Follow the key events of the Soyuz rocket’s ascent into orbit from the Guiana Space Center with four broadband communications satellites for O3b Networks.
Date source: Arianespace
T-0:00:03: Engines at Full Thrust
The five main engines of the Soyuz rocket’s core stage and four strap-on boosters are at full thrust.
T+0:00:00: Liftoff
Producing more than 900,000 pounds of thrust, the Soyuz 2-1b rocket soars into the sky from the Guiana Space Center.
T+0:01:58: Jettison Boosters
The Soyuz rocket’s four strap-on boosters, each powered by an RD-107A engine, are jettisoned after consuming their propellant.
T+0:03:58: Jettison Fairing
The ST-type payload fairing is released from the Soyuz rocket when it reaches the edge of the upper atmosphere. The 13.5-foot-diameter fairing protects the payload during the launch countdown and the flight through the dense lower atmosphere.
T+0:04:48: Core Stage Separation
Having burned its propellant, the core stage of the Soyuz rocket, also known as the second stage, separates and the third stage’s RD-0124 engine ignites to continue the flight.
T+0:09:23: Soyuz/Fregat Separation
The Soyuz rocket’s third stage releases the Fregat-MT upper stage just shy of orbital velocity.
T+0:10:23: First Fregat Ignition
The hydrazine-fueled Fregat upper stage ignites to place the O3b satellites in a low-altitude parking orbit.
T+0:14:19: First Fregat Shutdown
The Fregat upper stage shuts down to begin a coast phase. The Fregat and O3b satellites should now be in an orbit with a high point of 141 miles, a low point of 95 miles and an inclination of 5.15 degrees.
T+0:22:50: Second Fregat Ignition
The Fregat stage’s main engine fires for a second time to boost the O3b satellites into a transfer orbit.
T+0:31:22: Second Fregat Shutdown
After a 8-minute, 32-second burn, the Fregat upper stage shuts down to begin an 81-minute coast phase.
T+1:52:25: Third Fregat Ignition
The Fregat main engine ignites a third time to place the O3b satellites into a circular equatorial orbit.
T+1:57:27: Third Fregat Shutdown
The third Fregat burn ends after injecting the satellites in a 4,865-mile-high orbit.
T+2:00:46: First Spacecraft Separation
Spacecraft no. 2 and spacecraft no. 4 separate from a dispenser on the Fregat upper stage.
T+2:22:27: Second Spacecraft Separation
After the Fregat’s control thrusters move the rocket away from the two O3b satellites already deployed, spacecraft no. 1 and spacecraft no. 3 separate from a dispenser on the Fregat upper stage. The Fregat engine will fire again later to move the upper stage into a graveyard orbit.
An Ariane 5 rocket will fire into the sky from French Guiana Thursday evening and deliver a record heavyweight payload to orbit less than an hour later.
A United Launch Atlas 5 rocket is set to launch the U.S. Air Force’s fourth Advanced Extremely High Frequency communications satellite from Cape Canaveral. This timeline shows the major mission events planned over a three-and-a-half-hour flight to an optimized geostationary transfer orbit.
