  We propose a scheme based on a heterodyne laser link that allows for long
baseline gravitational wave detection using atom interferometry. While the
baseline length in previous atom-based proposals is constrained by the need for
a reference laser to remain collimated as it propagates between two satellites,
here we circumvent this requirement by employing a strong local oscillator
laser near each atom ensemble that is phase locked to the reference laser beam.
Longer baselines offer a number of potential advantages, including enhanced
sensitivity, simplified atom optics, and reduced atomic source flux
requirements.
