WASHINGTON — A key component of the close-range navigation system intended for use on NASA’s next-generation crew capsule flew successfully in space for the first time in May aboard Space Shuttle Endeavour.
On May 30, after undocking from the international space station, Endeavour conducted a mock rendezvous, approaching the orbital outpost on the same trajectory that the planned Orion Multi-Purpose Crew Vehicle would use to dock. The maneuver was designed to test a sensor package that will serve as the “eyes” of the capsule’s docking system, said Howard Hu, manager of the Orion System Performance and Analysis Office at NASA’s Johnson Space Center in Houston.
The central component of this sensor suite is the Vision Navigation Sensor (VNS), a laser-based sensor that bounces light off of a surface and feeds the resulting data into computer modeling software to create a three-dimensional image. A digital video camera serves as a second sensor.
The two-sensor package is intended to make docking with the international space station easier for future pilots. The shuttle fleet’s docking system uses four sensors and requires three crew members to operate. The VNS, in contrast, would allow a single pilot to perform docking operations.
VNS would also enable automated docking for uncrewed U.S. vehicles traveling to the space station, Hu said.
The Multi-Purpose Crew Vehicle was mandated by Congress to be a deep-space exploration vehicle. However, the same mandate requires the capsule to be capable of acting as a backup to commercial crew and cargo vehicles under development.
The sensor package that includes VNS was jointly developed and tested by NASA, Lockheed Martin Space Systems of Denver, and Ball Aerospace & Technologies Corp. of Boulder, Colo. VNS’ space debut marks the culmination of the three-year Sensor Test for Orion Relative Navigation Risk Mitigation (STORRM) project.
The total price tag for the STORRM project, including engineering and development, was about $13 million, said Larry Price, Orion deputy program manager for Lockheed Martin Space Systems.
The VNS itself is the latest evolution of technology that Ball has been testing for years, said the senior Ball engineer on the STORRM project.
“VNS was developed based on five generations of lab units that we’d developed at Ball,” said Jeanette Domber, senior payloads system engineer and Ball’s team leader for the project. Some of VNS’ forebears “have been on atmospheric flights [but] this was definitely the first space flight for our systems.”
So far, STORRM project engineers have parsed only about 2 percent of the data created by the in-orbit test, said Hu. But they already know, for example, that VNS was able to detect the space station from a distance of 5.7 kilometers. The minimum lock-on distance specified by NASA was 5 kilometers, said Hu. VNS could also track the international space station reliably in close quarters — about 6 feet was as near as the sensor got to the station, Hu said.
When Lockheed gets access to the full complement of STORRM test results, it plans to incorporate the data into the software algorithms that power its Space Operations Simulation, a 3,800-square-meter facility Lockheed recently opened outside Denver to rehearse on-orbit docking maneuvers with full-size Orion capsule and space station mockups.
The VNS, and the docking system of which it is a part, were designed for the Orion space capsule, a central component of the canceled Constellation program.
Orion and the Multi-Purpose Crew Vehicle became one in the same May 24 when NASA formally announced it would proceed with work on that vehicle — a congressionally mandated project from the NASA Authorization Act of 2010 — under Lockheed’s existing Orion contract. The $8.15 billion Orion contract was awarded in 2006.
When the Orion Multi-Purpose Crew Vehicle goes into service, VNS will fly with it. The current program of record calls for the capsule to be fully operational by 2016, but the capsule lacks a launch vehicle on which to hitch a ride to space. NASA has not yet unveiled details about the heavy-launch rocket that was ordered up in the same 2010 authorization act as the capsule, but the agency has indicated that development of the crew vehicle will be paced with the work done on the rocket.
Even if the Multi-Purpose Crew Vehicle does not fly in 2016 the VNS might. Hu said that project leaders for the agency’s next New Frontiers mission — the Osiris-Rex asteroid-sample return project selected May 25 — are interested in the VNS.
The Lockheed-built Osiris-Rex probe could use VNS to navigate close enough to asteroid 1999 RQ36 to scoop up a sample.