Suffredini: We learned a lot from Mir with our Russian counterparts, and we’ve tried to take all of our knowledge over the years and use that in deciding how we’re going to build and operate a space station. Every single thing that flies to the station gets assessed for its flammability and off-gassing. You know how you paint your house and it smells; with a space station you can’t air it out. We worried about toxicity and stowage. We put in smoke detectors. Most importantly were the steps we’ve done to mitigate our design. To make sure we have oversized wires so you don’t get inadvertent warmups, and to make sure our cables are built carefully so you don’t have a concern for short circuits. By design, you can’t cause a fire [aboard the ISS] with a short circuit. In the case of Mir’s fire, that was specific to their oxygen generation system, which is a common system by the way. It’s used in the Navy on our subs.
A & S: Early ISS crews used to spend a good part of each day maintaining the station. How has that changed, even as the station has grown?
Suffredini: In the early stages, we were learning about the systems. A lot of them were new, and we were working the bugs out. We’ve gotten pretty experienced now, and we’re just about done with the assembly. So that has helped us learn when we need to do preventive maintenance. You haven’t noticed it as much because we have six crewmen now.
A & S: There’s been talk of extending the mission until 2020. How likely is that to happen?
Suffredini: I think it’s very likely. We’ve pretty much gotten indications from our lawmakers and from our partners that they’re willing to do that. When we did our analysis, we looked at a total 30-year life, from the first element launch in November 1998. So that takes you to 2028 and our analysis is we make it to 2028. The system will be fine. Although it’s not formalized in some of our agencies, all the agencies have indicated an interest in extending [the ISS] to 2020.
A & S: Will station crews continue going up for six-month stays?
Suffredini: From an ISS operational and research standpoint, six months is a pretty good stay. It takes one to two months for a crew to get really efficient. They have to learn where everything is, how to bounce around, what order they have to do things, all the procedures. You want them efficient, but you don’t want to wear them out. Eventually, I could see us extending an increment crew to longer than six months to practice and train for long-duration spaceflight like a trip to Mars. But if we’re just doing normal research, then six months is a good way to rotate your crews.
A & S: Will the size of the crew come down?
Suffredini: No. In fact, we’re designed on the U.S. side to take four crew. The ISS design is actually for seven. We operate with six because first, we can get all our work done with six, and second, we don’t have a vehicle that allows us to fly a seventh crew member. Our requirement for the new vehicles being designed is for four seats. So I don’t expect us to go down in crew size. I would expect us to increase it.
A & S: Will the ISS be the last space station we build?