This week in 1999, space shuttle Columbia, mission STS-93, launched from NASA’s Kennedy Space Center on a four-day mission to deliver the Chandra X-ray Observatory to low-Earth orbit. Chandra was then be propelled to an orbit of 44,759 miles in altitude using a two-stage Inertial Upper Stage.

Source: This Week in NASA History: Chandra Launches - July 23, 1999