A glimpse at a gateway
by Jeff Foust
Monday, November 12, 2012
On Saturday, however, a NASA official provided a glimpse about what the agency was currently studying. Speaking at SpaceVision 2012, the annual conference of Students for the Exploration and Development of Space (SEDS) in Buffalo, New York, Harold White, Advanced Propulsion Theme Lead at the Johnson Space Center, discussed the current state of NASA’s studies of what it calls the Gateway Exploration Architecture. White, better known in some circles for his work on advanced propulsion physics (see “Building a starship’s foundation”, The Space Review, September 24, 2012), is the propulsion lead on the architecture study.
The architecture starts in 2019 with the launch of the core spacecraft—a generic service module plus a docking node similar to those on the US segment of the International Space Station—on a Space Launch System (SLS) heavy-lift rocket to the Earth-Moon L2 point. “Then we would have a cadence of missions, about once every year,” White said, “increasing the mission duration and, in some cases, also increasing the capability of the platform by bringing up additional modules.”
The initial crewed mission would fly to the platform at L2 on an Orion spacecraft launched by an SLS. That mission would last about 30 days, in order to gain experience on operations there. Before departing, the platform would transfer from the L2 to the L1 point on the other side of the Moon. After the crew left, the station would then move into a “near rectilinear orbit”, a stretched version of the halo orbits used to stationkeep around Lagrange points that, in this case, gives long dwell times over the lunar poles.
The current architecture features what White called a “decision tollgate” in 2022: in effect, a fork in the road with two options. In one approach, the platform moves to low lunar orbit, where it could later support human missions to the lunar surface. ... <snip> ...
In the other option, the platform would move out into deep space, perhaps out to the Earth-Sun L2 point, about 1.5 million kilometers from the Earth, ... <snip> ...