Astronomy and space

What next for humans on the Moon?

We may not have put boots on the Moon since 1972, but interest in returning is growing.

This time around, the promise of learning more about the lunar surface is not the only motivation. The Moon is the ideal stepping stone to Mars and other deep-space targets.

Moon fact: The last mission to land on the Moon was the first by a non-profit organisation: SpaceIL. This Israeli spacecraft crash landed on 11 April 2019 after an engine failure during descent.  

What next for lunar exploration?

Since astronaut Gene Cernan stepped back aboard his Apollo 17 lunar module for the last time, we have not returned to the lunar surface. Yet despite this, we continue to learn more about the Moon.

For instance, the rocks and soil Apollo astronauts collected are being analysed using fresh techniques. Among other findings, these studies have recently located where and when volcanic glassy beads in some of the Apollo Moon rocks formed.

How the Moon can serve as a launchpad for discovery and exploration in the future

Orbiting satellites are also making new discoveries. NASA’s Lunar Reconnaissance Orbiter (LRO) is most famous for discovering water in ice and rocks at the Moon’s north pole in 2009. But more recently, it has uncovered areas ideal for future human settlement. Images from LRO revealed places where the Sun shines 96% of the time. This would mean solar panels powering a Moon base would never experience total darkness for more than a 24 hour stretch.

Meanwhile, two NASA ARTEMIS probes are orbiting the Moon to see how the solar wind electrifies and weathers the lunar surface. Data from these probes have revealed how the Moon’s small, localised magnetic fields act like sunscreen. These fields deflect solar wind away, creating patterns of dark and light swirls on the surface.

The most exciting current mission though is the Chinese Chang’e 4 robotic lander and rover. On 3 January 2019 Chang’e 4 became the first to land on the far side of the Moon. It is exploring the South Pole-Aitken basin, thought to be a section of exposed lunar mantle. Sampling this region could reveal information about the formation and structure of the Moon. New findings are being reported every week from the mission, so watch this space.

Cartoon image of potential future uses of the Moon

Putting a human on the Moon… again

Though they continue to drive our knowledge of the Moon forward, what these missions lack are humans. But right now, humanity is less capable of sending people to the Moon than 50 years ago. With lighter and cheaper robotic space missions prioritised in recent decades, there is currently no rocket powerful enough to reach the Moon in one go, no crew capsule to house the astronauts during their journey and no lunar lander to reach the surface.

However, this is all about to change. Renewed interest in lunar and space exploration – in part, as a result of the 50th anniversary of the first Moon landing – has seen the US, Europe, China, Japan, Russia and even private companies announce plans for manned missions in the 2020s and 30s.

To get off the ground, astronauts will need a heavy-lift rocket like Saturn V. NASA has had no rocket of their own capable of even reaching the International Space Station since 2011. But it is now investing in the Space Launch System (SLS), which will be the largest rocket in history.

The problem is that SLS continues to face heavy delays. This is why NASA is considering using private company SpaceX’s Falcon Heavy rocket. The Falcon Heavy is the most powerful operational rocket in the world. It could complete a Moon mission with two launches. One would carry the crew capsule. The second would be a rocket within a rocket. Once in space, the inner rocket would join with the crew capsule to fire the astronauts to the Moon. This technique is also being explored by the Chinese space agency.

Alongside a powerful rocket, astronauts will need a crew capsule for their journey to the Moon. NASA is teaming up with the European Space Agency (ESA) for this. ESA’s European Service Module will provide propulsion, life support, power, air and water, and control the temperature in the NASA-made Orion crew module.

Orion looks just like the Apollo crew module. But looks can be deceiving. It features technology light years ahead of Apollo, has room for four crew members instead of three, and a slew of safety features to protect the astronauts.

SpaceX is also developing a crew module capable of journeying to the Moon. The Crew Dragon has already flown a demonstration mission to the International Space Station. And the next generation of Chinese Shenzhou spacecraft will be ideal for human missions to the Moon as well. Though still in the early stages of development, the craft will likely carry 4­–6 astronauts and be reusable to reduce costs.

Plans for getting down to the surface are radically different from Apollo. Working with all the major space-faring nations and companies, NASA intends to build a small robotic space station in orbit around the Moon. Called the Gateway, it will act like an airport. Spacecraft will refuel, resupply and replace parts. And astronauts and robots will use it as a hub to journey down to the Moon and back multiple times on landers.

Stepping stone to Mars

In the coming decades, these technologies being developed right now will propel humans back to the Moon for the first time this century. This will undoubtedly lead to new discoveries about the Moon and the Solar System. But there is another motivation – to lay the groundwork for deep-space exploration. Unlike the Apollo missions, the rockets, crew capsules and landers are all being designed to travel beyond the Moon. And their ultimate destination is Mars.

Sending astronauts to Mars is fraught with dangers. So knowing that the equipment works well at the Moon before firing them at the Red Planet – around 225 million kilometres away – is a sensible move. Moreover, longer stays on and around the Moon than those of the Apollo-era missions will help scientists understand the effects of deep-space travel on astronauts. They will be able to assess whether space radiation shielding is effective and how astronauts react to working in space for extended periods. The astronauts may even be able to fuel up for their Mars trip with Moon-made rocket fuel.