Quote from: TrevorMonty on 10/26/2019 03:59 amHow does lander handle boiloff at gateway while waiting months for crew missionFor hydrogen it would be a big deal, but lox and methane are sometimes referred to as "space-storeable."
How does lander handle boiloff at gateway while waiting months for crew mission
You can stack the Block 1B on ML-2 and then store it in one of the other VAB bays while the Orion carrying Block 1 is stacked on ML-1. You could even launch crew first so the lander departs shortly after arrival in lunar orbit. It probably makes sense to launch the crew first so that the lander has more flexibility in instituting an Orion rescue mission if need be.
Quote from: ncb1397 on 11/06/2019 06:43 pmYou can stack the Block 1B on ML-2 and then store it in one of the other VAB bays while the Orion carrying Block 1 is stacked on ML-1. You could even launch crew first so the lander departs shortly after arrival in lunar orbit. It probably makes sense to launch the crew first so that the lander has more flexibility in instituting an Orion rescue mission if need be.But the minimum interval between SLS launches is 120 days. Am I missing something?
Check out this new view of our Human Lander System docked with Gateway. The integrated lander’s flexible, reliable design will safely take astronauts down to the Moon’s surface. The Lander and Gateway combination is essential to sustained lunar exploration and to go to Mars.
I would think that being able to stay for a full Lunar day would be the gold standard for future human Lunar missions. Staying a whole lunar night as well after that would be very interesting. Could the Lander cope with that by being upgraded; or would future expeditions require a separate, 'hardened' surface Habitat? Doing EVA's during Lunar midday would be thermally challenging - but so would lunar midnight! It can get pretty darn cold there. The light levels from even a half-lit Earth should be sufficient to light a Lunar landscape though.
I found what appears to be a presentation going over the precursor to the current lander design:https://imgur.com/a/N6jgfBoAn ECLSS capacity for a two-week surface stay is going to be a big selling point, IMO. Doubt the national team will be able to match that. They'll probably be constrained to a one week surface stay.
Is there any indication that any part of Boeing's lander would be reusable?
Boeing’s lander would be capable of carrying a two-person crew to the lunar surface in 2024, meeting the requirements set in NASA’s solicitation for a Human Landing System. Future landers could include reusable ascent modules and cryogenic engines, McGrath said.
Quote from: Proponent on 11/15/2019 01:20 pmIs there any indication that any part of Boeing's lander would be reusable?Possibly the ascent module:QuoteBoeing’s lander would be capable of carrying a two-person crew to the lunar surface in 2024, meeting the requirements set in NASA’s solicitation for a Human Landing System. Future landers could include reusable ascent modules and cryogenic engines, McGrath said.https://spaceflightnow.com/2019/11/09/boeing-proposes-sls-launched-lunar-lander/You would presumably just launch tanks mounted on top of the descent module while some infrastructure like the arm aids the transfer of propellant. The fact that it appears there is a habitat inside the descent module would suggest possible re-use of the descent module for longer term pressurized volume(once you deploy power infrastructure that maintains power during lunar night). Beyond that, if you could refuel the descent module from local resources, it would be able to ferry back up to gateway (or you just use the ascent module both ways once you get to that point).
One of the major reasons for the Gateway's existence will be to make up for the Orion's relatively miserable delta-v and basically, lack of a decent propellant load
Quote from: MATTBLAK on 11/15/2019 09:11 pmOne of the major reasons for the Gateway's existence will be to make up for the Orion's relatively miserable delta-v and basically, lack of a decent propellant load And nobody is asking what it would take to stretch the service module a meter or so to where it could carry enough propellant. I understand it would need about a 56% increase in fuel load to handle injection into LLO and return to Earth. With the EUS, SLS should have no problem launching the heavier load into TLI.
You're quite right. In principle, 'stretching' the Orion Service Module to increase it's propellant load would be 'simple' to do. Widening would be a lot more complex and would basically be a complete redesign. Stretching the SM by 1 or 1.5 meters (I'm not sure) should give between 3 to 4 metric tons more propellants. A real engineer would have to crunch those numbers. As Eric said; the EUS should be able to handle the weight no problem.But a stretched SM would mean that the whole Orion spacecraft would have to be rebalanced, tested etc, which would take money and time an already late program can't afford, so...But could a 'two stage' solution be worked out? By that - I mean what if Orion used 2x 'stacked' Service Modules? The second SM could be simplified with no crew consumables and no solar arrays: it could just have the 9 ton propellant load and batteries to last a few days to get the CM & SM 'Stack' to low lunar orbit where that first SM could be jettisoned after L.O.I?Actually; it occurs to me that the two Service Modules would not have to be stacked - the second SM could be carried by the EUS as a co-manifested payload. After TLI, the Orion could do a transposition and docking maneuver and dock with a docking system-equipped SM, making it a propulsion Tug. When arriving at the Moon and doing L.O.I, the Orion then jettisons the Tug and goes to meet a waiting Lunar Lander. No Gateway required. Or substitute a propellant depot if we want to have an eventual reusable Crew Lander.
Both vehicles can be opreated independent of a gateway station...which if there is a Boeing plan, cannot be built..