There is no budget for landers, habitat modules, etc.

Sure there is. There’s that whole science side of the shop, after all.

NASA has been directed to spend billions of dollars over the next decade just to have an HLV and a crew capsule.

Except she hasn’t. She’s been directed to submit a budget proposal for 70-100/130 mT heavy lift.

There’s no money yet to actually do anything with them.

There’s no plan to spend money they don’t have yet anyway.

I don’t agree with how some people have been playing politics, either, though.

Neither do I, seeing as picking a fight with the Space Belt seems like a particularly stupid way to secure the necessary public infusion of capital to jump start a new age in commercial space.

Constellation’s initial goal was a return to the Moon, so of course they had mapped out the hardware needed to do that.

The Senate Launch System is just a rocket, and there are no planned or funded programs that require a 130mt capabilty, or even a 70mt capability.

Except, of course, the same moon mission in mind for Constellation. You think 70-100 mT/130 mT came out of nowhere?

Even the most recent NASA studies like HEFT, Nautilus-X and the recent FISO proposals don’t require the SLS.

HEFT called for selecting a heavy lifter for an asteroid mission in 2010, FISO’s dealing with architectures as imaginary as SLS is today, and Nautilus-X doesn’t exist.

But just for fun, let’s say there was ONE mission that was so designed that it required the SLS. What would you guess be for development costs for that?

I would imagine, in the worst case, on the order of $18 billion by 2017, with nothing to show for it.

Now take that number and add that to NASA’s budget every year for 20 years, and you’ll quickly see why the SLS is not just unaffordable from an operational standpoint, but we can’t even afford the missions that it would carry.

Still not seeing it. Let’s take the absolute worst case from Constellation, a $14 billion peak annual expenditure. That’s still $3.9 billion under NASA’s total budget even in a recession constrained funding environment like this one, enough for two flights a year that year.

What space tug? I though we were talking about where to assemble reusable spaceships and what orbits to have them move between.

In any case the LEO infrastructure and the low-cost reusable earth-to-LEO shuttle are the first steps.

The most crucial goals, certainly. But not necessarily the first steps. I know you disagree, but I believe RLVs will emerge fastest if we rely on demand-pull, which means we must create demand first. And in that case initial activity will focus on beyond LEO.

With the exception of RLVs I don’t believe in “build it and they will come”. A crew vehicle and space stations alone are likely unsufficient to generate enough demand even if they are provided free of charge. And an RLV while sufficient is probably only a theoretical exception, since there is little hope NASA could successfully complete such a project even if it tried.

“What do you mean no payloads? Hell, even Constellation had payloads.”

Constellation’s initial goal was a return to the Moon, so of course they had mapped out the hardware needed to do that.

The Senate Launch System is just a rocket, and there are no planned or funded programs that require a 130mt capabilty, or even a 70mt capability. Even the most recent NASA studies like HEFT, Nautilus-X and the recent FISO proposals don’t require the SLS.

But just for fun, let’s say there was ONE mission that was so designed that it required the SLS. What would you guess be for development costs for that?

Now take that number and add that to NASA’s budget every year for 20 years, and you’ll quickly see why the SLS is not just unaffordable from an operational standpoint, but we can’t even afford the missions that it would carry.

NASA’s budget isn’t big enough to use the SLS.