Lt Col Marcos Pontes has become the first Brazilian to go into space after a successful launch aboard a Russian Soyuz rocket from Baikonur.
Col Pontes had been in training for the flight since 1998
He will spend nine days on the International Space Station while a Russian and a US colleague accompanying him will stay for six months.
Col Pontes took with him a Brazilian flag and a football shirt - to help, he said, his team in the World Cup.
His father, 84, was at the launch with other relatives and friends.
They applauded and cheered afterwards, watching video from an onboard camera at the ex-Soviet base Russia leases in Kazakhstan.
"I am very emotional," said his wife Fatima, with tears in her eyes. "I cannot even explain how I feel right now. I am very, very happy."
The launch was broadcast live on television in Brazil.
Vyacheslav Davidenko, spokesman for Russia's Roskosmos space agency, told the AFP news agency that the new astronaut would undoubtedly become a national hero in Brazil.
"Marcos Pontes will allow his country to join the club of space powers," he said.
Many Brazilians are hoping the trip will give a crucial morale boost to the country's own space programme, the BBC's Tom Gibb reports from Sao Paulo.
The mission, which is costing Brazil about $10m (£6m), comes less than three years after Brazil's space programme met with disaster when a rocket exploded on the launch pad.
The International Space Station is not due to be completed until 2010
The explosion of the first Brazilian rocket, built to take satellites into orbit, killed 21 people at the site in the north of the country.
However, there has also been some criticism that the cost of putting a man into space could have been used better elsewhere.
Thursday's flight is the fulfilment of a childhood dream for Col Pontes, our correspondent adds.
He has been training since 1998 for such a mission, which was originally to have been on a US space shuttle.
Col Pontes is being accompanied by Pavel Vinogradov of Russia and US astronaut Jeffrey Williams.