Arianespace halted plans to launch two communications satellites into orbit on Friday (Oct. 22) to allow time for more ground equipment checks, but a new liftoff date remains uncertain.
The French launch provider was expected to launch the two satellites on an Ariane 5 rocket Friday night from the Guiana Space Center in Kourou, French Guiana. Liftoff was targeted for 9:01 p.m. EDT (10:01 p.m. local time in Kourou or 0101 GMT Saturday, Oct. 23).
"Due to additional checks on the ground support equipment, [the launch] has been scrubbed. Investigations are ongoing in order to identify a new launch date," Arianespace wrote at 7 a.m. EDT (8 a.m. local time or 1100 GMT), not specifying yet whether an issue had been found.
For now, the two satellites remain on the launch pad with their rocket. "The Ariane 5 launch vehicle and spacecraft SES-17 and Syracuse 4A are in stable and safe conditions on the launch pad," Arianespace continued in the tweet.
The launch, expected to be Arianespace's 11th of the year, was supposed to send an Ariane 5 rocket into geostationary transfer orbit, where the two satellites would make their way to geostationary orbit, according to Arianespace's website (opens in new tab). This would have been Ariane 5's second launch of the year after a dual communications satellite launch in July.
For the new mission, SES-17, from Thales Alenia Space, is a high throughput telecommunication satellite designed to assist aviation, maritime, government and enterprise customers in the Americas, Caribbean and Atlantic Ocean.
Syracuse 4A, a French military communications satellite, will be launched on behalf of the Armament General Directorate (a procurement and technology agency for the government.) It will be the first part of a three-satellite constellation aiming to serve the military for battlefield digitation, and is equipped with a modern anti-jamming antenna.
As of September 2018, Ariane 5 had a 98% reliability rate (opens in new tab) (according to Arianespace numbers) since it began launching in April 2003; in the last decade, Ariane 5's only major anomaly was in January 2018. On that occasion, the satellites made it safely to orbit despite Arianespace losing contact with the upper stage of the rocket, late in the launch.
Follow Elizabeth Howell on Twitter @howellspace. Follow us on Twitter @Spacedotcom and on Facebook.