On 28 February 2002, scientists in Kourou, French Guiana, were worried. They knew that in a few hours time the Ariane rocket would leave on its journey. On the rocket was Envisat, the biggest and most expensive satellite ever made in Europe. Envisat was ready and waiting after twenty years' work by hundreds of people. But now, at the last minute, something was wrong with the rocket carrying the satellite.
Scientists worked all night to get the rocket working again. Late in the evening on 1 March everyone in Kourou stopped working to watch the rocket leave. The weather was good and the rocket was ready. Five, four, three, two, one the Ariane rocket went up into the sky, carrying Envisat with it.