Endeavour Crew Tests Critical Docking Sensor
DENVER, June 1, 2011 — In an unprecedented on-orbit maneuver, space shuttle Endeavour crew members completed the first-ever Orion Multi-Purpose Crew Vehicle (MPCV)-like approach to the International Space Station as part of the Sensor Test for Orion Relative Navigation Risk Mitigation (STORRM). The orbital rendezvous verified the successful operation of the MPCV’s next-generation docking sensor, which NASA has identified as a critical technology for future space exploration missions.
Five retroreflectors, the first element of the Sensor Test for Orion Relative Navigation Risk Mitigation (STORRM) to go into space, were attached to the International Space Station during the STS-131 space shuttle mission in April. The reflectors were placed on the docking door of the space station in a precise pattern, as demonstrated in this lab test. (Photo: NASA)
STORRM features a robust relative navigation design that provides the required docking accuracy and range capability necessary to meet crew safety, mass, volume and power requirements for a wide variety of future NASA missions, including those into deep space. The STORRM hardware components consist of a high-definition docking camera, an advanced laser-based vision navigation sensor (VNS), an avionics assembly to provide power and record data, a space-certified laptop computer and reflective docking targets that were installed on the space station during STS-131. The VNS is an eye-safe flash lidar system that provides an image of the target – in this case, the space station – along with range and bearing data to precise accuracies.
The NASA, Lockheed Martin and Ball Aerospace team worked closely with STS-134 Mission Specialist Andrew Feustel to successfully complete the on-orbit test of this system, which will make rendezvous and docking maneuvers safer for future spacecraft. The flight test represented the first and only opportunity for in-flight collaboration of NASA’s three human spaceflight programs — space shuttle, International Space Station and Orion MPCV.
Byron Meadows, laser systems engineer at NASA Langley, talks about how different materials were tested for the reflective elements. (Photo: NASA/Sean Smith)
“This flight test demonstrated the exceptional capability of the vision navigation sensor and the docking camera, two key components of the Orion relative navigation system,” said Catherine Boone, the Lockheed Martin electro-optics engineer working in NASA’s Mission Control Center during the re-rendezvous event. “We were able to collect about 600 gigabytes of data that will verify the design meets the high performance standards required for Orion MPCV and other future spacecraft. Follow-on testing at our Space Operations Simulation Center in Denver will also provide an opportunity to look at how we may be able to expand on that performance to make the system as powerful and accurate as possible for the dynamic environments of deep-space exploration missions.”
Jeanette Domber, senior payloads system engineer and Ball’s lead for STORRM, explained that, unlike other navigation sensor flight experiments, which simply collected data during normal shuttle operations, the STORRM flight test leveraged America's human spaceflight assets in a true “test-like-you-fly” scenario. “This test exercised the Orion relative navigation sensors exactly as they will be flown on future human space exploration vehicles,” she said. “This mission provided NASA a one-of-a-kind opportunity to prove out the performance of this technology in a real spaceflight environment.”
STORRM reflector mounting concept. (Image: NASA)
During the mission, the laser-based VNS performed better than expected by providing continuous measurements from as far away as 3.5 miles to within 6 feet of the space station – three times the range capability of the current relative navigation sensor. The next-generation sensor technology also provided exceptional 3-D images of the docking target.
As its nickname indicates, STORRM was a whirlwind project. When given the opportunity to fly and test the system on one of the last shuttle missions, the project team kicked into high gear to rapidly design, build and test all the components to be ready in half the usual time required for such a system to be manifested for the shuttle flight’s payload.
For more information, visit: www.nasa.gov
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