T O P I C R E V I E W |
tetrox | Looking through Apollo 7 photographs on the Project Apollo Archive I have noticed what appears to be a small circular window towards the top of two petals on the Spacecraft-Lunar Module Adapter (SLA). For example in this photograph. I may be totally wrong but the Earth seems to show through which is most noticeable in high resolution. There also looks to be some kind of instrument across it which I would like to understand the purpose of. |
PeterO | It actually appears to be in all four petals, as shown in this photo. It will be tough to tell if it exists in the SLA panels of subsequent missions, since they were completely jettisoned from the S-IVB, rather than being hinged as on Apollo 7. |
tetrox | Thank you for that, you are indeed correct these small windows are on each of the Apollo 7 SLA petals. Looking further they appear as distinct circular black dots on the view of Apollo 7 on the pad. Also I cannot find the same features on subsequent Saturn V vehicles or later Skylab/ASTP Saturn 1B vehicles. |
SpaceAholic | That's a large cavernous (empty) space inside the SLA with 14.7 psi of pressure which needed to be rapidly equalized to vacuum during the ascent (recall that in most subsequent missions including ASTP the SLA had a resident). The other exception was Apollo 8, I think if you examine images from that launch vehicle you will see the ports are present as well. |
tetrox | Thank you for the kind reply and explanation but there is no evidence of these on this photo of Apollo 8. Also they do not show from what I can see on this photograph of Apollo 1, prior to the devastating fire or this of Skylab 2 on the pad, neither of which carried payloads. |
SpaceAholic | Apollo 8 undergoing stacking... |
PeterO | The holes in SpaceAholic's photo appear to match the covered plates in Tetrox's photo. The A7 holes are smaller and farther aft of the SLA/SM joint. Both circles are visible on A7 in this photo. Both sets of circles are also visible on the inside of the right and lower SLA panels in this photo. Incidentally, SpaceAholic's photo isn't Apollo 8, with that white CSM and Block I CM/SM umbilical. I believe it's the facilities checkout vehicle. |
tetrox | Thank you again for the reply, however I do not think the photograph you show is of the Apollo 8 CSM/SLA combination but of a test fit type article shown to the left in this photograph still in the VAB transfer isle during preparations for Apollo 14. The combination in the photograph you show is most certainly a mock up without protective coverings, rudimentary drawn on radiator panels and block 1 style Command Module. I was curious about the black circular dot on the SLA panel in your photograph but I believe it is closer in its position to represent a Service Propulsion System service port. I have no reason to dispute your explanation as to the purpose for these portals as I cannot offer a better explanation. However I am still left wondering why I cannot find evidence of these prior or subsequent to Apollo 7. |
SpaceAholic | I pulled that image off the Apollo 8 disk from Retro Space Images (part of a series in folder 1) - file name AS8-067--NOID-8.16.68. There were at least some design changes driven by the requirement to jettison the SLA panels subsequent to Apollo 7, could have been others resulting from SA-205 lessons learned. Another incidental data point - SA-205 employed SLA-5; Apollo 8 through Apollo 17: SLA-11A through SLA-21 respectively. |
PeterO | I doubt that the A7 ports are actually open holes. NASA went to great pains to tape and cover all openings on all launch vehicles, due to the Florida climate. The CSM was almost completely shrouded while on the pad. The photos showing the open SLA panels clearly have a rectangular box of some sort positioned over each hole with wiring leading to it. It's more likely that they are clear windows covering whatever sensor/camera/gadget is positioned there. |
SpaceAholic | I think you have nailed it...AS07-03-1539 provides a clearish shot of one of the cameras(?)..an extract: |
tetrox | The more I look at these as I describe as portals the more It seems to me that they appear as round windows. I have looked high and low for any description and the only clue I can possibly find is in the Apollo 7 mission report which makes mention of the crew during Sextant tracking having difficulties tracking Four lights on the S1VB. Whilst not technically part of the S-IVB (the petals) I wondered if these could be the lights mentioned, maybe similar to aircraft flashing lights and the windows would allow them to be seen no matter the orientation of the S-1VB. I cannot find any mention anywhere regarding cameras on the stage. Again I am grateful for any input and have no specific evidence of the above. |
J.L | quote: Originally posted by SpaceAholic: I pulled that image off the Apollo 8 disk from Retro Space Images (part of a series in folder 1) - file name AS8-067--NOID-8.16.68.
The photo shown from the Apollo 8 image disc is indeed a boilerplate. That series of images are dated August of 1968. The actual SLA/CM was not moved into position until early October of 1968. |
tetrox | Following on from my post yesterday I took a look on YouTube and found a NASA film (40 Years after Apollo 7 [part 1/2]). About 5 minutes 40 seconds in there is some footage of the SLA/S1VB combination rotating. There seem to be flashes of light coming from the portals on the SLA petals. There is of course the possibility that the light is being reflected off glass from maybe the Earth but a couple of the flashes look to me as though they are being generated from that area albeit somewhat randomly. |
mikej | I'd have to agree that the components on Apollo 7 are some sort of lights. The original film from the YouTube video is on the Spacecraft Films Apollo 7 disc set (chapter 5 "Rendezvous" of the onboards). The components can be seen flashing at random intervals starting at about 9:50 in the video, and more prominently around 11:35. Some of the flashes could have conceivably been caused by sunlight filtering through from behind, but certainly not all of them. Photo AS07-4-1568 shows one of the lights flashing: The specific reference from the Apollo 7 Mission Report is on page 6-2 (p. 260 of the PDF file): The crew reported that in the dark period at terminal phase initiation the flashing lights on the S-IVB were not visible in either the telescope or front window until the range had decreased to less than 15 miles. There's another mention of this same basic information on p. 6-25 (p. 283).The black circle on the Apollo 8/boilerplate photo posted above would be the SPS oxidizer service connection; the SPS fuel service connection would be on the next SLA panel clockwise (aft of the hatch). I've got photos of the SPS service connections and corresponding SLA access port on my website. |