Category: OSIRIS-REx

The Centaur engine has cut off after its successful first burn. The vehicle will coast for about 22 and a half minutes before the Centaur’s second and final burn.

Now nine minutes into the flight, Centaur’s RL-10 engine continues to perform well.

Image from NASA TV

Booster engine cut off and booster separation. The Centaur engine has taken over and will handle the rest of the job of delivering OSIRIS-REx to its release point. This is the first of two burns the Centaur will perform tonight.

The payload fairing covering OSIRIS-REx has been jettisoned.

The single solid rocket booster has been jettisoned and the first-stage RD-180 engine continues to burn. Next major milestone: booster engine cutoff.

The rocket has passed Mach 1 and is now flying through Max Q.

Liftoff! The United Launch Alliance Atlas V rocket is climbing toward space with NASA’s OSIRIS-REx spacecraft on a mission to boldly go to the asteroid Bennu — and back.

One minute to go. Eastern Range is ‘go.’

Two minutes remaining in the countdown. The Atlas V rocket is on internal power. The launch team’s primary communications channels are quiet as the final minutes tick by.

When the countdown clock reaches zero, the Atlas V booster engine and single solid rocket booster ignite and the flight begins. The vehicle reaches Mach 1 after about 57 seconds, then flies through “Max Q,” the area of maximum aerodynamic pressure, about 12 seconds later. The rocket’s single solid rocket booster will be jettisoned after two minutes and 19 seconds.

Watch for a rapid chain of critical events beginning just after the flight passes the four-minute mark. The Atlas V booster engine cuts off, an event known as BECO, then the booster separates from the vehicle, followed by the Centaur main engine’s first start, called MES-1. Shortly thereafter, the payload fairing is jettisoned. This entire sequence takes place in less than 30 seconds.

The Centaur upper stage will perform two separate burns tonight in order to send OSIRIS-REx off on its journey to Bennu. This first burn, MES-1, will last about eight minutes. Its first cutoff is called MECO-1. After a 21-and-a-half-minute coast phase, the engine will reignite for MES-2, a nearly seven-minute burn that will cut off at MECO-2 – about 40 minutes after launch.

OSIRIS-REx will separate from the Centaur 15 minutes later.