As hundreds of thousands of Americans lined the Atlantic coast and highways around Cape Canaveral and cheered, the Discovery roared off at 2:19pm (7:19pm London time). Eight-and-a-half minutes later, Mr Glenn and his six fellow travellers were officially "in space". Weather conditions were perfect on a clear scorching day after Hurricane Mitch obliged Nasa by shifting towards Central America.
There were six other astronauts on board but this had long since become the John Glenn show, attracting more sightseers and media members than any previous launch. The fact that the senator was outranked on board by all six fellow travellers, including Chiaki Mukai, a female heart surgeon from Japan, and the European Space Agency astronaut, Pedro Duque of Spain, was by the by.
They will carry out more than 80 experiments, notably on the effects of weightlessness on Mr Glenn's ageing body. Despite his exceptional physical condition, he appeared to totter slightly and lagged behind as the crew walked to the foot of the blast-off scaffolding. He and the others looked up in apparent awe at their massive craft, 122 feet high on its own, 184 feet including its towering fuel tank.
In sharp contrast to his Mercury flight in 1962, it took half a dozen helpers nearly an hour to get the senator and the rest of the crew into their 85-pound orange spacesuits and fitted into their launch seats.
In 1962, Glenn was the brush-cut, square-jawed all-American boy who socked it to the upstart Russians by becoming, in the midst of the Cold War, the first American to orbit the Earth. Yuri Gagarin had got there first but Glenn was more handsome, and American, and made it around the planet three times to Gagarin's once. Moreover, while the world had to take the Russians' word for Gagarin's feat, it watched Glenn every space- step of the way.
Yesterday, Mr Glenn was representing Generation G - G for geriatric. The accepted wisdom among those who gathered to watch him take off - most of them as grey-haired as the senator, for younger folk were working - was that he may help uncover the Fountain of Youth. His reaction to mid-space experiments might help us find ways to delay the ageing process, the believers said.
The cynics spoke of a public relations ploy to glorify a Last American Hero and divert attention from a country hung over from the Monica Lewinsky scandal and unnerving hiccups in the economy. Quelle coincidence, they said, that Mr Glenn, an outgoing Democratic senator, should be galvanising American patriotism five days before crucial American elections. Mr Glenn will spend election day - which includes the race for his Senate successor - in space.
After Glenn's first space orbits President John F Kennedy ordered Nasa not to let him fly again. A hero like Glenn should not be put in danger, thought Kennedy. Better groom him for a Democratic political career. Now about to give up his day job, Mr Glenn is determined to pull off his latest space mission.Reuse content