Jim Bridenstine spoke to reporters at the U.S. embassy in Moscow a day after a Soyuz rocket failure forced Russian cosmonaut Aleksey Ovchinin and United States astronaut Nick Hague to make an emergency landing shortly after takeoff in Kazakhstan.
A Russian rocket carrying an American and a Russian to the International Space Station failed on launch Thursday, forcing the astronaut and cosmonaut to careen back to Earth in a dramatic emergency landing.
NASA's deputy chief astronaut, Reid Wiseman, said the crew "handled their procedures exactly as planned" and are "in great shape".
Kenny Todd, space station manager at NASA, said that the existing crew can stay on ISS till January and, if Russian Federation doesn't resume the Soyuz launches by that time, the flight controllers can operate the station without anyone onboard.
Hague, who only joined NASA's astronaut corps in 2013, was on his first space mission. The three astronauts still on the station will likely need to return to earth in December. Russian space agency Roscosmos has released photographs of both astronauts being checked over after their abrupt landing.
Search and rescue teams were deployed to the landing site.
They were to dock at the orbiting outpost six hours later, but the booster suffered a failure minutes after the launch. The astronauts immediately reported a problem because they were feeling weightlessness instead of the expected g-force acceleration that should have pushed them back in their seats.
In 2008, Expedition 16 crew experienced a similar steep ballistic descent on return from the ISS as did cosmonauts returning from the Salyut space station in 1979.
In public comments about the launch and rescue operations, he said he saw NASA staff come together to support Hague's family after the launch failure.
Krikalyov said all Soyuz launches have been suspended pending the investigation.
It was the first such accident for Russia's manned program in over three decades, although there also have been launch failures in recent years involving unmanned vehicles.
This isn't the first time this has happened. "It has been a hard day", Bridenstine said on Thursday. NASA too is conducting an investigation of its own.
The launch failure raises questions about the continued reliability of Russia's Soyuz launch system, which lost a cargo spacecraft at the end of 2016 and sent a Soyuz capsule with a hole in it to the ISS earlier this year. But Russia would like to avoid mothballing the station, he said.
Wiseman said although crews are always ready for potential issues, "certainly there is a bit of shock in there for a moment, but communication with the crew was extremely professional". It is the same capsule that was found to have a tiny hole in it after causing an oxygen leak on the station in September. "We have resources well into next year for this crew, so there's no concern about resources on board". However, the two sides have continued their cooperation in space.