“Live, via Satellite”
In 1963, the GPO was willing to gamble that it could relay television signals to peoples’ homes using a satellite. The concept would mean that the existing network of ground based radio transmitters would not need to be expanded to cope with the higher frequency signals needed for high quality colour TV pictures, potentially saving millions of pounds. They accepted the risk that developing and launching two or three satellites to beam radio signals down to the UK would be cheaper than installing and maintaining dozens of TV transmitters all across the country.
To this day, no one knows if they were right.
The Hermes satellite TV relay system was a huge technical challenge and demanded the best minds that British industry and the GPO could provide. The spacecraft had to be able to function for years without maintenance, be powered by the sun (nuclear generators were ruled out at a very early stage) and must be stable enough to accurately point a 16’ dish antenna to within quarter of a degree of the UK. Although the basic radio systems were well understood, in 1963 no one had built a satellite with the power to transmit directly to the public. Spacecraft such as Telstar and Syncom weighed just a few hundred pounds and their low power signals could only be picked up by giant dishes, usually dozens of feet across. To broadcast to the public, who could only have small antennas on their homes, a massive increase in transmitter power would be needed. Syncom carried 2W transmitters. Hermes would need 150W transmitters, meaning that a power input of at least 1.5kW would be required for each TV channel to be broadcast. No satellite yet built had come close to meeting these requirements.
Once it was confirmed that the “Black Anvil” missile could be adapted as a space launch vehicle, the GPO was satisfied that it would be possible to launch a satellite large enough to carry all the systems and develop the power that would be required. Hermes satellites were big, even by today’s standards. In 1964, the design was ten times larger than any other Comsat being considered. When fully fuelled they would weigh 3 tons, a mass that would need to be placed into a circular orbit 36,000km above the Earth’s surface.
Hawker Siddeley Dynamics (HSD) were chosen to build this giant. The firm had worked with the GPO and several American firms during the development of Telstar and other early satellites, and had obtained access to details of a cancelled US Navy communications programme called Advent. Abandoned in 1962, Advent would have been a big satellite like Hermes, but fell victim to its own complexity, cost overruns and problems in the development of the rocket needed to launch it. By 1964, HSD were confident that they had solved or avoided these issues.
Three years later, the first prototype Hermes sits on top of the second Silver Star rocket, the world’s newest and most powerful launch vehicle. Engineers have checked and rechecked its systems and lessons have been learned from the first flight. The time has come to push the button.
“Hermes-P”, launches from Rainbow Beach on the 6th June 1967. This first modified Silver Star core performs well, without the excessive “pogo” seen on the earlier flights. The trajectory has been modified to allow the upper stage to fire continuously to put itself and the satellite directly into geostationary transfer orbit, eliminating one of the risky engine re-starts. It achieves a 203x36302km orbit at 37.6 degrees inclination, slightly higher than planned. A little over 5 hours later, the stage’s automatic sequencer performs the apogee burn on schedule, placing the satellite into a 36299 x 36152km orbit. A minor glitch in the vernier thrusters means this is also slightly higher than intended.
The satellite separates and its telemetry carrier signal is acquired by Goonhilly at T+06:03. The 50’ wide solar reflectors are deployed, after which the spacecraft stabilises and orientates itself to allow the reflectors to lock on to the sun. All four turbine units are producing power by T+07:32. Thrusters are used to trim the orbit to 35,802 x 35912km on the second day to stop the satellite “drifting” (as seen from the ground) too quickly to the West.
As Hermes is launched, it is estimated that there are only about 6,000 colour TV sets in the country. The new “satellite-receiver” sets and aerials are incompatible with the old style of ground-based transmission. The cheapest colour set costs £99 (plus £14 10s for an aerial, plus fitting). Although a few experimental test broadcasts have been made from a single transmitter in London, the new style sets have been essentially useless until now. A few dual receiver sets (which can work with both systems) have been marketed, but these are much more expensive and sales have been disappointing. Most of the public has therefore adopted a “wait and see” policy, and it is notable that demand shot up in the days after the successful launch of Hermes-P. Thanks to stockpiles of unsold sets, the availability of easy terms or rentals and a well-planned installation campaign by the GPO nearly 100,000 new TVs are installed into people’s homes in the 11 days after the launch.
