How to watch NASA launch its cosmic detective mission, SPHEREx

By Georgina Torbet Published February 25, 2025

Update: The launch has been moved to Thursday, March 4. NASA states, “The teams need additional time to evaluate launch vehicle hardware data.” The article has been updated accordingly.

This coming week sees the launch of a new NASA astrophysics mission, SPHEREx. This space telescope will investigate the origins of the universe, looking at how everything that exists went from being a tiny dot in the milliseconds after the big bang to being trillions of times that size.

The SPHEREx mission will launch using a SpaceX Falcon 9 rocket from Space Launch Complex 4 East (SLC-4E) at Vandenberg Space Force Base in California on Friday night.

This launch is notable in that it doesn’t contain just one NASA mission, but two, as alongside the SPHEREx spacecraft the rocket will also carry a set of four small spacecraft to study the sun called PUNCH (Polarimeter to Unify the Corona and Heliosphere). Both missions are heading into low-Earth orbit, so launching them together saves money and resources, as well as making extra excitement for keen space viewers.

“This is basically two for the two for the price of one,” said Shawn Domagal-Goldman, acting director of NASA’s Astrophysics Division, in a press conference.

Once launched, SPHEREx has an ambitious mission: to observe the entire sky in hundreds of wavelengths within the infrared, to survey where galaxies are located on a large scale. By tracking these positions backwards, this will give scientists information about the first seconds of the universe immediately after the big bang, and show how the universe evolved over time.

SPHEREx is primarily designed for research in astrophysics, which studies the universe on a grand scale. While telescopes like the James Webb Space Telescope take detailed images of distant objects, SPHEREx will take views of large areas of the sky to give broader context to some of the specific objects studied by Webb.

“We have the pleasure of answering three big questions in astrophysics: How does the universe work? How did we get here within that universe? And are we alone in that Universe?” said Domagal-Goldman. “Those are big enough questions where we can’t answer them with one instrument. We can’t even answer them with one mission. We need a full fleet to do that, and every time we fly a new telescope we make sure that it adds to that fleet in ways that are unique from everything we’ve built before.”

The SPHEREx launch is scheduled for 10:09 p.m. ET (7:09 p.m. PT) on Thursday, March 4, with coverage beginning at 9:15 p.m. ET (6:15 p.m. PT).

You can watch NASA’s livestream of the launch either by using the video embedded at the top of this page or by going to NASA’s YouTube page for the launch. If you want more information about the launch directly from NASA, then members of the public are also invited to register for virtual attendance, though registration isn’t necessary to watch the YouTube stream.