SPHEREx, a new NASA Space Telescpe joins the Fleet

On March 12, 2025, a Falcon 9 rocket successfully launched the Spectro-Photometer for the History of the Universe, Epoch of Reionization, and Ices Explorer (SPHEREx) Observatory in a Sun-synchronous orbit at 700 km.

Falcon 9 lifts off from pad 4E in California! pic.twitter.com/1Ef7iIBk2A
— SpaceX (@SpaceX) March 12, 2025

The launcher cleared the SLC-4E pad at Vandenberg Base at 03:10 UTC. The rocket stages separated almost two minutes into the flight, and booster B1088 landed back at Landing Zone 4 seven minutes after liftoff.

Before deploying the NASA Observatory at the planned altitude, the four microsatellites of the Polarimeter to Unify the Corona and Heliosphere (PUNCH) mission detached from the second stage as part of a rideshare flight. At 03:52 UTC, SPHEREx began its 25-month scientific mission to provide an all-sky spectral survey, unlocking new insights about the universe’s initial inflation and the evolution of galaxies.

Unique features added to NASA’s fleet of space telescopes

Space telescopes like Hubble or James Webb provide high-resolution, in-depth spectroscopy of individual objects or small sections of space. Others, like WISE or GAIA, were designed to survey the entire sky repeatedly. SPHEREx utilizes a combination of these capabilities to apply spectroscopy to the whole sky.

The space telescope, which has a megaphone-like shape, will map the entire sky in 102 infrared colors, making it the most colorful cosmic map ever.

“We are the first mission to look at the whole sky in so many colors. Whenever astronomers look at the sky in a new way, we can expect discoveries.”

— Jamie Bock, SPHEREx Principal Investigator

*NASA’s SPHEREx space observatory was photographed in November 2024 after completing environmental testing. Credits: NASA*

To run such scientific instruments, SPHEREx must keep them at about minus 210 degrees Celsius. The spacecraft is designed to maintain this low temperature without electricity or coolants, thanks to its unique passive cooling system consisting of three cone-shaped photon shields and a mirrored structure beneath them.

Part of one of the protective photon shields for SPHEREx telescope. Credits: NASA — *Part of one of the protective photon shields for the SPHEREx telescope. Credits: NASA*

Surveying the sky to explore the origins of the universe

A few moments after the Big Bang, the universe expanded almost instantaneously, a phenomenon called cosmic inflation, leaving ripples in the space-time fabric leading to the current distribution of galaxies. SPHEREx will provide new insights into this phenomenon by mapping the position of hundreds of millions of galaxies in 3D.

While collecting information about galaxies’ positions, the space telescope will measure their total glow, including the ones not easily detectable by other telescopes.

*Hubble Extreme Deep Field. Credits: ESA*

Scientists will use the observatory’s unique spectroscopic map to detect water ice and similar chemical compounds along more than 9 million unique directions across our galaxy since they leave a precise signature in the colors they absorb and emit. Their location and abundance in interstellar clouds of gas and dust will give researchers a better sense of their availability in the raw materials of newly forming planets.

SPHEREx will also identify targets for more detailed study by other missions, such as NASA’s James Webb and Hubble. The new encyclopedia of information about hundreds of millions of celestial objects will be freely available to scientists worldwide.