International Space Station Assembly - NASA
ASVS Was the First Personal Computer-Based Real-Time Machine Vision System
In the early 1990’s Neptec combined the power of microprocessor technology together with custom electronics and proprietary software to produce a real-time vision system not much bigger than a laptop computer. This tiny box was capable of producing very accurate 3-dimensional measurements by just processing the video signal from a standard video camera and it was able to update the measurements 30 times each second. This combination of accuracy and high update rate made it ideal for measuring objects that were moving relative to each other.
In 1992, we demonstrated the technology to NASA. This led to Neptec developing an Advanced Space Vision System which had its first operational use in docking the space shuttle Atlantis with the Russian space station Mir in 1995.
NASA Plans the Assembly of the ISS
Around the same time, NASA was planning the on-orbit assembly of the International Space Station. When completed that 400,000 kg structure would have 1,000 cubic meters of pressurized volume comprised of 15 modules; each the size of a large vehicle, trusses 70 meters long, solar panels, airlocks, robotics and various other modules. Each of the elements would need to be carefully aligned on orbit using the ISS robotic systems. This alignment would be no easy task. One planner described it as trying to position the front end of a city bus to within a fraction of an inch and a fraction of a degree while holding the other end of the bus with the robotic arm.
NASA selected Neptec to develop the Orbiter Space Vision System to do the on-orbit measurements needed to support ISS assembly operations. Development of the OSVS would require many innovations.
To meet the operational requirements of the mission, our developers concluded we would need to take advantage of the speed and functional density of contemporary commercial electronics rather than the slower, lower functionality space qualified components that would typically be used in mission-critical applications. This would require Neptec engineers to develop processes to qualify commercial grade components and certify them for flight, a practise that continues in many of our space products to this day.
In addition to process innovation and the proprietary hardware and software that were core to the operation of the real-time vision system, there were many functional innovations in the OSVS. One was the ability to upload software and database updates to the equipment during a mission. In this age of frequent automatic updates to operating systems over the internet this might not seem very innovative but in the mid-1990’s it was new and it was a feature that would prove invaluable in allowing the system to be adapted to unplanned mission events.
Neptec’s OSVS Flies for the First Time
The first operational use of the OSVS was on shuttle mission STS-88. Launched on December 4, 1998, mission STS-88 consisted of launching Unity, the second component of the International Space Station, into space. The shuttle Endeavour caught up with the first component, Zarya, which had been launched from Kazakhstan on November 20. The astronauts’ mission was to connect Unity with the orbiting Zarya. To do this, the Orbiter Space Vision System was essential. At the end of the mission the president of the Canadian Space Agency Mac Evans remarked:
“Connecting the two elements would have been impossible without the Orbiter Space Vision System.”
The OSVS would be used on ISS assembly missions for over a decade. In addition to developing and producing the OSVS, Neptec staff supported planning each assembly mission, conducting operational simulations, training astronauts on the use of the system, supporting real-time operational activities in Mission Control, conducting post-mission analysis and planning upgrades to support the continually evolving and expanding role of the system.
Neptec built 20 Orbiter Space Vision Systems for use on the space shuttles and also adapted the design to create two Artificial Vision Units for installation on the International Space Station.
Image credit NASA