MISSIONS TO THE MOON TIMELINE
PROF DAVE ROTHERY Professor of planetary geosciences, Open University, UK
“Lunar exploration has been going on fairly vigorously for 20 years. We have a series of missions around the Moon: there’s the GRAIL gravity mission from NASA; the Chinese are planning to go to the far side of the Moon; and there are plans from [private company] Lunar Mission One to go to the South Pole-Aitken basin to drill into that. So the unmanned exploration is happening but there’s only so much you can do from orbit.
You do need to get among the surface materials as well – both for seeing the geology at close quarters, and for taking measurements that you cannot take from orbit. Apollo left four seismometers on the Moon for recording moonquakes. They weren’t brilliant but it’s the only other planetary body that we’ve got seismology for. They told us about the Moon’s interior but they were turned off after a few years – stupidly to save money.
A few seismometers on the lunar surface would give us great insight into the Moon’s interiors. But you have to be on the surface to deploy them so that you can couple them properly to the ground.
And there are heat flow experiments. We don’t know at what rate the Moon’s internal heat is leaking out towards the surface. They tried to measure it on Apollo and it didn’t work. They had trouble getting a good hole into the ground. So we are guessing at the lunar heat flow until we can go back, drill a hole and put some equipment down it. And you’re probably going to need people to do something that fiddly.
Getting equipment to work on the Moon is a challenge we have yet to overcome. The lunar dust rises and falls with day and night because of electrical static charges. You can get dust flecks into your mechanisms that give you problems.
If you’ve got people there you can overcome
“I WAS A KID WHEN APOLLO HAPPENED AND I THOUGHT IT WAS THE FUTURE, I THOUGHT THAT WAS WHAT WE WERE GOING TO BE DOING: PEOPLE IN SPACE”
problems. They can deploy equipment and drill holes, and they can wander around making geological observations. The orange- coloured lunar soils were spotted by an astronaut from one of the later Apollo missions. They thought it was something rusty but it was orange beads from an explosive volcanic eruption. If you’ve got trained people there, they’ll spot the unusual things.
The Mars rovers – impressive though they have been – haven’t gone as far as astronauts driving the Moon buggies around. It’s a lot more expensive when people are there, but you get a lot more done.
I was a kid when Apollo happened and I thought it was the future, I thought that was what we were going to be doing: people in space. It was inspiration for me. There is a benefit from just seeing people up there because it inspires the next generation of scientists. I don’t think you can decouple that from the scientific facts that you are going to find out. As well as the mysteries that you are going to unravel, you’re also going to be inspiring the next generation of scientists.”