Spacecraft Recontact Simulations

Dr. Behcet Acikmese, UW associate professor in the College of Engineering, Aeronautics and Astronautics department

As we get closer to our SSO-A dedicated rideshare mission aboard a SpaceX Falcon 9, our preparations have moved into high gear. We’ve got an amazing team getting ready to deploy close to 90 satellites in the same orbit. To ensure a flawless mission, we’ve brought in experts from outside who are excited to be part of the mission.

As part of our preparations, Dr. Vivek Nagabhushan, Spaceflight’s Group Lead of Spacecraft Dynamics and Control, reached out to Dr. Behcet Acikmese, professor of Aerospace and Aeronautical Engineering at the University of Washington. Before coming to UW, Acikmese was a technologist and senior member of the Guidance and Control Analysis Group at NASA’s Jet Propulsion Laboratory (JPL). He was also a member of NASA’s Mars Science Laboratory (MSL) G&C team, where he developed and delivered G&C algorithms used in the “flyaway phase” of the successful Curiosity rover landing in August 2012. He is a well- known expert at guidance, control and estimation algorithms for spacecraft. His task was to develop an analysis tool to assess different deployment strategies with Dr. Nagabhushan’s guidance.

“Spaceflight gave me two very clear problem descriptions,” said Dr. Acikmese. “First, they are deploying multiple satellites in a certain sequence and there are a variety of strategies. How could they test each of these to simulate possible outcomes? The second problem was to determine a feasible deployment strategy to avoid collisions, given the number of satellites.”

Dr. Acikmese was intrigued by the challenges created by the proposed deployment. The developed simulation tool is unique and is setup to analyze a variety of the possible scenarios.

“I have done analysis work in this area before, at JPL. I knew the orbital mechanics involved,” said Dr. Acikmese. “But this application was unique. The pieces of algorithms existed, but never in this application.”


The first phase of 3 month project was concluded at the end of January, and Spaceflight’s Dr. Nagabhushan is very pleased with the work. “The analysis tools Dr. Acikmese developed were extremely helpful and delivered ahead of time which allowed us to give timely feedback to the launch vehicle,” he said. “We’re fortunate to have the expertise of Dr. Acikmese in our backyard, and we’re looking forward to working with him again in the future.” The program is an important part of the extensive preparations for the SSO-A mission and another unique benefit that Spaceflight customers have in getting to space.

Dr. Acikmese was pleased with the collaboration. “People should be aware of what Spaceflight does,” he said. “It’s a unique service.”

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