Disturbuted Aperture Array for Radio Astronomy In Space
The DARIS project is an ESA study in which ASTRON, EADS ASTRIUM, Radbound Universiteit Nijmegen, and ALTRAN participate. For further information please contact Albert-Jan Boonstra, boonstra [at] astron [dot] nl.
With large apertures in space at frequencies below 30 MHz, many interesting science cases can be studied. These range for example from surveys of the extragalactic low-frequency sky, coronal mass ejection mapping and research, investigation of planetary radio bursts, to detection of cyclotron maser emission from extra-solar planets.
The aim of this project is to study the feasibility of large aperture arrays in space for radio astronomy observations. Given the required very large apertures, an interferometric aperture synthesis telescope would be the preferred telescope concept. Studies of the interstellar plasma and interplanetary plasma indicate that baselines up to 100 km are optimal for the frequency range 0.03-30 MHz. Longer baselines seem not to be useful as the plasma would distort the interferometric phases, thus limiting the angular resolution. As the distribution and density of the plasma is not accurately known, these numbers are estimates.
In the project, several mission concepts will be studied. Formation flying, such as in-orbit around the earth, in-orbit around the moon, at L2, or a distributed aperture moon-based systems will be considered. Because of strong interference of Earth-bound long-wave HF transmitters, an in-orbit distributed satellite system around the moon or a system at the back side of the moon would be preferable. Moon-based systems have been considered, this project proposal however limits itself to space-based formation flying systems.