A precision pointing system for spacecraft's telescopes, other observation instruments, and experiments. It was designed and constructed by the European Space Agency for the Spacelab space station. Mounted on a pallet in the shuttle's payload bay, it can provide pointing accuracy for one large instrument or a cluster of smaller ones. The space shuttle can seldom maintain pointing accuracies better than 1/10th of a degree by using its thrusters, whereas the IPS can achieve 1/3 600th of a degree. It is a three-axis gimbal system that has accelerometers to allow it to compensate for motions to the shuttle. The IPS finds predetermined guide stars to determine its correct position.
Subjects: Astronomy and Astrophysics.