Two lunar orbital satellites, Luna 10 and Explorer 35, laid much of the groundwork for a working understanding of the Moon's magnetic field.

The instrument also needed to be able to perform its own self-calibrations on a regular cadence to account for wide temperature ranges experienced over a long period of time.

[1] The instrument's main magnetic measurements were calculated from three Ames fluxgate magnetometer sensor heads, located at the end of three 100 cm (39 in) booms, positioned perpendicular to each other.

[1] Each sensor consists of a flattened toroidal core made of permalloy tape placed inside a wound sensing element.

[4] The first LSM was fully deployed and activated on the Moon at 14:40 UTC November 19, 1969, by astronauts Charles Conrad and Alan Bean, within the Oceanus Procellarum.

The instruments detected a field strength of 32-36 nanotesla that was likely produced mainly by a nearby localised magnetised body, between 200 m (660 ft) and 200 km (120 mi) from the magnetometer.