SpaceX Won NASA’s $69 Million Contract To Launch The COSI Mission

NASA selected the service provider for launching the COSI (Compton Spectrometer and Imager) mission, planned to be in August 2027. The contract goes to SpaceX. It is planned to use SpaceX’s Falcon 9 rocket from the Space Force Station at Cape Canaveral. COSI’s mission is to advance the domain of gamma-ray astronomy by utilizing cutting-edge technology and the collaborative efforts of several prestigious institutes

Choice Without Choice

NASA named the winning company on 2 July. The cost of the fixed-price contract for launch services and other costs related to the mission is about $69 million. That’s about 37 percent more the price NASA paid SpaceX in a 2019 contract to launch the similarly sized IXPE X-ray telescope into an orbit similar to COSI. The higher price is likely due to inflation.

In addition, NASA didn’t have to make many decisions since Falcon 9 is the only currently certified rocket capable of launching a satellite with the mass of COSI into its equatorial orbit.

The situation with the lack of alternatives is not profitable for NASA, but the agency hopes that within the next couple of years, United Launch Alliance’s Vulcan rocket and Blue Origin’s New Glenn launcher will compete for contracts to launch missions like COSI. All remaining ULA Atlas V rockets are already booked by other customers.

NASA estimated the total cost of developing the observatory, excluding launch fees, at $145 million.

COSI Telescope

COSI is a relatively small satellite built by Northrop Grumman and less than a tonne in weight. It is planned to operate in an unusual orbit about 340 miles (550 kilometers) above the equator to avoid interference from radiation over the South Atlantic Anomaly, where the inner Van Allen radiation belt comes closest to the Earth’s surface.

It is an advanced gamma-ray observatory providing high sensitivity and resolution. Central to its design are sixteen 3D imaging germanium detectors (GeDs) with high spectral resolution, critical for accurate measurements of gamma-ray interactions. These detectors, housed in an evacuated aluminum cryostat and maintained at cryogenic temperatures using a mechanical cryocooler, provide high energy resolution.

COSI uses a compact Compton telescope design that combines the scatterer and absorber into a single detector volume. This design enables efficient imaging, spectroscopy, and polarisation studies of gamma-ray sources. The telescope can do precise position and energy measurements of gamma-ray interactions.

Thus, it will build detailed maps of gamma-ray sources and highly precisely analyze their properties.

Chasing The Sources Of Gamma Rays In Our Galaxy

The mission aims to study the life cycle of stars and the processes that lead to the formation of chemical elements in the Milky Way. To do this, COSI will monitor the emission of particles that are produced when massive stars explode – in this way, the project hopes to map nucleosynthesis in the Milky Way (i.e., where chemical elements are formed in our Galaxy).

COSI observations will also provide new insights into the origin of positrons, which are the antiparticles of electrons. Positrons have the same mass as electrons but carry a positive charge.

Also, the COSI target will rapidly report the location of short gamma-ray bursts, unimaginably powerful bursts that flash and then fade out in just a couple of seconds. Neutron star mergers likely cause these spikes.

The project management team, led by COSI’s principal investigator, is based at the University of California, Berkeley. NASA’s Astrophysics Explorers Program at Goddard Space Flight Center in Greenbelt, Maryland, supports project development for the Astrophysics Division within NASA’s Science Mission Directorate. The NASA Launch Services Program at Kennedy Space Center in Florida manages the Launch Services Program.

Background

COSI qualified in a competition for funding for the next mission in NASA’s Astrophysics Explorers Program, the agency’s oldest continuous program. Since the late 1950s, over 90 space missions, incl. telescopes such as WISE, SWIFT, and TESS, have been launched under this program. In 2019 the program received 18 telescope proposals and selected four for conceptual mission studies. After evaluations by scientists and engineers in 2021, NASA formally selected COSI to proceed with development.

The COSI mission has matured over decades through technology development with scientific balloon flights. Most notably, the COSI Team launched a balloon-borne version of the COSI instrument from Wanaka, New Zealand, in May 2016 aboard NASA’s Superpressure Balloon.