Space Safety for the Moon

Establishing a human presence at the Moon is a formidable challenge. The Moon lacks Earth’s thick atmosphere and magnetic field, leaving human explorers and their technology at greater risk from solar radiation, asteroid impacts and debris in orbit.

ESA established its Space Safety programme to address these hazards at Earth, but it will also play an important role in safeguarding human exploration at the Moon and beyond.

Space Weather

One of the greatest threats to astronauts and satellites at the Moon is the Sun. Unlike Earth, the Moon lacks a magnetic field and atmosphere to shield it from the energetic charged particles of the solar wind. These particles pose a hazard to astronaut health and to the sensitive electronics inside satellites and infrastructure on the surface.

ESA is developing new ways to monitor and forecast large space weather events, such as its Vigil satellite. Increasing our advanced warning of a severe event will give astronauts outside Earth’s protective magnetic bubble time to retreat to safe, radiation-hardened environments inside their space station or below the lunar surface.

“Reliable space weather forecasting services are a necessity for the exploration and long-term habitation of the Moon,” says Juha-Pekka Luntama, Head of ESA’s Space Weather Office.

Planetary Defence

The Moon’s surface is also bombarded by small asteroids that would burn up in the atmosphere if they struck Earth.

ESA's NELIOTA project analysed flashes of light created by small objects striking the Moon’s surface for more than six years. The results of the project will help researchers estimate the scale and frequency of lunar asteroid impacts, which will be important information for the design of lunar bases.

“Even small asteroids ranging in size from tens of centimetres to a few metres can be hazardous for infrastructure on the Moon. This research will help us better understand how many of them are out there,” says Richard Moissl, Head of the ESA Planetary Defence Office.

Future lunar structures are likely to be built underground to provide shielding against radiation and smaller impacts but monitoring and mitigating the risk of larger asteroids remains a priority.

The Lunar Gateway space station, located far from the interference of Earth’s lights and atmosphere, could be the perfect place to keep watch for hazardous asteroids heading towards Earth or the Moon.

Space Debris

The region between Earth and the Moon – cislunar space – will become increasingly busy with human and resource traffic in the coming decades. This region is not protected by modern space debris guidelines and is already littered with rocket bodies and smaller objects that must be monitored to protect spacecraft travelling to the Moon.

A collision between satellites in orbit around the Moon would be a disaster. Due to the Moon’s weak gravity and thin atmosphere, the motion of space debris fragments would quickly become unpredictable. Debris will also linger in orbit for a long time, creating a long-term hazard to crewed and uncrewed missions.

“Prolonged human activity at the Moon will require space debris monitoring and space traffic coordination,” says Tim Flohrer, Head of ESA’s Space Debris Office. “We will need to extend the principles of ESA’s Zero Debris approach to cislunar and lunar space.”

Clean Space

Establishing a human presence on the Moon will require a significant number of new missions, rocket launches and innovative spacecraft. To reduce the environmental impact of these space activities, ESA's Clean Space Office develops new technologies to minimise the impact of production, protect lunar orbits and reuse objects disposed on the surface of the Moon.

“We are dedicated to preserving a clean and safe environment on Earth and in space for future generations,” says Tiago Soares, Head of ESA’s Clean Space Office. "Our ultimate goal is the establishment of a circular economy in which satellites can be manufactured, refurbished and recycled directly in space, including on and around the Moon.”

Forward to the Moon

By developing advanced warning systems for solar radiation, monitoring potentially hazardous asteroids and implementing strategies to minimise and manage environmental impacts, ESA’s Space Safety programme will help secure a safe and sustainable future around Earth, on the Moon and across the Solar System.