On Thursday a crew of three people was due to launch on a Soyuz rocket, bound for the International Space Station.

However, the launch scrubbed at about 20 seconds before the planned liftoff time, just before the sequence to ignite the rocket's engines was initiated, due to unspecified issues. Shortly after the abort, there were unconfirmed reports of an issue with the ground systems supporting the Soyuz rocket.

The three people inside the Soyuz spacecraft, on top of the rocket, were NASA astronaut Tracy C. Dyson, Roscosmos cosmonaut Oleg Novitskiy, and spaceflight participant Marina Vasilevskaya of Belarus. This Soyuz MS-25 mission had been planned for liftoff from the Baikonur Cosmodrome in Kazakhstan at 13:21 UTC (6:21 pm local time in Baikonur).

Such scrubs are rare. The Soyuz booster and its launch systems are typically robust, launching regardless of weather conditions—watching an orbital, liquid-fueled rocket launch during a snowstorm is quite a trip. And the Russians have plenty of experience with the booster. Since its debut in 1966, across a number of variants, the Soviet Union and Russia have launched more than 2,000 Soyuz rockets.

A longer cruise to the station

The crew was never in significant danger during the scrub, but their trip to the space station will now be a little bit delayed and may take a little bit longer. Based on orbital dynamics, the crew had been due to dock with the Soyuz just three hours after liftoff on Thursday in a so-called "fast rendezvous" scenario.

Now, the earliest available launch window for the vehicle is Saturday, pending a resolution of the cause of Thursday's scrub. According to NASA commentator Rob Navias, a Saturday launch would require a much longer transit to the space station, with a docking not occurring until Monday. That is, unfortunately, a rather long time for the crew of three to remain inside the cramped Soyuz spacecraft.

Before NASA's webcast of the launch attempt ended, Navias said it was unlikely that the Soyuz delay would impact a NASA cargo supply mission launch planned for later on Thursday. This will be SpaceX's 30th commercial supply mission to the space station for NASA, and a Cargo Dragon spacecraft is expected to lift off at 4:55 pm ET (20:55 UTC) from Florida. A Dragon docking is planned for Saturday morning.

Notably, this will be the first time that a Dragon launches from SpaceX's oldest pad in Florida, Space Launch Complex-40. A crew tower has been installed there to facilitate astronaut launches beginning later this year.