And, it seems, we're returning.
As the 50th anniversary of the first Apollo landing approaches, a host of countries are undertaking lunar missions. What’s behind the new space race?
www.theguardian.com
I'll believe it when I see it. Sadly, every US administration over the past couple of decades has come up with a new goal, that totally changes NASA's direction. The end result has been the expenditure of vast amounts of money, for absolutely zero achievement.
The SLS basically duplicates what was done by the Saturn 5...and that first flew in 1967. SLS largely seems to be an employment program...even a political boondoggle. They're building the booster, so they need to find something to do with it. Cancelling that, and using commercial boosters might get them enough money to actually do something...but that doesn't spread the largesse to the correct states.
When they originally went to the moon, there were a number of mission modes that were considered. Direct ascent, was somewhat silly, but it had the positive (if you were a rocket builder) of needing a huge booster. The planned vehicle was appreciably bigger than Saturn. An alternative, which could use much smaller boosters was 'earth orbit rendezvous'. In that mode, you'd use a couple of launches, and assemble your final vehicle in earth orbit. The final mode, which they used, was 'lunar orbit rendezvous'. Space X could probably handle a combination earth orbit/lunar orbit rendezvous mission with their current Falcon Heavy, using two or three launches. Three launches would cost about $400 million, vs well over a billion for a single SLS.
SLS itself, whilst looking like the grandson of Saturn, is a vehicle that has morphed out of a couple of earlier programmes. Its main engines come from the Space Shuttle, so they are well proven. On the shuttle they went to great pains to re-use these engines. If they'd been prepared to throw them away, it would have allowed for a much lighter, smaller, and probably safer, shuttle design. The SLS will use four of them, and they will not be recovered. You have to wonder how many exist, and if they can actually make any more, or whether the production facility closed decades ago. SLS was originally conceived as part of the Ares system. That system consisted of two vehicles. One was meant to lift heavy loads, but was not going to be man rated...and that's the one that has become SLS. The smaller Ares I launcher would have lifted the astronauts. That vehicle was actually test flown way back in 2009.
