Next week's launch of an Orbital ATK Cygnus spacecraft packed with NASA cargo has been delayed by a few more days to Friday (March 24) to allow more time to replace a suspect rocket component, according to NASA officials.
The robotic Cygnus spacecraft was previously scheduled to lift off from Cape Canaveral Air Force Station in Florida on Tuesday (March 21) atop an Atlas V rocket provided by the United Launch Alliance (ULA). That March 21 target had already been delayed from March 19 due to concerns over the suspect hydraulic component on the Atlas V's first stage.
"The additional time allows the ULA team to replace and retest a first stage hydraulic component," NASA officials wrote in a status update.
Liftoff for Orbital ATK's OA-7 cargo mission for NASA is now scheduled for March 24 at 9 p.m. EDT (0100 Saturday GMT). Orbital ATK and ULA may have an option to move the launch a day earlier — to Thursday, March 23 — if time allows on the Eastern Range used to for Florida launches.
Orbital ATK typically launches its Cygnus cargo ships on the company's own Antares rockets, which fly from a pad at NASA's Wallops Flight Facility on Wallops Island, Virginia. For the OA-7 mission, Orbital ATK opted to launch Cygnus on ULA's Atlas V rocket due to the booster's increased lift capacity.
The OA-7 mission is expected to deliver 7,600 lbs. (3,447 kilograms) of supplies and research equipment to the International Space Station for NASA. Orbital ATK has named the Cygnus the S.S. John Glenn in honor of the astronaut pioneer John Glenn, the first American to orbit Earth, who died in December.