SpaceX launched Christmas gifts, goodies and supplies to the International Space Station on Tuesday and got a present in return: the company's 100th successful rocket landing.

The predawn liftoff from NASA's Kennedy Space Center was barely visible in the fog and clouds, as the Falcon rocket hoisted a Dragon capsule loaded with more than 6,500 pounds (2,950 kilograms) of gear for the station's seven astronauts. Several minutes later, the first-stage booster landed upright on an ocean platform, six years to the day that Elon Musk's company accomplished its first booster touchdown in 2015.

Aerospace engineers at MIT are testing a new concept for a hovering rover that levitates by harnessing the moon's natural charge.

Because they lack an atmosphere, the moon and other airless bodies such as asteroids can build up an electric field through direct exposure to the sun and surrounding plasma. On the moon, this surface charge is strong enough to levitate dust more than 1 meter above the ground, much the way static electricity can cause a person's hair to stand on end.

Engineers at NASA and elsewhere have recently proposed harnessing this natural surface charge to levitate a glider with wings made of Mylar, a material that naturally holds the same charge as surfaces on airless bodies.

Two teams of researchers are publishing their findings thus far after initial study of samples collected from the asteroid Ryugu and returned to Earth last year by the Japanese space probe Hayabusa2. Both teams are large and both are made up mostly of researchers from institutions in Japan. Both teams have also published their findings in Nature Astronomy.