I'll trust your judgement about what is an option for EM-2.
But note that for Apollo all TLI impulse was provided while in LEO reached from KSC. For EM-2 only the SLS portion of the TLI impulse must be provided in that kind of orbit.
And then there's yet another possibility. The Chinese have published (in the the AIAA Journal of Guidance, Control, and Dynamics) some research on what they call, "Multi Segment Lunar Free-Return Trajectories." In their scheme each trajectory segment is a free return. But they perform a maneuver days after TLI. (It's sort of like where some Apollo flights departed from free return.) I believe that approach might reduce the delta-t and perilune distance penalties.
It looks like Popular Mechanics is reporting the ideas laid out by the Advanced Concepts Office at Marshall as being the "plan of record." Not sure if that's true... but we can hope!Or is Popular Mechanics saying something different than what Smitherman said?https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20160012094.pdf
Quote from: sdsds on 12/10/2016 08:33 pmIt looks like Popular Mechanics is reporting the ideas laid out by the Advanced Concepts Office at Marshall as being the "plan of record." Not sure if that's true... but we can hope!Or is Popular Mechanics saying something different than what Smitherman said?https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20160012094.pdfLooking at the hab options considered they favor something sized like the SLS tankage at 8+ meter diameters.
Since 8 metres diameter is too wide for rail tunnels it will have to be brought in by barge. The workshop will have to be near a river or the sea shore.
Looking at the hab options considered they favor something sized like the SLS tankage at 8+ meter diameters.
I hope the large hab is openly competed. Would the RFP likely be timed before or after completion of EM-2? That is, would any lessons learned from EM-2 need to be carried forward into the hab requirements?
I'm disappointed in the timidity in decision making.Go for the Moon, get into orbit and show some marbles. It was possible in 1968, I would hope it's possible 50+ years later.
Quote from: wannamoonbase on 12/14/2016 06:55 pmI'm disappointed in the timidity in decision making.Go for the Moon, get into orbit and show some marbles. It was possible in 1968, I would hope it's possible 50+ years later.I don't think that's a fair thing to say. In 1968, a budget surge had NASA at 4.5% of the federal budget, and most of that was for the manned deep space program. Today NASA is getting about 0.5% of the federal budget and the manned deep space program is only a fraction of that. It's easy for us to sit back and criticize, but these guys have to be very careful with the limited amount of money they are given.
I'm disappointed in the timidity in decision making.-2 fGo for the Moon, get into orbit and show some marbles. It was possible in 1968, I would hope it's possible 50+ years later.
Basically, I'm just restating what redilox said about the budget being much less than Apollo's: with less money, less testing is possible.
Quote from: Proponent on 12/15/2016 01:09 pmBasically, I'm just restating what redilox said about the budget being much less than Apollo's: with less money, less testing is possible.Much appreciated As far as EM-2 itself is concerned, it still seems possible. If anything I just see the ESM as the weak point; both in schedule and for the fact it still limits Orion's performance. It could suffice for some activities, but not directly with lunar landings (as in descending as far as low lunar orbit where that magic happens). Just as the SLS is going to be upgraded, so should the SM for Orion, whether it be American or European-made. However I wouldn't expect an upgraded SM until at least EM-5+ due to the budget.
I think that is certainly possible. I also think is likely we'll see something similar to the 5 Seg boosters. Instead of a whole new design, we'll end up with upgraded versions of the current boosters. Both of which to happen towards end of 2020's.Everyone loves to rag on the EM missions, but there is not a single entity currently bending hardware that comes even close to this type of exploration outside of NASA. SpaceX may get into this game, but that is yet to be seen especially after the financial crunch they're experiencing from the recent failure.Gods Speed to both of them...