kraisee - 28/10/2005 12:43 AMThe SDLV 'Tug' is being folded into the design of the upper stage.
AndyMc - 28/10/2005 8:42 AMQuotekraisee - 28/10/2005 12:43 AMThe SDLV 'Tug' is being folded into the design of the upper stage.Hi,Great news. Where did you get this info from? Is the first I heard of it, and makes perfect sense. ...
AndyMc - 29/10/2005 2:50 PMHi,It's well within the realms of possibility that there will be a tug version and an expendable version of the upper stage. There has been plenty of research into cryo cooling done by NASA over the years. Where better to test it than in an unmanned vessel in LEO, before trying to rely on it for a 3 year round trip to Mars.
realtime - 29/10/2005 1:57 PMBut this upper stage "tug" is designed to be expendable, yes? If that's true then this is not a "tug", it is a disposable OMS, good for no more than the mission it launched on.My definition of a tug is a spacecraft that is designed to stay on orbit and handle payloads from multiple launches. It would contain a sophisticated OMS to allow it to dock with payloads and guide them to ISS or to rendezvous at assembly points. It may (or may not) be refuelable on orbit. To allow the tug to dock successfully, payloads would carry only a kick motor for circularization and a minimal RCS system to prevent tumbling.Theoretically, this configuration would allow mission planners to throw "dumb" payloads into LEO and then maneuver the payload without the expense of certifying, boosting, and discarding a full-up OMS on every HLLV flight.
This is Boeings first spacetug [astronautix], it seems like a very useful vehicle
The original BoeingSpace Tug design of the early 1970's was sized to be flown either in a singleshuttle mission or as a Saturn V payload. Optimum mass was found to be 20.6tonnes regardless. The Tug could be outftted with a variety of kits to serve inmany roles, including as a manned lunar lander. Aerobraking for recovery in lowearth orbit was considered for further study, but the baseline used RL10engines to brake into earth orbit for refurbishment and refuelling at a spacestation. All further work was cancelled by NASA in 1972, but resurrected as theaerobraking Orbital Transfer Vehicle in the 1980's.
http://www.astronautix.com/graphics/z/zstugmw.jpg" />http://www.astronautix.com/graphics/z/ztugcrew.jpg" />
This is Boeings first spacetug [astronautix]
Tap-Sa - 31/10/2005 6:05 AMQuote This is Boeings first spacetug [astronautix] Looks neat, but getting down to surface from the lunar version would be interesting."One small step for maAAAAAAAAANNN*THUMP*"
Avron - 30/10/2005 7:24 PMQuoterealtime - 29/10/2005 1:57 PM...Theoretically, this configuration would allow mission planners to throw "dumb" payloads into LEO and then maneuver the payload without the expense of certifying, boosting, and discarding a full-up OMS on every HLLV flight.Thats what I had in mind for a Tug. Now what would prevent a SDLV upper stage from being launch into LEO an remain there for say a year, playing the roll of a Tug?
realtime - 29/10/2005 1:57 PM...Theoretically, this configuration would allow mission planners to throw "dumb" payloads into LEO and then maneuver the payload without the expense of certifying, boosting, and discarding a full-up OMS on every HLLV flight.
Avron - 30/10/2005 8:24 PMQuoterealtime - 29/10/2005 1:57 PM...Theoretically, this configuration would allow mission planners to throw "dumb" payloads into LEO and then maneuver the payload without the expense of certifying, boosting, and discarding a full-up OMS on every HLLV flight.Thats what I had in mind for a Tug. Now what would prevent a SDLV upper stage from being launch into LEO an remain there for say a year, playing the roll of a Tug?
realtime - 31/10/2005 11:40 PMQuoteAvron - 30/10/2005 8:24 PMQuoterealtime - 29/10/2005 1:57 PM...Theoretically, this configuration would allow mission planners to throw "dumb" payloads into LEO and then maneuver the payload without the expense of certifying, boosting, and discarding a full-up OMS on every HLLV flight.Thats what I had in mind for a Tug. Now what would prevent a SDLV upper stage from being launch into LEO an remain there for say a year, playing the roll of a Tug?Propellant boil-off is a technical issue that has yet to be solved well. Failing that, on-orbit refueling.
AndyMc - 2/11/2005 5:15 AMHave some more info (not much) on the Prom Space-tug.http://www.friends-partners.org/pipermail/fpspace/2005-June/015892.html
stargazer777 - 6/3/2006 4:55 AMLots of interesting concepts. But, for the short term, doesn't it strike you that there are likely to be lots of largely unused CEV service modules floating about once the CEV is put into service transiting to the ISS. Could they be put to use rather than simply disposed of in the atmosphere? Or, alternatively, would it be cheaper for NASA to simply launch a dedicated CEV modified to serve as a tug for the duration of its fuel supply (assuming we still haven't licked the refueling situation by that point.)? This vehicle could be "parked" at the ISS and used for whatever "tug" duties might be required in orbit. If and when the service module exhausts its fuel, we could launch a new one and attach it while disposing of the old one, if the tug had been designed with that capability in mind. Make any sense?
stargazer777 - 6/3/2006 7:27 AMPerhaps I didn't make myself clear. My fault considering the hour I wrote my original message. I was thinking about using a modified CEV with service module as a tug. Depending on where the modifications were located, I was wondering if the CEV could stay in space and simply swap partially used service modules abandoned by other CEVs. Maybe a foolish question, but its often easier to use existing hardware than develop something new.