Follow the key events of the Soyuz rocket’s ascent into orbit from the Guiana Space Center with two satellites for Europe’s Galileo navigation system. A listing of exact times for the flight’s major events is posted below.
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 ST-B (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+0:03:29: 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+0:09:24: Soyuz/Fregat Separation
The Soyuz rocket’s third stage releases the Fregat-MT upper stage just shy of orbital velocity.
T+0:10:24: First Fregat Ignition
The hydrazine-fueled Fregat upper stage ignites to place the Galileo satellites in an elliptical transfer orbit.
T+0:23:32: First Fregat Shutdown
After a 13-minute, 8-second burn, the Fregat upper stage shuts down to begin a 3-hour, 15-minute coast phase.
T+3:38:35: Second Fregat Ignition
The Fregat main engine ignites to circularize its orbit before deployment of the two Galileo satellites.
T+3:42:57: Second Fregat Shutdown
The Fregat main engine shuts down after a 4-minute, 22-second burn to inject the Galileo satellites into a circular orbit at an altitude 23,522 kilometers (14,615 miles) and an inclination of 55.04 degrees.
T+3:47:57: Galileo Separation
The two Galileo navigation satellites deploy from a dispenser on the Fregat upper stage.
The MS-25 mission was scrubbed on Thursday, but the root cause is still under investigation. The earliest that liftoff from the Baikonur Cosmodrome can now occur is Saturday, March 23, pending the outcome of the investigation.
Presenting the results of an inquiry into a European Vega rocket failure last month, officials said Friday that misleading instructions and inadequate preflight checks caused teams to overlook wrongly-installed cables on the launcher’s upper stage steering system. Arianespace aims to resume Vega launches before the end of March.
The first in a new constellation of Russian Arctic weather satellites is poised for launch on top of a Soyuz rocket Sunday from the Baikonur Cosmodrome in Kazakhstan.
