What kind of heavy-lift vehicle does NASA want to build, or at least thinks it can build? That was one central topic of discussion in a speech and Q&A session by NASA administrator Charles Bolden on Capitol Hill on Friday, organized by the Space Transportation Association.
Congress has already provided direction to NASA on this in the 2010 NASA authorization act: build a “Space Launch System” (SLS) that can launch 70-100 tons into low Earth orbit, starting by the end of 2016, and is eventually upgraded to 130 tons. NASA, though, is still studying what the SLS would look like, and, to the consternation of some members of Congress, delivered an initial report to Congress in January that said an SLS concept that meets the payload and schedule constraints of the act isn’t possible within projected budgets. Bolden said those study efforts were proceeding, with an emphasis now on deciding on the propulsion system: “whether you go with LOX/hydrogen the way we did with shuttle, or LOX/RP the way we did back in the Saturn days… whether you use solids.” He said NASA is getting “really close” and, later, “perilously close” on making decisions on this.
However, it wasn’t clear from Bolden’s comments whether what emerged from those studies would meet the act’s requirements for payload capacity and schedule. Asked why the agency could’t just announce that it would develop the vehicle in the act, Bolden said, “Because I don’t want to, for one thing, and because it may be that we can’t do that. We don’t know.” (It’s unclear whether Bolden meant that he doesn’t want to build the SLS as specified in the act, or instead meant that he doesn’t want to say now that NASA will build such a vehicle; he later claimed he meant neither of those things.) Bolden cited budget uncertainties for 2011 and beyond in the new climate of fiscal conservatism as a key factor in determining what NASA can do for an HLV. “This time last year, the worst you could do [for a fiscal year 2011 budget] was 2010 level,” he said. “Today, 2010 level is pretty good.”
Bolden emphasized that his interest is on an evolvable launch system, in contrast to Constellation’s plans to develop the Ares 5 with only the Ares 1 as an intermediate step. “What got us in trouble with Constellation was there were people in NASA who believed that they were going to get one shot, and one shot only, at a heavy-lift launch vehicle, and ‘I gotta build the biggest rocket known to man because I’m never going to get to come back to that,” he said. “I don’t live by that philosophy. I think we have to be able to do small, incremental steps, demonstrate that we can keep to cost and schedule, and then people will begin to have confidence that we know what we’re talking about. If we can’t do that, we’re not going very far with anything.”
“NASA does not need a 130-metric-ton vehicle probably before the next decade,” Bolden said later. “We know we’re going to need it if we’re going to go to an asteroid, in a reliable way, and we’re definitely going to need it when we talk about going to Mars. But we would take a lesser capability in an earlier heavy-lift system so that we can get the job done,” he said, not specifying how lesser that initial capability could be. He added that “traditional rocket companies that want to sell me a 130-metric-ton vehicle, but don’t want to evolve it, they may lose. They may lose because there’s some other company that wants to give me the capability that I need right now that can be evolved to what we will need down the road.”
This is not the first time that Bolden has spoken out on heavy-lift development. In an appearance earlier this month at CSIS, Bolden said that “we can’t” go directly to a 130-metric-ton vehicle, and that NASA would “continue to negotiate and discuss with the Congress why that is not necessary.” That speech came shortly after the Senate Appropriations Committee had put forward a full-year continuing resolution that appeared to call for immediate development of a 130-ton HLV.
(As an aside, it’s worth noting that the NASA authorization act refers to payload capacity in “tons”, while Bolden’s comments, and some previous NASA documents, make use of “metric tons”, which are about 10 percent heavier (2,205 versus 2,000 pounds). It’s a minor point in the grander scheme of things, but you would think that an agency that lost a spacecraft because of a mismatch in metric versus English units would be more attuned to that.)
Bolden also, curiously, suggested that NASA would not be the only user of any heavy-lift vehicle it develops. “When I talk about a heavy-lift launch vehicle, it’s not a NASA vehicle any more. In this day and age, it’s a heavy-lift launch vehicle that’s going to be used by the national intelligence community, the DOD, because we’re the only ones building a heavy-lift launch vehicle, and we’re building it for that purpose,” he claimed. Later, when talking about a 130-ton vehicle, he suggested that while NASA does not have an immediate need for such a rocket, “probably the intelligence community can use it as soon as I can give it to them.” While there may be some concepts floating around the national security space community, unclassified and classified, for projects that could require a heavy-lift launcher, there are no existing projects under development or consideration that need anything larger than the Delta 4 Heavy, which can put about 25 tons into LEO.