Product Features

The autonomous docking of two spacecraft presents a complicated dynamics problem accompanied with significant risks to the spacecraft and their payloads, typically addressed via increased sensing and computation. However, this often makes the system more complex and less robust due to sensor failures, software faults, or the like. The Web Docking System (WDS) simplifies the docking operation by employing novel mechanisms, thereby allowing sensing and computation to become simpler and more robust. The design approach inverts the process of alignment followed by capture. Performing capture first, then drawing the spacecraft together for alignment, allows for greater angular and positional misalignment upon approach, and greatly simplifies autonomous rendezvous and docking operations such as those planned for spacecraft servicing and propellant depots.

The WDS dynamically compensates for large multi-dimensional misalignments (x-, y-, z-axes, pitch and yaw). The incoming active or inactive spacecraft is equipped with a telescopic capture release probe that, when extended, hooks (captures) a large web deployed on the target spacecraft, i.e., propellant depot or space station. After capture confirmation, the peripheral hold of the web is released and the tethered web is pulled into a cone with the incoming spacecraft probe securely captured in the web. As the incoming spacecraft is dragged down the cone, it is first aligned and then preloaded with the target. This effectively means that both the incoming and target spacecraft are actively engaging each other and hard docking begins.

After the incoming spacecraft is preloaded, a conventional electromechanical subsystem couples the electrical and fluid lines between the two mating bodies. This misalignment compensating system is unique because unlike the “cone-to-capture” scheme utilized by most prior art docking interface technologies, the WDS employs a revolutionary “capture-to-cone” approach. This eliminates the need for incoming spacecraft actuation, vastly reducing the control operations and pre-alignment requirements levied on the two mating bodies.

Honeybee Robotics developed the WDS for NASA’s ST4/Champollion mission, a comet sample return mission.