• Justin Friedberg

Celestial Sampling

If you’ve ever seen the 1998 movie Armageddon, you’ll know it’s about a massive asteroid on track to hit Earth and a group of people attempting to travel through space and destroy it. In November of 1998, humanity had just put the ISS, the International Space Station, into orbit, so the thought of attempting to travel to and return from something as remote as an asteroid, probably seemed more like science fiction than reality. However, in the year 2020, what was recently considered science fiction has, in some ways, become a reality.

The OSIRIS-REX spacecraft, short for origins, “spectral interpretation, resource identification, security, regolith explorer”, originally launched on September 8, 2016, and is currently orbiting at a safe distance around an asteroid called 101955 Bennu. The OSIRIS-REX managed to obtain samples from the asteroid.

Bennu is 4.5 billion years old, has an average speed of 63,000 mph, and stands over 500 meters tall, or about 0.3 miles, which is a little bit taller than the empire state building. So, yes, there is a 4.5 billion-year-old massive ball of rock the size of the empire state building plummeting around our solar system at 63,000 mph. Named after the Egyptian deity of the Sun, creation, and rebirth, asteroids like Bennu have been found to contain natural resources such as water.

The OSIRIS-REX spacecraft was developed by NASA, Lockheed Martin, and the University of Arizona. It’s 20.25 feet long, 8 feet wide, and 10.33 feet tall. It gets its energy, like most other spacecraft's today, from two giant solar panels, which generate, depending on its distance from the sun, between 1,226 watts and 3,000 watts of power. The mission will cost a total of one billion dollars, $588.5 million on development, $183.5 million on its launch vehicle, the Atlas V rocket, and $283 million to operate OSIRIS for the mission's estimated nine years. OSIRIS had to travel nearly 200 million miles to get to Bennu, which means it has to travel another 200 million miles to get back to us. For perspective, that's like going around the Earth over 16,000 times. Also, assuming that you were in a plane, which takes an average of 35 hours to travel around the Earth, that didn’t require refueling, the journey would take you over 560,000 hours, or over 65 years.

OSIRIS arrived at Bennu on December 3, 2018. Orbiting, analyzing, and taking dozens of extraordinary photos of the asteroid and space for over two years, it finally determined the right spot to collect a sample. So, on October 20, 2020, OSIRIS adjusted itself over the predetermined sampling site using its thrusters. Next, using its robotic arm, OSIRIS made contact with the asteroid for a total of 16 seconds, scooping up about four hundred grams of dust and rock, which is about the weight of an NFL football. This is remarkable, considering that their goal was a minuscule 60 grams, which is about the weight of a tennis ball. Then, after three days of inspecting the condition and amount of the specimen collected, it was determined to be satisfactory. If anything had gone wrong, OSIRIS had the option to attempt the operation another two times.

In March of 2021, then, OSIRIS will begin its return trip to Earth. Right now, it is estimated to return the sample it had collected in late September of 2023. However, OSIRIS will not be returning with the sample. Instead, while passing by Earth on its way back from Bennu, OSIRIS will release the return capsule containing the samples over our atmosphere, allowing it to glide through and eventually deploy a parachute. This will hopefully allow the samples to reach the ground safely. OSIRIS will then be diverted off course and sent into deep space. The samples, if all goes well, will then be studied, and the results may offer key information on how life began on Earth. Bennu, from one big ball of rock to another, happy travels!