Mission Log: Briefing for Flight 133: Arianespace takes a satellite swap-out in stride: Preparations move ahead for N-SAT-110’s launch
Arianespace’s ability to take mission changes in stride is being demonstrated once again as it rapidly modifies Flight 133’s launch campaign following a switch-out of the payload.
Flight 133 will now carry Japan’s N-SAT-110 telecommunications satellite on a launch scheduled for early October.
This reflects a shift from the original mission plan, which had called for the Europe*Star telecommunications satellite to be lofted on September 26. The change was required by the last-minute unavailability of Europe*Star, which will be orbited by Arianespace at a future date once the spacecraft is declared ready for flight by the customer.
The Ariane 4 version planned for Flight 133 with Europe*Star was a 44LP, equipped with a mix of two solid and two liquid strap-on boosters.
As a result of the payload swap, N-SAT-110 will be lofted by a 42L version of Ariane 4 – which uses two liquid strap-ons and no solid boosters.
The Ariane 4 family’s modularity enables a launcher to be reconfigured relatively easily – with only minor changes required to adapt the Flight 133 vehicle from the 44LP to the 42L version.
These changes will be made in the launch zone, where the Ariane 4 currently is undergoing final preparations for flight. The Ariane 4 already is equipped with its two liquid strap-on boosters, which were installed before the launcher’s September 12 transfer from the ELA-2 assembly building at Europe’s Spaceport to the launch zone.
The modification work that remains to be completed in the launch zone includes removing the attach points and related hardware for the solid boosters, and adding four fins to the first stage. Fins are used to provide additional stabilization on the Ariane 4 when the large liquid boosters are used.
Mission rehersal in the launch zone
This week’s activity in the launch zone began with a mission rehersal, which included a simulation of the final countdown and launch, as well as filling of the cryogenic third stage. For safety reasons, the large mobile service gantry was rolled back to the parked position, exposing the nearly completed launch vehicle.
The rest of this week will be spent making the changes to bring the Ariane 4 to its final 42L configuration, according to Daniel Groult, Arianespace’s head of operational production.
Flight 133’s N-SAT-110 payload arrived in French Guiana on August 28, and was transported to the S1A satellite preparation building. On September 18, it was moved to the S3B building, where it will be fuelled and installed on the payload interface adapter. The satellite will then be encapsulated in the Ariane 4 payload fairing and moved to the launch zone for integration atop the launcher.
N-SAT-110 was built by Lockheed Martin Missiles and Space (USA) and carries a Ku-band transponder payload. Its relay capacity will be shared by Japan’s Space Communications Corporation (SCC) and Japan Satellite Systems Inc. (JSAT). Positioned at 110 East, this telecommunications satellite will cover the Japanese archipelago.
