Apollo Lunar Surface Experiment Package (ALSEP)
General ALSEP Info & Support Equipment


ALSEP Subpackages

Left - B&W image of the 2 main ALSEP subpackages
Center - Two nice color photos of the subpackages
Right - Diagram of ALSEP packages, depicting how they were stored inside LM SEQ bay (quad II)

The ALSEP that never was. Apollo 13 CDR Jim Lovell practicing ALSEP deployment.  Note the twin UHTs attached to the pallets, sticking up at 45 degree angles from them.

Central Station
The central station relayed data to and from the experiments and routed power from the RTG to the experiments of the ALSEP. It was really the heart of the ALSEP station.

Left - Diagram depicting central station main structures. The top and bottom structures were actually the subpackage pallets
Center - Component layout of central station
Right - Antenna aiming mechanism

Left 2 images - Apollo 14 central station at Fra Mauro
Right - Did someone ask for details?

Radioisotopic Thermoelectric Generator (RTG)
The RTG produced 70 watts of electrical power for the ALSEP by converting the heat of decaying plutonium directly into electricity. The core was a SNAP 27 system. For its' time, it was a very sophisticated system.

Left - RTG nuclear fuel cask on LM mockup. The cask was designed to prevent nuclear contamination of the earth should the nuclear core ever reenter the atmosphere - which is exactly what happened when the Apollo 13 LM Aquarius brought the stricken CSM & crew home
(Photo courtesy Sven "Ninfingers" Knudson)
Center 2nd & 3rd images - Diagrams of RTG
Right - RTG fueling procedure.  The hand tools used to fuel the RTG are
covered in the next section.  The fueling procedure itself is covered in depth here

Left - Apollo 14 RTG with central station in background. Note that, unlike the experiments which used ribbon cables, the RTG used a heavy gauge round cable to connect it to the central station
Right - Apollo 16 RTG.  Can you say "Caked with dirt"?

ALSEP Hand Tools
RTG Dome Removal Tool and Fueling Tool
Also go here for in depth information on the RTG fueling procedure
There were 3 primary hand tools used with the ALSEP.  Two of these were single function tools, the RTG Cask Dome Removal Tool and the RTG Fuel Transfer Tool.  These were used to handle the radioisotopic fuel of the RTG.
All 3 of the Apollo Hand Tools RTG Fueling Tool Al Bean removing 
RTG fuel rod from 
cask.  All 3 tools are 
visible and labeled: 
1.  Fueling tool 
2.  Dome Removal Tool 
3.  UHT

Universal Hand Tool
The other tool, the Universal Hand Tool (UHT), was designed to fit into sockets on the ALSEP experiments and do everything from removing Boyd bolts, to opening arrays, to pointing the experiments.  The UHT was also adapted to be used as the LRV Sampling Tool on Apollo 17 as well as the Surface Sampling Tool.

UHT attached 
to Surface 
Sampling Tool
Jim Irwin practices 
deploying LSM
using UHT
Pete Conrad 
works at the 
ALSEP station 
with a UHT
UHT as used 
as the LRV 
Sampling Tool

Apollo Lunar Surface Drill
The ALSD was used to drill hollow tubes into the lunar surface. These tubes were used for emplacement of probes for the heat flow and neutron probe experiments, as well as to obtain deep core tubes of the regolith for geology

Left - Apollo 15 CDR David Scott threads a heat flow probe down the tube of a bore stem.  Note the drill head in background and bore stem rack in foregraound.
Right - Diagram of drill and associated hardware

Apollo Lunar Surface Close-up Camera

Left - Nice photo from the NASM
Right - Buzz Aldrin unpacks the ALSEP from Eagle, with ALSCC in foreground

Close-up stereo pair of lunar soil from Apollo 12 ALSCC

Also known as "the Gold camera", after it's inventor Tommy Gold, the ALSCC took stereo pairs of close-up photos of the lunar surface.  These images were used to help determine the properties of the lunar soils.  Although this camera wasn't technically part of the ALSEPs, I've included it here for clarity.
The ALSCC was an "aim and shoot" unit which needed very little of the crewmen's time to operate.  It was totally self-contained, requiring only that a crewman remove the film magazine when done using it.

Modeler's note: although there are no existing models of these devices, that may not always be the case. I've always wanted to reproduce at least some of these to stand next to an Apollo figure.  Someday...     someday....

Go back to ALSEP main page

Go to first ALSEP experiment report