Before launch, Glover made a presentation about the mission, boasting about the reliability of the Russian-made Soyuz rocket the two were to launch in.
Yuri Kochetkov/Pool via REUTERS Backup crew members Roscosmos cosmonaut Оleg Kononenko (R) and CSA astronaut David Saint Jacques look at the Soyuz booster rocket with the Soyuz MS-10 spacecraft installed on the launch pad at the Baikonur cosmodrome, Kazakhstan, Oct. 9, 2018.
Russian Roscosmos space agency and NASA said the three-stage Soyuz booster suffered an emergency shutdown of its second stage. After a nail-biting interval, a search and rescue team located the craft and retrieved Hague and Ovchinin in good condition.
The ballistic descent is a sharper angle of landing compared to normal, NASA said.
NASA Administrator Jim Bridenstine greets astronaut Nick Hague after his emergency landing during a crew launch to the space station. "But everything seems to be fine with the crew, we had good comms with them and they are OK".
Dmitry Rogozin, the head of Russian space agency Roscosmos, tweeted shortly after the incident that a commission of inquiry had already begun work on figuring out the cause, by studying telemetry data from the craft.
The International Space Station, a rare point of cooperation between Moscow and Washington, has been orbiting the Earth at roughly 28,000 kilometres per hour since 1998 and will mark its 20th birthday in November.
A few minutes after launch Roscosmos informed NASA that there had been an issue with the Soyuz booster.
The Soyuz spacecraft was thrown clear of the rocket and plunged back to Earth for a ballistic landing, with peak acceleration estimated at 6 to 7 G's.
It was to be the first space mission for Hague, who joined NASA's astronaut corps in 2013.
The astronauts were to dock at the International Space Station six hours after the launch and join an American, a Russian and a German now aboard the station.
"The crew is alive and is landing in Kazakhstan", a source told the Russian news agency Interfax.
Russian flight controllers described the forces experienced by Hague and Ovchinin as six to seven Gs due to the lack of velocity when the failure occurred.
Also, the December launch of the next crew members, which included Canadian astronaut David Saint-Jacques, could be on indefinite hold, as could any other crewed launches that have been scheduled.