Collins and the moon landing

Hello Everyone,

Could Michael Collins see Neil and Buzz on the moon as he orbited?

The Command Module orbited the Moon at an average altitude of about 60 miles. So no.

I wish I could find the text to quote it, but my copy of “A Man on the Moon: The Voyages of the Apollo Astronauts” is an audiobook :slight_smile:

Anyway, I recall in one or more places where the astronauts in the command module attempted to sight the astronauts on the ground using a telescope they had for star sighting. And with great effort they were able to see the site, but no dancing astronauts at that distance. The challenge was not so much in resolving tiny objects, but in finding the landing site among hundreds of miles of identical-appearing crater-pocked landscape.

But I assume Collins could talk to the Neil and Buzz while they were on the surface, at least when he wasn’t on the other side of the moon, or is that a faulty assumption?

I would think that Neil and Buzz would have been able to see Collins flying by overhead, if the glare in their face masks didn’t overwhelm it.

No, not faulty at all.

Almost certainly. We here on Earth’s surface can see satellites in orbit, and most of those are both more distant than 60 miles, and smaller than the Apollo CSM.

For anyone who wants these kinds of details about the moon missions, I highly recommend the book I mentioned above: A Man on the Moon: The Voyages of the Apollo Astronauts

The author interviewed all 12 astronauts who walked on the moon, and made a solid effort to cover each Apollo mission in a way that brings out individual detail, as well as providing depth to the persona of each astronaut.

The communications between command module and LM were covered several times, from different points of view, highlighting lessons learned as the program progressed. I seem to recall that the communication was not point-to-point, but that all communication was relayed from Earth (not sure if they ever had direct comm).
Regarding spotting the guys on the ground: with each landing the trajectory guys got better at planning the landing, so it was easier to find them in the fields of lookalike craters. One LM landed at a pre-selected large/small crater combo called “The Snowman” that was eventually spotted by the command module pilot.

Very fascinating read.

Right, and the surface guys had a black sky, but on the other hand their eyes were adjusted for daytime light, and there would have been glare in their helmet masks, so I’m not sure. Were they able to see any stars? I would think the command module would have been brighter than any star, on the order of Venus at opposition.

I would think that for the docking maneuver, they would have had to have direct comms because of the delay. But maybe that was for short-range only.

We’ve all seen those pics showing the “glare” on their helmet face-pieces. It looks like a mirror. But isn’t that glare seen only from the outside? From the inside looking out, there’s no such glare, is there?

Voice comm was typically relayed through earth on S-band (2,100 Mhz) but they had multiple frequencies, modes and paths available – including direct spacecraft-to-spacecraft.

During lunar EVA the space suit radios were usually relayed through the Lunar Module, however it was possible to directly communicate from earth to the astronaut’s 3.8 watt radios in the suit, using the huge parabolic antennas of NASA’s Deep Space Network:

In fact in 1969 a ham radio operator received the VHF voice transmissions direct from the moon’s surface, apparently as relayed by the spacecraft’s 30 watt radios:

There was a point in the landing of Apollo 11 where Mission control could communicate with the CSM but not the LM and Collins relayed a message.

The biggest source of ‘glare’ would be from the Moon’s surface itself. Even if you were to stand in the shadow of the Lunar Module and look up, you’d still be surrounded by the reflected light from the Moon’s surface. Not to mention the glare from your colleague if he happens to be standing nearby in the sunlight. Perhaps if you took great care to avoid all sources of glare you might see stars, but that is very tricky on the daylight side of the Moon.

I was talking about the glare that would result from the sun’s light hitting the helmet face mask, and any imperfections in it would be in the way of seeing the stars/CSM. I guess if they stood facing away from the sun, or in the shadow of the LM, that would help. Their eyes would still be adjusted for daytime light however. Surely it’s documented somewhere about whether they could see any stars?

Yes it is, and no, they could not. The glare from the helmet (as seen from the inside) is negligible compared to the glare from the Moon’s surface. To see the stars with their own eyes they;d need to isolate themselves from all reflected sunlight, including light reflected from the distant horizon and from the Lunar Module. Really the only way they could do this would be to stand at the bottom of a deep hole- and they didn’t have time to dig one.

Per Collins book (which was fantastic by the way) he wrote he couldn’t see the LM with the naked eye or the sextant. He felt he could have seen it with the sextant if he could have locked on to it, but the field of view was too narrow.

Here’s another factor to consider. The Command Module would have been visible from deep shade on the Moon (from the bottom of my deep hole observatory, for example) but the similarly-sized lunar module would have been practically impossible to spot from orbit. This is because of contrast. The Command Module would be set against a black sky; but the LM would be surrounded by a vast plain of illuminated moonscape, with approximately the same illuminance as the ship.