Spaceflight Insider

OSIRIS-REx – marks the spot


Artist’s rendering of the OSIRIS-REx Spacecraft at Bennu. Image Credit: James Vaughan / SpaceFlight Insider

NASA provided an update on Friday, Aug. 24, about the Origins, Spectral Interpretation, Resource Identification, Security-Regolith Explorer (OSIRIS-REx) spacecraft. By all accounts of the experts working on the expedition to the asteroid Bennu – things are going very well.

A graphic reviewing the various sizes of some of the small bodies that exist in our solar system. Image Credit: NASA

A graphic reviewing the various sizes of some of the small bodies that exist in our solar system. Image Credit: NASA

“Spacecraft commands are packaged and then sent to OSIRIS-REx from our facility hear in Littleton, Colorado ,”Sandy Freund, OSIRIS-REx mission support area manager at Lockheed Martin Space said. “The spacecraft is performing as expected, all of our cruise checkouts and cruise activities are complete – the spacecraft is ready to support proximity operations.”

The OSIRIS-REx spacecraft is part of NASA’s New Frontiers initiative and was built by Lockheed Martin Space Systems. Lockheed Martin is currently involved in mission operations with the different teams involved on the project. 

The spacecraft began the approach phase of its mission in the middle of this month (Aug. 17, 2018) and is being readied to conduct a series of maneuvers that will place OSIRIS-REx in the proper orbital corridor to begin studying the leftover of the formation of our solar system.

When it does so, it will be the first spacecraft to enter into orbit above a small planetary body (Bennu is a B-type asteroid with a ~500 meter diameter). At present, OSIRIS-REx is slated to rendezvous with Bennu on December 3. However, there’s still a bit of work to do before the spacecraft gets to that point.

“On October 15 we plan to use the main engine thrusters on the spacecraft to slow our approach with respect to Bennu,” Michael Moreau, OSIRIS-REx flight dynamics system manager at NASA’s Goddard Space Flight Center noted during Friday’s teleconference. “There are two asteroid approach maneuvers called ‘AAM 1’ and ‘AAM 2’ – they will slow our velocity down from nearly 500 meters per second to approximately five meters per second.”

Following this space flight “braking” procedure, OSIRIS-REx will undertake weekly maneuvers that will send the spacecraft down a “corridor” toward Bennu. If everything goes as planned, this corridor will allow mission managers to conduct a detailed study of the region around Bennu. The last approach maneuver, dubbed “AAM 4”, is slated to take place on November 12. This should see the spacecraft some 20 kilometers above the asteroid.

Between Dec. 3-17 OSIRIS-REx will conduct flybys of the asteroid that will bring the vehicle to within 7 kilometers of the surface. Moreau stated that he expected this phase of the flight to be one of the most challenging early moments of the mission for both the navigation and operations teams.

OSIRIS-REx's first image of asteroid Bennu. Image Credit: NASA/Goddard/University of Arizona

OSIRIS-REx’s first image of asteroid Bennu. Image Credit: NASA/Goddard/University of Arizona

These maneuvers should allow mission planners to get a sense of the amount of gravity and mass that the asteroid has. Moreau went on to note that when OSIRIS-REx is in its first orbit above Bennu, it will be between 1.5 and 2 kilometers above the asteroid. For those who have traveled on commercial flights, at an altitude of 35,000 feet (10,668 meters) – if one imagines being 10 times closer to the ground – that’s how far OSIRIS-REx will be from the asteroid’s surface. While in this tight orbit, the spacecraft will be traveling at about five centimeters per second – or .1 miles per hour.

The first order of business for the team operating the spacecraft during the approach phase of the mission was to visibly review Bennu. They will also survey the area for any potential hazards and collect data to allow researchers to produce a model of the tiny worldlet.

This OSIRIS-REx mission is also historic in that it is planned to have the spacecraft collect a sample of Bennu and return it to Earth. As noted, it is hoped that in doing so, scientists can gain a better understanding about how our solar system formed.

“We are seeking to return samples of a carbonaceous asteroid that we believe that dates back to the formation of our solar system and holds clues to not only the prebiotic molecules that might have led to the origin of life, but in general the delivery of volatiles like water that made Earth a habitable planet ,” said Dante Lauretta, OSIRIS-REx OSIRIS-REx’s principal investigator. 

Lauretta reinforced that this mission could be used to target potential resources located in this part of the solar system. He also provided specifics about the potential danger presented by Bennu, but went on note that, at its earliest, would not possibly impact our planet until some time in the 22nd Century. 

OSIRIS-REx lifted off atop a United Launch Alliance (ULA) Atlas V rocket from Cape Canaveral Air Force Station’s Space Launch Complex 41 in Florida on Sept. 8, 2016. The current schedule has the sample that the spacecraft collects from Bennu returning to Earth in 2023.

While OSIRIS-REx is ready to get to work studying Bennu, NASA is busy planning the next New Frontiers mission.

“NASA is currently in the process of conducting two Phase A studies to determine the next New Frontiers mission,” Lori Glaze, acting director of NASA’s Planetary Science Division said. “The two missions that are currently in  competition are CAESAR (Comet Astrobiology Exploration Sample Return) which is a comet sample return mission and Dragonfly, which is a mission to explore Saturn’s moon Titan.”

Video courtesy of NASA Goddard





Jason Rhian spent several years honing his skills with internships at NASA, the National Space Society and other organizations. He has provided content for outlets such as: Aviation Week & Space Technology,, The Mars Society and Universe Today.

Reader Comments

Mario Billiani

“When it does so, it will be the first spacecraft to enter into orbit above a small planetary body”

NEAR, Hayabusa, Rosetta, Hayabusa 2?

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