The ARISE Space VLBI mission

ARISE (Advanced Radio Interferometry between Space and Earth) is a proposed future space VLBI mission currently under consideration by NASA. The primary mission goal is to orbit a radio telescope whose performance for high-frequency VLBI is similar to a 25-meter antenna of the Very Long Baseline Array (VLBA). A VLBA antenna has a mass greater than 200 tons, but inflatable antenna technologies may enable launch of an orbiting antenna with a similar diameter, but a mass of only a few hundred kilograms. This would permit key scientific questions to be investigated, such as the nature of the innermost relativistic jets in gamma-ray blazars, and the physics associated with extragalactic H2O megamasers. If ARISE is selected by NASA, a launch date of 2008 is feasible. (C) 2000 COSPAR. Published by Elsevier Science Ltd.