some apollo questions

[gtvc]

Well I noticed some astronauts helmets are different after Apollo 12, Shepard helmet is different(less visor exposure) also some spacesuits have red lines this is for the commanders I presumed.

 I think in the Apollo 15 lift off from the moon the ascent stage losses some pieces in the back and I remember a video in lunar orbit where the command module checks the back of the ascent stage and you can see some panels missing, I'm wrong?

[Peter B]

Well I noticed some astronauts helmets are different after Apollo 12, Shepard helmet is different(less visor exposure) also some spacesuits have red lines this is for the commanders I presumed.

Yes, from A14 the Commander had red stripes on helmet and sleeves to make it easier to identify them more easily. On A13 Lovell had a distinctive helmet too (an anchor for his Navy background), but it didn't get much use. As for the visors, I believe helmets on later missions had a couple more compared with earlier missions, but I'm going from memory here.

I think in the Apollo 15 lift off from the moon the ascent stage losses some pieces in the back and I remember a video in lunar orbit where the command module checks the back of the ascent stage and you can see some panels missing, I'm wrong?

On one of the missions, panels on the rear of the ascent stage are buckled. But as these panels were only thermal and meteor protection, and not part of the airtight shell of the ascent stage, the buckling wasn't particularly serious.

As for the CMP checking the LM on return, I think they all did that, regardless.

[Peter B]

I think in the Apollo 15 lift off from the moon the ascent stage losses some pieces in the back and I remember a video in lunar orbit where the command module checks the back of the ascent stage and you can see some panels missing, I'm wrong?

Apollo 16 had some distinctive damage:

[Peter B]

Another example on Apollo 17:

[Glom]

Another example on Apollo 17:

"You came in that thing? You're braver than I thought."

[ka9q]

The LEVAs were visor/hood assemblies that were placed over the existing Lexan (polycarbonate) bubble pressure helmets that were part of the Apollo pressure suit. Based on the experiences of the first two crews, additional sunshades were added to the tops and sides, and that's why they start to look different on Apollo 14.

[ka9q]

As Peter B points out, it was Apollo 16 that had the most distinctive damage to the micrometeroid panels on the aft equipment bay of the LM. I don't think it caused any particular harm because the panels were not structural; the pressure vessel was well inside, and the aluminized Mylar thermal blankets underneath were still intact. The panels were intended to serve as the outer layer of a Whipple-type micrometeoroid shield, but that seems to have been an overblown hazard for Apollo and I have never heard of any problems on any of the missions, even the earth orbital ones. (The same is not true for the Shuttle and ISS because space debris has become far more serious in low earth orbit since Apollo.)

Hoaxers often ridicule the flimsy appearance of the LM, not understanding that the external surface was not the load (or pressure) bearing structure, or that one does not need aerodynamic surfaces in space.

Apollo 15 also had problems with a white paint used on some of these thermal panels, most notably on the +Y and -Y surfaces of the ascent stage. You can see them bubbled and cracked in pictures of the LM on the lunar surface. Apparently that occurred during cold-soaking on the way to the moon.

[raven]

Oh gods, I can not count how many  times I've seen some conspiracy theorist make some comment about the 'gold foil' covering and how 'flimsy' it looks.
So far, I've found photos taken during construction that show the pressure vessel help.

[gtvc]

thanks for the info the LEVAs were only for the apollo missions? the lunar module looks so fragile but at least they didn´t have any trouble.

[Nowhere Man]

Looks fragile, but isn't.  Think of it as the glass on the outside of an office building, or your aluminum/vinyl siding.  It's there to protect the interior of the structure, and incidentally hides all the strong supporting members that hold it up.

Fred

[ka9q]

I think modified versions of the LEVAs were also used for Skylab EVAs.

During trans-earth cruise in the Apollo J missions, the CMP used a LEVA during his deep-space EVA to retrieve film from the scientific equipment in the SM instrument bay. At least one was brought back from the lunar surface for this purpose. He also used one of the OPS brought back from the lunar surface for a possible contingency EVA transfer from the LM to the CSM.

[smartcooky]

Looks fragile, but isn't.  Think of it as the glass on the outside of an office building, or your aluminum/vinyl siding.  It's there to protect the interior of the structure, and incidentally hides all the strong supporting members that hold it up.

Fred

I like to explain it to people as being like an old style military tent...



It has a strong framework, that will stand up to most of the rigours asked of it, but it won't protect you from the elements, so you add a skin....



...which will protect you, but which on its own is flimsy and will not stand up without the supporting structure.