Gallery: Antares rocket explodes

Technicians working at launch pad 0A at NASA’s Wallops Flight Facility in Virginia completed the final loading of cargo into Northrop Grumman’s Cygnus supply ship late Tuesday, and the Antares rocket was raised vertical again in preparation for Wednesday’s countdown.

Northrop Grumman’s Cygnus supply ship set for liftoff Saturday will deliver to the International Space Station the final hardware for a series of ambitious spacewalks later this month to install a new coolant system on the Alpha Magnetic Spectrometer, a $2 billion particle physics experiment seeking the cosmic signatures of dark matter and antimatter.

Orbital ATK’s Cygnus cargo freighter loaded with over 5,000 pounds of crew provisions, equipment and science gear arrived at the International Space Station.