Orbital boffins cut four years off NASA mission to shiniest object in the Solar System

NASA has come up with a cunning plan that will allow it to shave four years of flight time off its mission to the biggest chunk of visible iron in the Solar System, and will use souped-up solar power to get there.

In January NASA approved the mission to send a probe out to the asteroid 16 Psyche, which is thought to be a remnant of a protoplanet core that got smashed apart eons ago. The asteroid, one of the larger objects in the Asteroid Belt, is around 90 per cent nickel-iron and is over 200km (120mi) across.

The NASA mission was due to launch in 2023, swing by Earth to get a gravity assist, then head off to Mars for more gravitational slingshotting, before getting to Psyche in 2028. But the steely-eyed rocket-folks of NASA have found that if they launch a year earlier, they can dump the Earth assist and still be there four years earlier than planned.

"We challenged the mission design team to explore if an earlier launch date could provide a more efficient trajectory to the asteroid Psyche, and they came through in a big way," said Jim Green, director of the Planetary Science Division at NASA headquarters.

"This will enable us to fulfill our science objectives sooner and at a reduced cost."

In addition to being quicker, the new orbital trajectory takes the probe further from the Sun, so NASA can cut down on the amount of thermal shielding the craft must carry. Instead, the probe's solar array space is being increased 20 per cent to give more power to the engines that will both speed it to its target and slow it down into a stable orbit.

"The biggest advantage is the excellent trajectory, which gets us there about twice as fast and is more cost effective," said principal investigator Lindy Elkins-Tanton of Arizona State University in Tempe.

"We are all extremely excited that NASA was able to accommodate this earlier launch date. The world will see this amazing metal world so much sooner."

Once it reaches its target, the Psyche probe will spend months orbiting the body and scanning its surface. NASA wants to find out what the core of a planet looks like – if that is the asteroid's provenance – and get clues as to how it was formed.