A satellite tv for pc firm named Maxar lately delivered a passenger-van-sized chunk of spacecraft to NASA’s Jet Propulsion Laboratory in California. This chassis will function the spine for a robotic spacecraft that can discover a metallic asteroid for the primary time. This formidable mission, named Psyche after the eponymous asteroid it’s going to discover, is because of launch subsequent summer season on a Falcon Heavy rocket.
Once in house, the spacecraft will use an progressive technique of propulsion, often known as Hall thrusters, to achieve the asteroid. This would be the first time a spacecraft has ventured into deep house utilizing Hall thrusters. Absent this expertise, the Psyche mission most likely would not be occurring—definitely not at its price of simply lower than $1 billion.
For David Oh, the massive, boxy chassis represents a kind of “full circle” moments in life. More than twenty years in the past, he labored on Hall thruster expertise as a graduate scholar on the Massachusetts Institute of Technology. He would go on to work for Space Systems/Loral, which first put the propulsive expertise on giant business satellites and would later be acquired by Maxar.
After engaged on the primary launches of business satellites powered by Hall thrusters, Oh left the personal sector in 2003 to return to NASA’s Jet Propulsion Laboratory, the place he has since labored on various missions, together with the flight of Curiosity to the Red Planet in 2011. Now he serves as technical lead for the Psyche mission.
“I’ve been working on electric propulsion for more than two decades,” he mentioned in an interview.
And now, the Hall thruster expertise Oh labored on as a graduate scholar will take NASA to a completely new place: Psyche. No spacecraft has ever visited a world like this, composed of about 60 % metallic. We actually have no concept what it’s going to appear to be.
Engines powered by chemical propulsion are nice for getting rockets off the floor of the Earth whenever you want a brawny burst of vitality to interrupt out of the planet’s gravitational effectively. But chemical rocket engines are usually not essentially the most fuel-efficient machines on this planet, as they guzzle propellant. And as soon as a spacecraft is in space, there are extra fuel-efficient technique of transferring round.
One of those is solar-electric propulsion, which makes use of photo voltaic panels to seize vitality from the Sun, which in flip ionizes and accelerates a fuel—sometimes xenon—to provide a thrust. It’s not a lot of a thrust. Actually, it is exceptionally mild. Each of the thrusters on the Psyche mission maxes out at about the identical pressure as that exerted by two or three quarters within the palm of 1’s hand. But as a result of they’re so fuel-efficient, solar-electric thrusters do not burn for a couple of minutes at a time. They burn for months, producing a gradual acceleration.
NASA has been experimenting with this expertise for some time. The house company first examined electrical propulsion expertise in its Deep Space 1 mission, which launched in 1998, and later within the Dawn mission in 2007 that visited Vesta and Ceres within the asteroid belt.
These spacecraft used ion thrusters. Hall thrusters, in contrast, use an easier design, with a magnetic subject to restrict the move of propellant. These thrusters have been invented within the Soviet Union and later tailored for business functions by Maxar and different corporations. Many of the most important communications satellites in geostationary orbit at present, resembling these delivering DirecTV, use Hall thrusters for station-keeping.
But now, for the primary time, they’re getting used for a deep house mission. NASA and Maxar imagine the expertise is prepared, however it nonetheless must be confirmed out in a brand new setting.
“It’s always a big deal when you go beyond Earth orbit,” mentioned Robert Curbeam, a former astronaut who’s a senior vice chairman at Maxar. “As you get further from the Sun, you’re going to generate less power from the Solar arrays. The radiation environment is going to be different. And there’s the question of whether we can keep these thrusters pulsing for that long.”