STS-93
| Chandra and its Inertial Upper Stage, prior to deployment from Columbia's payload bay | |
| Names | Space Transportation System-93 | 
|---|---|
| Mission type | Chandra X-ray Observatory deployment | 
| Operator | NASA | 
| COSPAR ID | 1999-040A | 
| SATCAT no. | 25866 | 
| Mission duration | 4 days, 22 hours, 49 minutes, 34 seconds | 
| Distance travelled | 2,890,000 km (1,796,000 mi) | 
| Orbits completed | 80 | 
| Spacecraft properties | |
| Spacecraft | Space Shuttle Columbia | 
| Launch mass | 122,534 kg (270,142 lb) | 
| Landing mass | 99,781 kg (219,980 lb) | 
| Payload mass | 22,780 kg (50,222 lb) | 
| Crew | |
| Crew size | 5 | 
| Members | |
| Start of mission | |
| Launch date | 23 July 1999, 04:31:00 UTC | 
| Launch site | Kennedy, LC-39B | 
| End of mission | |
| Landing date | 28 July 1999, 03:20:35 UTC | 
| Landing site | Kennedy, SLF Runway 33 | 
| Orbital parameters | |
| Reference system | Geocentric | 
| Regime | Low Earth | 
| Perigee altitude | 260 km (160 mi) | 
| Apogee altitude | 280 km (170 mi) | 
| Inclination | 28.4° | 
| Period | 90 minutes | 
| Left to right: Collins, Hawley, Ashby, Tognini, Coleman | |
STS-93 in 1999 marked the 95th launch of the Space Shuttle, the 26th launch of Columbia, and the 21st night launch of a Space Shuttle. Eileen Collins became the first female shuttle Commander on this flight. Its primary mission was to launch the Chandra X-ray Observatory, the heaviest payload ever carried by the Space Shuttle system, at 22,780 kilograms (50,222 lb).
STS-93 would be Columbia's last mission until March 2002. During the interim, Columbia would be out of service for upgrading and would only fly again on STS-109. The launch was originally scheduled for 20 July, but it was aborted at T−7 seconds.: 221 The successful launch of the flight occurred three days later.