Dream Chaser will be launched on the top of an Atlas 5 rocket (although it could be launched on Europe’s Ariane rocket), with the astronauts lying on their backs looking through the front windows at the sky. Although not yet rated for manned spaceflight, Atlas 5 is one of the most reliable US launchers ever built. The space plane’s engines would only be fired in space to change orbit, catch up and dock with the ISS and de-orbit before returning to Earth.
Similar SNC engines have already flown in space on the first privately operated human spacecraft, Spaceship One, and are being built for Virgin Galactic’s Spaceship Two. Like the Shuttle, and these other designs, Dream Chaser would glide back to Earth - a feature its designers are keen to highlight.
“Within eight to 10 hours of leaving the station, we’re on the ground on a runway,” says Sirangelo. “We come home with less than 2Gs – twice the force of gravity – unlike most capsules, which come down to an ocean landing or a desert landing and come down at a much higher rate of descent. That could damage the experiments and could make it much more difficult for the people coming home.”
The ability to return fragile equipment or experiments from the space station is one of the big selling points of the Dream Chaser concept. The only return option at the moment is a cramped and bumpy landing in a Russian Soyuz capsule, which barely accommodates its three astronauts. There’s certainly room for cargo in the Dream Chaser (depending on how many astronauts are being flown) but where space planes really have the edge over capsules is their versatility.
The Shuttle was so much more than a space cargo hauler. It allowed, for example, astronauts to fix satellites and telescopes in orbit. Without it, the Hubble Space Telescope would still have blurry vision (and would probably have failed by now). But with the demise of the Shuttle, that ability was lost.
Now, Dream Chaser could bring it back. Like the Shuttle (and unlike most capsules)it has an airlock enabling astronauts to leave the plane for space walks. “The missions ... could be to go out and repair things in space [or] help with the large and growing problem of space debris – how could we move a satellite out of the way before it causes a problem?,” says Sirangelo.
As a transport craft to and from the ISS, Dream Chaser faces stiff competition from SpaceX and Boeing. But Sirangelo believes, once the considerable development and construction work is done, it will find lots of different roles....just like any good family car.
“As with most SUVs, you haul your family around,” he says. "But sometimes you take supplies around, sometimes you go camping, sometimes you fix things with it and that’s what we’re trying to do with this vehicle.”