What’s it like to be an astronaut?

Moon fact: Apollo 15, 16 and 17’s Moon buggies were too big to fit in the Saturn V rocket, so engineers designed them to fold in half.

Surviving and thriving on the Moon

There are good reasons the Moon is a lifeless rock. Any creature trying to survive on the lunar surface has to deal with up to 127 °C daytime temperatures and lows of -173 °C at night. They need to be built to withstand space radiation from cosmic rays and solar flares that fries DNA. And they definitely can’t be air breathers or water drinkers. The little water that’s there is trapped in ice or rock, and the thin atmosphere is about as unbreathable as it gets.

It's clear humans weren't built for the Moon. So how did the Apollo astronauts survive? One word: ingenuity. The lunar module that landed the Apollo astronauts on the Moon was the first true spaceship. This was because, unlike all before, it spent its entire working life in the vacuum of space. It shielded the astronauts from radiation and micrometeorites with protective multi-layer insulation foil. And it had a robust hull made out of solid aluminium ingots. 

The most impressive part of the design was the environmental control system. With minimal sensors and electronics, it worked like a complex engine. The system took oxygen and water from tanks outside the cabin. It then fed oxygen into the cabin, and also pressurised the hull, managed the temperature and provided water for the astronauts. It was, to all intents and purposes, their lifeline.

Out and about

The Apollo astronauts might have been safe in the lunar module but they certainly weren’t comfortable. There were no cooking or washing facilities, and the polite way of describing the toilet situation is ‘basic’. With just 4.5 m³ of living space, it was also very cramped. The astronauts had nowhere to sit. And if they needed to sleep, they had to sling a hammock across the cabin or find a free corner.

As a result, leaving the lunar module was probably a relief. To do this, they had to vent all the air from the cabin, and then crawl feet first through the hatch and down the ladder till they finally touched lunar soil.

Once they vented the air, the only thing saving them from certain death was their Extravehicular Mobility Unit – better known as a spacesuit. These suits not only had to keep the astronauts alive, but also had to provide a decent level of mobility.

The spacesuit design consisted of several layers. Over a water-cooled nylon undergarment, the astronauts wore a 12-layer onesie made from white, non-flammable Teflon-coated cloth and other advanced materials that held pressure, and offered heat and scrape protection. Mobility was provided by complex rubber joints at the shoulders, elbows, wrists, hips, ankles and knees. And metal connectors allowed the astronauts to attach gloves and a fishbowl helmet that sealed them in. On top of all this, they wore a pair of protective overboots and a portable life support backpack that contained oxygen, carbon-dioxide removal equipment and cooling water.

If they would have been on Earth, the astronauts would barely have been able to stand up, with the whole suit having a mass of about 80 kilograms. But thanks to the Moon’s weak gravity, the suit felt like it was just under 14 kilograms on the lunar surface. So despite their lumbering appearance, Apollo spacesuits were light and flexible enough for walking on the Moon.

In fact, the astronauts could moonwalk for hours at a time. While outside, they performed many tasks that tested the spacesuit’s flexibility. They collected lunar soil and rock samples, deployed experiments, planted flags, and surveyed and photographed the surface. During the Apollo 14 mission, Commander Alan Shepard, best known as being the first American to travel into space in 1961, even found time to play a little golf.

Lunar joyride

The big problem was that these moonwalks were just that: walks. This restricted exploration to short distances around the landing site. What soon became clear was that these astronauts needed transport. The last three missions ­that landed humans on the Moon – Apollo 15, 16 and 17 – got it in the form of the Lunar Roving Vehicle. This vehicle is best known as a Moon buggy.

Moon buggies were four-wheel drive, battery-powered cars about the size of a Volkswagen Beetle. They used a T-shaped joystick instead of a steering wheel to get around. Their rather slow top speed of 13 km/h didn’t stop them from travelling up to 8 kilometres from the landing site, and covering a combined distance of 88 kilometres over the three missions. Using the Moon buggies, astronauts collected rock samples from a much wider area than previously possible. This has helped scientists get a better understanding of the Moon's surface.

With all this hi-tech equipment allowing the astronauts the freedom to explore the lunar surface, Nasa gave them numerous tasks to make as much of their short time on the Moon as possible. But they still got a chance to enjoy their alien surroundings. Alongside the fun of bouncing around in low gravity, many astronauts later recalled how they were in awe of the lunar landscape, and taken aback by seeing the beauty of our blue planet from the Moon's perspective. Apollo 11’s Buzz Aldrin summed it up best with his first words as he became the second human to set foot on the Moon: “Beautiful view. Magnificent desolation.”