Online Courses (English)
This just in:

State PCS

Daily Updates

Science & Technology

OSIRIS-REx Spacecraft Arrives at Asteroid Bennu

  • 04 Dec 2018
  • 5 min read

OSIRIS-REx (Origins, Spectral Interpretation, Resource Identification, Security-Regolith Explorer) mission has arrived at asteroid Bennu after a two-year journey.

  • OSIRIS-REx was launched from Cape Canaveral, Florida on September 8, 2016.
  • The OSIRIS-REx mission is not the first to ever visit an asteroid and attempt a sample return — Japan has done (Hayabusa Mission) it before and Europe (Rosetta Mission) has managed to land on a comet.


  • The Mission aims to study asteroid Bennu, collect a sample and return it to Earth in 2023.
  • The mission will spend 2.5 years, mapping its surface and studying its composition.
  • In mid-2020, scientists will direct Osiris-Rex to drop down to the asteroid and grab at least 60g of regolith, or "topsoil".
  • This will be packed away in a sterile capsule to be returned home in 2023.

Mission Objective

  • The OSIRIS-REx name is an acronym of the mission objectives, which are:
    • Origins: Return and analyze a pristine carbon-rich asteroid sample
    • Spectral Interpretation: Provide ground truth or direct observations for telescopic data of the entire asteroid population
    • Resource Identification: Map the chemistry and mineralogy of a primitive carbon-rich asteroid
    • Security: Measure the effect of sunlight on the orbit of a small asteroid, known as the Yarkovsky effect—the slight push created when the asteroid absorbs sunlight and re-emits that energy as heat
    • Regolith Explorer: Document the regolith (layer of loose, outer material) at the sampling site at scales down to the sub-centimeter

Significance of Mission

  • Origins of the Solar System
    • In order to understand the origin and evolution of the solar system.
    • Bennu may have molecules of carbon and water, both of which are necessary for life.
    • As Earth formed, and afterward, objects like Bennu delivered these materials to our planet. By studying Bennu, we can better understand how life originated on earth.
  • Protecting Earth
    • Bennu is one of the most potentially hazardous asteroids currently known to Earth. Bennu has a 1‐in‐2,700 chance of impacting earth during one of its close approaches to Earth in the late 22nd century.
    • Close observations by OSIRIS-REx will help get more information about Bennu's journey and help scientists working on safeguarding our planet against hazardous asteroids.
  • Mining, LaunchPad, and Future Explorations
    • The mission will help to explore the possibility of using asteroids as refueling stations for spacecraft on the way to farther-flung destinations.
    • Asteroids might also help astronauts restock their supplies. For example, Bennu likely has water bound in clay minerals, which could perhaps one day be harvested for providing water to astronauts.
    • Asteroids contain a range of valuable minerals, there is a possibility of mining asteroids in the future.

About Bennu

  • The asteroid was discovered by the Lincoln Near-Earth Asteroid Research (LINEAR) survey on September 11, 1999.
  • It was originally named as 1999 RQ36.
  • The name Bennu comes from an Egyptian deity related to the Sun, often depicted as a gray heron.
  • Bennu is a 500-meter wide asteroid in an elliptical orbit around the sun. It is a carbonaceous asteroid composition including a large amount of carbon.

Why Bennu?

  • It's close to Earth
    • Bennu’s orbit is close in proximity to Earth's, even crossing it. The asteroid makes its closest approach to Earth every 6 years.
    • It also circles the Sun nearly in the same plane as Earth, which makes it simple to launch the spacecraft out of Earth's plane and into Bennu's plane.
  • It's the right size
    • Small asteroids, with diameters of 200 meters or less, spin very fast. This rapid spinning makes it difficult for a spacecraft to match an asteroid's velocity and collect samples.
    • Bennu's size makes it approachable and makes landing possible.
SMS Alerts
Share Page