2016/08/14

The very first image of a Lunar Module on the Moon taken from space: Apollo 15, 1971

by Paolo Attivissimo. An Italian version of this article is available. Credit for all images: NASA/LROC/Arizona State University.

The Lunar Reconnaissance Orbiter probe is well-known for its photographs of the Apollo landing sites, which in 2009 finally showed the first glimpses of the hardware left on the Moon (link) and in 2012 offered even clearer views, such as the following picture of the Apollo 15 landing site, showing the descent stage of that mission’s Lunar Module, which like all LM descent stages used for Moon landings was left on the lunar surface. The image also shows the electric vehicle (LRV) used by astronauts Dave Scott and Jim Irwin to explore the area, the experiments they set up on the Moon (ALSEP) and the trails of footsteps they left.



However, LRO did not provide the very first visual documentation of Apollo hardware on the Moon from lunar orbit: there are photographs of the Apollo 15 landing site taken from space while the astronauts were still on the Moon.

The Apollo 15 Service Module, which remained in orbit around the Moon under the control of Command Module Pilot Al Worden while Scott and Irwin explored the lunar surface, was in fact equipped with a high-resolution Panoramic Camera, which took hundreds of photographs from lunar orbit (details are here and here). Each of the long, narrow images taken by this film camera resolved surface details of 1-2 meters over an area of 320 x 20 km. These photographs have been scanned and made available online at the Apollo Image Archive of the Arizona State University.

These Panoramic Camera image scans are truly huge: the PNG Large versions measure 60,000 x 6,500 pixels. However, there are even higher-resolution versions, the raw TIFF scans, spanning a whopping 320,000 x 25,000 pixels. They are so large that the ASU has split each Panoramic Camera image into eight tiles measuring approximately 40,000 x 25,000 pixels.

AS15-P-9377 is one of the best Panoramic Camera images of the Hadley Rille landing site of Apollo 15. This is the full-width version, resized to 1024 x 109 pixels (the Hadley Rille is right in the center of this long film strip):




Maximum zoom-in on the Arizona State University website yields only barely visible shadow of the LM. You’ll probably have to click on the picture below to see it next to the tip of the arrow.




Interestingly, it turns out that ASU's maximum zoom does not provide the full resolution of the scan. For that you need to download the TIFF raw scan. Tile 4 (2 GB) of this raw scan looks like this (resized and annotated; the box indicates the landing site area):




You can now zoom in on the landing site and get this (resampled and annotated):




Rotating this image so that north is up, increasing its contrast and cropping it yields this: the complete Lunar Module (both the ascent stage and the descent stages): notice the tapering shadow. This is the very first orbital image of an Apollo LM, and it was taken while its astronauts were still on the Moon.




Thanks to the ASU data we know exactly when it was taken: on July 31st, 1971, during the sixteenth lunar orbit of the Commmand and Service Module Endeavour. In other words, about an hour after Dave Scott’s Stand-Up EVA, so Scott and Irwin were inside the LM when this photo was taken by Al Worden from an altitude of 101.22 km.

I’d like to clarify that I’m not claiming this to be my discovery: I’m merely documenting the method you can use to access these images. The Apollo Lunar Surface Journal already has this image in its Apollo 15 Map and Image Library. The ALSJ library, additionally, notes that Apollo 15 also took other pictures of the landing site showing the LM from orbit during later orbits while Scott and Irwin were still on the Moon (frame 9430, orbit 27 and frame 9798, orbit 38) and after they departed (frames 9809 and 9814, orbit 50). The photograph shown here is the very first one.

3 commenti:

Gianluca Atti ha detto...

Molto bello Paolo, ma mi scriveva un amico se lo si potesse leggere in italiano.
Grazie.

Paolo Attivissimo ha detto...

Grazie Gianluca,

ho pubblicato poco fa la versione italiana.

Gianluca Atti ha detto...

Grazie a te Paolo anche a nome degli amici di @giaroun! :-)