UNIVERSITY PARK, Pa. — Like the beginning of a science fiction novel, the website for the 2017 Global Trajectory Optimization Competition (GTOC) reads: “It is the year 2060.” The annual event, sponsored by the European Space Agency, draws aerospace engineers and mathematicians across the globe to challenge themselves to solve a “nearly-impossible” problem of interplanetary trajectory design.
The Astrodynamics Research Group of Penn State (ARGoPS), co-led by, doctoral candidates in aerospace engineering Andrew Goodyear and Davide Conte, placed 1st out of U.S. student teams, 7th of all U.S. teams, and 23rd out of the 70 teams that competed around the world.
A paper detailing this competition will be published in the journal Acta Futura.
"Our team did very well thanks to the fact that we have a lot of diversity, giving us new ideas and making us able to obtain unique or new results,” said Matthew Shaw, a graduate student in aerospace engineering.
Trajectory optimization deals with devising a series of orbital maneuvers for a spacecraft while closely watching a performance index (like minimizing the amount of fuel used) and adhering to mission requirements. A challenging part of trajectory optimization is taking into account the movement of the starting and ending objects in orbit and the effects that gravitational and non-gravitational changes may have on them — it’s not easy to navigate through a pathway that is always moving.
The problem this year focused on a scenario known as the Kessler effect, in which the density of debris in Low-Earth Orbit (the same orbit that the International Space Station operates in) becomes so congested that colliding objects produce more debris, increasing the likelihood of additional collisions, setting off a cascade. In the scenario, teams were tasked with defining a path by which a spacecraft would visit 123 pieces of debris and deliver de-orbiting packages.
Although this competition dealt with a fictitious scenario, the problem of "space trash" is real. “Being able to devise a strategy to retrieve or de-orbit debris is no easy task and some of us from ARGoPS may one day be working on this exact issue using actual orbital debris data,” said Conte.
"Working on teams like this is an excellent step towards how teams operate, and how projects are completed, in our industry,” said Jason Everett, an undergraduate student in aerospace engineering. “This challenge specifically helped me to learn how a team of engineers can thrive when each member can be depended on to produce high-quality work.”
“In Italian, we have the saying ‘l'unione fa la forza’ which translates to ‘unity is strength,’” said Conte. “Not only can new ideas arise from brainstorming, but new solutions that none of the team members could have thought of individually can be found by working all together.”
In addition to Goodyear, Conte, Shaw and Everett, the other members of the team included Jason Reiter, Ghanghoon Paik, Guanwei He and Mollik Nayyar, doctoral candidates in aerospace engineering; and Jeffrey Small, a graduate student in aerospace engineering.