From what I can tell reading this NASA page, the answer is: pretty much how we got there in the first place. Which is either clever and efficient re-use of existing technology… or wildly underwhelming, depending on your point of view. What I find alarming, however, is how easy it is to find things to be snide about. A bit of a manned spaceflight rant from me, after the fold:
“Building on the best of Apollo and shuttle technology, NASA’s creating a 21st century exploration system that will be affordable, reliable, versatile, and safe.”
So, they’re starting from technologies that are, respectively, forty and thirty years old? OK…
“Astronauts will launch on a rocket made up of a super-sized shuttle solid rocket booster, with a second stage powered by a J-2X engine, like the ones used on the Apollo Saturn V rockets.”
Wow, they’re actually serious about re-using forty year-old technology. Uh… are those old Saturn engines really the best option? Or are they just something NASA has to hand, without having to lose face by going to ESA or the Russians?
(note, however, that we’re talking big engines here – both these rockets are on a similar scale to Saturn V. Breaking low-Earth orbit with a useful payload is a tremendous job. Also, I really am being simplistically snide – as Wikipedia points out, the J-2X engine is air-startable, which is unusual for a proven design of that sort of power.)
“These launch systems are 10 times safer than the shuttle because of an escape rocket on top of the capsule that can quickly blast the crew away if launch problems develop. There’s also little chance of damage from launch vehicle debris, since the capsule sits on top of the rocket.”
According to Wikipedia, there have been 114 Shuttle flights. As we all know, there have been two major accidents, both leading to the deaths of the crews. Wikipedia quotes this as a 2% death rate per astronaut per flight: that is, if you fly on the shuttle, you carry a 1-in-50 chance of death. That’s quite high.
Ten times better, 1-in-500, is still high. It’s not clear how many Constellation flights are planned, but six supply flights a year to the ISS are mentioned. If we assume a thirty-year programme (same as the Shuttle), and moonshots in addition to the ISS flights, this implies that NASA are already projecting one vehicle-loss type accident, or equivalent.
Personally, I’d rather they came clean about this. People died on Apollo; people died on the Shuttle. The mistake wasn’t in the risks they took, it was in pretending that the risk was minor. It wasn’t. They were brave people, for space flight is not a trivial endeavour. We do these things not because they are easy, but because they are hard, indeed.
“In just five years, the new ship will begin to ferry crew and supplies to the International Space Station.”
…assuming they haven’t had to abandon the ISS because Shuttle is deemed unsafe to fly, that is.
See, what worries me is this: a week ago, we had reports that NASA managers had declared the Shuttle safe to fly, despite disagreement from their own Chief Safety Officer and Chief Engineer. That’s… bizarre, and tends to lend credence to the view that we explore space first-hand for political, not scientific, reasons.
Because in the end, there’s only one question worth asking about manned space flight: “why now?”
It used to be that a large part of the answer to that was about capturing imagination, pulling people together and giving them a clear goal. It was about selling a dream. And you know, for a while there, it kinda worked. The Apollo programme demonstrated US industrial might not just to the Soviets (whom it arguably helped bankrupt), but to the American people themselves. The Space Shuttle captured the world’s imagination. It didn’t simply feel modern, it felt like the future, come early – that dangled promise of making space flight routine, oh wow!
The Constellation probe and returning to the moon? Meh, whatever.
But if that’s the general response – really, why bother?