The Ariane 4 launcher for Flight 156 has been equipped with its four large
liquid strap-on boosters that provide additional thrust during the vehicle’s
liftoff and initial ascent.

The activity occurred inside the vertical assembly building at the
Spaceport’s ELA 2 launch facility, where build-up of the Ariane 4 occurs.

The booster is powered by a Snecma Moteurs’ Viking VI engine. The Viking VI
is similar to Viking V engines used in Ariane 4’s core first stage.

During its first phase of flight, Ariane 4 rides on the combined power of
the first stage’s four Viking V engines and four Viking VIs.

The Viking VI engine, which operates on N204 and UH25 liquid propellant. The
engine’s nozzle is covered by purple-colored temporary protective blankets.

During launch, the four boosters burn for about 140 seconds.

Ariane 4 boosters are 19 meters in length and weigh 4.5 metric tons when
loaded with liquid propellant.

Flight 156 will carry the NSS-6 satellite for New Skies Satellites. Liftoff
of this mission is set for December