Tucson Standard

A mission spearheaded by the University of Arizona, known as Aspera, has reached a significant milestone with the recent completion of its spacecraft bus assembly. The bus provides the structure, power, and systems necessary for the mission's operation. On February 25, this accomplishment marked a crucial step towards the mission's launch.

Aspera, which includes a space telescope developed at the University of Arizona's Steward Observatory, aims to study galaxy evolution through ultraviolet light. The mission, led by Carlos Vargas, an assistant astronomer at Steward Observatory, will explore the circumgalactic medium—diffuse matter surrounding galaxies that might play a role in star and planet formation.

"Gas is the fuel needed to make stars," said Vargas, who serves as the mission's principal investigator. "We have a good understanding of how much gas there must be in galaxies to explain how many stars we see, but we've searched far and wide and still cannot find most of it."

Vargas suggests that the missing gas is likely within the circumgalactic medium, which is invisible in optical wavelengths. Aspera will be the first mission to gather and map the faint ultraviolet light signatures from nearby galaxies. This effort aims to understand the formation of stars, planets, and life itself, all of which originate from such matter. "Why do we care about that? Because every star that has formed, every planet that's formed, and all life on those planets must come from matter somewhere," Vargas said.

The name "Aspera" is derived from a Latin word meaning "difficulty" or "hardship," referencing the challenge astronomers face in observing the hot gases of the circumgalactic medium. However, Aspera might succeed where previous attempts have failed.

The spacecraft, a microsatellite constructed by Space Flight Laboratory (SFL) in Toronto, is scheduled to launch in early 2026. The 120-pound satellite will detect ultraviolet light "fingerprints" from the gases surrounding galaxies. The spacecraft bus developed by SFL is particularly noteworthy for its performance in a compact package resembling a mini fridge. Equipped with solar panels, it will power the satellite's systems, controlling its spin and maintaining instrument temperatures.

SFL's design minimizes launch costs without compromising performance, aligning with the goals of NASA's Astrophysics Pioneers Program, which funds the Aspera mission. This program, initiated in 2020, supports astrophysics research with affordable, smaller hardware technology.

Vargas credits the small satellite revolution for enabling missions like Aspera. "Big science can now be done on small platforms, and the University of Arizona and Steward Observatory are big players in the SmallSat revolution." said Vargas. "Our partnership with SFL makes that possible."

SFL, founded in 1998, has been involved in 86 successful smaller satellite missions, accumulating over 370 years in orbit. Currently, 21 spacecraft are under development by SFL, offering expertise in nano-, micro-, and small satellites.