Unique Features of the DSN
The Deep Space Network has unique capabilities as a radio astronomy facility,
both for
achieving NASA's research goals and for supporting astronomy research in
general.
In the southern hemisphere, the NASA 70-m at Canberra is about three times as sensitive and
has about half the beam diameter as the Parkes 64-m. In the northern hemisphere, the NASA
70-m antennas at Goldstone and Madrid have effective collecting areas and beamwidths
which are comparable to the Bonn 100-m telescope above 20 GHz.
When operating at 3 mm wavelength, the new beam-waveguide 34-m antennas will be
comparable to the world's largest mm-wavelength telescopes, and will be the largest in the US.
The angular resolution provided by these large antennas is crucial because it covers an
angular scale domain at which current interferometer arrays, operating at the same
wavelengths, lose their sensitivity due to the central hole in their UV-plane coverage.
The distribution of the 70-m antennas around the world has made them ideal for anchoring
the world-wide VLBI networks, by providing high sensitivity on crucial baselines. The
antennas at Canberra are unique for their access to the Magellanic Clouds and far better
suited for Galactic Center studies than northern telescopes.
The Goldstone and Canberra DSN Complexes have spectrometers which are without peer for
their combination of wide bandwidth and high angular resolution. They are ideal for
spectrum surveys of cold clouds.
The location of spacecraft around the sky dominates the DSN tracking schedule. This
necessarily leaves gaps which can often not be filled by other necessary activities such as
maintenance, particularly during non-workday hours. Thus, useful amounts of antenna
time are available for astronomy research that can be conducted in an automated or routine
fashion. Of course, radio astronomy projects with mission status and specific viewing
requirements, such as Space VLBI Co-Observing, can also compete with other missions for
prime antenna time.