Prospero 40th Anniversary

Attempts are being made to reactivate Prospero, the United Kingdom’s first satellite launched on a UK-built rocket, Black Arrow, on October 28, 1971. It is hoped Amateur Radio operators will be able to provide recordings of the signals on 137.560 MHz.

On October 19, Roger M0RJA provided details of tests to be carried out over the following two weeks:

Some of you may have heard that a team in the UK are trying to re-contact an old British launched satellite for the anniversary of its launch (28th October 1971).

We’ve been given a licence to transmit [on the 148.25MHz command uplink] and will be testing our re-engineered ground-segment in the next fortnight.  The passes we are going to concentrate on will be as far out west as possible, as to minimise QRM from Europe.  Earth is a lot more EM noisy than it was in 1971.

If anyone wants to try and tune in to the downlink, you can help ID any response we get from the old bird. To avoid interference the downlink is only planned to be active when the satellite is in range of the United Kingdom. The passes [times UK local = GMT+1] are summarised here:

There are other passes, though these are the ones which are out west.  We’ll see how we do.

Update Oct 23:   A recording would be grand.  We may have heard something on Friday [Oct 21], though we’re still piecing together what we can expect.  If recordings are made of the times when Prospero is to pass then we can get an idea of what everyone is hearing now.

On Friday we listened to a complete pass and definitely heard something different when Prospero was in our vicinity.  Whether this was coincidence with some QRM we don’t know.  As long as others aren’t transmitting at the same time as us on the Prospero frequencies, we have a reasonable chance to apply the scientific method to be certain of what we’re listening to.

We probably won’t make another attempt till Monday [Oct 24] – and we will probably try the passes at around 1800. [UK Local (GMT+1)]

There is information on this on the AMSAT-UK site front page:  this includes the passes we’ve marked out for definite attempts (we may try others) and there are some archived recordings of Prospero to compare to.

Roger J A Duthie M0RJA
Email: rjad at

N2YO Prospero predictions
VK3UKF Prospero real-time oribtal tracking

ITN TV news video of Prospero

Audio recordings of the 0.3 watt phase modulated signal with 2048 bit/s PCM from Prospero on 137.560 MHz can be heard on the Sounds from Space site of Matthias Bopp DD1US

Experiments on the Prospero satellite

Plan to revive 1970s UK satellite on 137.560 MHz

Wiki – Prospero

John Wright G4DMF says the Prospero satellite was featured in a BBC show called “Coast” Series 2 Episode 1 Dover to Isle of White. The item titled ‘Isle of Wight – UK’s Space Race of the 60’s’ showed an attempt to receive the signals using what appeared to be an AR2000. The show also dealt with the research into the propellants, and the launch from Australia.
Roger M0RJA says he thinks that what was received on Coast was almost certainly an Orbcomm transmission. Orbcomm was assigned the Prospero frequency.

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