NASA's number 1 priority should be to get an Orion flying to the international Space Station on a J-130.{snip}
Quote from: HappyMartian on 12/12/2010 03:41 amNASA's number 1 priority should be to get an Orion flying to the international Space Station on a J-130.{snip}Wrong target. Dragon on Falcon 9 will be cheaper than Orion on J-130 for trips to the ISS. if used more than once that will kill of SLS.Orion to EML1 gateway on J-246 is a better target since it uses the deep space ability of both machines.
Quote from: A_M_Swallow on 12/12/2010 04:02 amQuote from: HappyMartian on 12/12/2010 03:41 amNASA's number 1 priority should be to get an Orion flying to the international Space Station on a J-130.{snip}Wrong target. Dragon on Falcon 9 will be cheaper than Orion on J-130 for trips to the ISS. if used more than once that will kill of SLS.Orion to EML1 gateway on J-246 is a better target since it uses the deep space ability of both machines.SLS Block I flight(s) to ISS will be for "shakedown" purposes, and possibly to bring up large items (or a large number of smaller items) that an F9 would be unable to fly. SLS would not be used for normal crew rotation.ISS will not be the final destination for SLS. ISS will be a proving ground, a waystation, and possibly a staging area for BLEO missions. But access to ISS is not the reason for SLS, just a very nice side benefit.Mark S.
Quote from: kraisee on 12/12/2010 03:08 amQuote from: Jim on 12/12/2010 03:00 amWrong again. F9 is not a replacement for Atlas V. There is no need for the SSME. And Atlas V CAN do everything better. That is why NASA has selected it for 6 spacecraft since F9 has been availableTrue.Interestingly though, during the same period of time, NASA also bought 12 flights of Falcon-9 for CRS, in addition to the 3 test flights which were already planned for COTS.In terms of numbers of contracted missions for NASA, Falcon-9 seems to be doing about twice as much business compared to Atlas-V.They're doing something right.Ross.It is good to have 'friends' in high places. Maybe you should explain it to Jim. He doesn't seem to be getting it.
Quote from: Jim on 12/12/2010 03:00 amWrong again. F9 is not a replacement for Atlas V. There is no need for the SSME. And Atlas V CAN do everything better. That is why NASA has selected it for 6 spacecraft since F9 has been availableTrue.Interestingly though, during the same period of time, NASA also bought 12 flights of Falcon-9 for CRS, in addition to the 3 test flights which were already planned for COTS.In terms of numbers of contracted missions for NASA, Falcon-9 seems to be doing about twice as much business compared to Atlas-V.They're doing something right.Ross.
Wrong again. F9 is not a replacement for Atlas V. There is no need for the SSME. And Atlas V CAN do everything better. That is why NASA has selected it for 6 spacecraft since F9 has been available
Quote from: HappyMartian on 12/12/2010 03:41 amQuote from: kraisee on 12/12/2010 03:08 amQuote from: Jim on 12/12/2010 03:00 amWrong again. F9 is not a replacement for Atlas V. There is no need for the SSME. And Atlas V CAN do everything better. That is why NASA has selected it for 6 spacecraft since F9 has been availableTrue.Interestingly though, during the same period of time, NASA also bought 12 flights of Falcon-9 for CRS, in addition to the 3 test flights which were already planned for COTS.In terms of numbers of contracted missions for NASA, Falcon-9 seems to be doing about twice as much business compared to Atlas-V.They're doing something right.Ross.It is good to have 'friends' in high places. Maybe you should explain it to Jim. He doesn't seem to be getting it.Which 'friends' are you referring to? You seem to be implying Obama and/or Garver, I'm guessing. Neither was involed in the SpaceX COTS contract that was signed in 2006. And the CRS contract was awarded in Dec 2008, before Obama became president.
