NASA is trying to figure out exactly what they can do with just the Block 1A SLS.At this point it doesn't seem like much.I'm assuming a Lunar Lander can't be done without Block 2 because of stuff I've seen on L2.The destination is most likely going to be NEA around 2025 using 2x Block 1A vehicles.
*snip*(All that to say that I'd like such a grand plan ala Newt's, if I thought it had any chance of not having a negative public reaction like Newt's did.)
Quote from: Robotbeat on 03/27/2012 12:24 am*snip*(All that to say that I'd like such a grand plan ala Newt's, if I thought it had any chance of not having a negative public reaction like Newt's did.)I liked Newt’s grand plan too. But I think you misread why it was criticized from so many angles. It wasn’t because it was grand, it was because it’s an election year.....
Remember this is a 4 man sortie.This is a big lander.I'm not saying it can't be done with less than 130mt, it's in the document.
Quote from: spectre9 on 03/27/2012 06:08 pmRemember this is a 4 man sortie.This is a big lander.I'm not saying it can't be done with less than 130mt, it's in the document.You are saying that lunar missions can't be done with Block-1A, but clearly they can. It would just take multiple launches, just as you were saying that the NEA mission would probably use two Block-1A launches. We wouldn't have to wait for Block-2 for lunar missions any more than we would have to wait for Block-2 for NEA missions. Block-1A will give us amazing capabilities, in fact Block-1 with the pre-existing 5-segment boosters will also. I believe that NASA management has been downplaying Block-1 capabilities in order to justify their immediate move to the advanced booster implementation. NASA wanted an RP1 BFE out of the original FY11 proposal, and they're determined to get it, by whatever means necessary.Mark S.
This is why the exploration gateway is such a good idea. You decouple the lander from the crew launch (to some degree, at least), reuse the most expensive part of the in-space hardware. If using a fuel depot for the lander (with fuel launched separately from crew on whatever launch vehicle(s) made the most sense), a Block 1A (or even Block 1!) with the iCPS should work just dandy to get the crew to the EML1/2 gateway. May need a methane or even hypergolic lander for this to work with minimal tech development (i.e. low-boiloff).But if you go the Altair route, you'd still need a Block 2 SLS (at least) to do a single or '1.5' launch mission (i.e. Orion on Delta IV Heavy). Unless you develop very-low-boil-off technology or increase the launch frequency (which adds costs, as well).
Quote from: Robotbeat on 03/27/2012 06:59 pmThis is why the exploration gateway is such a good idea. You decouple the lander from the crew launch (to some degree, at least), reuse the most expensive part of the in-space hardware. If using a fuel depot for the lander (with fuel launched separately from crew on whatever launch vehicle(s) made the most sense), a Block 1A (or even Block 1!) with the iCPS should work just dandy to get the crew to the EML1/2 gateway. May need a methane or even hypergolic lander for this to work with minimal tech development (i.e. low-boiloff).But if you go the Altair route, you'd still need a Block 2 SLS (at least) to do a single or '1.5' launch mission (i.e. Orion on Delta IV Heavy). Unless you develop very-low-boil-off technology or increase the launch frequency (which adds costs, as well).This kind of depends on how they go.I believe that a certain amount of low boiloff tech will be developed for the CPS contract. That could be rolled into a storage tank on the Gateway for hydolox storage ahead of a mission. Heck, you could just send a CPS up there and permanently dock it on the Gateway, and use that as the tank. That Gateway will need station keeping anyway, so if you are using the GH2 as proposed by ULA for ACES, then you only need to suppress boil off to the point of your station keeping requirements. Which shouldn’t be that difficult. Whatever is developed for CPS will probably be sufficient. EELV (or EELV class) propellant launches can be launched shortly ahead of a crewed SLS Block 1A launch, from EELV launch pads (LC-40, LC-41, LC-37), so SLS still only needs just the one pad at LC-39 per mission. Contracts can be spread around the EELV/EELV-class providers for refueling, as long as they have some sort of upper stage tanker they can use. (SpaceX would have to figure out some type of hydrolox tanker if they wanted to try to get in on that). Anyway, yea, with a Gateway and EELV supplements, lots of options for a robust lunar architecture for single SLS Block 1A mission launches.
A methane lander would be better than LH2 anyway, as even the best LH2 designs still need to deal with the massive tanks. Plus, over long-term use hydrogen is going to infiltrate all the metals it can, causing weakness and failures. CH4 is high-density, metal-friendly, high-Isp, and non-toxic. And, unlike higher hydrocarbons, it doesn't leave nasty residue after lots of use. It's just the way to go.But yeah, a basic L2 station is way to go. And, give it enough of a capitalist spin (from commercial cargo services) and I can see either of the Republicans getting behind it (_after_ the election).