This month, a new kind of space telescope is setting out on a two-year mission to create four complete maps of the entire celestial sky that will catalog the origins of the universe and seek out the ingredients of life − chiefly water and carbon dioxide molecules − in distant interstellar clouds.

The $488 million SPHEREx − short for Spectro-Photometer for the History of the Universe, Epoch of Reionization and Ices Explorer − is a megaphone-shaped observatory roughly the size of a backyard storage shed. The former Ball Aerospace, which was purchased by BAE Systems in early 2024, helped build and assemble parts of the telescope in Boulder.

Every six months, the telescope will create a scan of the entire sky in 102 infrared colors, differentiating hundreds of millions of galaxies by their ancient light and heat signatures and compiling them into one complete map of the universe. Some of the light photons it will study have taken 10 billion years to reach Earth.

It’s design is unique because it needs to operate in temperatures of about minus 350 degrees. The concentric layers of photon shields protect the sensitive optical instruments from the heat of the Earth and sun.

When is SPHEREx scheduled to launch?

SPHEREx is set to launch no earlier than Tuesday aboard a SpaceX Falcon 9 rocket from Space Launch Complex 4 East at Vandenberg Space Force Base in California. The mission is managed by NASA’s Jet Propulsion Laboratory. The original Feb. 27 launch date was pushed back to give teams “additional time to evaluate launch vehicle hardware date,” per the mission site’s blog.

How does SPHEREx compare with the Webb and Hubble telescopes?

To simplify the mission of SPHEREx compared with that of the Webb or Hubble telescopes, it’s helpful to think of SPHEREx as a “big picture” survey of the galaxy, while Webb and Hubble are designed to focus on specific targets in tighter detail. And while Webb has instruments to study chemical compounds of its targets, the SPHEREx observatory is built to scan the galaxy for water ice and other compounds.

The SPHEREx observatory is much smaller and lighter than Hubble and Webb but serves a different purpose in conducting wide-field infrared surveys. Hubble and Webb were built for looking into deep space and creating high-resolution imaging.

The range of light detection for SPHEREx falls entirely in the infrared, just beyond the red end of the visible light spectrum. While it doesn’t observe as much of the infrared as the Webb telescope, SPHEREx can detect 102 distinct wavelengths across the entire sky, which allows it to measure the composition and distance of objects.