Originally planned for a 1:40 p.m. launch on Friday, July 11, the launch of Orbital Sciences' Cygnus cargo spacecraft will be postponed until 12:52 p.m. on Sunday. The resupply mission to the International Space Station was interrupted by severe weather.

The NASA mission, Orbital 2 Commercial Resupply Services Mission to International Space Station, was scheduled to lift off from the Mid-Atlantic Regional Spaceport's Pad 0A at NASA's Wallops Flight Facility in Virginia, but it was rescheduled for July 13. This is the second postponement of the resupply mission, with the first occurring on May 28 after an engine test aborted prematurely. It's essential that everything checks out before such a launch or else millions of dollars and other valuables could be compromised.

Orbital Sciences' 131.5-foot-tall Antares rocket will carry its Cygnus spacecraft, which is holding about 3,300 pounds of cargo for the astronauts aboard the ISS. The Weather Office at NASA's Wallops Flight Facility in Virginia already predicted a 90% chance of favorable weather for Sunday morning/early afternoon. NASA Television will begin coverage of the launch at noon on Sunday.

Expedition 40 aboard the International Space Station is awaiting the various cargo that Orbital Sciences is set to deliver. With a total of 3,293 pounds, the items consist of crew supplies (1,684 pounds), hardware (783 pounds), science and research (721 pounds), computer supplies (18 pounds), and spacewalk tools (87 pounds). Most notably, the science and research is expected to occupy the crewmembers for a number of months, and they will send the experiments back to Earth with the results. Students from around the world have the opportunity to submit their experiment to NASA for the astronauts to conduct in space.

The cargo shipment is expected to take three days to arrive at the ISS. NASA Television also plans to cover the capture and installation of the Cygnus spacecraft when ISS Commander Steve Swanson and Flight Engineer Alexander Gerst conduct the mission. The astronauts are scheduled to grapple the spacecraft at 6:37 a.m. on July 16, with coverage beginning at 5:15 a.m.

Earlier this month Orbital Sciences launched the Orbiting Carbon Observatory-2 (OCO-2) satellite, which is the first such device that will measure carbon dioxide levels in different parts of the Earth's atmosphere in different regions of the world. The space company hopes to continue their successful relationship with NASA through the execution of this upcoming resupply mission.

You can read more about the Orbital Sciences resupply launch on the International Space Station web page.