Rocket launches in1999

Eileen Collins commands STS-93 in July — the first woman to command a Shuttle — and the mission places the Chandra X-ray Observatory into a high elliptical orbit. The year closes with two Mars losses back to back: Climate Orbiter in September from an imperial-to-metric unit error, and Polar Lander in December, while the USA edges Russia for busiest country of the year, 31 launches to 30.