KASI develops test equipment for NASA's SPHEREx telescope

A computer-generated image of SPHEREx telescope developed by Caltech [MINISTRY OF SCIENCE AND ICT]

Korea Astronomy and Space Science Institute (KASI) developed test equipment for NASA's SPHEREx telescope, the science minister said Wednesday.

SPHEREx stands for Spectro-Photometer for the History of the Universe, Epoch of Reionization, and Ices Explorer. Scheduled to launch in April 2025, the SPHEREx is a space telescope with a two-year mission to survey the entire sky in optical and near-infrared spectra. It will collect data on more than 300 million galaxies and over 100 million stars in the Milky Way, according to NASA Jet Propulsion Laboratory (JPL).

Began in 2015, the SPHEREx mission is a medium-class explorer project spearheaded by the California Institute of Technology, or Caltech. Eleven other agencies, including KASI and NASA’s JPL, are participating in the SPHEREx consortium.

KASI joined the project in 2016 as the only non-U.S. organization. It took part in developing test equipment to verify the SPHEREx telescope’s performance before launch.

The core part of the KASI-developed test equipment is a cryogenic vacuum chamber. It creates a vacuum environment with an extremely low temperature below minus 220 degrees Celsius (minus 350 degrees Fahrenheit) which is similar to space environment. The SPHEREx observatory will be put into the vacuum chamber, and the KASI-developed device will test the performance of the telescope.

It took three years for KASI to develop the test equipment, according to the Ministry of Science and ICT. The completed equipment was delivered to Caltech’s Cahill Center for Astronomy and Astrophysics in Pasadena, California, in June.

KASI will conduct a test for the telescope’s optical performance in the first half of 2023 at Caltech with the SPHEREx research team and also participate in developing a data analysis software for the mission and other core science research projects.

"A number of factors can influence the focus position of our instrument as it gets down to its operating temperature,” said Phil Korngut, the SPHEREx instrument scientist at Caltech.

“It’s absolutely essential that we get this thing sharply into focus before we fly, and the only way to accomplish that is through specific cryogenic optical testing in the environment provided by the KASI chamber."

Jeong Woong-Seob, KASI’s principal investigator for the SPHEREx project, said that “through this co-development project with NASA, our space technologies in the cryogenic testing for infrared-spectra space telescopes will be able to jump to the same level as the space powers.”

“The equipment developed by Korea is one of the most important pieces of hardware in the SPHEREx project,” said Kwon Hyun-joon, director-general of the space, nuclear and big science policy bureau at the science ministry. “We will continue to conduct joint research projects with top-level research institutions in the world.”

BY SHIN HA-NEE [shin.hanee@joongang.co.kr]