A fall of Moondust ~ Apollo science

This look back at apollo, esp for a senior space cadet first class (16 in 69) , like me, is riveting stuff.

http://www.abc.net.au/rn/scienceshow/default.htm

40 years since Apollo 11 - first manned mission to the moon -
Australian science on Apollo missions - dust detectors
Echoes of Apollo celebrates Apollo missions -

Buzz Aldrin: Forty feet, down two and a half. Picking up some dust, big shadow, four forward, four forward, drifting to the right a little.

Mission Control: Thirty seconds.

Buzz Aldrin: Contact light. Okay, engines stop. ACA out of descent. Descent engine command override off. Engine arm off, 413 is in.

Mission Control: We copy you down Eagle.

Neil Armstrong: Houston, Tranquillity base here. The Eagle has landed.

Robyn Williams: July 1969, Apollo 11, the landing on the Moon 40 years ago. Dr Brian O'Brien, now living in Perth, was there with the experiments placed by the astronauts, and now 40 years later he's still publishing papers on Moon dust in the journal Nature. This is how it all began.

Brian O'Brien: I'd spoken to the astronauts, lectured to them, Buzz Aldrin and the rest, when they came in. But in 1965 NASA advertised for experiments to be put on the Moon in a self-contained scientific station which would transmit back data to Earth after the astronauts left. They got 90 proposals and they accepted seven, and I was fortunate enough to be one of those seven.

Robyn Williams: And what was the experiment?

Brian O'Brien: That one was Charged Particle Lunar Environment Experiment, known as CPLEE for short, which measured auroral electrons and protons, solar wind, magnetospheric electrons and protons and so on. It was the radiation measurement of the package.

Robyn Williams: What were you actually trying to find out there?

Brian O'Brien: I wanted to link it to the radiation environment of the Earth in the auroral areas and in the radiation zones of the Earth, as well as to see what the effect of the Moon was on the solar wind. That's the atmosphere of the Sun, the hot atmosphere of the Sun that blows at supersonic speeds, blows a plasma of electrons and protons out into space.

Robyn Williams: So the apparatus is duly deployed and presumably it worked. What happened?

Brian O'Brien: Well, all sorts of exciting things, but we discovered more or less what I'd guessed might be there and we combined that with a knowledge from spacecraft, knowledge from rockets into auroras, satellites and so on, but a whole suite of things too complex to go into here when we're trying to talk about lunar dust.

Robyn Williams: Bring in the dust. We had a vague idea before 1969 that there might be something really hazardous where people land on the Moon and they sink up past their helmets in dust and are never seen again. Was that actually thought to be possible?

Brian O'Brien: Asimov promoted that in the late '50s and early '60s...

Robyn Williams: That's Isaac Asimov, the science fiction writer.

Brian O'Brien: Yes, and it was appropriately science fiction. But the interesting part was, from the history of science, that when Surveyor and the Russian lunars landed and didn't sink out of sight, the engineering design switched away from focus on such a severe hazard and forgot about the insidious hazard of creepy-crawly dust, if you like, sticky dust, which they left to the astronauts to manage.

Robyn Williams: Yes, I'm astounded by your picture, which I have in front of me, of one of the astronauts from Apollo 17 which I think was towards the end of December 1972, the last one, yes, and he looks as if he's down a coal mine. I thought that you'd be totally protected in all that space suitery.

Brian O'Brien: No, the stuff stuck to everything, and it stuck to their spacesuits, so once they got back into the cabin it floated and got everywhere again, so much so that on Apollo 12 the command module pilot, on looking into the lunar module when they docked, said it looked like a dirty coal mine in there, take off your spacesuits before you come into my nice, clean command module.

Robyn Williams: What was it made of, this dust?

Brian O'Brien: The dust is very fine, think of talcum power-type fineness, which is the result just of 4,000 million years of bombardment of the surface of the Moon, the rocks of the Moon, continued pulverising by 25,000 kilometre an hour type of little rocks from space, micrometeorites, meteorites, big ones, small ones, just pounding, pounding, pounding until you get the lunar soil pulverised. And you get this faint dust which is...because there's no atmosphere, because there's no water and the rest like on Earth, the dust tends to be sharp and angular, and it hooks in in that way, which is nasty, but it hooked in in other ways that we didn't really understand. It really was very clinging, it clung to everything.

Robyn Williams: What was the effect on the human beings? Was it dangerous to health?

Brian O'Brien: They're speculating that it could be for the longer duration missions, yes. Think mesothelioma and asbestos dust. This stuff is as small as five microns, it averages about 70 microns, thickness of a human hair, but if they're free to breathe it for long periods then...well, I'm not a medico, but I would think there would be problems.

Robyn Williams: And as for the apparatus itself I would have thought that it was absolutely deadly for that because every machine, let alone the rocket, would have been clogged and they were lucky to get away afterwards.

Brian O'Brien: No, it wasn't dangerous for getting away, it was dangerous for landing because it blew up clouds of dust, the rocket's jets as they landed. It was an insidious sort of thing that when they took off, for example, clouds of dust were blown up again by the rocket exhausts and those clouds of dust contaminated the shiny gold surfaces of the experiments left on the Moon, and the very first one, a lunar seismometer on Apollo 11 overheated by 50°F and, in the words of the day, it carked it after about 21 days.

Robyn Williams: And what about the machinery within the module? Was any of the apparatus affected at all?

Brian O'Brien: No, it made the steps slippery, for example, but no there was no intrinsic danger there that I've known about. It got into chronometers, it got into machinery, it got into the screw top lids of things they wanted to put a vacuum seal on, and it stopped the vacuum seals being taken back to Earth. But it was everywhere.

Robyn Williams: When you warned NASA about this, what notice did they take?

Brian O'Brien: [chuckles] Not a great deal. I designed a dust detector, deliberately minimalist, so it had no moving parts, it was only matchbox-sized. I put the telemetry, the signals back from it, I tucked them into the engineering series of housekeeping measurements and so on, so it was minimalist intrusion. And then I satirised my way to get a flight for it.

Robyn Williams: And then what happened?

Brian O'Brien: Then it flew. It was one of the two active experiments landed on the first mission with Neil Armstrong and Buzz Aldrin. There was a big 47Kg seismometer and the tiny little 0.27Kg dust detector.

Robyn Williams: Now that you've published some of these results most recently, what's new to say in the journals?

Brian O'Brien: I published in 1970 in a peer reviewed journal, Journal of Applied Physics, the results of the lift-off of Apollo 11, saying that it had been contaminated; dust contaminated the experiments, and I showed those measurements, measurements every 54 seconds. NASA unfortunately published one data point every ten hours and of course drew straight lines between the data points and missed the lunar module ascent which only lasted ten seconds or so. So we had a difference of opinion then, and my report faded into oblivion. But there was still the fundamental problem of why was it so sticky? And there were no other experiments of movements of lunar dust made on the entire Apollo mission except those by the little dust detector on Apollo 11, 12, 13 we lost, 14 and 15. And the funniest part of all, the most ridiculous part of all, is that I've got the only measurements of that on digital magnetic tapes which were sent to me as principal investigator back in Sydney.

Robyn Williams: And the story of those unique tapes will be on The Science Show on July 11th as we remember Apollo 11 with Dr Brian O'Brien, now living in Perth. His paper on Moon dust was published in Nature News on April 24th.