Update: Orbital Prepares For Station Launch on Saturday

Update: Thunderstorms on Wednesday prevented the roll-out of the Antares booster. As a result, the launch has been delayed to 1:14 pm EDT on Saturday, July 12.

Image Credit: OSC

Orbital Sciences Corporation is preparing for its next Commercial Resupply Services launch to the International Space Station. Liftoff of the Antares booster carrying the Cygnus freighter is scheduled for 1:40:27 pm EDT on Friday, July 11 from Pad OA at the Mid-Atlantic Regional Spaceport at NASA’s Wallops Flight Facility on the Virginia coast.

Loaded with 3,293 lbs. of cargo, including 28 more of Planet Labs “Dove” Earth observation cubesats, the Cygnus will begin a 36 day mission which if everything goes according to plan will see a berthing to the Station’s Harmony module on Tuesday, July 15 at 9:30 am.

Friday’s launch of the Orbital-2 mission was originally scheduled for June 10th, but was delayed following the failure of an Aerojet AJ-26 engine during a routine test at NASA’s Stennis Space Center on May 22nd. Although that engine, which by some reports “blew up” 30 seconds into a planned 54 second acceptance test, was not scheduled for service until a later flight, it necessarily warranted further examination of the two modified forty year old Russian engines which will power the current Antares booster.  The engines have always been a matter of some concern,  an issue which was first brought into the spotlight during a previous test failure resulting in a fire in June 2011.

Despite the concerns, the AJ-26 engines have performed flawlessly during three previous flights, and a successful launch on Friday would mark four flights in just 14 months, an undeniably impressive pace for a new booster.

NASA television coverage is set to begin at 12:30 pm  on Friday.