The Supernova Acceleration Probe (SNAP) will use Type Ia supernovae (SNe Ia)
as distance indicators to measure the effect of dark energy on the expansion
history of the Universe. (SNAP's weak-lensing program is described in a
companion White Paper.) The experiment exploits supernova distance measurements
up to their fundamental systematic limit; strict requirements on the monitoring
of each supernova's properties lead to the need for a space-based mission.
Results from pre-SNAP experiments, which characterize fundamental SN Ia
properties, will be used to optimize the SNAP observing strategy to yield data,
which minimize both systematic and statistical uncertainties. SNAP has achieved
technological readiness and the collaboration is poised to begin construction.
