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NASA Selects Space Telescope to Study Milky Way Formation
NASA Selects Space Telescope to Study Milky Way Formation

On Monday, NASA selected a proposal for a new space telescope to study the evolution of the Milky Way. The Compton Spectrometer and Imager (COSI), a gamma-ray telescope expected to launch in 2025 as the agency’s latest small astrophysics mission, will explore the recent history of star birth, star death and the formation of chemical elements in the galaxy.

By examining the gamma rays produced by radioactive atoms leftover from massive stars that exploded, COSI can map where chemical elements were formed in the Milky Way. The mission will also seek to find answers about the origin of the galaxy’s positrons, also known as antielectrons – subatomic particles that have the same mass as an electron but a positive charge.

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Thomas Zurbuchen

“For more than 60 years, NASA has provided opportunities for inventive, smaller-scale missions to fill knowledge gaps where we still seek answers,” said Thomas Zurbuchen, associate administrator for the agency’s Science Mission Directorate in Washington. “COSI will answer questions about the origin of the chemical elements in our own Milky Way galaxy, the very ingredients critical to the formation of Earth itself.”

The COSI team developed its technology over decades through flights on scientific balloons. In 2016, for example, it loaded a version of the gamma-ray instrument on NASA’s 18.8 million-cubic-foot super pressure balloon, which completed its first circumnavigation of the globe with the payload onboard.

Although NASA has yet to select a launch provider for the mission, COSI’s budget will total approximately $145 million, not including launch costs. The principal investigator for the COSI is John Tomsick at the University of California, Berkeley.

As part of its Astrophysics Explorers Program, NASA selects certain applicants to conduct focused scientific investigations under the Astrophysics Division. It received 18 telescope proposals in 2019 and selected four for mission concept studies. After a detailed review of these studies by a panel of scientists and engineers, the agency gave COSI the green light for development.

Having launched more than 90 missions since 1958, Astrophysics Explorers is NASA’s oldest continuous program. Other missions managed by Explorers include the Nuclear Spectroscopic Telescope Array (NuSTAR), which is conducting a census of black holes and studying the birth of elements, and the Transiting Exoplanet Survey Satellite (TESS), which is now in operations identifying terrestrial planets in the habitable zones of nearby stars. The Cosmic Background Explorer, other Explorers program, even earned its principal investigators a Nobel Prize in 2006.

NASA Selects Space Telescope to Study Milky Way Formation

The Compton Spectrometer and Imager (COSI), a gamma-ray telescope expected to launch in 2025 as NASA’s latest small astrophysics mission/NASA







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