By Richard de Grijs
How do you explore a place where the Sun never shines? China’s space program will soon embark on one of the most innovative lunar exploration missions in recent years.
We’ve known for nearly two decades that some form of water exists on the Moon. What we still don’t know is exactly how much accessible water ice lies inside permanently shadowed craters, how deeply it is buried or what form it takes.
What we do know is that accessing that water ice will be a real challenge: it is found at the bottom of deep, hard-to-traverse craters where the Sun never shines, remaining untouched for billions of years at temperatures well below –200°C.
These are among the most valuable places on the Moon, but the hardest to reach and explore.
Lunar exploration has come a long way since the Soviet Union’s Luna-1 probe reached the Moon’s vicinity in January 1959.
The Apollo missions and their successors showed the challenge is no longer simply to reach the Moon. It is to explore places human and conventional rovers cannot easily go, and ultimately determine whether the Moon itself can provide some of the resources that future explorers will need.
China has spent two decades building an increasingly ambitious lunar exploration program, named after Chang’e, the ancient Chinese goddess of the Moon.
The Chang’e-7 mission is expected to set course for our celestial neighbour later this month, although a recent failure involving a different Chinese rocket has introduced some uncertainty over the launch date. Here’s what makes this latest mission so interesting.
What is Chang’e-7 set to achieve?
The mission will test several novel approaches to lunar exploration. It will consist of an orbiter, a lander, a rover and a hopper.
In addition, the Queqiao-2 lunar relay satellite is already in place. Launched separately in March 2024, it subsequently supported the Chang’e-6 mission and will facilitate communication between Earth and the lunar surface during the Chang’e-7 mission.
We don’t know precisely where the mission will land, but a site on or near an illuminated ridge close to the Shackleton crater in the Lunar South Pole’s Aitken region is a prime candidate.
The hopper will be the mission’s real star. Unlike a wheeled rover, it’s designed to leap over broken terrain and descend into craters where sunlight never reaches, places conventional vehicles may simply be unable to enter.
Adding it to the mission makes sense, given the steep crater walls, broken terrain, permanent shadow and the need for autonomous navigation and communications.
Chinese scientists won’t be looking for signs of water; we already have compelling evidence for lunar polar water. The question at the mission’s core is where exactly that water is located, in what form and concentration, and whether it could realistically be accessed.
This marks a transition from simply exploring the Moon to determining whether its resources can actually be used.
How NASA is taking a different tack
Other nations are similarly interested in addressing that same question. The United States is pursuing the same longer-term objective of making sustained lunar operations possible. Although NASA will be confronted by the same physical problems, the American space agency has opted for a different solution.
Chang’e-7 is a coordinated state mission whose elements have been designed around a single, specific objective and which can use the already operational Queqiao-2 infrastructure.
NASA, by contrast, is deliberately trying something different: building a lunar marketplace through its Commercial Lunar Payload Services (CLPS) program. The agency buys lunar delivery, mobility and technology services from companies that own and operate their own spacecraft.
NASA currently has 17 contracted deliveries carrying more than 60 instruments.
And the American effort has already yielded useful experience: Intuitive Machines’ IM-2 mission, Athena, attempted strikingly similar undertakings to Chang’e-7. It carried a drill and mass spectrometer looking for volatiles, a small hopping vehicle intended to explore difficult terrain and an experimental mobile communications network. However, the lander fell over at the landing site and was powered down just one day after arriving.
In essence, the destination dictates the problems; different space program are experimenting with different ways to resolve them.
Learning how to live on the Moon
Finding lunar resources is only the first step. Chang’e-7 will attempt to determine where useful lunar resources are found near the Moon’s South Pole and characterise their nature.
Chang’e-8, slated for potential launch in 2028, will move towards demonstrating how they might actually be used.
Crewed exploration will likely follow, culminating in the construction of the International Lunar Research Station, jointly led by the China National Space Administration and Russia’s Roscosmos space agency.
On the other side of the Pacific, the CLPS will feed technology and science into the broader NASA-led Artemis programme, which the agency explicitly describes as laying the foundation for sustained lunar exploration.
Ultimately, the lunar South Pole doesn’t care which flag is on a spacecraft. Any explorer entering its permanently shadowed craters faces the same darkness, severe cold, broken terrain and communications problems.
Getting to the Moon was one of the great technological challenges of the 20th century. Learning how to live and work there may be one of the great challenges of the 21st.
Richard de Grijs is a Professor of Astrophysics, Macquarie University. This article was first published by The Conversation
