retroreflector

Another is a laser retroreflector array which will bounce back laser beams fired from Earth.

There is also a NASA-contributed retroreflector, an upgraded version of the ones left on the moon by Apollo astronauts.

In 2017, Dr. Mazarico and his collaborators began firing an infrared laser from a station near Grasse, France — about a half-hour drive from Cannes — toward the orbiter’s retroreflector.

After accounting for the smaller size of the orbiter’s retroreflector, Dr. Mazarico and his colleagues found that it often returned photons more efficiently than the Apollo retroreflectors.

The mission will also analyze minerals and map the unexplored south pole’s surface with a camera, seismometer, a thermal instrument and a NASA-supplied laser retroreflector to help calculate the distance to the Earth.