Before the OSIRIS-REx spacecraft in orbit around asteroid Bennu can take a sample from the surface it needs to be mapped. That’s where Canada’s OSIRIS-REx Laser Altimeter (OLA) comes in.
The OSIRIS-REx spacecraft launched on September 8th, 2016. Canada is participating in the mission by providing the OSIRIS-REx Laser Altimeter or OLA, which is creating a 3-D map of asteroid Bennu’s shape along with helping with navigation. The instrument was funded by the Canadian Space Agency, built by MDA and professor Michael Daly of York University leads the Canadian Science Team.
According to NASA “from Feb. 12 through 17, OLA made more than 11 million measurements of the distance between OSIRIS-REx and Bennu’s surface as the spacecraft flew less than 1.2 miles (2 km) above the surface – the closest orbit ever achieved by spacecraft. OLA obtained these measurements by firing laser pulses at Bennu and measuring the amount of time it takes for the light to bounce off the asteroid’s surface and return to the instrument. That time measurement is then translated into altitude data. Using this data, the OLA team created the 3-D model of Bennu’s surface.”
“The colors represent the distance from the center of Bennu: dark blue areas lie approximately 197 feet (60 meters) lower than peaks indicated in red. Some parts of the asteroid have not yet been measured, which creates gaps in the image. OLA will take nearly a billion more measurements throughout 2019 to complete the first-ever high-resolution 3D lidar map of a near-Earth asteroid.”
“To create the image, over 11 million laser pulses were fired and captured by OLA between February 12 and 27 as OSIRIS-REx flew less than 2 kilometres from the asteroid’s rocky surface.”
The mission will continue until March 2021 when the spacecraft will return to Earth arriving 2 1/2 years later in September 2023. At that point the sample return capsule will reenter the Earth’s atmosphere and land in Utah where it will be collected and analyzed by researchers, including in Canada.