Charting the Universe: NASA’s Groundbreaking Space Telescope to Survey Hundreds of Millions of Galaxies

The SPHEREx space telescope, a NASA project poised for a 2025 launch, aims to survey the cosmos in unprecedented detail. Its mission is to explore the genesis of life’s essential elements, galaxy formation, and the early expansion of the universe. Utilizing infrared technology, SPHEREx’s findings will undergo international analysis and be shared publicly. The project is a collaboration between NASA and Caltech.

As NASA’s SPHEREx mission progresses, the construction of a unique space telescope, tasked with producing an unparalleled cosmic map, is nearing completion.

NASA’s SPHEREx, designed to map the entire sky, is taking shape. Officially known as the Specto-Photometer for the History of the Universe, Epoch of Reionization, and Ices Explorer, the telescope, resembling a large bullhorn, measures approximately 8.5 feet in height and 10.5 feet in width. Its distinct cone-shaped photon shields are currently being assembled at NASA’s Jet Propulsion Laboratory in California.

Sara Susca, NASA’s deputy payload manager and systems engineer for SPHEREx, oversees the assembly of the spacecraft’s photon shields. These shields are crucial for protecting the telescope from the Sun’s and Earth’s light and heat, which could otherwise impair the detectors. Credit is given to NASA/JPL-Caltech for this effort.

Shielding and Operation

SPHEREx will be enveloped by three nested cones, safeguarding it from solar and terrestrial light and heat. The telescope will methodically scan every part of the sky, creating two comprehensive sky maps annually.

A segment of SPHEREx’s photon shield, under assembly at Applied Aerospace Structures in Stockton, California, is showcased. Credit: AACS

“SPHEREx must be highly maneuverable to swiftly scan the sky,” explains JPL’s Sara Susca. “Despite appearances, the shields are lightweight, comprising aluminum sheets and an inner aluminum honeycomb structure, resembling cardboard in its light yet robust quality.”

NASA’s SPHEREx is on a mission to chart the sky in a manner never before seen, utilizing specialized hardware for pioneering scientific research. Credit: NASA/JPL-Caltech

Mission Objectives

Scheduled for a no-later-than April 2025 launch, SPHEREx will investigate the cosmic origins of water and other vital life ingredients. The mission involves measuring water ice abundance in interstellar clouds, the birthplaces of stars and planets. It will study galaxy evolution by analyzing their collective light, providing insights into their formation and evolution over time. Additionally, SPHEREx will examine the universe’s rapid expansion following the Big Bang by mapping millions of galaxies.

Amelia Quan, the mechanical integration lead for SPHEREx, works alongside a V-groove radiator, a component crucial for maintaining the telescope’s low temperatures. Credit: NASA/JPL-Caltech

Cool and Stable

SPHEREx will operate in the infrared spectrum, necessitating extremely low operating temperatures to avoid interference from its own infrared emissions. The outer photon shield, along with the gaps between the cones, will block external heat sources. The V-groove radiator, comprising three stacked, conical mirrors, will aid in maintaining these low temperatures by redirecting infrared light out into space.

JPL’s Konstantin Penanen, payload manager, emphasizes the importance of consistent temperature control to ensure detector accuracy and prevent false readings.

NASA’s SPHEREx telescope, currently undergoing tests at JPL, is strategically tilted to maximize sky coverage while remaining shielded from solar and terrestrial heat and light. Credit: NASA/JPL-Caltech

Eye on the Sky

The core of SPHEREx is its telescope, equipped with three mirrors and six detectors to capture infrared light from distant celestial bodies. The telescope’s design ensures maximum sky visibility while staying protected by the photon shields.

Constructed by Ball Aerospace and delivered to Caltech for integration with detectors and the V-groove radiator, the telescope underwent rigorous testing to simulate the conditions of space travel. It was then returned to Caltech for post-vibration focus verification.

NASA’s SPHEREx will employ filters for spectroscopy, isolating specific infrared wavelengths to study the composition and distance of celestial objects. Each filter, about the size of a cracker, allows only a particular wavelength of infrared light to pass through. Credit: NASA/JPL-Caltech

SPHEREx’s Infrared ‘Vision’

SPHEREx’s telescope gathers light from distant objects, which is then analyzed by its detectors specifically tuned to infrared wavelengths. This process, known as spectroscopy, will be facilitated by filters mounted atop the detectors, each segment allowing only a specific wavelength to pass.

This sophisticated setup will enable SPHEREx to map the universe in a way never before achieved.

NASA’s SPHEREx Mission

The SPHEREx project is managed by JPL for NASA’s Astrophysics Division and includes contributions from Ball Aerospace for the telescope and spacecraft bus. A team of scientists from the U.S. and South Korea

Frequently Asked Questions (FAQs) about NASA SPHEREx mission

More about NASA SPHEREx mission

• NASA’s SPHEREx Mission Overview
• SPHEREx Telescope Design and Features
• Scientific Objectives of SPHEREx
• SPHEREx Infrared Astronomy and Technology
• Understanding Cosmic Mapping with SPHEREx