The Obama administration recently announced its 2010 proposed budget, which includes $18.7 billion for NASA with a blueprint for retiring the space shuttles in 2010 and returning to the moon by the end of the next decade. But retiring the shuttles means that the United States is without a vehicle to travel to space until 2015, when NASA's next launch vehicle, the Ares rocket, is expected to make its debut.

In the interim, NASA must rely on the Russians' Soyuz spacecraft and the commercial sector to carry crew and cargo to the International Space Station (ISS), a $100 billion U.S. taxpayer asset.

Space Exploration Technologies (SpaceX) is a private company that won a $1.6 billion contract in December through NASA's Commercial Orbital Transportation Services (COTS) program to provide the agency with a launch vehicle capable of reaching ISS.

Technology Review spoke with Lawrence Williams, vice president of SpaceX, about the retirement of the shuttles, NASA's decision to partner with the private industry, and SpaceX's rocket design.

Technology Review: How does the retirement of the space shuttles, and more recently Russia's decision to stop taking paying passengers aboard the Soyuz spacecraft, affect the commercialization of space?

Lawrence Williams: People are so used to the U.S. having access to the space station that it has not really sunk in for most people that in 2010, under the current plan, the U.S. will no longer have its own vehicle, certainly [not] one with crew capability, to access space or the space station. We are going to be limited in the type of missions we can launch. The only option, without using companies like SpaceX, is to use the Russians, which is not a politically popular one.

NASA's plan therefore is to rely on the commercial sector to provide cargo capabilities to the station in the interim, until the successor system to the shuttle, the Ares-Orion program, is ready. So SpaceX and [a company called] Orbital Sciences have contracts to take cargo to ISS in that interim time period. We also have an option on our contract, which NASA has yet to exercise, that would allow us to also carry crew to space. In the absence of SpaceX taking crew, our only option, again, is the Russian Soyuz, which is how [the latest] space tourist, Charles Simonyi, is currently planning to travel to space. I think the Russians have decided to stop flying tourists because they are going to have to start flying a lot more U.S. astronauts.

TR: Can you expand on the terms of your contract with NASA?

LW: We have been awarded a contract to develop first the capability to just do cargo, and eventually demonstrations with crew, although NASA has yet to exercise that part of the contract. But we are developing our system with the plan in the future to evolve into carrying crew. The capsule that we have designed is a flexible system, so basically instead of carrying cargo to the space station you put in seats and a crew life-support system. We are currently the only company under contract with NASA to do crew, although again, that option has not been exercised.

The second part of the contract is for $1.6 billion for 12 flights of actual cargo. In other words, the first three flights are demonstration missions as part of the COTS program, and the 12 flights are actual cargo supply, and they start at the end of 2010.

TR: What's your schedule for the flight-demonstration missions?

LW: We are flying the booster later this summer without the cargo capsule on it. Then we will fly booster with the cargo capsule for our first demonstration flight the last quarter of this year [launching from] Cape Canaveral. We won't actually dock to the station, but we will be doing a demonstration flight of our capsule design and are scheduled to do the first docking with the station mid-2010. If we started doing crew development today, we think we could do the crew demonstration in 24 months.