SPHEREx

Key facts

Mission & specifications

Mission

SPHEREx is a telescope built not to stare deep, but to see everything. Launched on 11 March 2025, NASA's Spectro-Photometer for the History of the Universe, Epoch of Reionization and Ices Explorer sweeps the whole sky every six months, splitting the infrared light of every point into 102 colours. Where most telescopes photograph one patch at a time, SPHEREx builds a spectrum for hundreds of millions of galaxies and more than a hundred million stars at once. That map lets cosmologists test the theory of cosmic inflation — the instant of hyper-expansion just after the Big Bang — by measuring how galaxies are arranged across the universe, and lets them add up the combined glow of all the galaxies that ever formed. Closer to home, its colours reveal water ice and simple organic molecules frozen onto dust in the clouds where new stars and planets are born. Its nested cones pointing away from the Sun keep the optics passively chilled below about 80 kelvin. It works alongside its launch-mate, the PUNCH solar-wind mission.

1. 2025Launch on a Falcon 9Launch

   NASA's all-sky infrared surveyor lifts off from Vandenberg, riding with the PUNCH solar-wind mission.

2. 2025Science operations beginMilestone

   After checkout and first light, SPHEREx starts sweeping the whole sky in 102 infrared colours.

3. 2026First all-sky mapsMilestone

   Completes early full-sky surveys, spectra for hundreds of millions of galaxies building toward a test of cosmic inflation.

Images

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