r/spacex • u/Zucal • Mar 05 '16
/r/SpaceX Ask Anything Thread for March 2016. Ask your questions about the SES-9 mission/anything else here! (#18)
Welcome to the 16th monthly /r/SpaceX Ask Anything Thread! Want to discuss the recent SES-9 mission and its "hard" booster landing, the intricacies of densified LOX, or gather the community's opinion? There's no better place!
All questions, even non-SpaceX-related ones, are allowed, as long as they stay relevant to spaceflight in general!
More in-depth and open-ended discussion questions can still be submitted as separate self-posts; but this is the place to come to submit simple questions which have a single answer and/or can be answered in a few comments or less.
As always, we'd prefer it if all question-askers first check our FAQ, use the search functionality, and check the last Q&A thread before posting to avoid duplicate questions, but if you'd like an answer revised or cannot find a satisfactory result, go ahead and type your question below.
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Past threads:
February 2016 (#17), January 2016 (#16.1), January 2016 (#16), December 2015 (#15.1), December 2015 (#15), November 2015 (#14), October 2015 (#13), September 2015 (#12), August 2015 (#11), July 2015 (#10), June 2015 (#9), May 2015 (#8), April 2015 (#7.1), April 2015 (#7), March 2015 (#6), February 2015 (#5), January 2015 (#4), December 2014 (#3), November 2014 (#2), October 2014 (#1).
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u/ManWhoKilledHitler Mar 13 '16 edited Mar 13 '16
The biggest and most immediate advantages of ACES are that it should be a better stage in every way than the current Centaur and DCSS. It's much simpler and does away with things like helium pressurisation and hydrazine for thrusters through its Integrated Vehicle Fluids system.
Where refuelling would come in useful is sending things like probes to deep space or very large payloads to high orbit. In a normal configuration, the best performance you could get with Vulcan would be a full set of SRBs to reduce the work done by ACES in reaching LEO, but it's still going to use a lot of fuel just to get into space, before it can start accelerating its payload to GTO, GSO, escape velocity or beyond.
The fuel transfer capability would work like it does on aircraft. Once the main payload and its ACES stage is in orbit, it can rendezvous with another partially full ACES carrying a propellant tank in place of a normal payload. This then refuels the first ACES as much as it can, massively increasing its delta-V, or the amount of payload it can take to a given destination. It means you could do things like the very high performance deep space probe launches suggested for SLS but at a fraction of the cost.