Two directions for OSP<< page 1: the case for a capsule The case for a winged vehicleDespite its stated advantages, not everyone is convinced that a capsule is the best approach for the OSP. Robert Walker, the former chairman of the House Science Committee who recently led the Commission on the Future of the US Aerospace Industry, is among those who argue that the capsule approach represents a step backwards in technology and operations. Walker in particular thinks that a capsule OSP would be a tough sell in Congress. “It becomes, in the minds of people here on Capitol Hill, a huge step backwards,” he said. “It means, essentially, that we’re trying to adapt technology that we know how to build.” “You will get a question of the investment, which means you will get a question of the politics, which means that the money may not be there in the numbers that we need in the short term to make this all work,” he elaborated. “You have to give them a view of the future, not just a view of the present.” He believes that any OSP design should be scalable for various missions that will be conducted not only by NASA but also by the Air Force. “The Air Force wants space access, they want the ability to deliver munitions, they many want personnel in space at some point,” Walker said. “NASA obviously has the need for a shuttle replacement at the present time, and they have the need to do it in the near term. I believe you can design a scalable vehicle that can meet both of those ends, but it is certainly not going to be a vehicle that looks a lot like the capsule that took people to the Moon.”
Such a vehicle, Walker said, should at least initially be able to be launched on an EELV, but eventually could become part of a future two-stage reusable launch vehicle. Such a vehicle could incorporate hypersonic technologies that the Air Force is currently researching as part of its National Aerospace Initiative. “What you want is a vehicle that has EELV capabilities to begin with, but ultimately has the potential of being scaled into a two stages to orbit vehicle, with both stages fully reusable,” he said. Thus, he added, he is wary of concepts like capsules that are too closely wedded to expendable vehicles alone. NASA’s decisionNASA has given few hints regarding what direction it is leaning on OSP, forcing journalists and others to scrutinize every statement made by NASA officials in an effort to discern the agency’s preferences. For example, Space News reported in its July 21 issue that NASA appeared to be leaning towards a capsule design for OSP because NASA Deputy Administrator Fred Gregory said at an AIAA conference that “you will see things that some will call retro.” With a final decision on the OSP design still one year in the future, the debate on the merits of the two general approaches continues. “There’s no shortage of opinions about where we should be going,” noted Phil McAlister, director of the Space and Telecommunications Division of the Futron Corporation and the one participant in the Capitol Hill forum who did not express a particular preference for an OSP design. While OSP is portrayed as an interim vehicle, a stopgap between the shuttle and a future RLV, some caution that whatever approach NASA selects it may be stuck with for decades. “Whatever we design and spend money on is going to be the vehicle for the next 20 years,” said Walker. “You can kid yourself that there are going to be followon vehicles and all that, but we kidded ourselves that way throughout the shuttle program. So you can depend upon the fact that whatever we do here is going to be around for a long time. It seems to me that you want something that at least will be adaptable.” That doesn’t mean, though, that the OSP has to be a direct replacement for the shuttle. “We don’t want a shuttle replacement,” McAlister said. “The shuttle was developed back in 1972; we had a much different world back then. To say the OSP doesn’t do the mission of the space shuttle is not a valid criticism. We don’t want the shuttle, we want something next.”
The question that faces NASA now is what the primary purpose of that “something next” is. If it is to provide crew rescue and transfer capabilities as soon as possible, and likely as inexpensively as possible, then there is a strong argument for a capsule-based OSP. However, if NASA is also interested in developing technologies that can be directly applied to future reusable launch systems, then a winged or lifting-body vehicle may be the superior approach. Based on NASA’s recent history, notably development efforts like the X-33, X-34, and X-37, it would seem like the agency would lean in the direction of a winged vehicle that would push the technology envelope. However, it’s clear that the Columbia accident has changed the decision-making calculus, perhaps pushing NASA in the direction of the tried-and-true capsule approach that can meet the agency’s near-term needs. With estimates of the total cost of the OSP approaching $20 billion (half of which to be spent on human-rating the Atlas 5 and Delta 4), the OSP represents one of the biggest NASA programs since the ISS. Whatever decision NASA makes will clearly be scrutinized for years to come. Home |
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