Despite the considerable press, TV and public information film coverage, some still expected their new colour sets to “spring to life” immediately. Much to their frustration, ground controllers will now spend several days testing the satellite, while also allowing it to drift towards its final position near the prime meridian.
On the 11th, the high power signal transmitter is switched on and allowed to thermally stabilise for 48 hours. Directional control of the spacecraft is switched over to the reaction wheels during this time, but is switched back to thrusters when an unexpected torque overwhelms the wheels three hours later.
To help avoid any negative public reaction to early faults, non-TV signals are used to test the relay receiver-transmitter. Signal strengths, distortion and noise levels are checked and the system passes these tests with flying colours on the 14th and 15th.
The first colour TV test card is broadcast for 10 minutes starting at 0235 in the morning of the 16th June. The test is not announced and as far as is known no-one other than BBC, ITV and GPO engineers saw it; its purpose was as a final check, both of the satellite and signal monitoring stations around the country. The first publicly announced colour test card is broadcast between 1900 and 2200 on the following day to allow the public to adjust their sets. Simultaneous broadcasts on “old” television shows viewers what to do and what they should expect to see.
Regular colour TV broadcasting in the UK begins on BBC 2 at 7PM on the 18th June, when the BBC’s new "World Circling Satellite” ident is shown for the first time. The BBC has decided to use the part-time BBC 2 channel for the duration of the experimental phase, leaving its regular BBC 1 programming in black and white on the existing ground based transmitters.
After the briefest of introductions, “Good evening and welcome to BBC Satellite Television”, the first programme is an ambitious series of live broadcasts from locations around (and off) the country, including the deck of the liner Queen Elizabeth in the English Channel and from the Orkney Islands, which have never previously received any TV signals. This latter telecast is the first example of a double satellite relay, as the outside broadcast from the Orkneys is sent up to an Intelsat satellite over the Atlantic, back down to one of the big dishes at Goonhilly then up again to Hermes-P for rebroadcast to the nation.
A later programme describing how the system works includes colour footage of the launch of Hermes-P and in a special edition of "The Sky at Night", astronomer Patrick Moore shows viewers how and when to try to spot the satellite in orbit high over the equator.
At 7pm the following evening, ITV colour broadcasting is started with a brief announcement, followed by the first colour advert to be shown on British television (it was for Kellogg's cereals). A live broadcast from Abbey Road studios includes the debut of the Beatles' latest song "All You Need Is Love", which is also transmitted to the US and Europe via the Intelsat network, for relay by those countries' traditional ground based TV systems.
The single transponder on Hermes-P can only broadcast one channel at a time. The BBC and ITV have agreed that during this experimental phase they will each broadcast on alternate days to allow both networks access to colour programming. As it is a single frequency, the public can receive the BBC and ITV programmes without retuning.
However, with only 6 colour TV cameras in the entire country it is not possible to produce everything to the new standard. A simple and very popular approach is tried by the BBC, where controllers decide to concentrate on sports broadcasts, something that can be done easily with just one camera at an event. Centre court matches at the 1967 Wimbledon lawn tennis championships are first to be shown. The first test match in colour (between England and India) is broadcast from Edgbaston in July. Football fans have to wait for the start of the season in August, when Everton meet Manchester United “in glorious colour” on the 19th.
The Hermes-P satellite itself surpasses everyone’s expectations with its reliability. A single thruster failure in August 1968 marginally increases fuel consumption, but the electronics and payload are still operating normally in July 1970 when the satellite’s fuel begins to run low. After the launch of Hermes-2 it has only been used as a backup and for a variety of experiments. The satellite is nudged into a slightly higher orbit in August 1970 and is left to "drift" (i.e. not maintain a constant position over the ground). The transmitter payload ceases to function in February 1971 when the main receiver fails. By April 1972 two of the four generator turbines have failed and it is not considered worth the effort of monitoring the spacecraft any longer.
On 2 May 1972, Hermes-P is commanded to turn its solar reflectors away from the sun. It is then placed in a slow spin to naturally stabilise its attitude before being permanently switched off.
