Deployable antenna concepts for the Dark Ages Radio Explorer mission

The Dark Ages Radio Explorer (DARE) is a concept for a space-based cosmology mission designed to measure the sky-averaged spectrum from the highly-redshifted hyperfine 21 cm transition from neutral hydrogen (J.O. Burns, J. Lazio, et al., Adv. Space Res., 49, 433–450, 2012). From this sky-averaged spectrum, the formation of the first luminous objects at the end of the Dark Ages and during Cosmic Dawn (redshifts z = 11–35) can be tracked by their effect on the neutral intergalactic medium. The specific science objectives for the DARE mission are (1) When did the first stars form? (2) When did the first accreting black holes form? (3) When did Reionization begin? (4) What surprises does the end of the Dark Ages hold (e.g., dark matter decay)? The DARE spacecraft orbits the Moon for a mission lifetime of 3 years and takes data above the lunar farside, the only location in the inner solar system proven to be free of human-generated radio frequency interference and any significant ionosphere.