ASTHROS
Planned NASA balloon-borne telescope, largest ever balloon observatory.
ASTHROS—short for Astrophysics Stratospheric Telescope for High Spectral Resolution Observations at Submillimeter-wavelengths—is a NASA balloon-borne telescope that, if launched as originally scheduled on December 1, 2024, would become the largest balloon observatory ever built. Its balloon measures 400 feet across, and the telescope itself is a 2.5-meter far-infrared instrument. The mission is set to launch from Antarctica and is expected to operate for about four weeks.
The primary mirror, 8.2 feet (2.5 meters) in diameter, is made up of nine panels. Italian manufacturer Media Lario produced the optics. When fully inflated, the 40-million-cubic-foot helium balloon reaches roughly 400 feet (150 meters) wide and can ascend to an altitude of 130,000 feet (40 kilometers). The entire observatory—including the gondola, solar panels, antenna, scientific instrument, and communication gear—weighs an estimated 5,500 pounds (2,500 kilograms). To function, the telescope’s detectors must be chilled to 4 Kelvin, a temperature achieved by a cryocooler powered by electricity from its solar panels.
One of ASTHROS’ main scientific objectives is to study stellar feedback in the Milky Way and other galaxies—the process by which stars either speed up or slow down the formation of new stars in their galaxy. It will be the first mission to perform high spectral resolution spectrometry at a few specific light wavelengths, targeting two particular nitrogen ions produced by the mechanisms driving stellar feedback. As a secondary target, ASTHROS will also observe TW Hydrae.
- Planned launch date
- December 1, 2024
- Balloon size
- 400 feet (150 meters) wide
- Telescope diameter
- 2.5 meters (8.2 feet)
- Primary mirror panels
- 9
- Altitude
- 130,000 feet (40 kilometers)
- Observatory weight
- 5,500 pounds (2,500 kilograms)
- Detector temperature
- 4 Kelvin
Lore & Background
ASTHROS is a planned NASA balloon-borne telescope, originally scheduled to launch on December 1, 2024. It will be the largest balloon observatory ever built, with a 400-foot (150-meter) wide helium balloon that, when fully inflated, holds 40 million cubic feet of helium. The telescope's primary mirror is 8.2 feet (2.5 meters) in diameter and consists of nine panels, produced by Italian manufacturer Media Lario. The observatory, including gondola, solar panels, antenna, scientific instrument, and communication systems, weighs about 5,500 pounds (2,500 kilograms). It will be launched from the Antarctic and is envisioned to last for four weeks, reaching an altitude of 130,000 feet (40 kilometers). The telescope's detectors must be cooled to 4 Kelvin using a cryocooler powered by electricity from its solar panels.
Reader's Guide
ASTHROS is notable as the largest ever balloon observatory, designed to conduct high spectral resolution spectrometry at submillimeter wavelengths. Its primary science goal is to provide new information about stellar feedback in the Milky Way and other galaxies—a process in which stars either accelerate or decelerate the formation of new stars. ASTHROS will be the first mission to conduct high spectral resolution spectrometry in a few specific wavelengths of light, and to identify two specific nitrogen ions formed by the processes that drive stellar feedback. As a target of opportunity, it will also observe TW Hydrae. The mission's significance lies in its ability to study these phenomena from a balloon platform at high altitude, offering a unique vantage point for far-infrared observations. Its legacy may include advancing understanding of how stellar feedback influences galaxy evolution, and demonstrating the capabilities of large balloon-borne observatories for future astrophysical research.
Did You Know?
- ASTHROS will be the largest ever balloon observatory, with a 400-foot balloon.
- It will be the first mission to identify two specific nitrogen ions formed by stellar feedback.
Frequently Asked Questions
What is ASTHROS?
ASTHROS (Astrophysics Stratospheric Telescope for High Spectral Resolution Observations at Submillimeter-wavelengths) is a NASA balloon-borne far-infrared telescope. It is designed to be the largest balloon observatory ever built, carrying a 2.5-meter primary mirror aloft to study submillimeter and far-infrared emissions.
How big is the ASTHROS balloon?
The balloon spans 400 feet (roughly 150 meters) in width, giving it an enormous footprint in the stratosphere. The full observatory package, including the nine-panel 2.5-meter mirror assembly, tips the scales at about 5,500 pounds (2,500 kilograms).
Where and when does ASTHROS launch?
The mission is scheduled to lift off from Antarctica on December 1, 2024. Once airborne, the balloon will climb to an operating altitude of approximately 130,000 feet (40 kilometers), well above most of Earth's water vapor.
How long does the ASTHROS mission last?
The balloon is expected to remain operational for roughly four weeks after launch. During that window the telescope continuously collects far-infrared and submillimeter data from the stratospheric vantage point.
Why is ASTHROS a big deal for astrophotography and astronomy?
Its 2.5-meter, nine-panel primary mirror (manufactured by Italy's Media Lario) makes it the largest balloon-borne telescope ever constructed. By operating above the bulk of the atmosphere, it captures far-infrared and submillimeter wavelengths that ground-based scopes simply cannot resolve, opening a new observational window for researchers and imaging enthusiasts alike.
More in Astrophotography 1-24
Spotted an error? Know more?
Reader corrections go straight into our review queue. Suggest an edit · How this site is sourced