Britannia Rules the Airwaves
Artist's Impression of a Hermes satellite in orbit
Artist's Impression of a Hermes satellite in orbit
In 1963, the GPO was willing to gamble that it could relay television signals to peoples’ homes using a satellite. The concept would mean that the existing network of ground based radio transmitters would not need to be expanded to cope with the higher frequency signals needed for high quality colour TV pictures, potentially saving millions of pounds. They accepted the risk that developing and launching two or three satellites to beam radio signals down to the UK would be cheaper than installing and maintaining dozens of TV transmitters all across the country.
To this day, no one knows if they were right.
The Hermes satellite TV relay system was a huge technical challenge and demanded the best minds that British industry and the GPO could provide. The spacecraft had to be able to function for years without maintenance, be powered by the sun (nuclear generators were ruled out at a very early stage) and must be stable enough to accurately point a 16’ dish antenna to within quarter of a degree of the UK. Although the basic radio systems were well understood, in 1963 no one had built a satellite with the power to transmit directly to the public. Spacecraft such as Telstar and Syncom weighed just a few hundred pounds and their low power signals could only be picked up by giant dishes, usually dozens of feet across. To broadcast to the public, who could only have small antennas on their homes, a massive increase in transmitter power would be needed. Syncom carried 2W transmitters. Hermes would need 150W transmitters, meaning that a power input of at least 1.5kW would be required for each TV channel to be broadcast. No satellite yet built had come close to meeting these requirements.
Once it was confirmed that the “Black Anvil” missile could be adapted as a space launch vehicle, the GPO was satisfied that it would be possible to launch a satellite large enough to carry all the systems and develop the power that would be required. Hermes satellites were big, even by today’s standards. In 1964, the design was ten times larger than any other Comsat being considered. When fully fuelled they would weigh 3 tons, a mass that would need to be placed into a circular orbit 36,000km above the Earth’s surface.
Hawker Siddeley Dynamics (HSD) were chosen to build this giant. The firm had worked with the GPO and several American firms during the development of Telstar and other early satellites, and had obtained access to details of a cancelled US Navy communications programme called Advent. Abandoned in 1962, Advent would have been a big satellite like Hermes, but fell victim to its own complexity, cost overruns and problems in the development of the rocket needed to launch it. By 1964, HSD were confident that they had solved or avoided these issues.
Three years later, the first prototype Hermes sits on top of the second Silver Star rocket, the world’s newest and most powerful launch vehicle. Engineers have checked and rechecked its systems and lessons have been learned from the first flight. The time has come to push the button.
“Hermes-P”, launches from Rainbow Beach on the 6th June 1967. This first modified Silver Star core performs well, without the excessive “pogo” seen on the earlier flights. The trajectory has been modified to allow the upper stage to fire continuously to put itself and the satellite directly into geostationary transfer orbit, eliminating one of the risky engine re-starts. It achieves a 203x36302km orbit at 37.6 degrees inclination, slightly higher than planned. A little over 5 hours later, the stage’s automatic sequencer performs the apogee burn on schedule, placing the satellite into a 36299 x 36152km orbit. A minor glitch in the vernier thrusters means this is also slightly higher than intended.
The satellite separates and its telemetry carrier signal is acquired by Goonhilly at T+06:03. The 50’ wide solar reflectors are deployed, after which the spacecraft stabilises and orientates itself to allow the reflectors to lock on to the sun. All four turbine units are producing power by T+07:32. Thrusters are used to trim the orbit to 35,802 x 35912km on the second day to stop the satellite “drifting” (as seen from the ground) too quickly to the West.
As Hermes is launched, it is estimated that there are only about 6,000 colour TV sets in the country. The new “satellite-receiver” sets and aerials are incompatible with the old style of ground-based transmission. The cheapest colour set costs £99 (plus £14 10s for an aerial, plus fitting). Although a few experimental test broadcasts have been made from a single transmitter in London, the new style sets have been essentially useless until now. A few dual receiver sets (which can work with both systems) have been marketed, but these are much more expensive and sales have been disappointing. Most of the public has therefore adopted a “wait and see” policy, and it is notable that demand shot up in the days after the successful launch of Hermes-P. Thanks to stockpiles of unsold sets, the availability of easy terms or rentals and a well-planned installation campaign by the GPO nearly 100,000 new TVs are installed into people’s homes in the 11 days after the launch.
