Veteran NASA astronaut Joseph Acaba and two Russian cosmonauts were scheduled to launch to the station on March 29, but they will now fly on another Soyuz on May 15.

On Wednesday, Acaba tweeted, “Looks like I’ll b on the Planet a little longer. Issues with our Soyuz during a test will cause a delay. . . . We’ll b ready.”

The delay will push the return of the station commander, NASA’s Daniel Burbank, and two Russian crew members into late April, prolonging their mission by 45 days.

“This particular event is very unfortunate, but this is a complicated business and things sometimes happen,” Suffredini said. “To me, this is not indicative of some overarching problem at Energia,” the Russian company that builds the Soyuz, which has been flying since the Cold War’s space race.

But the failure does add to a string of problems for the Russian space industry. In August, an unmanned space station re-supply vessel crashed five minutes after launch. And in November, a robotic Russian spacecraft bound for a moon of Mars failed to depart Earth’s orbit. After circling the planet for two months, the $165 million Phobos-Grunt probe fell to Earth on Jan. 15.

The investigation into the August rocket crash postponed for two months the launch of Burbank and two cosmonauts, leaving the football-field-sized outpost with half a crew — three instead of six — and raising the possibility that NASA and its international partners might have to abandon the nearly $100 billion outpost.

But in November, Russia rebounded and successfully launched a Soyuz to deliver Burbank and the crew.

With NASA’s space shuttle program shuttered, the agency now relies on Russia to send its astronauts aloft. Each seat on the three-person capsule costs NASA about $56 million.

To replace the shuttle, NASA in 2009 began funding four U.S. companies now racing to build new taxi spacecraft.

But Congress delivered less than half of the funding that NASA wanted for the program this year, $406 million instead of $850 million. The funding gap means the spaceflight gap — the time until U.S.-built space vehicles might fly again — will extend to at least 2017, Bill Gerstenmeier, NASA’s director of human spaceflight, told The Washington Post.

One high-profile company racing to fly astronauts to the station, Hawthorne, Calif.-based SpaceX, is suffering delays of its own. The company was scheduled to launch a test — without a crew — of its Dragon capsule from Cape Canaveral Air Force Station on Feb. 7. But software and hardware issues will probably delay the launch until early April, Suffredini said, “assuming no new surprises.”

On Jan. 28, an unmanned Russian re-supply vessel did successfully dock with the station, bringing water, oxygen, food and other supplies.