Ariane 5 is ready to take off, only weather can interfere

Countdown. Ariane 5 . missile Which must be paid on Saturday in the space Spatial Telescope James Webb, was waiting at the shooting point Friday for the final count to begin, which could still interrupt the choppy weather. If all goes well, the European operator should start from 9.20 am on Saturday (1.20 pm Paris time).

In the middle of a vast expanse surrounded by barbed wire and the Guyanese jungle, the white rocket was erected on the launch table, a large movable steel structure, crowning itself with four massive lightning rod towers. So far, only rain and wind in particular have played tricks on the machine, forcing the date to be postponed.

The nearby massive water tower must supply the “flood,” at a rate of 30 tons per second, which will run under the engines when ignited, scheduled for 9.20 am. To dampen the temperature up to 3000 degrees, and especially to drown out the shock of the take-off sound wave, which can damage the electrical components on board. At about 180 decibels, this is the loudest sound a man-made machine can make.

210 tons of hydrogen and liquid oxygen

Two long silver tubes connect the top of the table’s mast to the Ariane 5 slot, which houses the telescope. Ensure it has cool and dry air conditioning, keeping it from the hot and humid surrounding air. The most sophisticated minimal monitoring instrument ever sent into space.

Just below, two bright yellow levers carry the fuel supply lines to the upper stage, and the lower stage is fed directly from the table. The rocket’s tanks, which are still empty, will hold a total of 210 tons of hydrogen and liquid oxygen. These motives are wisely awaited in cabinets placed at a good distance. Because it is their mixture, highly combustible, which will allow to take off.

“When the filling maneuvers start at H-7 in the morning, no one will be able to stay on site anymore,” explains Jean-Marc Durand, Arianespace Guyane’s deputy director. The missile will remain alone, all its controls, including those for filling, coming from the launch center located 2.3 kilometers away. From the fortified part of this building, which was closed 45 minutes before takeoff, the site manager and his teams would give their orders to the operator, such as filling the tanks, and receive all parameters.

Friday by day, rows of screened tables in the middle were still empty, “because the sequence is going to start late,” defines Jerome Reeves, Ariane 5 program manager at Arianespace. It will even be scratched all night from Friday to Saturday.

Auto boot

With a countdown, it launches from Jupiter’s control center, which should start precisely at 9:57 PM. In this large “jar”, the operations department “concentrates all the information to allow the coordination of the launch,” explains Jean-Luc Meister, Deputy Director of Operations.

If the red doesn’t come from those in charge of the telescope, space base, operator, or weather forecast, the operations manager will start the synchronous sequence at H minus seven minutes. At that moment, all operations will switch to automatic mode, led by the control center and rocket computers.

At H, the Ariane 5 Vulcain’s engine will start, but after just seven seconds the two powder engines will ignite allowing the rocket to tear itself off the ground. All this beautiful ballet would only be possible if the weather was playing the game, under a cloudy and windy sky.

At 1:00 p.m. on Friday, the forecast center gave the go-ahead. He will still be shooting several weather balloons into the air to improve his forecast at launch, including the last less than three hours before that. At the center of Jupiter on Friday, a manager saw this interest in the sky as a good sign: “If we talk about the weather, it’s because everything has been so well done so far, because it’s the last thing to look at before launching.”