To add to this: NASA says SpaceX can use a previously flown booster on this mission.

IXPE is a small satellite, but this launch contract is less than what NASA paid for for the still-pending Pegasus XL launch of ICON ($56.3M in a 2014 contract). Think about that… https://t.co/sJlWVMHC5c

— Jeff Foust (@jeff_foust) July 8, 2019