Apparently a technical problem: Soyuz launch to the ISS is aborted 20 seconds before the planned launch. The next possible launch would be on Saturday at the earliest, NASA TV said.
On board were Belarusian cosmonaut Marina Vasilevskaya, NASA astronaut Tracy Dyson and Russian cosmonauts Oleg Novitsky and Oleg Nowizki. It was also the first time that two women were scheduled to fly together aboard a Soyuz capsule to humanity's outpost 400 kilometers above Earth.