The Asteroid Retrieval Mission
The star of the NASA video, set to dramatic music, is a massive rock hurtling through silent space toward a rendezvous with destiny.  Suddenly the school-bus sized asteroid meets a spaceship equipped with what looks like a big, rubber catcher’s mitt.  Blue light glows from the ship’s thrusters as it sneaks up, encircles the asteroid, and slowly pulls it in. The blue thrusters kick in again and push the whole package toward the moon where astronauts arrive to sample the exotic space rock.  This is NASA’s dream, the asteroid retrieval mission, and Cleveland’s NASA Glenn Research Center is helping make it real.

An eerie blue glow and a gentle nudge
The spaceship’s blue thrusters are being designed and built at NASA Glenn by engineers like Dan Herman. He’s forced to shout over the incessant pulse of cryo-pumps that create a space-like vacuum inside a tanker-sized chamber by freezing stray atoms inside it. A glowing blue drum inside the chamber emits a faint cloud of vapor. Herman says this tank has been under vacuum for over eight years, and the glowing blue ion thruster, “has operated for over 46,000 hours of operation…”

That’s more than five years of constant use for this ion engine under Herman’s watchful eye. NASA’s ion engine is the future of deep space trave. The blue glow of the ionized xenon gas, as Herman notes, will deliver tiny amounts of thrust to the several kiloton asteroid payload. Herman says the ion engine delivers the equivalent amount of thrust as two pieces of paper pushing on your hand. But in space, that’s enough, over years, to move mountains.

Slow and steady wins the race in outer space 
Lead engineer Rick Manella compares the ion thruster to the familiar blast of a rocket’s engine.  He says the fiery chemical propulsion provides, “large thrusts for short periods of time, this is low thrusts for long periods of time.”  He says space travel with ion engines is not for the impatient.  Manella estimates the asteroid capture vessel will take two years to get to the rendezvous location and about a year and a half to bring it back to lunar orbit where astronauts can access it. But Manella says the energy sipping ion engines require ten times less fuel than chemical engines, which means lighter payloads, and cheaper missions. 

NASA's dreams of deep space
Right now about 200 commercial satellites are kept in orbit with smaller versions of the ion engine. The asteroid retrieval mission will be NASA’s highest profile use of the technology since it was invented at Glenn more than 50 years ago. Manella says Glenn is developing more powerful ion engines for this mission, which he says is merely a stepping stone to further exploration.

Manella says, "it’s a good combination of science and unlocking deeper space where we all want to go.”

The plan over the next three years is to find a suitable asteroid.  Then in 2017 launch the retrieval capsule, push it to lunar orbit with the ion engines, and send astronauts to rendezvous near the moon in 2021. They’ll take samples of the asteroid to learn more about these rocks and where they come from.  Beyond that lies Mars and dreams of deep space, all powered by ion engines built in Cleveland.