1999 in spaceflight
| Launch of STS-93, to deploy the Chandra X-ray Observatory | |
| Orbital launches | |
|---|---|
| First | 3 January | 
| Last | 27 December | 
| Total | 79 | 
| Successes | 73 | 
| Failures | 6 | 
| Catalogued | 73 | 
| National firsts | |
| Satellite | Denmark Republic of China South Africa | 
| Rockets | |
| Maiden flights | Delta II 7320 Delta II 7426 Dnepr Long March 2F Long March 4B Zenit-3SL | 
| Retirements | Ariane 4 40 Athena II H-II | 
| Crewed flights | |
| Orbital | 4 | 
| Total travellers | 22 |