Post by occam Post by Peter Moylan
Back in 1969 I got to walk on the Parkes dish. The operators tilted
it far enough that we could climb on to it, and then tilted it back
as we walked to the centre. This put us much further from the
ground than I had expected.
Post by occam
A fact I was unaware of until now is the second Australian satellite
dish site - Honeysuckle Creek.
By now there are radio-telescopes all over the world. A partial list of
those in Australia can be seen at
In the 1980s, or possibly it was the 1990s, I was part of a team that
developed a system for steering such dishes. We were, however, working
more with tracking telecommunications satellites than with
radio-astronomy. In astronomy, as we all know, there are databases to
tell you where to point your telescope. With telecommunications
satellites, the aim at the time was to keep the satellite in a known
orbit. This was true for geosynchronous satellites, and for
low-earth-orbit (LEO) satellites, and everything in between. With a
known orbit, you could steer your dish according to a pre-planned schedule.
But satellites drift away from their orbits, because of random
disturbances, so they must carry fuel for orbit corrections. When the
fuel runs out, the satellite becomes useless, even if it is still in
Our system extended the useful life of satellites by tracking their
changes in orbit. Initially the dish searched in the vicinity of the
supposed orbit. Once it obtained a lock on the position, it built up a
software model of the orbit, and kept correcting that model as time
The system worked well, with a number of successful installations, until
some idiot in the military specified that our system had to be
"upgraded" to run under Windows. That seriously degraded its quality.
Post by occam
From the perspective of someone planning a visit starting in
Melbourn, both look doable in one trip. "A two-dish course" is a
likely pun, in French.
Melbourne to Canberra is an easy drive - about six hours, IIRC - with
freeway-standard roads all the way. Then Honeysuckle Creek is about an
hour from Canberra. Expect bad roads, because it's off the beaten track.
I believe camping is allowed there, but you need to bring all your
supplies including food. Of course you can always drive back to Canberra
if the food or water run out.
Canberra to Parkes is along less good roads, but it can be done in well
under four hours. There are plenty of motels in Parkes. Parkes back to
Melbourne is an eight-hour drive. Sydney is a bit closer - about 4-5 hours.
These days, of course, such a trip is complicated by having to get
permits to cross state borders, and a risk of a rule change at short
notice forcing you into quarantine. Just a month ago my wife and I had
to cancel a planned vacation in Tasmania because the risks were too high
of that sort of rule change.
Peter Moylan Newcastle, NSW