After extensive negotiations and technical information exchanges between the U.S. and Russian space teams, the Russians concluded close approach could be safely achieved and the STS-63 crew was given 'go' to proceed. R1U thruster manifold was closed and the backup thruster was selected for the approach. Ship-to-ship radio contact with Mir was achieved well ahead of time, and Titov, who had previously lived on Mir for more than a year, communicated excitedly with the three cosmonauts aboard the space station: Mir 17 Commander Alexander Viktorenko; Flight Engineer Yelena Kondakova; and Valery Polyakov, a physician who had broken Titov's record for extended time in space. After stationkeeping at a distance of from Mir and with Wetherbee manually controlling the orbiter, "Discovery" was flown to from the Russian space station. "As we are bringing our spaceships closer together, we are bringing our nations closer together," Wetherbee said after Discovery was at point of closest approach. "The next time we approach, we will shake your hand and together we will lead our world into the next millennium." The Closest approach to Mir of occurred on 6 February 1995 at 19:23:20 UTC.