October 21, 2017

Launch timeline for Vega rocket’s flight with Sentinel 2B

Europe’s fifth Sentinel Earth observation satellite will ride a four-stage Vega rocket into polar orbit 488 miles (786 kilometers) above Earth to begin tracking changes in agriculture and forestry patterns and monitoring natural disasters.

The ascent will take nearly an hour following launch from French Guiana at 0149:24 GMT March 7 (8:49:24 p.m. EST March 6).

Credit: Arianespace

T+00:00:00 – Liftoff

The Vega rocket's first stage P80 solid rocket motor ignites and powers the 98-foot-tall booster off the launch pad 0.3 seconds later. The P80 first stage motor generates a maximum of 683,000 pounds of thrust.
The Vega rocket’s first stage P80 solid rocket motor ignites and powers the 98-foot-tall booster off the launch pad 0.3 seconds later. The P80 first stage motor generates a maximum of 683,000 pounds of thrust.

T+00:00:31 – Mach 1

The Vega rocket's first stage P80 solid rocket motor ignites and powers the 98-foot-tall (30-meter) booster off the launch pad 0.3 seconds later. The P80 first stage motor generates a maximum of 683,000 pounds of thrust.
The Vega rocket surpasses the speed of sound as it soars on an easterly trajectory from French Guiana. The rocket will reach Max-Q, the point of maximum aerodynamic pressure, at T+plus 53 seconds.

T+00:01:55 – First stage separation

Having consumed its 194,000 pounds (88 metric tons) of solid propellant, the 9.8-foot-diameter (3-meter) P80 first stage motor is jettisoned at an altitude of about 33 miles (53 kilometers).
Having consumed its 194,000 pounds (88 metric tons) of solid propellant, the 9.8-foot-diameter (3-meter) P80 first stage motor is jettisoned at an altitude of about 33 miles (53 kilometers). The second stage Zefiro 23 motor will ignite a second later to begin its 102-second firing.

T+00:03:39 – Second stage separation

The Zefiro 23 motor burns out and jettisons.
The Zefiro 23 motor burns out and jettisons.

T+00:03:51 – Third stage ignition

Moving at a velocity of nearly 9,000 mph, or about 3.9 kilometers per second, the Vega rocket's Zefiro 9 motor ignites for the third stage burn.
Moving at a velocity of nearly 9,000 mph, or about 3.9 kilometers per second, the Vega rocket’s Zefiro 9 motor ignites for the third stage burn.

T+00:03:56 – Fairing separation

The Vega’s 8.5-foot-diameter (2.6-meter) payload fairing is released as the rocket ascends into space.

T+00:06:32 – Third stage separation

The Zefiro 9 third stage shuts down and separates, having accelerated the rocket to nearly orbital velocity.
The Zefiro 9 third stage shuts down and separates, having accelerated the rocket to nearly orbital velocity.

T+00:08:23 – First AVUM ignition

The Vega rocket’s Attitude and Vernier Module, or fourth stage, ignites for the first time. The AVUM burns hydrazine fuel with an RD-843 engine provided by Yuzhnoye of Ukraine.

T+00:15:27 – AVUM first cutoff

The Vega’s AVUM fourth stage is turned off after a 7-minute, 4-second burn, beginning a nearly 40-minute coast until the engine is ignited again.

T+00:55:07 – Second AVUM ignition

The AVUM fires a second time for a two-minute burn to put the Sentinel 2B satellite into its targeted orbit.

T+00:57:07 – AVUM second cutoff

The AVUM engine shuts down after reaching a circular orbit with an altitude of 488 miles (786 kilometers), and an inclination of 98.57 degrees.

T+00:57:57 – Sentinel 2B separation

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