Despite the considerable press, TV and public information film coverage, some still expected their new colour sets to “spring to life” immediately. Much to their frustration, ground controllers will now spend several days testing the satellite, while also allowing it to drift towards its final position near the prime meridian.
On the 11th, the high power signal transmitter is switched on and allowed to thermally stabilise for 48 hours. Directional control of the spacecraft is switched over to the reaction wheels during this time, but is switched back to thrusters when an unexpected torque overwhelms the wheels three hours later.
To help avoid any negative public reaction to early faults, non-TV signals are used to test the relay receiver-transmitter. Signal strengths, distortion and noise levels are checked and the system passes these tests with flying colours on the 14th and 15th.
The first colour TV test card is broadcast for 10 minutes starting at 0235 in the morning of the 16th June. The test is not announced and as far as is known no-one other than BBC, ITV and GPO engineers saw it; its purpose was as a final check, both of the satellite and signal monitoring stations around the country. The first publicly announced colour test card is broadcast between 1900 and 2200 on the following day to allow the public to adjust their sets. Simultaneous broadcasts on “old” television shows viewers what to do and what they should expect to see.
Regular colour TV broadcasting in the UK begins on BBC 2 at 7PM on the 18th June, when the BBC’s new "World Circling Satellite” ident is shown for the first time. The BBC has decided to use the part-time BBC 2 channel for the duration of the experimental phase, leaving its regular BBC 1 programming in black and white on the existing ground based transmitters.
After the briefest of introductions, “Good evening and welcome to BBC Satellite Television”, the first programme is an ambitious series of live broadcasts from locations around (and off) the country, including the deck of the liner Queen Elizabeth in the English Channel and from the Orkney Islands, which have never previously received any TV signals. This latter telecast is the first example of a double satellite relay, as the outside broadcast from the Orkneys is sent up to an Intelsat satellite over the Atlantic, back down to one of the big dishes at Goonhilly then up again to Hermes-P for rebroadcast to the nation.
A later programme describing how the system works includes colour footage of the launch of Hermes-P and in a special edition of "The Sky at Night", astronomer Patrick Moore shows viewers how and when to try to spot the satellite in orbit high over the equator.
At 7pm the following evening, ITV colour broadcasting is started with a brief announcement, followed by the first colour advert to be shown on British television (it was for Kellogg's cereals). A live broadcast from Abbey Road studios includes the debut of the Beatles' latest song "All You Need Is Love", which is also transmitted to the US and Europe via the Intelsat network, for relay by those countries' traditional ground based TV systems.
The single transponder on Hermes-P can only broadcast one channel at a time. The BBC and ITV have agreed that during this experimental phase they will each broadcast on alternate days to allow both networks access to colour programming. As it is a single frequency, the public can receive the BBC and ITV programmes without retuning.
However, with only 6 colour TV cameras in the entire country it is not possible to produce everything to the new standard. A simple and very popular approach is tried by the BBC, where controllers decide to concentrate on sports broadcasts, something that can be done easily with just one camera at an event. Centre court matches at the 1967 Wimbledon lawn tennis championships are first to be shown. The first test match in colour (between England and India) is broadcast from Edgbaston in July. Football fans have to wait for the start of the season in August, when Everton meet Manchester United “in glorious colour” on the 19th.
The Hermes-P satellite itself surpasses everyone’s expectations with its reliability. A single thruster failure in August 1968 marginally increases fuel consumption, but the electronics and payload are still operating normally in July 1970 when the satellite’s fuel begins to run low. After the launch of Hermes-2 it has only been used as a backup and for a variety of experiments. The satellite is nudged into a slightly higher orbit in August 1970 and is left to "drift" (i.e. not maintain a constant position over the ground). The transmitter payload ceases to function in February 1971 when the main receiver fails. By April 1972 two of the four generator turbines have failed and it is not considered worth the effort of monitoring the spacecraft any longer.
On 2 May 1972, Hermes-P is commanded to turn its solar reflectors away from the sun. It is then placed in a slow spin to naturally stabilise its attitude before being permanently switched off.
