Quote from: clongton on 12/04/2011 11:43 amWhat's the slam for?Not a slam, just more irony. You're not generally known as a proponent of eliminating the need for HLVs.
What's the slam for?
I like the Reusable Lander concept, but how about saving some money and speed up development. Use Orion as a basis for the Lander as well. They could transform the demo flight with the Delta upper stage into a Lander similar to the Phoenix. No need to develop a pressure vessel for the Lander. They don’t have to retain the heat shield for the Lander. OTOH they could retain it as a back-up contingency vessel to return to Earth. http://www.nasaspaceflight.com/2011/09/sls-mission-improving-crewed-moon-mission-2019/http://www.nss.org/settlement/moon/LUNOX.html
Quote from: Rocket Science on 12/04/2011 12:43 pmI like the Reusable Lander concept, but how about saving some money and speed up development. Use Orion as a basis for the Lander as well. They could transform the demo flight with the Delta upper stage into a Lander similar to the Phoenix. No need to develop a pressure vessel for the Lander. They don’t have to retain the heat shield for the Lander. OTOH they could retain it as a back-up contingency vessel to return to Earth. http://www.nasaspaceflight.com/2011/09/sls-mission-improving-crewed-moon-mission-2019/http://www.nss.org/settlement/moon/LUNOX.htmlI've always liked this idea, where the SM would accompany Orion to the station and upon arrival be detached and stored and the lander itself attached to Orion in the SM's place. In the forward end of the lander would be a “utility compartment”, a “mud room” if you will , accessible to the crew via a “thru the Heat Shield hatch”, wherein are stored surface EVA suits, various tools and supplies, and an inflatable airlock which would allow surface operations. This would also minimize lunar rigoleth dust from actually getting into Orion's interior, as well as always protecting Orion's heat shield from outside contact.Upon return to the station from the surface, the lander would be docked for reuse and the SM reattached to Orion for the return trip home. This would make the most efficient use of the investment in the development of Orion itself.It also allows the lander to be developed independently of crew accommodations, which would be an Orion function. This would allow a continual upgrade path for the lander as we learn more and adjust accordingly, as well as allow special purpose landers to be developed. The only necessity would be to maintain a common interface with Orion.
Chuck, the engineering problem with lunar night isn't visibility, it's power and thermal. In lunar night, you have zero option for solar power, but you have much greater power requirements due to having to heat the crew and electronics (and any hypergolics). Not a happy combination. So unless you mount an RTG on your reusable lander, it's not going to land at night.Of course, the point is moot, as ostensibly the entire reason for landing is field geology, which will require illumination for rock-hunting (if not power/thermal for the suits).
I see a lot of arm-waving on this thread but little or no numbers.There's no way to get a crewed Orion to EML-1 with only one launch of any LV smaller than SLS. There's no way to get a (non-ZBO) hydrolox crasher stage to EML-1 with only one launch of any LV smaller than SLS. There's no way to get a hypergolic crasher stage to EML-1 with only one launch of any LV smaller than SLS or Falcon Heavy. Yes you could use an SEP tug, but that would still require several tons of reaction mass. SEP still uses propellant, if more efficiently....
I see a lot of arm-waving on this thread but little or no numbers.There's no way to get a crewed Orion to EML-1 with only one launch of any LV smaller than SLS.
There's no way to get a (non-ZBO) hydrolox crasher stage to EML-1 with only one launch of any LV smaller than SLS.
There's no way to get a hypergolic crasher stage to EML-1 with only one launch of any LV smaller than SLS or Falcon Heavy. Yes you could use an SEP tug, but that would still require several tons of reaction mass. SEP still uses propellant, if more efficiently.
This use of EML-1 related to the launch of a single HLV, carrying a depot to be refuelled using commercial vehicles, reducing the mass required to launch from Earth’s surface on a Lunar or deep space mission via “dry” – and potentially reusable – landers.
“A propellant depot at the Earth-Moon L1 point would significantly improve lunar and deep space exploration mission operations by providing an infrastructure capability for deep space transportation and by opening up participation to international partners and commercial vehicles.
From the ULA AIAA 2010-8638 Evolving to a Depot-Based Space Transportation Architecture:"Existing Atlas/Centaur performance is highly constrained and upgrading to a larger upper stage, while valuable, is only a small incremental benefit. Taking those same stages and departing from a LEO {...} depot enables the same hardware to deliver far larger payloads to extremely high energies"
Heh, I guess that it's not as much fun to talk to folks that agree with you.
Leaving the lander in LLO removes all benefit of a reusable lander because then it's future use is limited to a narrow band beneath its orbital track. LLO is not the right place to stage surface operations from. EML-1 or EML-2 is the right place.