Early this morning, Orbital Sciences Corp. decided to scrub today's launch attempt of the Antares rocket and the Cygnus cargo spacecraft on the company's first resupply mission to the International Space Station due to an unusually high level of space radiation that exceeded constraints imposed on Antares.
The solar flux activity that occurred late yesterday afternoon resulted in an increasing level of radiation beyond what the Antares engineering team monitored earlier in the day. Overnight, Orbital's engineers conducted an analysis of the radiation levels, but the Antares team decided to postpone the launch to further examine the potential effects of the space radiation on the rocket's avionics. The Cygnus spacecraft would not be affected by the solar event.
Today, in consultation with NASA, Orbital Sciences will continue to monitor the levels of space radiation with a goal of setting a new launch date as soon as possible. If a launch can be scheduled for Thursday, the targeted launch time would be 1:10 p.m. EST, with Cygnus arriving at the ISS Sunday morning, January 12 for a grapple at 6:02 a.m. EST. If a launch can be conducted Thursday, NASA TV coverage would begin at 12:45 p.m. EST.
At Mission Control in Houston, the flight control team reported that the ISS crew is not affected by this solar event and does not require any special precautionary measures.