Project Vanguard facts for kids
Project Vanguard was a program run by the United States Navy's Naval Research Laboratory (NRL). Its main goal was to launch the first American artificial satellite into space. They planned to use a special Vanguard rocket for this mission. The launches took place from Cape Canaveral, Florida.
The Soviet Union launched the first satellite, Sputnik 1, on October 4, 1957. This surprised and worried the United States. To catch up in the "Space Race," the U.S. quickly restarted a program called Explorer. The Army Ballistic Missile Agency (ABMA) and the Jet Propulsion Laboratory (JPL) built Explorer 1. It successfully launched on February 1, 1958. However, before that, the Soviet Union launched a second satellite, Sputnik 2, in November 1957. To make things worse, the first Vanguard rocket, Vanguard TV3, exploded right after launch on December 6, 1957. This was shown on TV and made Americans feel even more disappointed.
Despite these early challenges, Vanguard 1 became the second successful U.S. satellite to reach orbit on March 17, 1958. It was also the first satellite to be powered by solar energy. Vanguard 1 was very small, only about 15.2 centimeters (6 inches) wide and weighing 1.4 kilograms (3 pounds). The Soviet leader, Nikita Khrushchev, even called it "The grapefruit satellite." Vanguard 1 and its upper rocket stage are still in space today, making them the oldest artificial objects orbiting Earth. Earlier satellites like Sputnik 1, Sputnik 2, and Explorer 1 have already fallen out of orbit.
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What Was Project Vanguard?
In the early 1950s, scientists in the U.S. started thinking about launching an Earth satellite. Milton W. Rosen, who worked on the Viking rocket for the Naval Research Laboratory (NRL), wrote a report in 1954. This report talked about how useful an Earth satellite could be. The U.S. decided to try and launch a satellite with a science experiment as part of the International Geophysical Year (1957–1958). This was a worldwide effort to study Earth.
Choosing the Best Rocket Plan
Different branches of the U.S. military offered ideas for launching a satellite.
- The United States Army suggested using a modified Redstone rocket. This rocket was known as Juno I.
- The United States Air Force proposed using the Atlas rocket. But this rocket wasn't ready yet.
- The United States Navy suggested building a new rocket system. It would be based on their existing Viking rocket and Aerobee rocket designs.
The Air Force's plan wasn't chosen because their Atlas rocket was still years away from being ready. The Army's plan focused mostly on the rocket itself. It assumed that the satellite and tracking stations would be handled by others. The Navy's plan, however, covered everything: the rocket, the satellite, and how to track it.
In August 1955, the U.S. Department of Defense picked the Navy's plan. It seemed the most likely to succeed by spring 1958. The Navy's plan promised to:
- Put a satellite into orbit during the International Geophysical Year.
- Carry out a scientific experiment in space.
- Track the satellite to make sure it reached orbit.
Another reason the Navy's plan was chosen was that it used rockets designed for civilian science. Military missiles were seen as less suitable for peaceful scientific exploration. The U.S. government also had a secret spy satellite program. They worried that the Soviets would object to military satellites flying over their country. By launching a clearly "civilian" and "scientific" satellite first, the U.S. hoped to set a rule: space was above national boundaries and open to everyone.
The program was named Project Vanguard. The Naval Research Laboratory (NRL) was in charge. John P. Hagen, an astronomer, led the project. The first Vanguard satellites were small spheres, weighing about 1.4 kilograms (3 pounds). They had seven batteries, two radio transmitters, and six clusters of solar cells on their surface. The very first satellite was called Vanguard TV3.
NRL was also responsible for building the Vanguard rockets. They hired the Martin Company, which had built the Viking rockets. NRL also developed the tracking system called Minitrack. This system had 14 stations along the east coast of North America and the west coast of South America. Minitrack was an early version of today's NAVSPASUR, which still tracks objects in space.
The Space Race Heats Up
The Vanguard team had planned to launch TV3 in September 1957. But there were delays. On October 4, 1957, the team learned that the USSR had launched Sputnik 1. This was a big blow to the Vanguard team. However, their Minitrack system successfully tracked Sputnik, which was a success for NRL.
On December 6, 1957, at 11:44 AM, they tried to launch TV-3. The Vanguard rocket lifted only about 1.2 meters (4 feet) into the air. Then its engine lost power. The rocket fell back onto the launch pad and exploded. The small satellite broke free and landed nearby. Its radio beacon was still beeping! But the satellite was too damaged to be used. It is now in the National Air and Space Museum.
After the Soviet Union launched Sputnik 2 in November 1957, the U.S. Army was told to launch a satellite using their Juno I rocket. On January 31, 1958, the U.S. Army successfully launched the Explorer 1 satellite. With Sputnik 1 and 2 already in orbit, the idea that satellites might not be allowed to fly over other countries became less of a concern. The Soviet rockets were clearly military, and much larger than Vanguard.
