Space missions are evolving and now span a wide range of orbits and mission lifetimes that require different levels of mitigation for radiation.  Some missions now leverage commercial electronics that allow for state of the art performance at costs appropriate for the programs.  Microsemi continues to provide timing for applications such as GPS and SBIRS that require stringent performance, reliability and radiation performance.  In addition, Microsemi has adapted several products from either military heritage or commercial designs that have adequate radiation tolerances for short duration and low earth orbit (LEO) or experimental missions. The presentation will describe Microsemi’s COTS quartz oscillators and atomic clocks, and the results of radiation testing to 100 krads (Si.) In addition, background information regarding single event effect (SEE) radiation susceptibility of quartz oscillators to more severe environments that contain neutrons and heavy ions will be reviewed.  Context for the decision to use of COTS products in comparison to radiation hardening by design will be provided.