Stopping For Gas on the Way to the Moon

Today’s release of the final report of the Augustine Commission–a blue-ribbon panel charged with reviewing America’s human spaceflight program–contains a laundry list of possible future options for the White House and Congress to consider. While making explicit recommendations was outside the Commission’s charter, the panel’s members managed to make their feelings clear on at least a few points.

For example, take the Ares-I, the light launcher intended to ferry crews to the International Space Station. Pictures of the feasible future are painted in the report, pictures in which the Ares-1 is conspicous by its absence. Instead, the Commission appears to believe that commercial companies should fly crews and cargos into orbit, but it if they fail to deliver, a combination of the Orion Crew Exploration Vehicle and a cut-down human-rated version of the Ares-V heavy-lift launcher (both intended for exploration missions beyond low Earth orbit) could fill in. Noting that crew transport to low Earth orbit requires a vehicle not much more complex than the Gemini spacecraft that was developed in the mid 1960s, the report states that a commericial crew launch service could be in operation as early as 2016.

An artist’s impression of a rocket destined for a journey beyond Low Earth Orbit being refueled at this space depot designed by Boeing.

On the positive side, the panel is clearly taken with the potential of in-space refueling technology, which enables spacecraft to tank up in low Earth orbit. With this technology smaller (and cheaper) rockets could be used for missions that would otherwise be outside their weight class and larger rockets would have their capabilities considerably enhanced. For example, without in-space refueling, a launcher derived from today’s smaller expendable rockets could launch 26 tonnes towards the Moon. With in-space refueling that figure would more than double to 55 tonnes. For missions using the Ares-V, which will be able to launch 63 tonnes to the Moon unaided, in-space refueling could bring the capacity up to 130 tonnes.

The panel also claims that pursing this technology could provide a boost to the private space sector, if NASA purchased fuel in orbit from commercial companies which would operate refueling tankers or possibly even permanent depots. (It’s not too much of a stretch to imagine that tourist facilties could be combined with these depots, creating multiple revenue streams for future orbtial entreprenuers.)

The report is a big vote of confidence in a technology that has been somewhat neglected by the U.S.. Russia has been performing in-space refueling of its space stations using Progress vehicles since 1978, but the U.S. has conducted only a handful of research projects over the years in this area. Most notable of these is the military’s Orbital Express mission in 2007, which demonstrated the in-space refueling of a satellite, and work done at the Creek Road Cryogenic Research Complex at NASA’s Glenn Research Center, which is developing ways to refuel spacecraft in orbit with high-energy cryogenic fuels such as liquid hydrogen and oxygen.

So while the arguments rage about one launch vehicle over the other, or one destination versus the next, we hope that funding becomes available to develop this eminently feasible technology which has the ability to enhance America’s future in space, whatever direction is ultimately chosen.