The final location of Lunokhod 1 was uncertain until 2010, as lunar laser ranging experiments had failed to detect a return signal from it since 1971.

For the Moon-Earth system, this effect has been measured with the help of lunar laser ranging.

The discoveries made by laser ranging include not only the large Love numbers but surprising perturbations in the Moon's orbit.

Lunar laser ranging experiments had failed to detect a return signal from its retroreflector since the 1970s.

Secondary mission objective is the flight testing of the novel-type spherical retroreflector for precise laser ranging.

An onboard computer provides laser ranging and target location within 10m.

Lunar laser ranging experiments tightly constrain the variation of the gravitational "constant" with time and , so these theories are also looking unlikely.

The robot also has a laser ranging scanner that acts as a "virtual" bumper.

A passive satellite, it is a sphere of aluminium covered with retroreflectors to reflect laser ranging beams emitted from ground stations on Earth.

The sensors include stabilised day and night cameras, infrared imaging as well as laser ranging and designation.