Seeker / Kenobi

Seeker & Kenobi [NASA]

Seeker is an ultra-low cost approach to highly automated extravehicular inspection of crewed or uncrewed spacecraft that has been designed and built in-house at the NASA Johnson Space Center (JSC) based on a 3U-CubeSat form factor.

The first version of Seeker is intended to be an incremental development towards an advanced inspection capability. This effort builds on past free-flying inspector development efforts such as the AERCam Sprint and Mini AERCam.

Seeker was funded as an International Space Station (ISS) “X-by” Project, which required delivery of the vehicle approximately one year after authority to proceed and within the budget of $1.8 million. Seeker will fly onboard the Cygnus CRS-11 (NG-11) mission in 2019 and will deploy after Cygnus’ primary mission is completed.

The mission consists of the Seeker free flyer and the Kenobi supporting communication relay unit, which remains attached to Cygnus. Both are bult on similar 3U-CubeSat structures.

Seeker features a proulsion system using cold, gaseous nitrogen and twelve 0.1N thrusters to provide control authority in all six DOF. The system was designed entirely in-house at JSC and is comprised of COTS fluid components, custom machined manifolds, and custom additively manufactured thrusters. The propulsion subsystem is advertised to provide approximately 5m/s delta-V to a 5.7 5kg vehicle with the subsystem itself packed within an approximately 1.25U form factor.

Seeker has a sensor suite that includes a Sensonor STIM 300-400-5 Inertial Measurement Unit (IMU), Jenoptik DLEM-SR laser rangefinder (LRF), four Solar MEMS nanoSSOC-D60 sun sensors, and a Sony FCB-MA130 camera paired with algorithms developed by the University of Texas at Austin (UT).

Seeker will perform inspection-like maneuvers within 50 m of the target vehicle (Cygnus) and then dispose itself. The Seeker Guidance, Navigation, and Control (GNC) system is composed entirely of com-mercial off-the-shelf (COTS) and space-rated COTS items, an inertial-relative Multiplicative Extended Kalman Filter (MEKF), point-to-point guidance (with various additional modes such as stationkeeping), proportional-integral transla-tional control, phase plane rotational control, and a state machine for automated mission moding with minimal ground input.

Seeker was deployed on 17 September 2019.