So, NASA is supposed to just wait for these proposed launch vehicles to finally appear? Falcon Heavy was supposed to fly in 2013. [...] NASA can't wait for promises when it has the propulsion in hand.
Quote from: okan170 on 06/03/2017 03:32 amQuote from: UltraViolet9 on 05/30/2017 08:50 pmGood Government 101 tells us that there is a public sector and a private sector and that the government should not try to duplicate in the public sector what industry can deliver from the private sector. National policy should move NASA out of the ETO segment, focus NASA resources on the in-space (transit, EDL, surface) technologies and systems that industry is not pursuing, and leverage and build on the ongoing ETO developments in the private sector.How long until the same argument is used to say that NASA shouldn't be building any in-space vehicles at all? After all commercial interests might do that on their own as well...Does the US government build cars? Boats? Trains? Aircraft? If not, what makes spacecraft so unique that NASA should build them?(And yes I know that much of the Stuff NASA builds is done through contractors, but for the purposes of this discussion I assume that "NASA builds" means "NASA designs and oversees contractors building it")
Quote from: UltraViolet9 on 05/30/2017 08:50 pmGood Government 101 tells us that there is a public sector and a private sector and that the government should not try to duplicate in the public sector what industry can deliver from the private sector. National policy should move NASA out of the ETO segment, focus NASA resources on the in-space (transit, EDL, surface) technologies and systems that industry is not pursuing, and leverage and build on the ongoing ETO developments in the private sector.How long until the same argument is used to say that NASA shouldn't be building any in-space vehicles at all? After all commercial interests might do that on their own as well...
Good Government 101 tells us that there is a public sector and a private sector and that the government should not try to duplicate in the public sector what industry can deliver from the private sector. National policy should move NASA out of the ETO segment, focus NASA resources on the in-space (transit, EDL, surface) technologies and systems that industry is not pursuing, and leverage and build on the ongoing ETO developments in the private sector.
The Grumman Long Life Vehicle (LLV) is an American light transport truck. The Grumman LLV was designed as a mail truck for the United States Postal Service, which is its primary user.
Propulsion = SSME of which NASA has 15 in hand. Of course, this is not a significant advantage, since propulsion for at least Falcon Heavy is also in hand. RD-180 and RS-68 are also available, though they and SSME have all outlived their usefulness.
Quote from: envy887 on 06/04/2017 07:21 pmPropulsion = SSME of which NASA has 15 in hand. Of course, this is not a significant advantage, since propulsion for at least Falcon Heavy is also in hand. RD-180 and RS-68 are also available, though they and SSME have all outlived their usefulness.Typo maybe?16 RS25s are available, 14 with flight experience, and 2 new build green engines that haven't even been fired at all, ME2062(built in 2010) ME2063(built in 2015). Both engines are EM-1 contingency engines and are scheduled for primary flight usage on EM-2.
(And yes I know that much of the Stuff NASA builds is done through contractors, but for the purposes of this discussion I assume that "NASA builds" means "NASA designs and oversees contractors building it")
Quote from: Hog on 06/05/2017 01:29 pmQuote from: envy887 on 06/04/2017 07:21 pmPropulsion = SSME of which NASA has 15 in hand. Of course, this is not a significant advantage, since propulsion for at least Falcon Heavy is also in hand. RD-180 and RS-68 are also available, though they and SSME have all outlived their usefulness.Typo maybe?16 RS25s are available, 14 with flight experience, and 2 new build green engines that haven't even been fired at all, ME2062(built in 2010) ME2063(built in 2015). Both engines are EM-1 contingency engines and are scheduled for primary flight usage on EM-2.I thought it was 15, without going to check. Regardless, NASA has sufficient available, but I disagree with NASA's assessment that they are the most expedient propulsion for a new SHLV.
Quote from: envy887 on 06/04/2017 07:21 pmPropulsion = SSME of which NASA has 15 in hand. Of course, this is not a significant advantage, since propulsion for at least Falcon Heavy is also in hand. RD-180 and RS-68 are also available, though they and SSME have all outlived their usefulness.Actually, it is costing them $1.15B for the next 6 engines... not hardly 'in hand' when you have to pay $200M for the next one.
Quote from: edkyle99 on 05/27/2017 10:12 pmSo, NASA is supposed to just wait for these proposed launch vehicles to finally appear? Falcon Heavy was supposed to fly in 2013. [...] NASA can't wait for promises when it has the propulsion in hand.What "propulsion" does NASA have "in hand"? They haven't even figured out how to weld the tanks.Meanwhile, for FH, the actual flight-hardware is in test-firing before final vehicle assembly. It's likely that they'll have at least three FH flights under their belt before SLS flies. And a dozen FH flights before SLS flies a second time. So in what way would NASA be "waiting" for FH, but have SLS "in hand"?
Quote from: Paul451 on 06/04/2017 06:55 pmQuote from: edkyle99 on 05/27/2017 10:12 pmSo, NASA is supposed to just wait for these proposed launch vehicles to finally appear? Falcon Heavy was supposed to fly in 2013. [...] NASA can't wait for promises when it has the propulsion in hand.What "propulsion" does NASA have "in hand"? They haven't even figured out how to weld the tanks.Meanwhile, for FH, the actual flight-hardware is in test-firing before final vehicle assembly. It's likely that they'll have at least three FH flights under their belt before SLS flies. And a dozen FH flights before SLS flies a second time. So in what way would NASA be "waiting" for FH, but have SLS "in hand"?NASA has RS-25 and five-segment booster and RL10 and, for Orion, AJ-10. In-hand.As for Falcon Heavy, there is no waiting. It is not an SLS replacement. The way SpaceX wants to fly it (recovering boosters and first stage) it will barely boost 5.5 tonnes toward the Moon, compared to SLS Block 1's 24.5 tonnes. Even if the entire rocket was thrown away it would not match even SLS Block 1, and would only lift a bit more than half as much as Block 1B's 39 tonnes. The engines for rockets that might one day be SLS class are still in development. - Ed Kyle
The way SpaceX wants to fly it (recovering boosters and first stage) it will barely boost 5.5 tonnes toward the Moon...
As for Falcon Heavy, there is no waiting. It is not an SLS replacement. The way SpaceX wants to fly it (recovering boosters and first stage) it will barely boost 5.5 tonnes toward the Moon, compared to SLS Block 1's 24.5 tonnes. Even if the entire rocket was thrown away it would not match even SLS Block 1, and would only lift a bit more than half as much as Block 1B's 39 tonnes.
Back on topic: With this 'no second stage' SLS, would the first stage then arrive in a stable orbit?
If it does, would it be possible to use it in the same fashion as proposed for Shuttle external tanks -collect them up in orbit and use them as building bricks for a large space station?
Taking a huge assumption that the technical problems of cryogenic on-orbit refueling could be conquered, would there be any advantage to using these things to send hefty payloads around the solar system?