Extravehicular Mobility Unit
1. Portable Life Support System (PLSS)
2. Oxygen Purge System (OPS)
3. Remote Control Unit (RCU)
4. PLSS Tool Carrier Harness
5. Links to related sections of
My Little Space Museum
Life Support System (PLSS)
Very nice photo of Haise's (left)
and Lovell's PLSS (right), rear and front. Note the serial numbers:
#020 for Haise and #021 for Lovell. Lovell's PLSS shows how the system
was packed before being stowed on board the LM. The OPS is a separate
unit that was installed prior ro EVA.
(J-Series PLSS with Auxillary Feedwater
(top to bottom, without OPS)
Above photo courtesy Kipp
Teague's Project Apollo Archive
Above - The innards of a PLSS
Center photo has interior details
Above - NASA PLSS Diagrams
Left - Note the location of the
LiOH canister, and stowed antenna on top of OPS
Left Center - Location of fill
and drain ports
Right Center - Excellent diagram
showing location of indicators, dials, and controls
Right - Ther interconnections between
the PLSS, OPS, and RCU
Interesting photo of Armstrong
practicing recharging the water system
My diagram of the OPS
Left - NASA photo of PLSS showing
Center - Very nicely detailed diagram
of the inner workings of the OPS
Right: Beauty photo of an OPS.
Note the actuator umbilical coiled around the side
The OPS was designed as an emergency
backup system to provide oxygen to a crewman while on EVA on the moon in
the event of PLSS failure. In combination with the Buddy Life Support
System (BLSS) for cooling, it could give the crewman enough life support
time to return to the LM and repressurize the ascent stage cabin.
It was primarily made up of a pair of oxygen cylinders and an actuator
cable which was mounted on the side of the RCU.
To run the system, the crewman
pulled down on the actuator cable to start flow of O2 then opened the diverter
valve of the front of the suit to create a presure gradient which would
force the O2 into the suit.
The OPS was covered by a plastic
shell which in turn was covered by a Beta cloth cover. The American
flag was stitched to the back of it.
The OPS was carried on board the
LM into lunar orbit to serve as a backup system in case the LM crew had
to make an emergency EVA from the LM to the CSM. On the later J-Series
missions it was also used by the CMP and LMP during the SIM Bay data retrieval
EVA. None of the OPS flown on Apollo were ever used in an emergency
situation, a great testimonial to the reliability of the PLSS.
Above: Side, front, and top
views of RCU
Photos above and first 2 photos below courtesy Mr.
Above: Alas, the mystery
of how the RCU attaches to the EMU is solved!!!
Photo at right shows Jim Irwin
in training, with the PLSS clips attached to the EMU.
The 2 "fingers" that would clamp
down on the bars on the clips are visible in the center image.
Right photo courtesy Kipp
Teague's Project Apollo Archive
Left - Diagram of the RCU control
displays, switches, etc.
Center - Photo of top of RCU and
electrical connector to the PLSS, with labels
Right - Similar to center photo
Tool Carrier Harness
Above- Three pages of diagrams
of the PLSS Tool Carrier Harness
Above Left - LMP PLSS Tool Carrier
Harness. Note the geology hammer and core tube rammer. The Core Tube
Cap Dispenser was mounted in the small cylindrical holder at the bottom
right of the photo, just to the right of the hammer.
Left Center - Another shot of the
LMP's PLSS Tool Carrier Harness
Right Center - Opposite side of
the LMP's PLSS Tool Carrier Harness, showing the Sample Collection Bag
(SCB) mounted on the side of the PLSS. The CDR's PLSS Tool Carrier
Harness held only a single SCB, mounted on the other side of the PLSS,
so that it would be outboard while he was driving the LRV.
Right - The Core Tube Cap Dispenser
Above Left - CDR's PLSS
Tool Carrier Harness, showing the quick release straps mounted on the side
of the LEVA
Right - Interesting closeup from
a photo taken on Apollo 17, showing a PLSS Tool Carrier Harness after it
was removed from the PLSS just prior to closeout of the final EVA
Links - for more information on the PLSS
PLSS, OPS & RCU Diagrams & Blueprints
- includes Hamilton Standard blueprints!
NASA EMU Diagrams
My EMU Diagrams - drawn by me
You must also go to the Apollo
Lunar Surface Journal PLSS page
here to return to EMU Gallery