Hayabusa asteroid rovers send back first footage

Japan's Hayabusa asteroid rovers send back first footage

By Euan McKirdy

Japan's intrepid, hopping asteroid rovers have sent back footage and high-resolution imagery of the surface of the celestial body they have been exploring, according to tweets from Japan's space agency.

In a series of six tweets, the Japan Aerospace Exploration Agency (JAXA) showed the first images taken by the two rovers -- including a 15-frame video -- from the surface of Ryugu, a kilometer-wide asteroid that has been visited by the agency's Hayabusa spacecraft.

"Rover-1B succeeded in shooting a movie on Ryugu's surface! The movie has 15 frames captured on September 23, 2018 from 10:34 - 11:48 JST. Enjoy 'standing' on the surface of this asteroid!"

A series of specially designed cameras -- four on the first rover and three on the second -- are taking stereo images of the asteroid's surface. The rovers are also equipped with temperature gauges and optical sensors as well as an accelerometer and a set of gyroscopes.

JAXA also released a high-res photo of the asteroid's surface taken as Hayabusa descended to the surface to unload Rover-1A and 1-B.

The agency also posted photos on its official Hayabusa-2 website which showed the location of the image snapped by Hayabusa on the asteroid's surface.

Hopping robots

Unlike NASA's Curiosity Rover on Mars, which has six wheels, the 1kg autonomous Ryugu rovers move about by hopping.

"Gravity on the surface of Ryugu is very weak, so a rover propelled by normal wheels or crawlers would float upwards as soon as it started to move," JAXA scientists explained.

"Therefore, this hopping mechanism was adopted for moving across the surface of such small celestial bodies. The rover is expected to remain in the air for up to 15 minutes after a single hop before landing, and to move up to 15 m (50 feet) horizontally."

Some of the JAXA tweets confirmed that the rovers had successfully hopped since landing on the surface.

The imagery -- the first taken from rovers from an asteroid -- shows a rocky landscape against the backdrop of space.

The agency made history on Sunday by successfully landing the two unmanned rovers on Ryugu.

A third rover called MASCOT will be launched from Hayabusa-2 in early October.

Material to be collected

Later in the mission, scheduled for the end of October, the spacecraft will land on the asteroid after blowing a small crater in it using explosives, so samples that haven't been exposed to space can be gathered from below the object's surface.

After examining the far distant object and taking samples, Hayabusa-2 will depart Ryugu in December 2019 before returning to Earth by the end of 2020 with its cargo of samples.

If successful, JAXA has said it will be the "world's first sample return mission to a C-type asteroid."

Japanese scientists are racing NASA for that achievement, with the US agency's sample retrieval mission due to arrive back on Earth in 2023.