James Webb Space Telescope (JWST) mission experts have successfully completed fueling operations ahead of its December 22 launch from French Guiana. The process spanned about ten days.
Following multiple delays due to technical challenges and budget constraints, the JWST remains on schedule for launch on December 22 from the Guiana Space Center in Kourou, French Guiana, atop an Arianespace Ariane 5 rocket.
A key pre-launch step involved refueling the observatory through an international collaboration between NASA, ESA, and the Canadian Space Agency, conducted from November 23 to December 3.
"The propellant tanks were filled with 79.5 liters of dinitrogen tetroxide oxidizer and 159 liters of hydrazine," ESA reports in a press release. The oxidizer "enhances the combustion efficiency of the hydrazine fuel."
Specialists handled these highly toxic propellants in self-contained atmospheric protection suits, known as SCAPE suits.
The fuel and oxidizer will power the telescope's major thruster burns for mid-course corrections and to achieve and maintain its position at the Sun-Earth Lagrange L2 point, 1.5 million kilometers from Earth, where gravitational forces balance.
Hydrazine alone will fuel the precision thrusters for fine-pointing adjustments and momentum management.
With fueling complete, the team will now integrate the telescope into the Ariane 5 fairing before transferring it to the final assembly building for launch preparations.
Post-launch, JWST will execute a complex deep-space deployment sequence en route to L2. Upon arrival, it will undergo six months of commissioning to verify instrument performance—a process demanding flawless execution.
As the most powerful observatory ever sent to space, JWST will observe the universe in infrared, peering deeper into cosmic history than ever before. Its advanced instruments will tackle astrophysics' biggest enigmas, including dark matter and dark energy.
