Decelerating and Dustfree: Efficient Dark Energy Studies with
Supernovae and Clusters


We propose novel techniques for achieving both high redshift
observations and robust systematics control simultaneously in
supernovae and cluster measurements, eliminating difficulties in
the use of GOODS data, and greatly increasing HST efficiency and
science yield per orbit.  These key measurements will serve as the
linchpin for next generation studies of dark energy and cosmology.
By targeting massive galaxy clusters at z > 1 we obtain a high
efficiency in detection of Type Ia supernovae, minimization of the
dominant systematic of host galaxy extinction using cluster ellipticals,
and we leverage cluster studies through weak lensing, optical, X-ray,
and Sunyaev-Zel'dovich measurements.  The data will set the stage for
improvement of (unbiased) supernova constraints on dark energy time
variation by a factor two, and serve as a bedrock scientific resource
for cluster studies.