When unsuspecting asteroid Dimorphos passed close to Earth in late September 2022, it sparked panic in some, but delight in others. NASA took it as the perfect opportunity to test out its first-ever planetary defense technology: the Double Asteroid Redirection Test (DART) mission.
DART Mission’s Purpose
The purpose of the mission was to see if it was possible to alter the trajectory of Dimorphos (the minor-planet moon of Didymos, a near-Earth asteroid) by slamming a small satellite into it. The goal was to impact the face of Dimorphos, thus altering its trajectory and bringing it closer to Didymos and—researchers hoped—shortening its orbit by 10 minutes. In reality, the test was even more successful; NASA was able to shorten Dimorphos’ orbit by 32 minutes. The success of this test proves that making even small changes to the trajectory of a threat approaching Earth can avoid disaster if acted upon early enough.
The Journey to Success
This wasn’t a fast process however. DART spent 10 months flying through space before its final impact. During this time, its systems needed to stay fully operational, so the team at Johns Hopkins Applied Physics Laboratory in Laurel, Maryland chose to work with the thermal management experts at ACT to ensure that happened.
ACT had two active groups on the project: a development team of engineers and a technical flight hardware team. Together, they developed, qualified, and produced constant conductance heat pipes (CCHPs) to manage the thermal heat load of the DART satellite during the critical operations of its flight path.
Removing heat from a satellite can be difficult since there is no air or other medium in space to simply cool by convection. CCHPs are thermal management vessels that provide efficient heat transfer by evaporating and condensing a working fluid. In ACT’s case, CCHPs are aluminum-ammonia heat pipes that are designed to meet the most challenging operating cases for spacecraft: highest power and worst-case temperature. The unique extrusions of ACT’s CCHPs help return the liquid to the hot spot and repeat the cycle. This method of transporting heat uses the latent heat of the working fluid as it passively circulates through the closed system. The CCHPs transfer the payload heat into the radiators on the exterior of the craft to dissipate the heat.
With these design criteria implemented, ACT ensured that DART was able to fulfill its groundbreaking mission, proving that the safety of our planet can be secured with a simple nudge in the right direction.