Following a small hiccup in launch preparation a few weeks ago, the James Webb space telescope is again making progress.
Now scheduled to lift off from Europe’s spaceport in Kourou, French Guiana, on 22 December, technicians there have finished fuelling the telescope.
This is a delicate operation, which took 10 days, because the hydrazine fuel is highly toxic – the whole thing had to be supervised by a skeleton staff of experts who each wear a self-contained atmospheric protective ensemble, or “scape” suit.
The Webb now holds 159 litres of hydrazine and 79.5 litres of dinitrogen tetroxide oxidiser, which improves the efficiency of the fuel when burnt. Webb will use the fuel to help guide it to its operational orbit, about a million miles (1.5m km) away from Earth, to maintain this orbit and to repoint the telescope.
Now the telescope must be secured to the Ariane 5 rocket and then fastened inside the payload fairing that will protect it during its ascent through the atmosphere.
Once in space, Webb, a collaboration between Nasa, the ESA and the Canadian Space Agency, will be the largest space telescope ever launched.
