NASA’s next-generation space telescope, the Spectro-Photometer for the History of the Universe, Epoch of Reionization, and Ices Explorer (SPHEREx), developed with participation from the Korea Astronomy and Space Science Institute (KASI), was launched into space on Mar. 12.
Unlike traditional space telescopes that focus on narrow regions, SPHEREx is designed to scan the entire sky, with the ambitious goal of creating the world’s first infrared 3D cosmic map. Scientists hope this mission will expand the frontiers of astronomy by identifying celestial bodies that contain water and ice, as well as uncovering clues about the origins of the universe.
According to the Korea Aerospace Administration, SPHEREx lifted off from California’s Vandenberg Space Force Base aboard SpaceX’s Falcon 9 rocket at 12:10 p.m. KST.
Just over 40 minutes later, at 12:52 p.m., the telescope separated from the rocket and entered a sun-synchronous orbit about 650 kilometers above Earth. Soon after, at around 1:30 p.m., it successfully made contact with NASA’s ground station.
The Korea Aerospace Administration explained that the telescope will go through an initial 37-day operational phase, during which it will undergo test operations. The launch had originally been scheduled for Feb. 28 but was postponed eight times due to issues with the launch vehicle and poor weather conditions.
One of SPHEREx’s key advantages is its ability to detect infrared light, which is largely absorbed by Earth’s atmosphere and thus difficult to observe from ground-based telescopes. By operating in space, SPHEREx will be able to capture infrared wavelengths that would otherwise be invisible. Measuring 3.2 meters in width and length and 2.6 meters in height, it is equipped with a 20-centimeter aluminum telescope that will help it conduct its observations.
What sets SPHEREx apart is its ability to perform spectroscopic observations in infrared.
While existing space telescopes can observe only four to six wavelengths, SPHEREx is capable of capturing data across 102 wavelengths, essentially creating a cosmic map in 102 colors. By analyzing these wavelengths, researchers can determine detailed information about celestial objects, including their distance, composition, size, and brightness.
Much like a smartphone’s panorama mode, SPHEREx will systematically shift its telescope’s direction to capture the entire sky in a seamless sequence. By layering and analyzing the collected data, scientists will be able to construct a three-dimensional cosmic map, offering a clearer view of the universe’s large-scale structure.
With this map, researchers aim to track the distribution of ice and water within galaxies, which could help identify celestial bodies with the potential to support life. Moreover, by studying the distribution of galaxies, they hope to uncover the reasons behind the universe’s rapid expansion following the Big Bang some 14 billion years ago.
While NASA’s flagship James Webb Space Telescope (JWST) also specializes in infrared observations, it is designed to capture highly detailed images of narrow regions, covering only about 1% of the universe.
In contrast, SPHEREx is built to survey the entire sky, though at a lower resolution. After completing its initial operational phase, the telescope will spend the next 25 months capturing more than 600 images per day, ultimately compiling four full-sky 3D maps containing data on approximately one billion celestial objects.
The SPHEREx mission, launched in 2019 as a $242 million NASA exploratory project, is led by the California Institute of Technology (Caltech) in collaboration with 12 institutions, including NASA’s Jet Propulsion Laboratory (JPL). Notably, KASI is the only non-U.S. institution involved in the project.
KASI played a crucial role in SPHEREx’s development by designing a cryogenic vacuum chamber capable of simulating the extreme space environment at minus 220 degrees Celsius. This facility was used to test the telescope’s optical and spectroscopic performance. Additionally, KASI contributed to the development of software that will process the telescope’s observational data.
Jeong Woong-seop, the researcher of KASI emphasized that the infrared 3D cosmic map and all-sky spectral catalog produced by SPHEREx will provide vital clues to understanding the formation and evolution of the universe, offering astronomers around the world a valuable resource for studying celestial bodies.
