Orbital delays first cargo flight

Orbital Sciences said the first full-up test flight of its Cygnus cargo ship to the International Space Station will likely slip to September due to a variety of factors, including an engine replacement on the mission's Antares rocket and a scheduling conflict with a Japanese logistics spacecraft. The first flight of Orbital's Cygnus resupply freighter, an automated cargo carrier developed in partnership with NASA, was expected this summer. But Orbital officials decided to swap out one of the AJ26 first stage engines on the spacecraft's Antares rocket, adding up to four weeks of prep time. The first Cygnus mission is a demonstration flight under NASA's Commercial Orbital Transportation Services program. Orbital's Antares rocket launched for the first time April 21. (Source: Spaceflight Now, 05/06/13) Note: Aerojet AJ26 engines are tested at Stennis Space Center, Miss. Previous