▲ An illustration depicting the space probe Osiris Rex dropping a sample capsule collected from the asteroid Bennu toward Earth. Osiris Rex will continue to fly again to perform other missions. A sample capsule from the National Aeronautics and Space Administration’s (NASA) asteroid probe ‘OSIRIS-REx’ containing soil and gravel from the asteroid ‘Bennu’ provided by NASA was released at 8:55 a.m. on the 24th (US western time, Korean time). The BBC reported that it fell to Earth at 11:55 p.m.
NASA announced the day before that Osiris Rex’s asteroid sample capsule was scheduled to land at the Department of Defense’s Utah Test and Training Center in the Utah desert, and that the scene would be broadcast live on NASA TV (social media) an hour before landing.
A sample the size of a car tire is expected to settle on the surface approximately 13 minutes after entering the atmosphere. Because it falls at a speed of 12 km per second, it is expected to emit heat of more than 3,000 degrees Celsius and look like it is on fire.
Osiris Rex is currently flying toward Earth at a speed of 23,000 km per hour. On the 17th, the final speed and orbit adjustment for return to Earth was completed by briefly operating the thruster at a point more than 3 million km away from Earth. ▲ The sample was dropped to Earth in this way. ▲ This is the expected arrival area for samples falling with parachutes open. Osiris Rex will release a capsule containing samples of Bennu on the 24th at an altitude of 102,000 km above the Earth. The released capsule will fall to Earth, open a parachute, slow down, and then land in an area of 58 km x 14 km in the Utah desert. It is scheduled to fall in the expected drop area.
“We spent an inordinate amount of time preparing for emergencies, all the terrible things that could go wrong, all the terrible things we could encounter,” Dante Loretta, one of the mission leaders, told the BBC. “The good news is that we practice, practice, practice.” He said, “I am prepared by practicing.” Of course, he added, the decision whether to enter the atmosphere will be made 4 hours before the scheduled touchdown time.
In 2004, an attempt to bring solar wind samples collected by the Genesis probe to Earth failed. The parachute did not open properly and exploded as it rushed to the ground at a speed of 300 km per hour. At the time, it was said that the cause of the failure was that the gravity converter was standing upside down, and intensive inspection was conducted to avoid repeating the same mistake.
Osiris Rex, with an investment of 1 billion dollars, was launched from the Cape Canaveral Space Center in September 2016, and after a two-year flight, it was launched in December 2018 as a 500m wide diamond orbiting the sun 130 million km away from Earth. Arrived above the shaped asteroid Bennu. Afterwards, after conducting exploration activities around Bennu for about two years, they landed on the surface of Benu in October 2020 and collected 250g of samples, including soil and gravel, from the sponge-like surface of Benu using a 3.35m robotic arm. Then, it set off to return to Earth in May 2021.
NASA plans to retrieve the sample capsule and send it to Johnson Space Center (JSC) in Houston, Texas. JSC announced that it will not only analyze the samples itself, but also preserve more than 75% of the samples at the center so that scientists around the world, including future generations, can study them. ▲ Bennu is such a small planet. Scientists hope that by analyzing asteroid samples containing materials from the early days of the solar system, they will be able to find clues about the role that carbon-rich asteroids like Bennu played in the emergence of life on Earth. It is presumed that rocky asteroids such as Bennu, which formed the planets in the early solar system, collided with the early Earth and released carbon, delivering organic substances that could become the building blocks of life to Earth.
The Osiris Rex probe will drop the asteroid sample capsule to Earth and continue flying for the next exploration mission. The probe is scheduled to arrive at Apophis, another potential Earth-threatening asteroid, in 2029 and conduct exploration activities.
To celebrate the return to Earth of asteroid samples collected by Osiris Rex, NASA will open the NASA Goddard Visitor Center in Greenbelt, Maryland, to the public on this day.
The graphic below will allow you to see at once how small an asteroid Bennu is.
Senior Reporter Lim Byeong-seon
