Russia’s attempt to launch a cargo spacecraft on a Soyuz 2.1a rocket to the International Space Station (ISS) went awry this morning. The Progress MS-08 spacecraft and its Soyuz 2.1a rocket are still on the launch pad. Russia’s Roscosmos space state corporation said it will try again on February 13. The cause is under investigation, but the incident bears resemblance to an October 12, 2017 scrub of Progress MS-07.[UPDATE: Progress MS-08 was successfully launched on February 13.]

In the October 2017 instance, Russia successfully launched Progress MS-07 two days later. The only real impact was that a newly developed trajectory that could get the spacecraft to the ISS in just two-and-a-half orbits could not be tested. By the time the launch took place, the orbital position of the ISS and the launch site were no longer properly aligned to permit the shorter route.

Today’s launch once again was intended to test the new trajectory. Launch was scheduled for 3:58 am Eastern Standard Time (EST), with docking at the ISS at 7:24 am EST, 3 hours and 26 minutes later.

For decades, Russia used a 34-orbit (about 2 day) trajectory to get spacecraft to space stations, whether they carried crews or cargo. (Russia’s first of seven successful space stations, Salyut 1, was launched in 1971. The first Progress cargo spacecraft was launched in 1978 to resupply the Salyut 6 space station and have been in use ever since, with many upgrades).

A shorter 4-orbit (about 6 hour) trajectory was introduced in 2013, but this new iteration would reduce that to 2.5 orbits (about 3.5 hours).

In the case of Progress MS-07, an electrical connector (“umbilical”) did not retract from the Soyuz 2.1a rocket as planned and the computer terminated the countdown 12 seconds before launch. That seemed to be what happened today. The countdown was proceeding as planned until seconds before the scheduled liftoff.

Roscosmos tweeted just minutes later that the launch was postponed to the backup date of February 13.

На старте прошла команда на автоматическое выключение двигателей, причины выясняются. Пуск перенесен на резервную дату – 13 февраля. Роскосмос будет информировать по мере поступления дополнительной информации.​#ПрогрессМС08 pic.twitter.com/fNjQqyWFKz — РОСКОСМОС (@roscosmos) February 11, 2018

If the launch does take place that day, celestial mechanics will require use of the 34-orbit trajectory.

NASA refers to this as “69P” or Progress 69 because it is the 69th Progress launch to support ISS.

Progress MS-08 is filled with 1,390 kilograms (kg) of dry cargo, 890 kg of fuel, 420 kg of water, 46 kg of compressed air and oxygen, scientific equipment, food, clothing, medicines, and personal hygiene products for the crew according to a Roscosmos press release.