Author
|
Topic: Earth views from on board Apollo 13
|
LM-12 Member Posts: 3324 From: Ontario, Canada Registered: Oct 2010
|
posted 08-03-2016 10:29 AM
Compare the Earth views from the Apollo 13 lunar module seen in frames 8993, 8994 and 8995. The first two frames look like the Earth views were taken out the overhead docking window. However, in frame 8995, it looks like the Earth is inside the LM. Is that a double-exposure, or are we seeing a reflection of the Earth (off the COAS perhaps) in all three frames? |
schnappsicle Member Posts: 396 From: Houston, TX, USA Registered: Jan 2012
|
posted 08-04-2016 06:37 AM
The earth is definitely reflecting off something, but I'm not sure what. This is a common phenomena when shooting bright objects. The object reflects off the front piece of glass on the camera lens and sometimes other glass in the lens as well. These Apollo 11 shots show the sun reflecting off two pieces of glass in the Hasselblad lens. I think your Apollo 13 examples are also reflecting off the glass in the lens, but in those cases the photos are probably picking up the earth reflecting off the lens and back on to the window. I'm not qualified enough to make a definitive declaration. Like you said, the window through which the photos were taken is thick enough (I think it's 2" thick) to cause the same thing to happen. I can say however, that it's definitely not a double exposure. The Hasselblad cameras used during Apollo had motor drives to advance the film. In other words, every time they pushed the button to shoot a photo, the camera would automatically advance the film immediately after the shutter closed. A person would need one of the hand crank manual cameras in order to shoot a double exposure with a Hasselblad. I know because I have both models. |
LM-12 Member Posts: 3324 From: Ontario, Canada Registered: Oct 2010
|
posted 08-04-2016 08:59 AM
I'm wondering if the LM Alignment Optical Telescope (AOT) might be involved somehow. Or maybe we have it backwards: maybe the photos of Earth were taken out the CDR window, and the rendezvous window / LM interior is the reflection. If the Earth and a rendezvous window reflection lined up closely in the CDR window, then it could look like the Earth is being viewed through the rendezvous window in photos. That might be what is happening here. Plausible? |
One Big Monkey Member Posts: 171 From: West Yorkshire, UK Registered: Jul 2012
|
posted 08-15-2016 09:55 AM
The Apollo 13 images were taken at around 12:30 GMT on April 16th (as deduced from the view of Earth and the weather systems on display). You get excellent double reflections in Magazine 63 images, which you can find at the Gateway to Astronaut Photography - here's one with lots of detail that can allow you to identify which window was used. This image from magazine 62 shows the double window very well and you can see the same features in the bottom right of AS13-62-8993. |
LM-12 Member Posts: 3324 From: Ontario, Canada Registered: Oct 2010
|
posted 08-15-2016 11:55 AM
In photo AS13-59-8555 you can see the Earth reflected in the overhead docking window as the LM is jettisoned from the CM. |
One Big Monkey Member Posts: 171 From: West Yorkshire, UK Registered: Jul 2012
|
posted 08-15-2016 04:28 PM
That is a fantastic spot.I'm trying to match up what can be seen with what the weather satellite data from the 17th show, and I think I can identify a storm system over southern Africa, which would match what ought to be on view. I need to be more certain before I add it to my site though. |
LM-12 Member Posts: 3324 From: Ontario, Canada Registered: Oct 2010
|
posted 08-15-2016 08:43 PM
It looks like you can see the terminator. The LM was jettisoned 70 minutes before re-entry, at an altitude of 11, 257.48 miles. The time in Houston was 10:43 a.m. |
LM-12 Member Posts: 3324 From: Ontario, Canada Registered: Oct 2010
|
posted 08-16-2016 05:12 AM
I would say the black and white photos of the LM jettison were taken by Haise in the right seat position looking out CM window 4. |
LM-12 Member Posts: 3324 From: Ontario, Canada Registered: Oct 2010
|
posted 08-24-2016 01:10 AM
quote: Originally posted by One Big Monkey: I think I can identify a storm system over southern Africa
The mission report has an Earth-referenced latitude and longitude of 1.23S and 77.55E for the LM jettison. |
One Big Monkey Member Posts: 171 From: West Yorkshire, UK Registered: Jul 2012
|
posted 08-24-2016 02:19 AM
Thanks. I spent some time and a lot of head scratching over this, but sadly haven't been able to pinpoint a precise location for what we can see. Logical deduction and a process of elimination points to a a similar pattern of broken cloud over south-west Africa (not the one I originally surmised), but the level of detail in the available satellite image, and the roughly 6 hour time gap between them, means I can't be certain. I've written it up here. |
LM-12 Member Posts: 3324 From: Ontario, Canada Registered: Oct 2010
|
posted 08-24-2016 09:55 AM
Terrific write-up about the Earth reflection seen in frame 8555. I too was impressed by the amount of detail in that reflection.The amount of research you have done in comparing mission photos of Earth to the corresponding weather satellite images to disprove the nay-sayers is nothing short of mind-boggling! Thanks for including a few of my observations. |
LM-12 Member Posts: 3324 From: Ontario, Canada Registered: Oct 2010
|
posted 08-24-2016 11:36 AM
This Apollo 13 photo AS13-60-8577 of Earth is most probably the first image taken on the mission. Barely visible in the distance is the thin crescent moon.
|
LM-12 Member Posts: 3324 From: Ontario, Canada Registered: Oct 2010
|
posted 08-26-2016 09:35 PM
quote: Originally posted by One Big Monkey: I've written it up here.
Can you do a "Frame By Frame" of the LM jettison on your website? That would be frames 59-8549 to 59-8576. Another suggestion: the LRV traverses. |
LM-12 Member Posts: 3324 From: Ontario, Canada Registered: Oct 2010
|
posted 09-02-2016 09:54 AM
The overhead docking window in the LM is window 2.I do not think the Apollo 13 crew took any 16mm footage of the LM jettison. |