Lunar Surface Magnetometer

The Lunar Surface Magnetometer (LSM)
Tthree-station network (Apollo 12,15,16)


Mass: 8.9 kg

Power (avg): 5.5 W
3.5 W average power in the daytime and 7.5 W at night.

Bit rate (avg): 0.11594 kbps

Three fluxgate magnetometers (x, y, and z) mounted on orthogonal 100-cm booms, protruding from the top of a base box with support legs. The booms extend from the box at an angle of 35 degrees with the horizontal, with the sensors about 70-75 cm above the lunar surface and approximately 150 cm from each other. 

Magnetic fields measuerment:  ± 100, ± 200, or ± 400 gammas as selected by ground command, with a resolution of 0.2 gamma.
Frequency response: 0 (d.c.) to 3 Hz.
Sensor orientation was initially determined by the astronauts' using a bubble level and a shadowgraph, and has been subsequently monitored (with an accuracy of 0.2 degrees) by gravity-level sensors. 

The package was set up with the z-axis sensor pointing east and the x-axis sensor pointing towards the northwest.

Instrument Operation (A-12)

The LSM (12) was deployed at 14:00 UT and turned on at 14:39 UT on 19 November 1969 at 3.01 S, 23.42 W.
The first site-survey sequence was started at 22:50 on 22 November 1969. 

The instrument measured the magnetic field constantly for about three weeks after deployment, then on the dayside continuously for several months, then on the dayside very intermittently until data became static and invalid on 29 June 1970. 

The instrument was commanded off on 14 June 1974. 

고장의 원인은 회로의 용접부가 떨어진 것으로 추정됩니다. 이는 오랜동안 열변화를 격으면 일어날 수 있는 예상문제 중 하나이다. 이에 아폴로 15호 및 16호 LSM의 경우 납땜부위와 열 제어를 개선했다고 했지만 어느부분을 어떻게 수행 했는지는 .....?

Spacecraft component (A-12)
Landing date: November 19, 1969, 06:54:35 UTC
Return launch: November 20, 1969, 14:25:47 UTC
Landing site: Ocean of Storms 3.01239°S 23.42157°W

Sample mass: 34.35 kilograms (75.7 lb)
EVA duration


from ..    (R) https://nssdc.gsfc.nasa.gov/nmc/experiment/display.action?id=1969-099C-04