Vid SpaceX has released video showing the hovering capabilities of its Dragon 2 crew capsule that could eventually eliminate the need for astronauts to land using parachutes.
The test took place at SpaceX's engineering facility in McGregor, Texas and saw the 6,000-kg (13,228-lb) spacecraft suspended from a cable before the eight SuperDraco thrusters fired up. Over two tests, the capsule hovered and rotated, before settling down on the cable again.
The thrusters will solve two engineering challenges. Firstly, they act as the emergency evacuation rockets if a Falcon rocket runs into trouble during takeoff, blasting the crew free of the debris and returning them to terra firma.
SpaceX successfully tested this capability last May, taking the unmanned capsule from 0-100mph in just 1.2 seconds after the SuperDraco rockets went to maximum safe thrust of 54,431kgf (120,000 pounds-force). In that case, the capsule fell to earth under parachutes.
That's all well and good, but why bother with parachutes? The second and more important point of the rockets is to enable astronauts to return to earth under rocket power alone – although that will take time.
"The ultimate plan is for the capsule to dispense with parachutes altogether and have it land under rocket power using the SuperDraco engines," said NASA on Thursday. "The capsule would undergo reentry, then jettison its heat shield and be slowed, and eventually landed under rocket power alone."
Propulsive landing will not be used initially for missions with NASA astronauts to the International Space Station. The Crew Dragon will splash down safely in the ocean under parachutes as its passengers return from the space station.
Looking even further ahead, the rockets will be a key stage in getting humans safely onto the Martian surface. Landing on Mars is tricky, because the atmosphere is thick enough to cause serious heat friction on entry, but not thick enough for parachutes to work for the whole trip.
When the Curiosity rover landed on Mars, it deployed the largest supersonic parachute ever created to slow itself down, but was still going too fast to land safely. After the parachute was jettisoned, the rover landed under rocket power – that's what SpaceX wants to emulate.
Mars landings are off the cards for the moment, as are purely rocket-powered landings. But the tests show the idea is valid – we'll just have to do a lot more testing first. ®