Quote from: Jim on 12/12/2010 03:00 amWrong again. F9 is not a replacement for Atlas V. There is no need for the SSME. And Atlas V CAN do everything better. That is why NASA has selected it for 6 spacecraft since F9 has been availableTrue.Interestingly though, during the same period of time, NASA also bought 12 flights of Falcon-9 for CRS, in addition to the 3 test flights which were already planned for COTS.In terms of numbers of contracted missions for NASA, Falcon-9 seems to be doing about twice as much business compared to Atlas-V.
SLS Block I flight(s) to ISS will be for "shakedown" purposes, and possibly to bring up large items (or a large number of smaller items) that an F9 would be unable to fly. SLS would not be used for normal crew rotation.
Wrong target. Dragon on Falcon 9 will be cheaper than Orion on J-130 for trips to the ISS. if used more than once that will kill of SLS.Orion to EML1 gateway on J-246 is a better target since it uses the deep space ability of both machines.
Is it wrong? When they are influenced by lobbyists, telling them that it 'NEEDS' to be 130t, THAT is designing the launch vehicle.
To me, Congress' first order is really to debate & then fund what the President requests, for the good of the nation.
SpaceX got the politics right...
Having said that I personally think an EML-1 station is a very good idea as part of a much broader HSF program of BEO exploration. There should be an EML-1 station for human-based missions and a similar station at EML-2 for cargo-based missions. BTW, it has been said, and quite correctly, that once you are docked at EML-2, you are literally halfway to nearly any location in the solar system. It is the perfect location for earth departure and arrival spacecraft on interplanetary missions.
Quote from: HappyMartian on 12/11/2010 01:01 pmIf the President ever gets tired of sitting on his hands and wants to make a serious contribution to getting us back to the Moon, he could hire OV-106, Clongton, or Ross to work in the White House and explain to him and the nation how to do Lunar space Exploration in a cost efficient and practical manner.Wrong, Direct/SLS is not a cost efficient and practical manner. It is a political manner. And who says they are the experts in this. EELV can do it too. And what say we should go back to the moon?
If the President ever gets tired of sitting on his hands and wants to make a serious contribution to getting us back to the Moon, he could hire OV-106, Clongton, or Ross to work in the White House and explain to him and the nation how to do Lunar space Exploration in a cost efficient and practical manner.
BTW, it has been said, and quite correctly, that once you are docked at EML-2, you are literally halfway to nearly any location in the solar system. It is the perfect location for earth departure and arrival spacecraft on interplanetary missions.
Quote from: clongton on 12/12/2010 12:57 pmBTW, it has been said, and quite correctly, that once you are docked at EML-2, you are literally halfway to nearly any location in the solar system. It is the perfect location for earth departure and arrival spacecraft on interplanetary missions.That's not what I learnt from orbital mechanics. You want departure and arrival for interplanetary missions to have as low a perigee to Earth as possible, not way up there at EML-1 or EML-2.From Zubrin's presentation to the Augustine Committee.
Quote from: Jim on 12/11/2010 01:12 pmQuote from: HappyMartian on 12/11/2010 01:01 pmIf the President ever gets tired of sitting on his hands and wants to make a serious contribution to getting us back to the Moon, he could hire OV-106, Clongton, or Ross to work in the White House and explain to him and the nation how to do Lunar space Exploration in a cost efficient and practical manner.Wrong, Direct/SLS is not a cost efficient and practical manner. It is a political manner. And who says they are the experts in this. EELV can do it too. And what say we should go back to the moon? Didn't they all work on constellation? Did you think constellation was cost effective and efficient?
Steven's chart seems to indicate LEO to Mars surface at 3.9 km/sec? What is it that I'm not getting here?
That's not what I learnt from orbital mechanics. You want departure and arrival for interplanetary missions to have as low a perigee to Earth as possible, not way up there at EML-1 or EML-2.
Part of it is that orbital mechanics is too complex to be expressed as a simple table, and part of it is that neither really define their terms. So, they are likely talking about two very different initial LEO orbits (with different inclinations and/or altitudes), and two different transfer trajectories (with different transfer times)...