Next Atlas V Launch Now Delayed Indefinitely

The United Launch Alliance (ULA) said very late yesterday that the launch of the next Atlas V rocket is now delayed indefinitely.  ULA is investigating what went wrong on the launch of Orbital ATK’s OA-6 Cygnus spacecraft on March 22.

Orbital ATK’s OA-6 cargo mission to the International Space Station (ISS) was successful thanks to the Atlas V’s Centaur upper stage, which was able to compensate for the under performance of the first stage.  The first stage’s RD-180 engine shut down 6 seconds early.  The Centaur fired about one minute longer than planned to make up the difference in thrust needed to place Cygnus in the proper position for its ultimate rendezvous with ISS. 

This was the first problem for the Atlas V in 62 launches.

ULA soon announced that it was delaying the next Atlas V launch — of a military communications satellite, MUOS-5 — for one week, from May 5 to May 12, while it investigated what happened.  On March 31, the company said it had traced the anomaly to the first stage fuel system.

Late yesterday, ULA said in an emailed statement that the launch postponement is “indefinite:” 

Cape Canaveral Air Force Station, Fla. (April 8, 2016) — The Atlas V MUOS-5 launch is delayed and indefinite on the Eastern Range due to ongoing evaluation of the first stage  anomaly experienced during the OA-6 mission. ULA successfully delivered the OA-6 Cygnus spacecraft to the International Space Station (ISS) on March 22. The MUOS-5 spacecraft and launch vehicle are secure at their processing facilities. 

Somewhat ironically, ULA’s announcement came shortly after a signature success by its competitor, SpaceX, which not only launched its own cargo mission to ISS, but landed the Falcon 9 first stage on a drone ship at sea.