Integration and Test Challenges of Parker Solar Probe

On August 12, 2018, NASA and the Johns Hopkins Applied Physics Laboratory (APL) successfully launched Parker Solar Probe (PSP) on a mission to study the Sun, as part of NASA's Living With a Star program. As of this writing, the spacecraft has successfully completed its third close approach to the Sun and is returning new data to scientists here on Earth. The journey leading up to this point was difficult and full of many unique challenges. PSP will be flying within the corona of the sun over twenty times and traveling more than seven times closer than any spacecraft has come before (1). PSP was designed to withstand intense heat by sitting behind a first-of-its-kind Thermal Protection System (TPS), while still being able to perform all of its necessary functions. This mission required an extensive knowledge base and multiple teams working in conjunction to bring this flight to fruition. This paper will discuss some of the many difficult integration and test challenges faced leading up to launch; their origin, development, and steps that the team executed to overcome them and ensure success. The spacecraft was exceptionally complex, with multiple systems that were redundant, and required an extremely large portion of the schedule to be dedicated to testing. The Autonomy system had to be very robust as the mission is designed to have large periods of time where the spacecraft will be out of contact with the Earth. PSP was also mass constrained; all of the systems had to fit into a relatively small bus that restricted the integration order of operations and limited the amount of activities that could be performed in parallel. Due to these numerous challenges, the team had to be very flexible and adaptable to the needs of the spacecraft and the mission. From the integration of the bus at APL, to environmental testing at the Goddard Space Flight Center, to the final pre-flight processing at Astrotech Space Operations and on the Delta IV Heavy launch vehicle at the Cape Canaveral Air Force Station, PSP was a learning experience every step of the way.