Feature, Science & Technology
NASA Got Its First Asteroid Sample
Volume 4 Issue 1
November 6, 2023
Image Provided by NASA/Keegan Barber
On September 8, 2016, NASA launched a spacecraft to an asteroid to collect a sample of rocks and dust from its surface. Seven years later, on September 24, 2023, the craft landed on Earth, carrying the first NASA samples from an asteroid in its history.
The spacecraft’s name is OSIRIS-REx, standing for Origins, Spectral Interpretation, Resource Identification, and Security-Regolith Explorer. This name sounds complex, and it is, but it simply means that the craft’s goal was to fly to an asteroid, scan it, take a sample from it, and return to Earth. The asteroid used for the mission was called 101955 Bennu, considered a near-Earth asteroid. Bennu is only around one-third of a mile wide at its equator but is a time capsule from the Solar System’s early days – it gained its present composition only a little bit after the formation of the Solar System. NASA suspects that it may have organic molecules in its carbon-rich environment like those that helped start life on Earth.
To find out more about Bennu, NASA began developing the mission with help from scientists at the University of Arizona and built the OSIRIS-REx spacecraft. NASA equipped it with a camera suite, laser technology, light and heat scanners, an X-ray imaging device, and a sampling device. These pieces of equipment, along with the rest of the craft, weighed around 4,650 pounds. On September 8, 2016, the Atlas V rocket carrying the craft launched from Cape Canaveral and about 55 minutes after launch separated from the rocket and deployed its solar arrays to power it in space.
Around a day after the launch, OSIRIS-REx crossed the Moon’s orbital path at roughly 240,200 miles away from Earth. Three days later, it began to orbit the Sun. About a week later, on September 19, 2016, the mission team at NASA’s Goddard Space Flight Center began to activate the craft’s scientific instruments. To position it for a gravity assist from Earth, the craft fired its main engine on December 28, 2016. This assist came on September 22, 2017, when OSIRIS-REx passed Earth at roughly 10,710 miles above its surface, took high-resolution pictures of the planet and the Moon, and used the energy from Earth’s gravity to tilt its orbit to match Bennu’s.
Nearly a year later, in August 2018, the spacecraft sent a grainy image of Bennu 1.4 million miles away from the asteroid. In early November, it took more detailed images of the asteroid’s shape and certain surface features. Its official arrival would not come until a month later, on December 3, 2018, when OSIRIS-REx completed its journey and arrived at Bennu. From there it mapped the asteroid in detail while NASA’s mission team searched for a safe sample site on the extremely rocky and hazardous surface. After a year of deliberation, the team selected a site named “Nightingale,” a young crater with freshly exposed rocks and dust. The team reckoned it would provide a pristine sample of the asteroid, and OSIRIS-REx collected the sample on October 20, 2020, with an extremely brief touchdown called a “Touch-And-Go" maneuver. Two days later, images confirmed it had collected more than enough material and on October 28, the mission team commanded the spacecraft to close the sample capsule.
With the sampling complete, on April 7, 2021, the craft completed its last flyover over Bennu and took fresh images of the sampling site. After flying for two and a half years and orbiting the Sun twice, OSIRIS-REx returned to Earth on September 24, 2023, releasing the capsule with the sample from the rest of the craft. It landed at the Department of Defense’s Utah Test and Training Range where scientists retrieved it. The spacecraft, however, did not land and went to explore another asteroid, Apophis, with the new name OSIRIS-APEX, standing for OSIRIS-Apophis Explorer.
The sample is currently in a clean room at the Johnson Space Center in Houston. In the meantime, NASA has reported that the initial analysis revealed carbon and water in the sample and there was so much extra material that it slowed down the sample collection process. The analysis will continue for the next two years; after that, NASA will keep at least 70% of the sample at the Johnson Space Center for future research, the fruitful reward of a highly successful mission by NASA to study the cosmos.