The tragic loss of the Space Shuttle Columbia and crew in 2003 has resulted in a requirement to inspect the Shuttle Thermal Protection System (TPS) on-orbit so that the crew may remain at the International Space Station (ISS) in the event of damage that might pose an unacceptable risk to their safe return. An instrumented inspection boom manipulated and operated from the Shuttle’s Canadarm will provide an interim solution for the initial flights. However, a longer term solution has been planned that will permit the required inspection to be performed from within the ISS through the ISS windows. This plan involves the Shuttle performing a pitching maneuver to expose the underside for inspection purposes as it approaches the ISS prior to docking. The central approach in this plan is for the ISS crew to photograph the Shuttle TPS through the ISS windows using high-definition cameras. As an augmentation to this plan, the ISS-based Shuttle Inspection Lidar, or I-SIL, is a proposed lidar instrument that will generate a 3D topographic surface of the Shuttle underside to enable rapid identification and volumetric analysis of tile damage to generate safety and repair data. This paper presents the mission requirements and derived requirements for I-SIL, analyzes specific details of the inspection requirements, and discusses various phases of operating scenarios. The conclusion of the paper outlines the current status of the proposed technology.
SALLI is a conceptual instrument design that will efficiently acquire altimetric data for a planetary body or asteroid from orbit while maintaining a minimum power demand. SALLI scans its measurements off-nadir using a novel circular scanning technique that simultaneously permits a large instrument aperture using a motion-bandwidth efficient scanning mechanism. By combining spacecraft ephemeris data with SALLI’s measurement set, a complete digital elevation map of a planet or similar body can be generated in less time and using less spacecraft power than similar scanning and multi-beam instruments designed for the same purpose. SALLI was originally designed to generate measurement data to produce a topographical map of the lunar surface from a polar-orbiting host spacecraft; however, its benefits extend to a variety of other mapping missions of planets or asteroids.
Many on-orbit rendezvous missions would benefit from the ability to locate and track a spacecraft at a distance, compute its pose and attitude with high accuracy during close-in maneuvers, and to provide a visual record of the final mission event. The Rendezvous Laser Vision System (RELAVIS), designed by Optech and MD Robotics, meets such needs.
Installed on a seeker vehicle, RELAVIS provides an integrated laser-based vision system that obtains relative position and orientation of a target vehicle. RELAVIS supports targetless operation, does not require any external illumination sources and operates irrespective of location of a solar disk. The primary use of RELAVIS is to support autonomous satellite rendezvous and docking operations. RELAVIS can also be used for 3D workspace mapping and calibration, target vehicle inspection and reconnaissance in space environments.
RELAVIS has the unique capability of producing highly accurate data over a range of 0.5 metres to 3 kilometres and providing 6 degrees-of-freedom (pose) bearing and range data of a target spacecraft, which may be processed by an autonomous Guidance Navigation and Control (GNC) system for orbital rendezvous and docking operations. RELAVIS can also be equipped with a space-qualified camera unit to view on-orbit events.