PARIS, April 20 (UPI) -- The European Space Agency says it has again postponed the joint launch of its Herschel and Planck spacecraft.
The space agency said the latest delay was caused by "an anomaly discovered during tests on a subassembly identical to the one on the Ariane 5 launcher." Officials said Arianespace has decided to conduct additional checks, which will take several days.
The ESA last month postponed a scheduled April 16 launch, citing the need to validate operational procedures following a software update.
The Herschel telescope mirror will be the largest ever launched into space and will be the first space observatory to cover the full far infrared and sub-millimeter wave band, Wikipedia said, while Planck is designed to observe the cosmic microwave background.
The Herschel and Planck satellites, currently at the ESA's spaceport in French Guiana, are reported in perfect condition.
The ESA said a new launch date will soon be announced.
