The Federal Space Agency said Monday that a glitch in a Soyuz capsule's communication system has forced it to delay this month's launch of one U.S. astronaut and two cosmonauts to the International Space Station.
The delay from March 30 is likely to increase concerns about relying solely on Russia for rides to the space station just before NASA mothballs its shuttle later this year.
"A decision has been taken to postpone the launch of the Soyuz TMA-21 from March 30 to a later date due to technical problems," the Federal Space Agency said in a statement.
It did not specify a new launch date, but Russian news agencies cited industry sources as saying the launch would be delayed to a date between April 5 and April 10.
The Federal Space Agency said its experts needed more time to test the Soyuz craft after an error with the communication system was discovered in pre-launch trials.
The Soyuz TMA-21's March 30 mission was named in honor of Soviet space pioneer Yury Gagarin and had been timed to celebrate the 50th anniversary of his historic flight — the first human venture into orbit in 1961.
NASA astronaut Ronald Garan and cosmonauts Andrei Borisenko and Alexander Samokutyayev are set to travel to the space station aboard the Soyuz when it blasts off from the Baikonur Cosmodrome in Kazakhstan.
The Federal Space Agency said troubles with the Soyuz would not delay the planned return from orbit this week of three members of the station's current crew — U.S. astronaut Scott Kelly and cosmonauts Oleg Skripochka and Alexander Kaleri.
Their landing is set for March 16 in Kazakhstan.
Delays to the Soyuz launch are the latest in a string of embarrassing setbacks for the Federal Space Agency. It has lost control of three Glonass navigation satellites and one military satellite in two failed launches over the last three months.
Two high-ranking space officials were fired over the botched launches, and a government official issued a scathing rebuke of the space agency last month, accusing it of "childish" errors costing more than 2.5 billion rubles ($87 million).
Last year, difficulties undocking with the space station meant astronauts had to stay for an extra day in orbit.