MIT students studying mission to asteroid Apophis
Apophis, an asteroid the size of an aircraft carrier, will make a close approach to Earth in 2029. It will come within approximately 18,300 miles (29,500 kilometers), less than one-tenth the distance from Earth to the Moon. A group of students from Massachusetts Institute of Technology (MIT) is designing a mission to study the asteroid up close as it passes by.
“Apophis is coming!”
The good news is, according to NASA’s Center for Near Earth Objects, Apophis is not going to strike Earth in 2029, but having a rock that big and that close is too good an opportunity not to study. The student mission, called Surface Evaluation & Tomography (or SET), is designed to investigate:
- The asteroid’s physical and orbital properties;
- Structural changes caused by tidal forces as the asteroid passes near Earth;
- Like the OSIRIS-REx mission, the Apophis mission investigates the “Yarkovsky effect” – where heat from the Sun is radiated into space as the asteroid rotates, acting as a thruster, possibly changing its path.
A group of 20 students is designing the SET mission as part of a space systems engineering course. The first slide in one student presentation reads: “Mission Motivation: Apophis is coming!”
The name Apophis comes from Egyptian mythology and is the god of chaos and evil. Appropriately enough, Set is the god sent to thwart him. A rock the size of Apophis would, indeed, bring a lot of chaos were it to crash into Earth.
The engineering class is being led by Professor of planetary sciences Richard Binzel, along with David Miller, the Jerome C. Hunsaker Professor of Aeronautics and Astronautics, who recently returned to MIT after serving as chief technologist for NASA. Binzel, who also led a student project to build an instrument for OSIRIS-REx, and Miller challenged their students to build a major science robotics mission combining planetary defense with scientific learning.
The student’s proposed design would operate using primarily proven, off-the-shelf hardware, including the spacecraft bus (Orbital ATK LEOStar3, which flew on Dawn and Deep Space 1) solar panels, and instruments. The instruments would include heritage hardware from New Horizons (LORRI), OSIRIS-REx (RALPH), Mars Reconnaissance Orbiter (SHARAD), and Lucy (TES).
Earlier in the semester, the students performed a System Requirements Review (SRR) and Preliminary Design Review, leading up to their high-powered Critical Design Review, which was attended by officials from NASA Headquarters as well as engineers from the Jet Propulsion Laboratory (JPL).
Getting to Apophis
To reach Apophis in time for rendezvous, a spacecraft would have to launch in August 2026. The objective of the orbital mission is to get close enough to Apophis to conduct measurements before, during, and after the 2029 event.
The student-designed mission is the first significant attempt to study Apophis from space, in part because asteroid defense is not precisely NASA’s responsibility. Miller says, “That kind of falls between the cracks at NASA.”
The SET mission, like the OSIRIS-REx spacecraft that will orbit the asteroid Bennu later this decade, could teach scientists more about the construction of asteroids, which were some of the early building blocks of the Solar System. New information could lead to a deeper understanding of the formation of the Solar System and planets in other star systems.
What happens next
The primary importance of the SET mission would be to improve human knowledge about close-approaching asteroids with the hope of learning how to defend against them. The bad news is that this exciting, student-driven study is not being funded by NASA or any other space agency – yet.
Binzel hopes Project Apophis will serve as a “kickstarter”, with the goal being to encourage NASA Centers and major contractors to consider their own response, perhaps basing formal funding proposals closely following the student design. “Apophis is coming so close that Earth’s gravity is going to tug and redirect its path. The Earth is going to give it a big thunk.”
When asked if there were plans to submit SET as a formal proposal to NASA, student team member Alissa Earle told Spaceflight Insider: “Right now we are mostly focused on getting the idea out there to get the scientific community thinking about how to take advantage of this once per 1,000-year opportunity. Whether it ultimately ends up looking like the SET Mission or something completely different, the most important thing is that we find a way to effectively watch and learn from this natural experiment.”
Even if the mission does not become a reality, this mission-design experience has been a useful learning experience for Earle and the rest of her MIT classmates: “For me, it was really interesting to see the starting steps of how missions get designed and to work with the engineering students. We all wanted to design a really great mission but the scientists and engineers approached the problem from different directions. This class offered a great opportunity to […] see how a mission goes from a vague idea (we should send a spacecraft to study Apophis) to a mission design (like the SET Mission).”
Bart Leahy is a freelance technical writer living in Orlando, Florida. Leahy's diverse career has included work for The Walt Disney Company, NASA, the Department of Defense, Nissan, a number of commercial space companies, small businesses, nonprofits, as well as the Science Cheerleaders.