OSIRIS-REx will ultimately collect and deliver 60 grams of regolith from Bennu to Earth.

The Origins, Spectral Interpretation, Resource Identification, Security-Regolith Explorer (OSIRIS-REx) spacecraft of NASA reached its target, asteroid Bennu, on 3^rd December 2018 after completing a journey of 2 billion kilometers. The primary science objective of this mission is to improve the estimates of Bennu’s spin rate and mass.

In addition to that, researchers want to get a more precise model of its shape. They believe that all this will help them in determining potential sites for sample collection in the future.

On a broader scale, scientists want to investigate the formation of planets and the origin of life through the OSIRIS-REx mission. Similarly, it will improve our understanding of asteroids that could impact Earth. Bennu has abundant supplies of natural resources like Organics, Metals, and Water.

A lot of experts claim that future space exploration and economic development may depend on these resources. Lori Glaze, the Acting Director for Planetary Science Division of NASA, talked about the importance of this mission in the following words:

“As explorers, we at NASA have never shied away from the most extreme challenges in the solar system in our quest for knowledge. Now we’re at it again, working with our partners in the U.S. and Canada to accomplish the Herculean task of bringing back to Earth a piece of the early solar system.”

OSIRIS-REx took a defining maneuver which transitioned it from flying toward Bennu to operating around the asteroid. The flyovers of the spacecraft will cover the equatorial region and both the poles of the asteroid. While doing so, it will fly as close as 7 kilometers above Bennu. Currently, the spacecraft is approximately 19 kilometers away from the sun-facing surface of the asteroid and the navigation team of the mission plans to use the preliminary survey of Bennu to navigate around it.

The slowing down phase of the mission began in October, after which OSIRIS-REx performed a series of braking maneuvers. It also included the final maneuver which marked the arrival of the spacecraft on Bennu and initiated the first North Pole flyover. If all continues to go well, OSIRIS-REx will enter the orbit of the asteroid on 31^st of December.

This event will make Bennu the smallest object (492 meters across) ever orbited by a spacecraft. This is one of the most crucial steps in the journey of OSIRIS-Rex which ultimately aims to transfer 2 ounces of dirt and rocks from Bennu to Earth. Dante Lauretta, the Principal Investigator of OSIRIS-REx at the University of Arizona, praised the efforts of the team by saying,

“The OSIRIS-REx team is proud to cross another major milestone off our list — asteroid arrival. Initial data from the approach phase show this object to have exceptional scientific value. We can’t wait to start our exploration of Bennu in earnest. We’ve been preparing for this moment for years, and we’re ready.”

This mission is getting a lot of appreciation from the scientific world for a number of reasons. Firstly, it will orbit the smallest object ever in space. It is also the first U.S. mission to bring samples from an asteroid back to Earth since the Apollo Missions. Likewise, OSIRIS-REx is the first spacecraft to study a primitive B-type asteroid, an asteroid which is extremely rich in Organic Molecules that make life on Earth.

Last but not least, it is the first effort to study a potentially hazardous asteroid. Rich Burns, the Project Manager of OSIRIS-REx at the Goddard Space Flight Center in Maryland, referred to this and said,

“During our approach toward Bennu, we have taken observations at much higher resolution than were available from Earth. These observations have revealed an asteroid that is both consistent with our expectations from ground-based measurements and an exceptionally interesting small world. Now we embark on gaining experience flying our spacecraft about such a small body.”

OSIRIS-REx will begin its operation at the end of this month. The spacecraft will start trying to globally map Bennu in February 2019. It will help researchers to figure out the best site for sample collection. Once the site is finalized, OSIRIS-REx will briefly touch the surface of Bennu to get the sample. According to the estimates of the researching team, the spacecraft will send the sample to Earth in September 2023.