Description: We propose the development and space-qualification of a 1.06 micron ultrastable fiber laser source that fully satisfies the requirements of this SBIR opportunity (Laser Technologies for Gravitational Wave Detection). Our recommended approach builds on extensive experience developing and using single-frequency laser sources in the near infrared, both for aerospace and commercial applications. Our technical approach is based on emerging technology, spawned by the telecom industry that is only now reaching the maturity level where space qualification can be undertaken. NASA requires ultrastable laser sources for a variety of ongoing and planned missions including LISA and GRACE.