Actually, size does matter when it comes to optics. There's no substitute for a big lense or a big mirror and these things are hard to fold.

A couple of years ago, I wouldn't have be surprised if there was a hidden CIA/NRO agenda behind the SLS program, because it doesn't make any sense to develop such a vehicle with no real purpose, and Congress seemed to have a weird fixation on the 130mt payload capacity. However, you can't keep an SLS launch secret and we would probably be seeing a military payload in the manifest at this stage. After all, never attribute to malice what can be explained by stupidity.

(I also wouldn't be surprised if Stratolaunch is a modern-day equivalent of the Glomar Explorer...)

Yes even if the keyhole satellites are good you might want something who watched larger areas, putting it in GEO let you watch an hotspot over time, during the cold war you needed watch all of Soviet union who lies far to the north and is huge, current conflicts tend to be small scale and multi years and closer to equator so an huge GTO spy sat makes sense. With modern computers its fairly easy to notice changes or movement. 
You also have signal intercept, an huge radio telescope could listen to cell phone signals from orbit. 

Large telescopes are a thing, its plans about an space telescope twice the diameter of web. 
http://www.nextbigfuture.com/2016/08/upcoming-telescopes-that-will-provide.html
It would require an SLS type launcher. 
 

[regex]

4 hours ago, tater said:

I just don;t think we have a reasonable plan for using that capability

I personally hope NASA comes up with some longer-termed human-spaceflight concepts for it. We might even want to consider a new station when ISS comes down, but who knows if SLS will be around that long. Hell, some high-energy probes, stuff that could orbit a Jovian moon, bring back samples... All a question of money, unfortunately.

[Bill Phil]

9 hours ago, Nibb31 said:

Actually, size does matter when it comes to optics. There's no substitute for a big lense or a big mirror and these things are hard to fold.

A couple of years ago, I wouldn't have be surprised if there was a hidden CIA/NRO agenda behind the SLS program, because it doesn't make any sense to develop such a vehicle with no real purpose, and Congress seemed to have a weird fixation on the 130mt payload capacity. However, you can't keep an SLS launch secret and we would probably be seeing a military payload in the manifest at this stage. After all, never attribute to malice what can be explained by stupidity.

(I also wouldn't be surprised if Stratolaunch is a modern-day equivalent of the Glomar Explorer...)

Size does matter when it comes to optics, of course. But the optics of spy satellites are already amazing.

Now, if they wanted to send one to another planet, that'd be better, but why send spy satellites to other planets?

Here's the Mars Reconnaissance Orbiter's camera:

https://en.wikipedia.org/wiki/HiRISE

0.3 meters per pixel for 64.2 kilograms. You don't need 130 tonne spy satellites.

Edited August 26, 2016 by Bill Phil

[tater]

56 minutes ago, regex said:

I personally hope NASA comes up with some longer-termed human-spaceflight concepts for it. We might even want to consider a new station when ISS comes down, but who knows if SLS will be around that long. Hell, some high-energy probes, stuff that could orbit a Jovian moon, bring back samples... All a question of money, unfortunately.

Well, given that they will be struggling to find work for it, maybe they will invent some.

[cantab]

The physical resolution on the ground depends on the distance between the imaging target and the satellite though. If that distance increases then the mirror needs to get wider to match. One weakness of spy satellites is their orbits are predictable and well-known by other nation states, who can then hide things during the spy sat passes. Countermeasures for the spy are to put the satellites in a higher orbit, but the orbits for modern spy sats are somewhat dictated by a desire to be sun-synchronous, and to take images at a shallower angle, but both increase distance to the target and thus decrease the resolution. The USA is thought to have already employed features "allowing images to be taken from angles unusual for a satellite" (though I'm not sure if it means such an approach, or instead means that the satellite can take an image in a direction it doesn't appear to be physically pointing).

Not to mention I'm sure the USA would like to have even more amazing sats. I would think being able to identify a person from orbit is the "Holy Grail" for spy sats. A 24m telescope could plausibly do that, and I suspect that's within the capabilities of SLS. (Though I don't believe the USA is building such a satellite any time soon). Size is as important as mass here I feel; sure Falcon Heavy is a powerful rocket, but there's no plans to give it a payload fairing anything like the 8.4 m diameter planned for SLS Block 1B Cargo.

And for more speculation, I wonder if the increased light-gathering of a large-mirror spy satellite would enable taking more useful images in low light conditions? Yet another way to "catch out" the target, by being able to see what they're up to when they think it's dark enough to be safe.

[Bill Phil]

2 minutes ago, cantab said:

The physical resolution on the ground depends on the distance between the imaging target and the satellite though. If that distance increases then the mirror needs to get wider to match. One weakness of spy satellites is their orbits are predictable and well-known by other nation states, who can then hide things during the spy sat passes. Countermeasures for the spy are to put the satellites in a higher orbit, but the orbits for modern spy sats are somewhat dictated by a desire to be sun-synchronous, and to take images at a shallower angle, but both increase distance to the target and thus decrease the resolution. The USA is thought to have already employed features "allowing images to be taken from angles unusual for a satellite" (though I'm not sure if it means such an approach, or instead means that the satellite can take an image in a direction it doesn't appear to be physically pointing).

Not to mention I'm sure the USA would like to have even more amazing sats. I would think being able to identify a person from orbit is the "Holy Grail" for spy sats. A 24m telescope could plausibly do that, and I suspect that's within the capabilities of SLS. (Though I don't believe the USA is building such a satellite any time soon). Size is as important as mass here I feel; sure Falcon Heavy is a powerful rocket, but there's no plans to give it a payload fairing anything like the 8.4 m diameter planned for SLS Block 1B Cargo.

And for more speculation, I wonder if the increased light-gathering of a large-mirror spy satellite would enable taking more useful images in low light conditions? Yet another way to "catch out" the target, by being able to see what they're up to when they think it's dark enough to be safe.

Oh sure, there are advantages that bigger spysats have, but none of them require 70 tonne satellites.

The resolution depends on the distance, yes. That's pretty much the case for anything.

Putting the satellite in a higher orbit makes it more predictable.

Sun synchronous orbits can be as low as 282 km above Earth's surface.

We have a satellite that gets amazing resolution at 300 km orbiting Mars, and it's old tech as of now. Newer spy sats will be even better.

Also, the larger the satellite, the easier it is to detect.

If they wanted to build larger spy satellites, they would likely use another launch vehicle. Perhaps, if Vulcan gets developed, it would likely be used. There's no reason to use SLS for spy satellites.

[Frozen_Heart]

I think the SLS itself is a capable rocket that could be incredibly useful for exploring the out solar system with probes, something that it could do far far better than the BFR it is often compared with.

 

What I am concerned about however is that it will sit around while only doing a mission or two, then get cancelled. Then straight after a new rocket program would be started and 20 years on from that get cancelled itself without doing anything either.

[tater]

SLS is certainly capable, but it's a capability we don't have a plan for, which makes it a waste. We can certainly use it for large probe missions, but those need to be developed and paid for as well, and only really huge, really expensive missions need SLS. So NASA is stuck with a 2B$ fixed cost, plus marginal launch costs, plus costs to develop and build giant class missions.