The Imaging X-ray Polarimetry Explorer (IXPE) was selected by NASA in early 2017 as the most recent SMEX mission chosen for development.
In July 2019 NASA awarded SpaceX a contract to launch the Imaging X-Ray Polarimetry Explorer (IXPE) astrophysics mission on a Falcon 9 in April 2021.
SpaceX received launch awards in 2019 for the DART asteroid intercept mission and the IXPE X-ray astronomy mission.
The Falcon 9 contract for IXPE was valued at $50.2 million, compared with the $56,400,000 value of the 2014 contract NASA awarded for the ICON launch on a Pegasus XL.
NASA awarded a contract in July to SpaceX for a Falcon 9 launch of the Imaging X-Ray Polarimetry Explorer (IXPE) mission despite IXPE being baselined to launch on the Pegasus XL.
The SpaceX Falcon 9 contract for the IXPE launch was valued at $50.8 million, which was less than the $56,400,000 cost for the Pegasus launch of ICON.
NASA selected IXPE in January 2017 as part of its Small Explorers program of astrophysics missions.
Mission officials had baselined use of the Pegasus XL rocket to launch IXPE from Kwajalein Atoll in the Pacific.
The Falcon 9 launching IXPE will use a reused first stage booster.