Probably from the film Apollo 13, which depicts (likely wise) hesitance to fire the SPS due to suspected damage and instead firing midcourse correction burns with the LEM descent stage while attached to the CSM. By contrast, during the otherwise normal Apollo 11, SPS was responsible for returning Collins and the CSM to Earth (TEI) whether he retrieved Armstrong and Aldrin or not. The latter case was a rehearsed abort and the stakes were known, but the maneuver was otherwise the same as a normal TEI (excluding LEM jettison, obviously). Nixon’s backup speech illustrates this, as it eulogizes those two alone; Collins would have most likely returned on his own in that horrible circumstance barring a further failure of some kind.
> instead firing midcourse correction burns with the LEM descent stage while attached to the CSM.
The descent stage was left on the moon so that would have been the LM ascent stage. They had 2 separate motors for descent and ascent.
But indeed Apollo 13 was very different. I think on normal missions they only brought the LM back along for TEI so as not to litter the surface with crashed LMs.
Why make (wrong) guesses when you can find the answer in minutes on Wikipedia? Plus it doesn’t make sense to do a TEI with unnecessary mass. From https://en.wikipedia.org/wiki/Apollo_Lunar_Module :
“The six landed descent stages remain at their landing sites; their corresponding ascent stages crashed into the Moon following use. One ascent stage (Apollo 10's Snoopy) was discarded in a heliocentric orbit after its descent stage was discarded in lunar orbit.“
Elsewhere, I read that the ascent stages were crashed into the moon to provide impulses for the seismometers left on the moon. Snoopy is still in orbit around the sun. And the one from Apollo 13 is in the Tonga Trench. Two fascinating lists:
As for littering the surface of the moon, I was surprised to see in videos that in addition to the scientific equipment ( and golf balls) they left on the moon, there was a lot of other little pieces. In one of the videos on the rover, they literally remove the cover off something and just throw it aside on the ground.
I was on my phone (materialistic app) so even a wikipedia search is difficult :) I hate using the web on a mobile, it feels like I'm looking through a toilet roll.
But I mentioned it was an assumption... The parent poster mentioned that the ascent stage was carried into TEI so I assumed that was true.