Realistic SLS Launch Rate

[Nibb31]

The SLS' first flight should be a manned lunar landing, since we should at least get something out of it besides a circumlunar flyby and a asteroid rendezvous before it gets cancelled.

For that, it would need a lander. There are no plans for a lunar lander, and building one would take at least 10 years, so if you started today (which isn't going to happen) you might be able to attempt a moon landing in 2025, which is 4 years after the EM-2. What are you going to do with it between 2021 and 2025 ?

Orion imo should have a Soyuz-like orbital module on top in the form of a BA-330.

That would make abort situations much more complex. Putting it on top would require a LAS that would be 10 times bigger and heavier than the current one, so it probably wouldn't make it to orbit. You would have to put it underneath the Orion, but for what purpose? It would still need a new propulsion module to go anywhere (which would take 10 years to develop) and you would still be limited by the lack of any mission-specific module.

[fredinno]

For that, it would need a lander. There are no plans for a lunar lander, and building one would take at least 10 years, so if you started today (which isn't going to happen) you might be able to attempt a moon landing in 2025, which is 4 years after the EM-2. What are you going to do with it between 2021 and 2025 ?

That would make abort situations much more complex. Putting it on top would require a LAS that would be 10 times bigger and heavier than the current one, so it probably wouldn't make it to orbit. You would have to put it underneath the Orion, but for what purpose? It would still need a new propulsion module to go anywhere (which would take 10 years to develop) and you would still be limited by the lack of any mission-specific module.

You can use leftover ISS modules (such as the unlaunched Habitation Module https://en.wikipedia.org/wiki/Habitation_Module) or create new ones based off ISS modules to create a long-term HAB, then use that to build a Earth-Moon L2 Station with minimal development time. This would buy time for a lunar lander, or a NEO lander based off the ARM probe.

[78stonewobble]

The difference between SLS and Falcon Heavy is that the Falcon infrastructure and boosters are shared with Falcon 9. They can build a FH on demand whenever the need arises. If nobody orders one, it's no big deal because it doesn't cost much to maintain the capability.

Well, I presume that depends on the Falcon 9 production rate... If that is high, you cannot "just" build a Falcon heavy, nor if it's low and you've had to scale back employees, but correct.

However, on orbit assembly via smaller multiple launches, might make certain projects too expensive. Your project might need capabilities that only the sls have and so forth.

Get the cost low enough, and entrepreneurs will suddenly start finding uses for it. Like that Mars reality tv show, or rich folks who want to go play Neil Armstrong on the moon. Doesn't have to be pure science.

Well... I can comfortably predict that the falcon heavy (trips to space) will not be found in the bubblegum machines either, nor will it exactly help that billionaires can pay allmost billions for going to space.

That will happen, when we have some superlight super strong alloy/thingy for craft and engines, that can survive a hundred launches and reentry's with exceedingly little maintenance. So possibly never... Or get a space elevator.

The only way for space use to boom, til then, so theres actually places to go and stuff to do, is regular scheduled access, heavily subsidised by government(s).

Edited June 25, 2015 by 78stonewobble

[Nibb31]

You can use leftover ISS modules (such as the unlaunched Habitation Module https://en.wikipedia.org/wiki/Habitation_Module) or create new ones based off ISS modules to create a long-term HAB, then use that to build a Earth-Moon L2 Station with minimal development time. This would buy time for a lunar lander, or a NEO lander based off the ARM probe.

ISS modules aren't standalone spacecraft. To turn them into a viable station, you would need station-keeping, attitude control, life support, power, etc... Count another 10 years.

[fredinno]

ISS modules aren't standalone spacecraft. To turn them into a viable station, you would need station-keeping, attitude control, life support, power, etc... Count another 10 years.

I know ISS modules aren't standalone spacecraft- they're space station modules. What I meant, was that they could become the basis for a L2 Station/ Interplanetary HAB, allowing for a station quicker than otherwise (especially since we also have experience making the ISS from similar modules). Concequently, I doubt a plan like this would take 10 years- I wouldn't be surprised if an L2 Station began materializing in 5 years. If a decision is made in 2016, after the next election, on what to do, then construction could begin in 2022 from Block IBs.

TLDR; I doubt making a new space station from already leftover ISS modules would take 10 years.

[Nibb31]

ISS modules are basically just empty tin cans. To turn them into a space station, you need a whole lot of equipment that doesn't exist including CMGs, solar arrays, propulsion, life support, docking systems... USOS modules were designed to be attached to Russian-built Zarya which provided all of those services. Designing equivalent systems takes time. Integrating them takes time. Testing takes time. Launching takes time. Not to mention that those modules were designed to be launched on the Shuttle, which doesn't exist any more. The structural loads involved in an SLS launch and being tugged around by an Orion are completely different. They might be able to take the loads, they might need to be modified, but you are going to need some long and expensive studies to determine that.

Like most of the "let's recycle this spacecraft into something else" proposals, you will be better off designing a whole new spacecraft from scratch, which is why NASA is leaning towards a "Skylab II" proposal for their DSH rather than the "recycled ISS modules" proposal.

Pretty much any aerospace project these days takes at least 10 years from kick-off to operational status, even much simpler ones than a new space station. I really don't see how it could only take 5 years to build a DSH without a crash program with unlimited budget, which we all know isn't going happen.

[CptRichardson]

Maybe three.

Ever.

[Skyler4856]

If the goal is to simulate interplanetary conditions, you'd want to send all the supplies for the entire mission in the first launch.

Orbital construction sounds like a better plan.

[fredinno]

Orbital construction sounds like a better plan.

I don't understand, orbital construction won't reduce mission time to the point where you don't have to learn how to keep crew alive on a single delivery of supplies for years.