NASA intended on studying newly-formed giant stars by using a huge “football stadium” sized balloon called ASTHROS (astrophysics stratospheric telescope for high spectral resolution observations at submillimetre-wavelengths) with a 2.5-meter telescope attached to it.
The main goal NASA hope to achieve through ASTHROS, is to get a clear understanding of how exactly star formation and supernova explosions affect their surrounding materials. The organisation will achieve this by studying the gases around newly-formed giant stars by observing the far-infrared light they emit.
The far-infrared wavelengths NASA are looking to study are usually blocked by the Earth’s atmosphere. This means ASTHROS will need to reach an altitude of around 40 kilometres, or four times higher than commercial airlines fly.
To reach this altitude, ASTHROS will need a big balloon. According to NASA ,“When fully inflated with helium, it will be about 150 meters wide, or about the size of a football stadium.”
The telescope attached to ASTHROS will around 2.5-meter in size and be made up of dish antenna’s as well as a series of mirrors, lenses, and detectors designed and optimised to capture far-infrared light.
“Because far-infrared instruments need to be kept very cold, many missions carry liquid helium to cool them. ASTHROS will instead rely on a cryocooler, which uses electricity (supplied by ASTHROS’ solar panels) to keep the superconducting detectors close to minus 268.5 degrees Celsius — a little above absolute zero, the coldest temperature matter can reach.” NASA explained on its website.
The telescope will be tasked with observing four targets, including two star-forming regions in the Milky Way galaxy. It will also be used to detect and map the presence of two specific types of nitrogen ions. “These nitrogen ions can reveal places where winds from massive stars and supernova explosions have reshaped the gas clouds within these star-forming regions,” NASA explained.
ASTHROS is expected to launch in December, 2023, where it will make two or three loops around the South Pole over 28 days, carried by stratospheric prevailing winds. Once the 28 days have come to end, operators will send flight termination commands that separate the gondola, which is connected to a parachute, from the balloon. The parachute will then return the gondola to the ground so that the telescope can be recovered and refurbished to fly once more.
“We will launch ASTHROS to the edge of space from the most remote and harsh part of our planet. If you stop to think about it, it’s really challenging, which makes it so exciting at the same time.” said JPL engineer Jose Siles, project manager for ASTHROS.
Image credit: NASA’s Goddard Space Flight Center Conceptual Image Lab/Michael Lentz