How did the Apollo astronauts toss their spacesuits overboard?
Hint: They kept the most important part.
- By Joe Pappalardo
- AirSpaceMag.com, January 01, 2007
The Apollo 17 astronauts photographed one of their PLSS backpacks, unceremoniously dumped on the lunar surface at mission's end.
NASA
Sometimes a little knowledge can be a dangerous thing, no matter how good your reasoning skills. Take the following question from Gianni Berati in Italy, who writes: "I have read that [Apollo 11 astronauts] Armstrong and Aldrin, after their extravehicular activities on the moon, had to throw off everything superfluous onto the lunar surface, even the lunar suits, in order to get the lunar module (LM) lighter. Is that true? How could they do that without a depressurized LM cabin?"
Berati is correct—the LM cabin did not have a safe area where unclad astronauts could seek refuge from the vacuum when they opened the hatch. Before going outside, they had to first put on spacesuits, then depressurize the entire landing craft. After a moonwalk they reversed the process, only taking off their suits when the LM pressure had been brought back up to normal. The next generation of moon lander will rectify this, adding an airlock as a "mud room" where astronauts can enter and exit while others lounge unprotected inside the craft.
So how did the Apollo astronauts manage to throw their spacesuits overboard? For an answer, the good folks at NASA's history office directed me to the Apollo Lunar Surface Journal, which explains in detail the unceremonious discarding of equipment onto the lunar surface. It turns out Berati is only partly right. The lunar explorers did not ditch the suits themselves, but rather the 84-pound Portable Life Support Systems (PLSS). The PLSS units, worn like backpacks, supplied enough air for four hours on the surface.
Armstrong, standing inside the LM in his space suit, opened two valves to bring the cabin pressure down to zero, then opened the hatch to the outside. The astronauts took the boxy PLSS packages, which they'd detached from their suits, and pitched them out the door with gloved hands (later lunar explorers found it more effective to use their feet).
"We didn't have any problems," Aldrin recalled during a technical debriefing. "I didn't notice you (Neil) had any difficulty giving the packages the heave-ho. I think each PLSS bounced once on the porch before it went down." (The "porch" was a lip of the LM jutting out just outside the hatch.)
Seismic sensors left on the surface by the astronauts even recorded the thumps of the gear hitting the moon. As Mission Control radioed to the two explorers: "We observed your equipment jettison on the TV, and the passive seismic experiment recorded shocks when each PLSS hit the surface" Armstrong responded, "You can't get away with anything anymore, can you?"
Examples of the PLSS gear and an unused Apollo lunar lander can be found at the National Air and Space Museum in Washington D.C. The real ones, of course, are now lunar litter.
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Comments (10)
why are the space suits required - ?? what kind of effect will be there on the human body in vaccume ( assuming we only had the qxygen breathing equipment) - or on the surface of moon
Posted by Deepankar Tiwari on July 10,2008 | 08:05 AM
Deepankar, without the pressure provided from a space suit, your blood would literally boil.
Posted by Dennis Wurster on December 22,2010 | 08:29 AM
If we put a large weight into an geostationary equatorial earth orbit and somehow attached a line, of some description, between it and a place directly below it on the earth, then loaded the weight with more mass to keep the line taught, couldn't this be used as a lift to launch satelites.
Posted by Alan on April 17,2011 | 03:32 PM
Dennis, your blood will not actually "boil". It will fizz up like an opened soda can due to the lack of air pressure.
Posted by Vincent on May 15,2011 | 10:23 PM
What did they where DURING the landing? Did they wear g suits? They were going from weightlessness to 1/6 gravity. Isn't that hard on the body?
Posted by Aaron on June 8,2011 | 12:00 PM
This is a great article on space suits. The technology on the suits is amazing. I went down to the Smithsonian with my family and looked at some of them although I think some are replicas.
I found this site
http://www.spacetoys.com/categories/Space-Suits/
that carries replica space suits and I bought one to display in my home. Very cool.
Posted by jay on March 23,2012 | 10:45 AM
Why are all the lunar module ascent stage facing backwards when lifting off the moon as seen from the rover and never the hatch side?
Posted by maurice theriault on November 30,2012 | 05:34 PM
Maurice,
The LM launches were all viewed from the rear because the aim was to follow the ascent stage in flight for as long as possible. After gaining some altitude the stage would commence arcing over toward the horizontal. Photography from the rear allowed the camera to follow the craft until it became too far away to register. From the front the craft could only be followed a short way before getting too high for the camera to follow without necessitating a complex turnabout, with the risk of losing it altogether. As it turned out, the camera operator had plenty of trouble following the craft as-planned on the liftoffs of Apollos 15 & 16. Having those two experiences, the operator finally got the timing just right on Apollo 17 and managed to follow the stage for quite some time.
Posted by Mark on January 9,2013 | 03:14 PM
Actually Mark, you're incorrect.
All 6 of the lunar modules to land on the moon were oriented with their backs to the sun so they would be able to see their landing sites clearly and use the LM's shadow as a reference. With no atmosphere the sun's glare is blinding, which is also why all of the lunar landing missions were done at a time where the sun was fairly low on the horizon. The LM launches that were video'd were Apollo 15, 16 & 17, using the Lunar Rover camera that was remote controlled by Ed Fendell in mission control Houston.
The lunar surface video cameras that the astronauts set up were angled from the side or behind the LM because the video cameras had 3 tubes that were extremely sensitive to the sun. There is only a few seconds of video from the Apollo 12 mission because Alan Bean accidentally pointed the camera directly at the sun, which burned out the tubes, making the camera useless. There is a funny story about Alan Bean hitting the camera with his rock hammer after the camera stopped working, as a last gasp attempt to correct the problem. He later said he had no idea the camera wasn't supposed to be pointed at the sun.
As far as wearing a G-Suit, the G forces experienced in the LM while landing were minimal. In fact the G's were so small that the LM astronauts, who were standing the entire 12 minute descent and ascent profiles, didn't notice any real change in the G-forces.
As far as space suits in the Smithsonian Air & Space Museum, there are no replica's, they are all genuine suits that were made for the astronauts or for training purposes. All of the space suits, helmets and other material related to suits in the Smithsonian's collection is in cold storage at the Garber facility. You can go online to see most of the suits and because the Mercury, Gemini & Apollo space suits are fragile, they are rotated from being on display to the Garber facility.
Posted by Ray on February 19,2013 | 10:23 PM
Good post Ray, I was going post some of the same details myself with regard to the sun and the spot for the LRV at launch time.
As to Apollo 12, that's always been a bit of a disappointment for me, and millions of others I'm sure. But at least we do have many hours of excellent footage from Apollo's 15 through 17. I can watch the EVA's for hours on end and never get bored with them.
For anyone that has never been to the Air & Space Museum in Washington, let me highly suggest that you do so if possible. It is my favorite of all the museums in Washington.
Posted by Kevin on March 25,2013 | 06:05 PM
This is far fetched, They disconnect their oxygen supply that was in the PLSS pack and stand there in just their suits with whatever small amount of oxygen is left inside them doing this depressurize / re-pressurize open the hatch close the hatch task. I wonder how long that took ? How comes they didn't suffocate ? They must have worked quickly....
Posted by john smith on May 9,2013 | 03:30 AM