We, as humanity, have a tendency for remembering firsts. When something is done for the first time, or when someone comes first in something, the event or person enjoys greater recall value. The same, however, doesn’t apply when the feat is repeated, even when it is just the second time.
Most of us will surely know who the first person to set foot on the moon was, but maybe not the second (Neil Armstrong and Edwin Aldrin are the first and second, respectively, in case you wanted to know). Why, even when it comes to events at school, chances are that you will remember who came first in a given year – be it in academics or sports – much later, than who came second.
The same applies to the communications satellites Telstar 1 and Telstar 2. The Telstar mission was an international collaboration among AT&T, Bell Telephone Laboratories, NASA, the British General Post Office, and the French National Post, Telegram, and Telegraph Office. Mainly developed by Bell Labs for AT&T, the onboard equipment was powered by a solar array and had a battery back-up system.
Telstar 1’s many firsts
Launched on July 10, 1962, Telstar 1 is still remembered as the world’s first active communications satellite. It was the first commercial payload in space, it relayed the world’s first transatlantic television signal and was behind the first-ever live broadcast.
Telstar 1, however, remained operational only until November the same year. The effects of radiation meant that it suffered an on-board electronics failure, putting an end to its usability, though it still remains in orbit.
Radiation resistance
Essentially identical to the Telstar 1 satellite, Telstar 2 weighed 79 kg and had some upgrades when compared to its predecessor. Telstar 1’s failure owing to radiation exposure prompted the makers to give it a significant design change. The command decoders were therefore fitted with radiation-resistant transistors.
It also differed from Telstar 1 in that it employed provisions for scientific information to be transmitted in real time. This was done through the microwave telemetry system and as a result of this, telemetry could be obtained even after the two-year timer had turned off the VHF beacon.
50 years ago
Carrying experiments designed to measure the energetic proton and electron distribution in the Van Allen belts (a zone of energetic charged particles) in addition to carrying telephone channels and one television channel, Telstar 2 was launched by the U.S. on behalf of AT&T on May 7, 1963. While the initial spin rate of the spacecraft was 180 rpm, it varied slowly through the life of the spacecraft.
The apogee – the point at which the satellite is farthest from Earth – of Telstar 2 (10,800 km) was higher than that of Telstar 1. This allowed the satellite to have an increased time in view of the ground stations, while at the same time decreasing the time in the Van Allen belts.
Telstar 2 operated successfully for two years and even had a first of its own when it transmitted the first transatlantic TV programme seen in colour during its 10th orbit. On May 16, 1965, during its 4736th orbit, the VHF transmitter was turned off.
Just like Telstar 1, Telstar 2 too remains in orbit even though it is no longer functional. Unlike Telstar 1, however, Telstar 2 does not enjoy the same fame, even though it remained operational for longer and had successes of its own.
- Telstar 1 was the world’s first transatlantic television signal and was behind the first-ever live broadcast.
- Telstar 1’s failure owing to radiation exposure prompted the makers to give it a significant design change to Telstar 2.
- Telstar 2 operated successfully for two years and even had a first of its own when it transmitted the first transatlantic TV programme seen in colour during its 10th orbit.
Published - May 07, 2023 12:12 am IST