WASHINGTON – NASA has selected four small astrophysical missions for further study, although the agency warns that not all may be completed.
NASA announced on January 7 that it had selected three smallsat missions and one high altitude balloon mission as the first of its new Astrophysics Pioneers program. The program, established last year, is intended to support small astrophysical missions, including small satellites and balloons as well as payloads for the International Space Station. The agency selected four of the 24 proposals received in the fall.
“Each of the proposed experiments would do something that no other NASA telescope or mission can do, filling important gaps in our understanding of the universe as a whole,” said Thomas Zurbuchen, NASA associate administrator for science, in a press release on the Selections of Astrophysics Pioneers. He praised the scientists who proposed the missions for applying “innovative and original thinking to the problem of how to do high-impact astrophysics experiments on a low budget.”
A selected small satellite, Aspera, will study the evolution of galaxies by observing hot gases between galaxies at ultraviolet wavelengths. A second, Pandora, will observe 20 stars known to have exoplanets at visible and infrared wavelengths. A third small satellite, StarBurst, will detect gamma rays from neutron star fusions, in collaboration with ground-based gravitational wave observatories. The Payload for Very High Energy Observations (PUEO) is a balloon-mounted instrument that will measure very high-energy neutrinos from neutron star fusions and the creation of black holes.
Each mission has a cap of $ 20 million, which puts them at the bottom of what Paul Hertz, director of NASA’s astrophysics division, described in a Jan. 8 meeting of several astrophysics advisory groups as a set of “logarithmically spaced” mission classes that range from 5 million cubesats to flagship missions costing billions of dollars. Astrophysics Pioneers is intended to accommodate missions too large to fit into the cubesat program, but does not require the size and complexity of larger satellite programs, like Explorer.
All four missions have received funding for six-month concept reviews, after which they will undergo what Hertz has called “bridge” reviews. “They are not competing with each other, but they are competing with their cost cap of $ 20 million,” he said.
Hertz said he expected, based on experience from previous NASA smallsat missions, that one or more of the pioneering concepts of astrophysics will not fit into that cost cap. “It’s really hard to keep these little missions in their little cost boxes,” he said. “We think it’s likely that some of these missions fail to get through that door.”
By selecting four, he said, it’s likely that at least one or two will go through the gateway exam and be approved by NASA for full development. “Over time, we will be better able to forecast the cost of small satellites,” he said.
If all four missions passed this bridge exam, NASA would face another challenge. “We didn’t budget for the four to fly by plane,” Hertz said, assuming some would not be successful. “If we are wrong, we will try to find the money” to steal the four.