Vanguard TV-3, also called Vanguard Test Vehicle-Three, was the first attempt of the United States to launch a satellite into orbit around the Earth, after the successful Soviet launches of Sputnik 1 and Sputnik 2.
Vanguard TV-3 was a small satellite designed to test the launch capabilities of the three-stage Vanguard and study the effects of the environment on a satellite and its systems in Earth orbit. It was also to be used to obtain geodetic measurements through orbit analysis. Solar cells on Vanguard TV-3 were manufactured by Bell Laboratories.
At its launch attempt on 6 December 1957, at Cape Canaveral Air Force Station, the booster ignited and began to rise, but about two seconds after liftoff, after rising about 1.2 m, the rocket lost thrust and fell back to the launch pad. As it settled the fuel tanks ruptured and exploded, destroying the rocket and severely damaging the launch pad.
The Vanguard 1A satellite was thrown clear and landed on the ground a short distance away with its transmitters still sending out a beacon signal. The satellite was damaged, however, and could not be reused. It is now on display at the National Air and Space Museum of the Smithsonian Institution.
The exact cause of the accident was not determined with certainty, but it appeared that the fuel system malfunctioned. Other engines of the same model were modified and did not fail.
More information: NASA
The history of the Vanguard TV-3 project dates back to the International Geophysical Year (IGY). This was an enthusiastic international undertaking that united scientists globally to conduct planet-wide geophysical studies. The IGY guaranteed free exchange of information acquired through scientific observation which led to many important discoveries in the future.
Orbiting a satellite became one of the main goals of the IGY. As early as July 1955, President Dwight D. Eisenhower announced, through his press secretary, that the United States would launch small, unmanned, earth-circling satellites as part of the U.S. participation in the I.G.Y.
On 9 September 1955, the United States Department of Defense wrote a letter to the secretary of the Navy authorizing the mission to proceed. The US Navy had been assigned the task of launching Vanguard satellites as part of the program. Project Vanguard had officially begun.
The payload of the TV-3 was very
similar to the later Vanguard 1. It was a small aluminium sphere, 16.3
cm in diameter and with a mass of 1.5 kg. It carried two transmitters: a
10-mW, 108-MHz transmitter powered by a mercury battery, and a 5-mW,
108.03-MHz transmitter powered by six solar cells mounted on the body of
the spacecraft.
Using six small aerial antennae mounted on its body, the satellite primarily transmitted engineering and telemetry data, but the transmitters were also used to determine the total electron content between the satellite and the ground stations.
Other instruments in the satellite's design included two thermistors, which were used to measure the satellite's internal temperatures for the purpose of tracking its thermal protection's effectiveness.
Although the satellite was damaged beyond reuse capability during the crash, it was still transmitting after the incident.
The Vanguard TV-3 utilized a three-stage launch vehicle known as the Vanguard designed to send the satellite into orbit around the Earth. The fins were removed from the rocket as a way to reduce the drag and instead, the launch motor was mounted in gimbals which allowed it to pivot and direct its thrust for steering. The second and third stages of the rocket were also gimballed.
As designed, the first stage would cause the rocket to rise under the thrust of burning liquid oxygen, ethanol, gasoline and silicone oil which would propel the vehicle to a velocity of 6,400 km/h, lifting the satellite through the denser layers of the atmosphere in 130 seconds. Next, the second stage would burn its fuel, carrying it away from stage one motor and tanks.
More information: Smithsonian National Air and Space Museum
The satellite would rise to an altitude of 480 kilometres above the earth. The flight path had been programmed to tilt from a vertical into a more horizontal course. Then, the third stage would take over to provide spin and the final boost, shoving stage three into orbit at 29,400 km/h.
The satellite would slowly disengage from the third-stage rocket, where at this speed it would fall toward Earth at the same rate the earth's surface curves away from it. As a result, the satellite's distance from the earth would remain about the same.
At launch on 6 December 1957 at 16:44:34 GMT at the Atlantic Missile Range in Cape Canaveral, Florida, the booster ignited and began to rise but about 2 seconds after liftoff, after rising about a meter, the rocket lost thrust and began to settle back down to the launch pad.
As it settled against the launch pad the fuel tanks ruptured and exploded, destroying the rocket and severely damaging the launch pad.
The Vanguard satellite was thrown clear and landed on the ground a short distance away with its transmitters still sending out a beacon signal. The satellite was damaged, however, and could not be reused. It is now on display at the Smithsonian Air and Space Museum.
More information: NASA
All of us know today the value of communications satellites,
weather satellites, resources satellites...
Rusty Schweickart
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