Three-body probe: China is working on a complex mission to explore and sample asteroids
China is developing plans for a mission to flyby, track and collect samples from near-Earth asteroids as part of plans to explore the solar system and the origins of life.
The mission, being developed by Purple Mountain Observatory, proposes to launch a probe to first fly alongside and orbit near-Earth asteroid Apophis, then flyby asteroid 2002 EX11, and finally rendezvous with and land on asteroid 1996 FG3.
The mission outline was presented to Chinese media by Ji Jianghui, a researcher at PMO under the Chinese Academy of Sciences (CAS), in February.
Ji said the mission aims to study the formation and evolution of asteroids, which could give insight into the origins of the solar system and the origins of life and water on Earth.
According to details that have previously emerged, one proposal is for a launch via Long March 3B rocket to take place in early 2022, with rendezvous with Apophis a year later and spend 220 days in orbit.
Above: A presentation slide for one Chinese near-Earth asteroid mission outline.
Ji, together with colleagues, has conducted an in-depth studyof asteroid 1996 FG3, a carbonaceous binary asteroid around 1.8 kilometres in diameter, indicating a regolith surface composed of a mixture of dust, fragmentary rocky debris and sand.
The paper also states that other properties indicate that 1996 FG3 could be a very suitable target for a sample return mission.
Apophis meanwhile was initially considered a possible threat to Earth upon its discovery in 2004, with it due to make a close approach to Earth in 2029.
An animation of 6 images of 99942 Apophis taken by Sormano Astronomical Observatory (OAS) in December 2004 (Courtesy of OAS).
Alternative asteroid activities
The PMO mission plan has not been officially approved, with another group at the China Academy of Space Technology (CAST) also developing their own version of an asteroid mission.
The good news is that asteroid exploration is an area explicitly mentioned in "China's Space Activities in 2016", a government policy paper released in December which outlines the country's ambitions for space for the next five years and beyond.
This strongly indicates a mission proposal will be accepted and begin development in the near future, with a launch date around the early 2020s.
Lunar activities pave the way
China has already conducted one flyby observation of an asteroid, named Toutatis, in 2012 when the country's second lunar probe, Chang'e-2, rendezvoused with Toutatis at a distance of 770 metres after successfully completing its primary mission to orbit and map the Moon.
The research revealed new insights into the geological features and formation of the asteroid, showing it was essentially rubble and that the impact craters on its surface could be 1.6 billion years old, according to Xinhua.
China will also in November this year attempt to collect samples from the Moon and return them to Earth with its Chang'e-5 probe.
"If that mission succeeds, it would mean China, like Japan, would be able to bring back samples from asteroids to study in labs on Earth," Ji said.
Above: Scientists work on China's Chang'e-5 landing and ascent vehicles (Framegrab/CCTV).
Chang'e-5 will be followed in late 2018 by humanity's first ever attempted landing on the far side of the Moon with Chang'e-4, with the country's first independent interplanetary mission to launch for Mars in summer 2020.
With the development of new, larger launch vehicles, China is planning missions to the outer solar system and even a Mars sample return mission in 2020s and beyond.