Follow the major events during the launch of Europe’s LISA Pathfinder gravitational probe testbed, from liftoff of its Vega rocket booster from French Guiana through deployment into its initial orbit.
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+00:01:53 – 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 103-second firing.
T+00:03:37 – Second stage separation
The Zefiro 23 motor burns out and jettisons.
T+00:03:49 – Third stage ignition
Moving at a velocity of nearly 9,000 mph, or 4 kilometers per second, the Vega rocket’s Zefiro 9 motor ignites for the third stage burn.
T+00:04:03 – Fairing separation
The Vega’s 8.5-foot-diameter (2.6-meter) payload fairing is released as the rocket ascends into space.
T+00:06:30 – Third stage separation
The Zefiro 9 third stage shuts down and separates, having accelerated the rocket to nearly orbital velocity.
T+00:07:29 – 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-869 engine provided by Yuzhnoye of Ukraine.
T+00:16:23 – AVUM first cutoff
The Vega’s AVUM fourth stage is turned off after an 8-minute, 54-second burn, beginning an 85-minute coast until the engine is ignited again. The first AVUM burn places the rocket and its payloads on a ballistic trajectory.
T+01:41:19 – Second AVUM ignition
The AVUM fires a second time for a 94-second burn to put LISA Pathfinder into its preliminary orbit.
T+01:42:53 – AVUM second cutoff
The AVUM engine shuts down after reaching an elliptical orbit with a high point of 957 miles (1,540 kilometers), a low point of 128 miles (207 kilometers), and an inclination of 5.96 degrees.
T+01:45:33 – LISA Pathfinder separation
The 4,202-pound (1,906-kilogram) LISA Pathfinder spacecraft deploys from the AVUM fourth stage of the Vega rocket. A ground station in Kourou could acquire the first signals from LISA Pathfinder to confirm its health about two minutes later.
Two direct-to-home broadcasting satellites have launched from French Guiana aboard an Ariane 5 rocket. Liftoff with DirecTV 15 and Sky Mexico 1 occurred at 2116 GMT (5:16 p.m. EDT) Wednesday.
Launch of a SpaceX Crew Dragon capsule carrying four astronauts to the International Space Station has been delayed 24 hours to Friday because of bad weather in the Atlantic Ocean where the crew could be forced to ditch in an emergency, NASA announced Wednesday.
After replacing a faulty inertial measurement system blamed for a scrubbed launch attempt Sunday, a Soyuz rocket headed to space from French Guiana today with five satellites, including the next spacecraft for Europe’s multibillion-dollar Earth observing network and a French experiment to probe the validity of Einstein’s theory of general relativity.
