NASA’s asteroid-sampling spacecraft OSIRIS-REx will descend on asteroid Bennu with help from the Canadian Space Agency’s lidar altimeter, which is crucial to the spacecraft’s landing. (Photo : NASA Goddard Space Flight Center / Wikimedia Commons)

A laser altimeter from the Canadian Space Agency (CSA) is on board NASA's asteroid-sampling spacecraft.

NASA's OSIRIS-REx (Origins, Spectral Interpretation, Resource Identification, Security, Regolith Explorer) mission aims to make a daring descent on Bennu by 2020, with help from the CSA's OSIRIS-REx Laser Altimeter (OLA).

OLA, which was built for CSA by MacDonald, Dettwiler and Associated Ltd and Optech, is the most sophisticated lidar (light detection and ranging) system ever launched to an asteroid, Photonics reports. It contains about 4,000 mechanical parts and 3,000 electrical parts, but using less power than a 75-W light bulb.

Upon arriving at the asteroid, the instrument is tasked to create 3D maps of the asteroid, particularly at the touchdown site where the sample will be collected. The lidar system will provide mission astronomers with critical data about Bennu's topography, shape, surface processes and evolution. The map will also help scientists maneuver the spacecraft around the asteroid. In return, Canada will own 4 percent of the returned asteroid sample, which will be curated and studied.

In 2008, a Canadian lidar instrument had helped NASA's Phoenix lander track the movement of dust particles in Mars' atmosphere. According to a report from Seeker, CSA had a budget of only $334 million (CDN 432 million), about less than half the cost of the OSIRIS-REx mission.

NASA's OSIRIS-REx is considered one of the most ambitious sampling missions since Apollo. The spacecraft launched from Cape Canaveral Air Force Station on Sept. 8 on board the Atlas V rocket from United Launch Alliance. It will intercept the asteroid Bennu to collect samples to bring back to Earth by 2023. It will take OSIRIS-REx two years to reach Bennu, and the actual sampling will happen in 2020 after successfully picking out the perfect collection site.

The organic matter from the asteroid sample could provide knowledge about early life on Earth and help scientists understand the composition of hazardous space rocks that might one day impact Earth.