Antares Flies, Falcon 9 Stays

Update: SpaceX CEO Elon Musk tweeted the Falcon 9 launch was aborted due to an “nexpected pressure rise in the turbomachinery gas generator. No word on when they will try launching again.

A Cygnus resupply ship carrying nearly 8,000 lb of cargo for astronauts aboard the International Space Station (ISS) was blasted into orbit by an Antares rocket on Friday night.

The Northrop Grumman booster lifted off on time at 9:16 p.m. EDT from the Mid-Atlantic Regional Spaceport on Wallops Island in Virginia. The flight followed a scrubbed launch on Thursday due to a software problem with ground equipment.

Cygnus, which is also a Northrop Grumman vehicle, is scheduled to arrive at the ISS early Monday morning.

Results were not as good on Friday night for SpaceX, which suffered its second Falcon 9 abort of the week in Florida. The countdown from the Cape Canaveral Air Force Station was halted two seconds prior to a planned 9:43 p.m. EDT liftoff for an unknown reason.

The rocket is carrying the GPS IIII SV-04 navigation satellite for the Global Positioning System.

On Thursday morning, the launch of a Falcon 9 rocket carrying 60 Starlink broadband satellites from nearby Kennedy Space Center was halted with 18 seconds left in the count due to an out family reading from a ground sensor.