1.   Astronomical interferometry is the art of combining light or radio waves collected by two or more instruments from a single celestial target.

2.   A full complement of four internal flywheels awaits commands to point the telescope from one celestial target to another.

3.   Like the gyros, the sensors are crucial to aiming the telescope at celestial targets and holding it steady.

4.   The operating mode ensures that the telescope continues to generate electricity for its scientific equipment and flight controls, though it is unable to point at celestial targets.

5.   Four astrophysicists aboard the shuttle are helping to aim the telescopes toward scores of celestial targets during the flight.