Why doesn’t NASA attach the Hubble Space Telescope to the International Space Station (ISS) to service the telescope safely? Is that technically feasible?

Of all orbital maneuvers, altering a spacecraft’s orbital plane requires the greatest change in velocity and consumes the most fuel. The orbital inclinations of Hubble and the Space Station differ by a minimum of 23.1°.

To move Hubble into the ISS orbit, we would have to change the telescope’s speed by about 3,000 meters (9,800 feet) per second. To put this number into perspective, consider that it amounts to about 40 percent of the speed needed to keep Hubble in orbit at all. The space shuttle has the ability to change velocity by 700 meters (2,300 feet) per second in orbit, so the short answer to your question is no. Even the shuttle doesn’t carry enough fuel to do the job. — BILL COOKE, MARSHALL SPACE FLIGHT CENTER