The European Space Agency has begun work on a planetary defence mission that will intercept an asteroid predicted to come within 32,000km of Earth in 2029.

The Rapid Apophis Mission for Space Safety (RAMSES) mission targets asteroid 99943, aka Apophis, which is about 375 meters wide - the length of 30 giant squid - and expected to pass closer to Earth than some geosynchronous satellites.

"Astronomers have ruled out any chance that the asteroid will collide with our planet for at least the next 100 years," explained the ESA, which added that another rock of this size typically would not approach so closely for another 5,000 to 10,000 years.

This fly-by is therefore an opportunity to observe Apophis in the hope doing so helps humanity to learn how future visitors of this sort might be deflected.

The ESA's Space Safety program - its team dedicated to gathering and publishing info about threats from space - green-lit initial work on the mission on Tuesday, meaning the agency can "kickstart mission prep using current resources," according to ESA director general Josef Aschbacher.

RAMSES is not, however, cleared to fly. Commitment from the space agency's Ministerial Council Meeting in November 2025 is needed before the mission will be certain.

Ashbacher promised that while waiting for the verdict, ESA and its member states are showing "their willingness to become more agile, streamline processes, and shorten unnecessary bureaucracy."

"We are on the path to a new ESA … and to Apophis," declared the director general.

Should the mission receive full support, Ramses will launch in April 2028, rendezvous with Apophis beginning in February 2029, and accompany it through its flyby set to occur two months later. Researchers will use the opportunity to study the effect of Earth's gravity on the asteroid.

"All we need to do is watch as Apophis is stretched and squeezed by strong tidal forces that may trigger landslides and other disturbances and reveal new material from beneath the surface," explained France's National Center for Scientific Research (CNRS) director Patrick Michel.

A suite of scientific instruments will do the "watching" by measuring asteroid shape, surface, orbit, rotation and orientation before and after the flyby, as well as asteroid composition, interior structure, cohesion, mass, density, and porosity.

ESA expects measuring those properties will reveal some secrets on how best to knock a future object off course, and perhaps also offer insights into the formation of the Solar System.

ESA's similar activities include the Hera mission, which later this year will study the Didymos binary asteroid system and investigate how NASA's Double Asteroid Redirection Test - which slammed into one of the rocks in 2022 - affected the space rubble.

Apophis will also be visited by NASA's OSIRIS-REx spacecraft, which is enroute to the asteroid after being rebranded as OSIRIS-APEX.

OSIRIS-Rex was intended to collect samples from asteroid Bennu in May 2021 and return them to Earth, which it did. However, the craft was in good condition and had a quarter of its fuel left, so it was sent on a bonus mission to Apophis.

OSIRIS-APEX is slated to arrive at the asteroid approximately one month after Apophis completes its flyby. ®

https://www.theregister.com//2024/07/17/esa_ramses_prelim_approval/