Wildthing - 1/4/2008 10:28 PMHistory will only judge Mike Griffin's time as Nasa's Administrator in a favourable light if he significantly reduces the gap between the end of the Shuttle Program and Cx. If that's Ares, fine...if it's DIRECT, thats fine as well. Mike Griffin's primary job is to convince Congress to fund NASA's programs. If he can't get the funding to accomplish his programs, he should revisit his plans and look for alternatives....otherwise he will have failed NASA.
jkumpire - 2/4/2008 2:32 AM... a very simple question ... why is it that NASA sticks with Ares?
Nathan - 2/4/2008 3:53 PMFolks,Congress will not choose one or the other proposal as they are not qualified to do so. They have an agency set up to do the analysis and report to them - that's NASA. The only thing that Congress could realistically do is say to NASA that it's budget is going to be flat for the next five years and that any VSE architecture should take that into account. Budget realism is the key here.
renclod - 3/4/2008 9:58 AM Quotejkumpire - 2/4/2008 2:32 AM ... a very simple question ... why is it that NASA sticks with Ares? 1/ Provide crew transport to ISS. Do it with a minimalistic system, but don't forget to assure the 6 months life boat. Do not expand into ISS cargo transport - there is another venture for that called COTS. Do not expand into prolonged/augmented ISS operations. We have international obligations but enough is enough.
jkumpire - 2/4/2008 2:32 AM ... a very simple question ... why is it that NASA sticks with Ares?
I have been reading about DIRECT for a while on this forum and I am yet to see this point addressed -
How will DIRECT satisfy the requirement for a minimalistic crew transport vehicle? (definition:minimalistic - Ares I)
DIRECT has, from a cursory glance (i.e. not even requiring a detailed look into the system) much more of a booster than Ares I (2-off SRB plus a liquid stage vs. 1-off SRB)
Is the DIRECT team arguing that an additional SRB (neglect 4/5/6 seg) and liquid fuel stage represents the gap between Ares I and a booster with 'safe' ascent performance, or,
-does the crew version of DIRECT really have much more performance than is required to satisfy crew launch?
MB123 - 3/4/2008 12:48 AM Can someone please explain to me how DIRECT/which configuration of the DIRECT vehicle will satisfy the requirement for a minimalistic crew transport vehicle?
MB123 - 3/4/2008 5:48 AMHow will DIRECT satisfy the requirement for a minimalistic crew transport vehicle? (definition:minimalistic - Ares I)
J-120 Crew Launch Vehicle:Two existing 4-segment SRB, plus an ET-derived core stage with two ground-lit existing RS-68. No upper stage. Variable cost: $130 million per flight. Estimated in-service availability: Late 2012 (85% confidence level). Capable of launching a non-ZBV Orion CEV and SM with full safety systems, two-string fault-tolerance, and airbags for hard landings, along with additional ballistic shielding between the CEV and LV and a wee bit more extra payload margin.Compared with Ares I:One new (to-be-developed for $1.8 billion) 5-segment SRB, plus an upper stage with one new (to-be-developed for $1.2 billion) air-lit J-2X engine. Variable cost: $120 million per flight. Estimated in-service availability: Late 2015 (65% confidence level). May or may not be capable of launching a ZBV Orion CEV and SM to ISS after the weight penalty of TO mitigation.If NASA desires to reduce the capabilities and cost of the J-120 to more closely match Ares I's duplication of an EELV-class launcher, and wishes to more closely match the Constellation budget profile through an increase in the overall development and fixed cost by having multiple launch vehicle variants, the $115 million per launch J-110 option is also available.
MB123 - 3/4/2008 12:48 AMI have been reading about DIRECT for a while on this forum and I am yet to see this point addressed - How will DIRECT satisfy the requirement for a minimalistic crew transport vehicle? (definition:minimalistic - Ares I)DIRECT has, from a cursory glance (i.e. not even requiring a detailed look into the system) much more of a booster than Ares I (2-off SRB plus a liquid stage vs. 1-off SRB)Is the DIRECT team arguing that an additional SRB (neglect 4/5/6 seg) and liquid fuel stage represents the gap between Ares I and a booster with 'safe' ascent performance, or, -does the crew version of DIRECT really have much more performance than is required to satisfy crew launch?
jkumpire - 1/4/2008 6:33 PMWhen Sean O'Keefe left, Griffin had his chance. O'Keefe left the agency in the position of doing a lot of studies - all based upon EELV architectures which Congress was strongly against because of the jobs situation. By all accounts they made it *very* clear they wouldn't accept an Administrator who would abandon the STS infrastructure.