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Topic: Venting of the Apollo S-IVB rocket stages
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Promisse
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posted 10-22-2013 04:44 PM
   
During the Apollo flights to the moon the discarded S-IVB rocket stages vented the excess of hydrogen and oxygen. This was done primarily as a safety measure in order to change the course of the rocket preventing a possible collision with the Apollo spacecraft.During Apollo 8 and 12 I have observed these gas clouds in the night sky. It was a pretty spectacular sight. I have always wondered why there never have been published any photographs of these events taken from space. According to the transcript of the communication at least during Apollo 8 it was observed by the astronauts and possibly also photographed. Does anyone have a comment to this, or even better know where I might find these pictures? |
mikej
Member Posts: 481
From: Germantown, WI USA
Registered: Jan 2004
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posted 10-22-2013 05:43 PM
The S-IVB venting may not have been photographed because the Command Module would have been fairly far away from the S-IVB, and on a different trajectory.I grabbed the first Flight Evaluation Report I found (AS-510). It reports that the final SC/LV separation took place at 15,481 seconds (about 4 hours 18 minutes) into the mission. LOX dump took place between 18,080 and 18,128 seconds (about 5:01), or about 43 minutes after separation. The velocity after the S-IVB's second burn was 34,240 ft/sec, or about 23,346 mph. Not accounting for decceleration due to Earth's gravity (I'll leave that calculation for someone else :-)), the CSM/LM would be nearly 16,731 miles away by the time venting was initiated. Since mission planners wanted no possibility of collision, the S-IVB was sent off in a slightly different direction than the CSM/LM. So, it may just be that the S-IVB was too far away and not in view of one of the relatively small CM windows. For missions after Apollo 8, the LM would have also substantially blocked the astronauts' field of vision. That being said, it would be possible for you to review all of the film from all of the Apollo missions, using information contained here. I did a very quick review of the Apollo 8 film rolls and found AS08-13-2371. There's no caption and no direct information as to when in the mission the photo was taken (again, I'll leave it to someone else to determine when that particular roll/frame was exposed), but there is some manner of "smudge" to the lower left of earth which could conceivably be the S-IVB venting. However, the smudge doesn't appear in some of other photos in that range, so it may literally be just a smudge. |
Headshot
Member Posts: 891
From: Vancouver, WA, USA
Registered: Feb 2012
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posted 10-22-2013 09:02 PM
As I recall, images of S-IVB venting from various missions appeared in various issues of Sky and Telescope magazine from that era. Also, NASA SP-201 and 232 from the Apollo 8 and 10 missions, has some images too. |
ehartwell
New Member Posts: 8
From: Waterloo, ON, Canada
Registered: Feb 2007
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posted 10-23-2013 07:38 AM
After separation, the SIVB was rotated perpendicular to the flight path and fired an evasive burn of the APS module engines. The final venting was delayed until it was well away from the spacecraft, so the astronauts would have had little chance to see it.The Apollo 14 crew captured a nice photo of a non-propulsive vent during transposition and docking. The full vent would have been spectacular. AS14-72-9920:  There's a detailed timeline of these events for Apollo 17 here. |
SaturnV
Member Posts: 24
From: Fowler, Ohio, USA
Registered: Sep 2013
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posted 10-23-2013 11:41 AM
The May 1969 issue of National Geographic, page 611, has a photo of the venting from Apollo 8. |
One Big Monkey
Member Posts: 171
From: West Yorkshire, UK
Registered: Jul 2012
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posted 10-23-2013 11:30 PM
AS08-13-2371 was taken well after TEI at about 13:15 on 26/12/68, as determined by the position of the terminator and weather satellite photographs (and all the pictures of the lunar surface preceding that!).The venting was done on the 21st. |
Promisse
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posted 10-27-2013 05:38 PM
Thanks guys for your postings to this topic. They were most helpful and the subject still intrigues me. I'm still curious to know what it must have looked like from the other side, from space. Maybe the only souls that are able to answer that are the astronauts themselves. Anyone knows how I might contact e.g. Frank Borman? |
Headshot
Member Posts: 891
From: Vancouver, WA, USA
Registered: Feb 2012
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posted 10-28-2013 02:43 PM
This might be a good subject for one of Alan Bean's paintings. |
LM-12
Member Posts: 3324
From: Ontario, Canada
Registered: Oct 2010
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posted 10-28-2013 03:43 PM
This S-IVB photo is from Skylab 3. |
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