On March 17, 1958, the Vanguard program finally had a success. They launched the Vanguard satellite TV-4. It reached a stable orbit, going as high as 3,969 kilometers (2,466 miles) and as low as 650 kilometers (404 miles). Scientists estimated it would stay in orbit for at least 240 years. This satellite was renamed Vanguard I. It, along with its upper rocket stage, is still the oldest human-made satellite in orbit.
In late 1958, Project Vanguard was moved to NASA, the new space agency. The core of the Goddard Space Flight Center was formed from the Vanguard team. After four more failed launches, the program succeeded again with SLV-4, which was renamed Vanguard 2. After two more failures, the program ended with the launch of Vanguard 3 in 1959.
Vanguard's Achievements
Even though Sputnik 1 got more attention, and Vanguard had some embarrassing early failures, the project eventually achieved its scientific goals. It gave scientists a lot of new information. This included details about the Earth's size and shape, the density of air in space, temperature ranges, and how often tiny space rocks (micrometeorites) hit objects.
The radio on Vanguard 1 kept working until 1964. The tracking data from this satellite showed that Earth is not a perfect sphere. It's slightly pear-shaped, a bit wider at the North Pole and flatter at the South Pole. Vanguard also helped correct ideas about the atmosphere's density high above Earth. It also made world maps more accurate.
The Vanguard rocket, called the "Satellite Launch Vehicle" (SLV) for its operational versions, was much smaller and lighter. It was smaller than the Redstone-based Jupiter-C/Juno 1 rocket that launched the Explorer satellites. It was also much smaller than the huge R-7 rocket the Soviets used for the early Sputniks.
Project Vanguard introduced many new technologies that are still used in U.S. satellite programs today. For example, it proved that solar cells could power radio transmitters for many years. Vanguard's solar cells worked for about seven years. In comparison, regular batteries on another transmitter only lasted 20 days.
Even though Vanguard's solar-powered radio stopped working in 1964, it still helps scientists. Tracking the silent Vanguard satellites from the ground helps us learn about how the Sun, Moon, and Atmosphere of Earth affect satellite orbits. Vanguard 1 celebrated its 50th year in space on March 17, 2008. Since its launch, this tiny satellite has orbited Earth more than 196,990 times. It has traveled about 5.7 billion nautical miles (10.6 billion kilometers). That's like going from Earth past the dwarf planet Pluto and halfway back! Scientists first thought it would orbit for 2,000 years. But they later found that pressure from solar radiation and drag from the atmosphere changed its orbit. This reduced its expected lifetime to about 240 years.
Vanguard Launch History
The first Vanguard flight was a successful test of a single-stage rocket. It launched on December 8, 1956. On May 1, 1957, a two-stage test rocket called TV1 was successfully launched. Vanguard TV2, another successful test, launched on October 23, 1957.
The Vanguard rocket launched three satellites out of eleven attempts:
- Vanguard TV3 - December 6, 1957 - Failed to orbit a 1.36 kg (3 lb) satellite. The engine cut off after 2 seconds due to low fuel tank pressure.
- Vanguard TV3 Backup - February 5, 1958 - Failed to orbit a 1.36 kg (3 lb) satellite. The rocket broke apart after 55 seconds due to a control problem.
- Vanguard 1 - March 17, 1958 - Successfully orbited a 1.47 kg (3.2 lb) satellite.
- Vanguard TV5 - April 28, 1958 - Failed to orbit a 9.98 kg (22 lb) satellite. The third stage failed to separate.
- Vanguard SLV-1 - May 27, 1958 - Failed to orbit a 9.98 kg (22 lb) satellite. The second stage had a problem with its attitude control.
- Vanguard SLV 2 - June 26, 1958 - Failed to orbit a 9.98 kg (22 lb) satellite. The second stage lost power after only 8 seconds because of a blocked fuel line.
- Vanguard SLV 3 - September 28, 1958 - Failed to orbit a 9.98 kg (22 lb) satellite. The second stage didn't have enough power to reach orbit due to a blocked fuel line.
- Vanguard 2 - February 17, 1959 - Successfully orbited a 10.8 kg (23.8 lb) satellite.
- Vanguard SLV 5 - April 13, 1959 - Failed to orbit a 10.3 kg (22.7 lb) satellite. The second stage lost control due to a hydraulics failure.
- Vanguard SLV 6 - June 22, 1959 - Failed to orbit a 10.3 kg (22.7 lb) satellite. The second stage exploded because a helium vent valve got stuck.
- Vanguard 3 - September 18, 1959 - Successfully orbited a 22.7 kg (50 lb) satellite.
