…just shocked to hear that the exploration mission hardware has outgrown the planned launchers:
Once characterized as “Apollo on steroids” by NASA administrator Mike Griffin, the architecture surrounding the ESAS (Exploration Systems Architecture Study) has grown too heavy for its launch vehicles.
I wish there were more to the story. The last bit, about a rendezvous thousands of kilometers above the far side of the moon is tantalizing. Are they proposing to use L-2 instead of L-1? Why? Inquiring minds want to know.
This was (almost) inevitable. And it shows the shortsightedness of the “Apollo on steroids” approach. By insisting on doing it all in one and a half launches, they put off the day that we developed the necessary spacefaring capabilities of orbital rendezvous, docking and routine operations, including propellant transfer and storage. What did they plan to do when after a few lunar flights, they decided to go to Mars? Develop a Seadragon?
[Update a couple minutes later]
I see that I was channelling Clark Lindsey (as often is the case). He has more, including the fact that it was apparently due to their (other shortsighted) decision to abandon methane.
And a big D’OH! There was a lot more to the story that I mentioned above–I just didn’t realize that I had to scroll down. Yes, it is an L-2 architecture. Let me go read, and think about it, and I’ll have more later.
[Not much later]
OK, I’ve at least glanced through it, and here are initial thoughts. First, the understatement:
It appears that the changes made to the ESAS architecture in the near-term may have long-term ramifications for the entire VSE.
Which was exactly why Steidle wanted to perform the CE&R studies–to consider all of these possibilities, and their implications, both short term and long. But the architecture that NASA came up with doesn’t resemble any of them (as far as I know). There’s little evidence that they even bothered to look at the reports–they’re simply gathering virtual dust on the servers.
I like a Lagrange rendezvous point, but all of the analysis that we did at Boeing indicated that L-1 was a better choice than L-2. The advantage of L-1 is that it’s always visible from earth, and it’s a relatively short trip home from there. We were strongly driven in our trades by NASA demands (unreasonable ones, in my opinion) that astronauts be able to get home in an arbitrarily short amount of time. The disadvantage of L-1 is the propulsion cost, and L-2 is indeed more efficient from that standpoint. But it wasn’t considered in the Boeing CE&R studies because of the trip-time constraint. Its other problem is that unlike L-1, which is continually visible from earth, L-2 never is. For communications, a relay satellite in a halo orbit, or a series of them in lunar orbit, will be required.
I would think that the problems they’re running into at this point would justify a complete reconsideration of their approach, including their previous aversion to orbital operations and propellant depots. Not to mention, as Clark points out, methane. It’s funny, because I was just in a telecon a little while ago in which I was told to expect “big changes” in CEV. Now I understand what that means. It will be interesting to see how this ripples down, and right now, it makes it hard for the contractors to move forward in requirements analysis.
on returning to the moon.