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Author
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Topic: Apollo 13 service module's reentry
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Paul78zephyr
Member Posts: 678
From: Hudson, MA
Registered: Jul 2005
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posted 10-16-2010 11:03 AM
  
Did the Apollo 13 service module re-enter the atmosphere and burn up after being jettisoned? If so when/where? |
ilbasso
Member Posts: 1522
From: Greensboro, NC USA
Registered: Feb 2006
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posted 10-16-2010 08:23 PM
There's a famous photo of the SM and the LM re-entering over Australia. At separation from the CM, there was a short burn to increase the distance between them, but reentering at 25,000 mph, and needing to delay the separation as long as possible to preserve the batteries in the CM, there's only so far apart they could get. Once in the atmosphere, the LM and SM followed a ballistic trajectory. The CM could be steered by rolling the spacecraft to move the center of gravity, enabling it to be targeted to the landing zone. |
chenry
Member Posts: 60
From: Zionsville, IN 46077
Registered: Oct 2010
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posted 10-17-2010 11:14 AM
I may be wrong, but I thought I could remember seeing a picture of the remains of the LM after were recovered. Does anyone else remember this? |
Skylon
Member Posts: 277
From:
Registered: Sep 2010
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posted 10-17-2010 12:35 PM
I thought Aquarius was dumped very deep into the Pacific due to a radioactive experiment carried aboard.Frankly, the LM was so thin-skinned I'd be shocked if much survived. |
Tom
Member Posts: 1610
From: New York
Registered: Nov 2000
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posted 10-17-2010 12:45 PM
quote:
Originally posted by chenry:
Does anyone else remember this?
If I recall correctly, the remains that were found were of the first lunar module test flight (LM 1). |
mikej
Member Posts: 481
From: Germantown, WI USA
Registered: Jan 2004
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posted 10-19-2010 07:17 PM
quote:
Originally posted by Tom:
If I recall correctly, the remains that were found were of the first lunar module test flight (LM 1).
Yes, portions of the descent stage of LM-1 (Apollo 5) were recovered from Columbia, South America. I have information about Apollo 5, as well as pictures of some of the returned debris, on my web site. |
MadSci
Member Posts: 230
From: Maryland, USA
Registered: Oct 2008
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posted 10-20-2010 02:06 AM
I believe the comment about the LM being aimed at a trench in the pacific due to concerns about the radioactive thermal generator for the ALSEP is correct. It was heavily built so that if there was an explosion and crash during launch the container wouldn't be breached, hence the concerns about it surviving reentry.As for the LM itself, its skin was thin to be sure, however there were many parts that were of necessity heavily built or otherwise capable of surviving reentry. The helium and other tanks for example, and of course the engine thrust chambers were built to withstand both high temperature and erosion from high velocity gases, so it's reasonable to assume some identifiable pieces would get back home to earth. |
ilbasso
Member Posts: 1522
From: Greensboro, NC USA
Registered: Feb 2006
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posted 10-20-2010 08:46 AM
"Aimed at a trench" is probably being a little generous in terms of the extent to which the reentry could be targeted. The best that could be done was to time the trans-Earth burn such that the LM's eventual reentry would be over deep water. They couldn't adjust the impact point north or south of the reentry vector. There simply wasn't enough propellant or time to make significant changes to the LM's trajectory before it hit the atmosphere.I do remember concerns being raised at the time about the RTG cask, and the public being reassured that the impact would be in the deep ocean, and I do recall the PR that it would be going into a trench. However, the reentry was ultimately timed to maximize the chances of crew survival as the overwhelming primary consideration. Since Apollo recoveries happened in deep water, the LM would be going into deep water, too. |
Robert Pearlman
Editor Posts: 43576
From: Houston, TX
Registered: Nov 1999
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posted 10-20-2010 09:18 AM
Various NASA missions that also employed radioisotope thermoelectric generators (RTG) for power cite in their environmental impact reports the Apollo 13 RTG as a case study. For example, from the final report for Galileo: In April 1970, the Apollo 13 lunar module reentered the atmosphere and its SNAP 27 RTG, which was jettisoned, fell intact into the 20,000 foot deep Tonga Trench in the Pacific Ocean. Measurements show that there was no release of radioactive material into the atmosphere. I'm not sure what the reference to "jettisoned" applies to -- I don't believe the RTG was further separated from the lunar module after reentry -- but it does appear its reentry was tracked in order to conduct atmospheric measurements. |
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