Kaputnik - 20/2/2008 11:27 PMQuotekkattula - 20/2/2008 1:05 PMThe Russians will soon be launching from Guyana anyway.That's only true in the same way that they are currently launching from the Pacific.
kkattula - 20/2/2008 1:05 PMThe Russians will soon be launching from Guyana anyway.
kkattula - 20/2/2008 2:48 PMQuoteKaputnik - 20/2/2008 11:27 PMQuotekkattula - 20/2/2008 1:05 PMThe Russians will soon be launching from Guyana anyway.That's only true in the same way that they are currently launching from the Pacific.I thought they were launching Salyut's not Zenit's?Anyway, they can definitely launch propellant re-fills from either.
kkattula - 20/2/2008 10:05 PM1. Study the rocket equation: that 6.3% is huge. For example for a LOX/LH2 SSTO mass ratio goes from 8.8 to 10.1 for an extra 6.3% delta v. That will eat your payload.2. Leave the ISS as the laboratory it is. It doesn't have any of the facilities needed by a propellant depot except life support.No tanks, spare power, spare docking adaptors, vehicle servicing equipment. You have to launch all those things anyway, so launch them to the best orbit. A propellant depot at 28.5 degrees, with minimal "lay-over" crew facilities.3. The Russians will soon be launching from Guyana anyway.
kkattula2 - 20/2/2008 8:49 PM As I understand it, 6.3% is the effect on the total delta v of a lunar mission. Not shuttle ops to the ISS vs 28.5 LEO. .
Patchouli - 21/2/2008 11:00 AM1. Obama will likely dump Ares I too which is likely a good move it's only real value is as a test mule for Ares V and he may even seek to replace Orion with a series of much cheaper private vehicles.2. The Orion makes no sense at all if you are not going to the moon if LEO is your destination then a vehicle like Dream Chaser or Dragon makes a lot more economic sense.
renclod - 19/2/2008 1:55 PMQuoteluke strawwalker - 19/2/2008 8:41 PMIf Ares I is going to be SO cheap and safe why not just launch the Orion first and have the LSAM/EDS meet up with it. http://www.flightglobal.com/articles/2007/12/21/220464/nasas-moon-mission-could-see-major-change-in-concept-of.html>> NASA is studying a major change to its Moon mission plan to cut the time its spacecraft have to wait in low Earth orbit before setting off. Loitering in LEO presents challenges for cryogenic propellant storage and spacecraft energy budget.A revised mission plan could see the Ares I launcher, carrying the Orion crew exploration vehicle, lift off before an Ares V cargo launcher takes the Earth departure stage and Altair lunar lander into space.<<
luke strawwalker - 19/2/2008 8:41 PMIf Ares I is going to be SO cheap and safe why not just launch the Orion first and have the LSAM/EDS meet up with it.
kkattula2 - 20/2/2008 10:17 PMThanks Jim, so the ISS penalty is about 6% total orbiter mass, 25% payload and probably around 1-2% delta v?Also, I thought the reason Columbia didn't visit the ISS was that it didn't have the correct docking adaptor.Possibly because, being heavier, it couldn't carry both the adaptor and a worthwhile cargo.
Jim - 20/2/2008 9:21 PMQuotekkattula2 - 20/2/2008 10:17 PMThanks Jim, so the ISS penalty is about 6% total orbiter mass, 25% payload and probably around 1-2% delta v?Also, I thought the reason Columbia didn't visit the ISS was that it didn't have the correct docking adaptor.Possibly because, being heavier, it couldn't carry both the adaptor and a worthwhile cargo.Exactly. Ask wingod for the exact numbers, I was showing the effect