The Robotic Lunar Observatory (ROLO) is an astronomical observatory funded by NASA and located at the United States Geological Survey Flagstaff Science Campus atop McMillan Mesa in Flagstaff, Arizona.

Its purpose is to enable the Moon to be used as a radiometric calibration reference for Earth-orbiting remote-sensing spacecraft instruments.

[1][2] The ROLO project is currently ongoing, but the program ceased observations in September 2003.

It consists of two 20 cm (7.9 in) Ritchey-Chrétien telescopes attached to an equatorial mount made by DFM Engineering.

One telescope is fitted with a sensor optimized for visible and near-infrared (VNIR) wavelengths, while the other is tuned to short-wavelength infrared (SWIR).