Apollo Lunar Surface
Experiment Package (ALSEP)
Active Seismic Experiment
(ASE)
.
Top - Apollo 14 ASE. The white box to the left is the Mortar
Package Assembly (MPA). Between it and the central station is the Apollo
Simple Penetrometer (ASP), which was also used to anchor the geophone
line so it wouldn't get pulled loose. The geophone line can be seen going
from the ASP to the bottom right corner of the picture.
.
.
Above left - Apollo 14 LMP Edgar Mitchell operates the Thumper.
Left Center - Closeup of the Thumper.
Right Center - Apollo 14 backup LMP Joe Engle practices EVA with a
Thumper. Note the UHT attached to his waist.
Photo courtesy Kipp Teague's Project
Apollo Archive
Right - Closeup of Apollo 16 MPA. You get a little sense of the
ruggedness of the Descartes highlands in this nice photo. In the
background are (L - R) the Central Station, RTG, and Magnetometer.
Apollo Experiment Number: S 033
Apollo missions: 14, 16
Weight (MPA): 11.2 kg
The ASE consisted of 3 separate pieces of equipment.
First, a set of 3 geophones were layed out along a cable connected to the
ALSEP Central Station. Also, the Mortar Package Assembly (MPA) was deployed
as part of the ALSEP. Finally, one of the crew used the Thumper during
the EVA.
The geophone system
was the simplest of the 3 parts of the ASE to deploy and operate. One of
the crewmen (Usually the LMP) unreeled the cable, walked a predetermined
distance (marked on the cable) and stuck the spike of the geohpne into
the regolith.
The MPA proved difficult
to deploy and align. It was designed to lob a set of 4 explosive charges
away from the ALSEP site after the crew had left the moon, in order to
produce an active seismic signal. The Apollo 14 MPA was never activated,
because problems deploying it caused concern that it might damage other
parts of the ALSEP if it was fired. The Apollo 16 MPA was able to fire
3 of its' 4 rounds.
The "Thumper" was a neat
little device. Essentially it was a staff with a large base containing
21 seismic charges, called "single bridgewire Apollo standard initiators".
These were activated by a dial on the staff, and provided a small seismic
shock for the geophones to monitor.
A similar system, the Lunar Seismic
Profiling Experiment, was carried out on A 17.
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