The first U.S. mission to bring samples from an asteroid back to Earth is the Origins-Spectral Interpretation-Resource Identification-Security-Regolith Explorer, or OSIRIS-REx. Scheduled for launch in September 2016, OSIRIS-REx will increase our understanding of asteroids, and it could shed new light on the origin of life on Earth.
Near-Earth asteroid (101955) 1999 RQ36 is the mission's target. The most accessible organic-rich asteroid from the early solar system, its average diameter is approximately 1,600 feet or about the size of four football fields. Asteroids, little altered over time, contain the original material of dust and gas from the solar nebula that collapsed to form our Sun and the planets about 4.5 billion years ago, so they can tell us about the conditions at our solar system's birth. Because this asteroid is rich in carbon, a key element in organic molecules necessary for life, it may tell us much more about the building blocks of life on our own planet.
Dr. Dante Lauretta, Principal Investigator
OSIRIS-REx is managed for NASA by the Goddard Space Flight Center in Greenbelt, MD. The Principal Investigator is Dr. Dante Lauretta of the University of Arizona in Tucson. Lockheed Martin Space Systems in Denver will build the spacecraft.
Return and analyze a sample of pristine carbonaceous asteroid regolith in an amount sufficient to study the nature, history, and distribution of its constituent minerals and organic material
Map the global properties, chemistry, and mineralogy of a primitive carbonaceous asteroid to characterize its geologic and dynamic history and provide context for the returned samples
Document the texture, morphology, volatile chemistry, and spectral properties of the regolith at the sampling site at scales down to the subcentimeter
Measure the Yarkovsky effect on a potentially hazardous asteroid and constrain the asteroid properties that contribute to this effect
Characterize the integrated global properties of a primitive carbonaceous asteroid to allow for direct comparison with ground-based telescopic data of the entire asteroid population
The instrument suite includes:
OSIRIS-REx Camera Suite (OCAMS) provides cameras for long-range acquisition of RQ36 and imaging of its surface, along with global mapping, sample-site characterization, and sample acquisition documentation
OSIRIS-REx Visible and IR Spectrometer (OVIRS) provides mineral and organic spectral maps and local spectral information
OSIRIS-REx Thermal Emission Spectrometer (OTES) provides mineral and thermal emission spectral maps and local spectral information
OSIRIS-REx Laser Altimeter (OLA) provides ranging data in support of radio science; global topographic mapping; and local topographic maps of candidate sample sites
Regolith X-ray Imaging System (REXIS), a student collaboration experiment, provides an X-ray map of the asteroid
In 2019, three years after a planned autumn 2016 launch, the probe will approach its target. During a reconnaissance period lasting over a year, the spacecraft's cameras and instruments will image the asteroid and measure its surface topography, composition, and thermal emissions. Radio science provides mass and gravity field maps. This information will provide new knowledge about asteroids, help refine navigation around 1999 RQ36, and assist the mission team in selecting the most promising sample site.
Once the sample location is chosen, the spacecraft will approach the surface at .2 mph, a fraction of walking pace, and, without landing, stretch out its sample collecting arm. The device will agitate the asteroid's surface and collect more than two ounces of material for return to Earth in 2023.
Asteroid 1999 RQ36 has a higher probability of hitting the Earth than any other asteroid comparable in size. If it were to strike the Earth, the collision would occur late in the 22nd century. By learning much more about this primitive object, scientists will be better able to project the orbit of a threatening asteroids. If researchers can track a Near Earth Object's precise path, they can devise a way to nudge it out of a collision course with Earth.
The mission will also help NASA learn to navigate near an asteroid, laying the groundwork for landing on one, which is tricky because they have so little gravity.
Sample return missions allow scientists to use the most sophisticated, precise instruments that exist now and those that will be built in the future to study extra-terrestrial samples. Pristine carbonaceous material has never before been analyzed in laboratories on Earth. Samples will be available for analysis by future generations of scientists using instruments not yet dreamed of, answering questions not yet asked.
Artist’s depiction of sample collector.
Artist’s concept of sample return capsule heading for Earth.
OSIRIS-REx will accurately measure the "Yarkovsky effect." The effect is a small push caused by the Sun on an asteroid, as it absorbs sunlight and re-emits that energy as heat. The small push adds up over time, but it is uneven due to an asteroid's shape, wobble, surface composition and rotation. For scientists to predict an Earth-approaching asteroid's path, they must understand how the effect will change its orbit. OSIRIS-REx will help refine 1999 RQ36's orbit to ascertain its trajectory and devise future strategies to mitigate possible Earth impacts from celestial objects.