Lift-off for China’s Chang’e 5: the first chance since 1976 to bring lunar samples back to Earth
- Long March 5 rocket carrying spacecraft takes off in China’s most complex mission yet
- Technology has brought the drilling and retrieval project a long way but may also bring the most difficult problems
China’s first lunar mission to bring samples back to Earth faces new technical challenges and much could go wrong, according to Chinese space authorities.
“A long journey just begins,” Pei Zhaoyu, deputy chief of the lunar programme at the China National Space Administration, said as the rocket lifted off.
The 8-tonne (8.8 ton) spacecraft comprises four independent but interactive components: one to stay in lunar orbit as a docking station; one to go down to the moon’s surface and drill for samples; one to take the material back to the dock; and one to bring the samples back to Earth.
“It is the Chinese space programme’s most complex mission ever,” Pei said on state television.
On August 23, 1976, the Soviet Luna 24 craft returned to Earth, bringing back 170 grams (6 ounces) of moon rock samples from up to 2.5 metres (8.2 feet) underground. The Luna 24 mission marked the end of the intense race between the Soviet Union and the United States to go to the moon. The last American Apollo mission ended in 1972, and the Russians ended their manned landing programme a few months before the Luna 24 launch.
More than 40 years on, the Chang’e 5 spacecraft is an improvement on the Luna 24. It is about 60 per cent heavier, and it will ferry back more than 10 times the amount of moon samples. It will drill a 2-metre hole beneath the moon’s surface and scoop up rocks and other debris with a robotic arm, the first lunar mission to use a combination of these processes.
The total weight of the samples could reach 2kg.
While the Lunar 24 was operated largely by remote control via engineers on the ground using telemetry, the Chang’e 5 is designed to complete most of the job on its own using artificial intelligence.
But the technical complexity may also increase risk, according to Chinese space authorities.
For example, the sample will need to be passed from the drilling platform to the ascender, a tiny spacecraft that will lift off from the moon to the docking station. There, the sample will be transported from the ascender to a capsule for the return journey. There is no way to manually check if the capsule is entirely sealed.
One of the Chinese space scientists’ biggest worries is that a tiny leak could cause the samples to burn and be lost in the atmosphere.
Nasa issued a somewhat stern statement after the Chinese launch.
“With Chang’e 5, China has launched an effort to join the US & the former Soviet Union in obtaining lunar samples,” the US space agency said on Twitter.
“We hope China shares its data with the global scientific community to enhance our understanding of the moon like our Apollo missions did & the Artemis programme will.”
The administration of US President Donald Trump plans to return American astronauts – including a woman – to the moon by 2024. Trump’s Artemis programme also includes a space station orbiting the moon as well as permanent infrastructure on the lunar surface for human activity. But with a high chance that he had lost the election, and the effects of the coronavirus pandemic, the plan is widely anticipated to be delayed, if not scrapped.
Pei said the Chang’e 5 mission would be China’s first step towards building the International Lunar Research Station, an unmanned base on the moon by 2030. The station would be run entirely by robots for a wide range of activities, including exploration, space astronomy, mining and other experiments.
But China will not, and probably cannot, do this alone.
“We welcome international partners to join this effort,” China Youth Daily quoted Pei as saying.
Russian and European space agencies have expressed interest in the project but Nasa is banned by law from cooperating with China unless Congress grants an exception.
China has launched just six lunar spacecraft. The gap with leading countries was still large, but “we are committed to our own pace”, Pei said.
Less than half of all attempts to land on the moon have succeeded. Some spacecraft did not reach lunar orbit due to booster failure, some overshot the moon, some crashed, and some burned up re-entering the Earth’s atmosphere.