The Nancy Grace Roman space telescope has passed a new milestone before its launch. NASA teams completed filling its fuel tanks on July 25, 2026, at the Kennedy Space Center in Florida. The observatory must now be attached to the upper stage of its rocket, then enclosed in its protective fairing.
Technicians loaded about 290 US gallons of hydrazine, or nearly 1,100 liters. Roman will use this fuel after separating from the rocket to correct its trajectory and reach its observation post about 1.6 million kilometers from Earth.
NASA illustration
This destination corresponds to the L2 Lagrange point of the Sun-Earth system. In this region, gravitational forces allow a spacecraft to maintain a nearly stable position relative to our planet. The James Webb Space Telescope also orbits this region, which is favorable for distant observations.
Roman will then use its thrusters to stay in orbit around L2. They will also keep its solar panels pointed toward the Sun. The primary mission is expected to last five years. According to NASA, the amount of fuel carried could allow five additional years, if the telescope's condition permits.
The observatory will study vast portions of the sky with a field of view much wider than Hubble's. Astronomers in particular want to spot thousands of exoplanets, these worlds located around other stars. Some of them will be detected through the gravitational effects they produce on the light of more distant celestial bodies.
A composite image illustrates the region of Andromeda covered by the Roman space telescope simulation. The latter would be able to image Andromeda's main body in only a few pointings, scanning the galaxy nearly 1,500 times faster than the Hubble Space Telescope.
Image Wikimedia
Roman will also observe the distribution of matter in the Universe. These measurements will help study dark matter, invisible but detected through its gravitational effects. They will also help better characterize dark energy, the name given to the phenomenon associated with the acceleration of cosmic expansion.
NASA and SpaceX are currently targeting liftoff as early as August 30, 2026, aboard a Falcon Heavy, nine months ahead of the original schedule, which is rare enough to be mentioned. The next operations will involve installing the telescope on its adapter, then enclosing it in the fairing before transfer to the launch pad.