Joint Dark Energy Mission

In August 2010, the Board on Physics and Astronomy of the National Science Foundation (NSF) recommended the Wide Field Infrared Survey Telescope (WFIRST) mission, a renamed JDEM-Omega proposal which has superseded SNAP, Destiny, and Advanced Dark Energy Physics Telescope (ADEPT), as the highest priority for development in the decade around 2020.

This would be a 1.5-meter telescope with a 144-megapixel HgCdTe focal plane array, located at the Sun-Earth L2 Lagrange point.

The space telescope will derive the expansion of the universe by measuring up to 3,000 distant supernovae each year of its three-year mission lifetime, and will additionally study the structure of matter in the universe by measuring millions of galaxies in a weak gravitational lensing survey.

[2] The satellite observatory would be capable of measuring up to 2,000 distant supernovae each year of its three-year mission lifetime.

SNAP was also planned to observe the small distortions of light from distant galaxies to reveal more about the expansion history of the universe.

To understand what is driving the acceleration of the universe, scientists need to see greater redshifts from supernovas than what is seen from Earth.