An unmanned spacecraft is set to fly to the International Space Station in less time than it takes to fly from Toronto to Edmonton on a passenger plane.
If all goes well, the robotic Progress 70 spacecraft will dock itself at a Russian port on the station at 9:39 p.m. EDT (0139 July 10 GMT).
It was the third attempt to execute the short two-orbit flight scheme for the Progress MS freighter, which required a coordinated effort to realign the orbit of the ISS.Two previous attempts were hindered by delays in the final moments of the countdown that exceeded narrow launch opportunities for the fast-track flight. Progress spacecraft (and crew-carrying Soyuz capsules) originally took two days to reach the station before Roscosmos cut that trip down to 6 hours in 2013.
Russia's space agency Roscosmos said the faster maneuver became possible thanks to a new version of the Soyuz booster rocket, noting that it puts the ship into orbit with higher precision.
This was the first Russian cargo mission to demonstrate an "expedited capability" that will likely be used again in future, NASA said in a statement.
Roscosmos director Dmitry Rogozin hailed the faster rendezvous as a "big step forward" in a call with Russian crew on board the station after the docking.
The station's current crew includes NASA astronauts Drew Feustel, Ricky Arnold and Serena Aunon-Chancellor, a European Space Agency's astronaut from Germany, Alexander Gerst, and Russians Oleg Artemyev and Sergey Prokopyev.