An exercise in Anglo-American cooperation is to give the world its second ''talking satellite'' that relays spoken messages to the ground using speech synthesis.
The project, involving a team of university researchers from England, also challenges the belief that space technology is the province only of the aerospace industry giants.
The satellite will be built for about one-thirtieth of the cost of a conventional craft constructed by industry, using cheap components and a workforce whose main attributes are enthusiasm and a willingness to put in long hours.
A group of some 20 engineers from the University of Surrey in Guilford, near London, will construct the vehicle, a more advanced form of a Surrey satellite that has been in orbit for two years.
One feature common to both satellites is their speech-synthesis circuitry. An electronic mechanism sends spoken messages that people on the ground can tune into.
NASA has informed the Surrey team that it will take the new vehicle into space for no charge on board a rocket due to lift off next March. The British satellite, called UOSAT-2, will hitch a ride with a Delta rocket launching a replacement for the US's ailing remote-sensing craft, Landsat 4.
The new British craft will provide a novel service to radio amateurs. The satellite will contain an electronic memory that stores messages sent from the personal computers of radio enthusiasts around the world.
The memory will act as a ''mailbox in the sky,'' releasing the messages in radio signals when the satellite is passing over specific parts of the globe.
In this way, computer hobbyists will be able to swap messages with people in virtually any part of the world. Although the satellite is not intended to offer anything like a full service, in time this technique could prove a cheaper way of exchanging data than does the conventional telecommunications system.
The space vehicle will also continue the role of the first Surrey satellite in sending to earth the sound of a human voice. In the first vehicle, circuitry containing the sound of about 100 English words converts into speech form information about the performance of the spacecraft. This information is sent to Earth, where the signals can be picked up by a cheap radio receiver.
On the second spacecraft, the Surrey engineers plan to expand the vocabulary of the speech unit by a factor of three. And they hope to incorporate circuitry that gives spoken messages a British accent. The speech unit on the current space vehicle has a pronounced American drawl because it is based on chips built by Texas Instruments.
Martin Sweeting, the leader of the Surrey team, regularly tunes into the ''speaking spacecraft'' with a lightweight receiver while working in his yard. He has also listened into the speech unit while on holiday in the Himalayas.
Some 2,000 receiving stations around the world regularly obtain information from the first spacecraft, which, besides talking, collects data about the Earth's magnetic field and radiation levels in space.
Many of these receiving stations are schools and colleges which use the signals from the spacecraft (which another NASA rocket launched in October 1981) as way to teach pupils about engineering.
The Surrey project will also test cheaper ways of constructing satellites. UOSAT-2 is to be built with a budget of (STR)350,000 ($525,000), as opposed to the (STR)10 million ($15 million) or so that a conventional spacecraft of similar weight (60 kilograms) would cost.
Part of the reason for the difference in cost is that the vehicle will be constructed by engineers at the university, and they are paid less than their counterparts in industry.
Further, the team will cut corners by using relatively inexpensive components. Sweeting thinks a lot of today's space hardware is costly simply because people have grown used to satellite projects consuming vast sums of money.
For example, an aerospace firm quoted a price of (STR)15,000 for the honeycomb material used in the structure of the first spacecraft. Sweeting ''shopped around'' and bought similar material normally used in train doors. The new material cost just (STR)300 - and seems to have worked as well.
The University of Surrey team hopes to recoup the construction cost of the UOSAT 2 from donations from friendly industrialists and from organizations for radio enthusiasts.