Conceived of over three decades ago in Canada's National Research Council laboratories and built by NEPTEC, the Space Vision System (SVS) is designed to enhance astronauts' vision in the difficult viewing conditions of space. It provides information on the exact location, orientation and motion of a specified target, helping astronauts to perform precise tasks in extreme lighting conditions. The Space Vision System was first tested by Canadian astronaut Steve MacLean during Shuttle Mission STS-52 in 1992.
Since then, a more robust and improved vision system was installed on the space shuttle. Used in conjunction with the Canadarm, it was retired in 2011. However, the same version is still currently in use on the International Space Station (ISS) with Canadarm2. The SVS has proven to be an invaluable tool for handling payloads.
How it works
The Space Vision System uses TV cameras as sensors. These cameras monitor a pattern of special target dots placed on the object to be tracked. As the object moves, the system tracks the changing position of the dots, calculates the location and orientation of the object, and presents this information to the operator in the form of both graphical and textual cues. This information can be used to position and orient a payload using Canadarm2, or to join two objects as in the case of Space Station assembly.
The Space Vision System has many enhanced features that increase its accuracy, versatility and usefulness, making it able to operate in a wider range of lighting conditions. Frequent periods of extreme dark or bright light make it difficult for astronauts working in space to gauge the distance and speed of objects such as satellites. With the addition of improved target tracking features, the Space Vision System is able to switch from one set of targets to another when one moves out of its field of vision. The system is also capable of "losing" some targets as they become obscured, allowing the calculations to continue on the remaining targets. In past operations, this system could overcome conditions such as the Shuttle turning or shaking, and for current operations, it assists in berthing manoeuvres of an object in space. The Space Vision System is relied upon for sophisticated tasks and ensures that NASA meets their stringent requirements for precision and safety.