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.
T+00:00:31 – Mach 1
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). 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.
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.
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.
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.
SpaceX’s next Falcon 9 rocket rolled out of its hangar and up the ramp to launch pad 39A Sunday in preparation for liftoff on a two-day trek ferrying more than 6,400 pounds of supplies and experiments to the International Space Station.
With a fix in place for a propulsion system alarm that cut short a countdown in the final seconds Monday, U.S. time, Rocket Lab readied an Electron rocket for another try Wednesday night, but unfavorable upper level winds kept the booster grounded. The Electron rocket is awaiting launch on a test flight aiming to deliver three small commercial CubeSats to orbit from a remote New Zealand launch pad.
A secret Chinese military payload, believed to be a surveillance satellite, successfully flew into space Sunday aboard a Long March 4C rocket on China’s 39th and final scheduled orbital launch attempt of the year.
