1998: John Glenn returns to space

In 1998, the first American to orbit in space, John Glenn, gained the title of oldest man in space when he joined the crew of STS-95 on board Discovery.

Speaking from on board the shuttle, the 77-year-old said he had been "more nervous the first time" he went into space.

His participation in the mission was criticised by some, but others pointed out that sending up a 77-year-old who had last been in orbit 36 years earlier provided an ideal opportunity to study the effects of space flight on the elderly.