Project Vanguard

By Gregory P. Kennedy

On March 17, 1958, the Navy Vanguard rocket successfully orbited the second American satellite. Named Vanguard-1, the satellite comprised a 6.5-inch diameter ball weighing a mere 3.25 pounds. In many ways, Project Vanguard pushed the development of American rocket technology to its limits and the program was fraught by many problems throughout its lifespan.

Beginnings of the Vanguard program can be traced to the Viking and Aerobee research rockets, both of which were developed by the Naval Research Laboratory (NRL) in the late 1940s. There were two versions of Viking rockets. The initial series of seven rockets were 32 inches in diameter. Originally built to carry a 50-pound payload to 100 miles, by the time Viking 7 flew, engine improvements allowed it to reach 136 miles. In an effort to improve upon this, Viking's diameter was increased to 45 inches so it could carry more propellants and reach altitudes of 150 miles. Both versions consumed alcohol and liquid oxygen and used the same engine; the XLR10-RM-2. Built by Reaction Motors, Incorporated of New Jersey, the XLR10-RM-2 produced a thrust of 20,750 pounds.

The Aerobee was a much smaller rocket, with a capability of launching a 150-pound payload to 300,000 feet. It was a two-stage rocket with a liquid-propellant second stage initially boosted by a solid-fuel first stage. The second stage burned Inhibited Red Fuming Nitric Acid (IRFA) and Aniline. These propellants can be stored at room temperature and ignite spontaneously on contact with one another. Such propellant combinations are called hypergolic propellants.

Initial Vanguard studies looked at using a 45-inch diameter Viking for a first stage; an Aerobee for the second stage; and a solid-fuel third stage that provided the final "kick" to put a small satellite in orbit. On July 28, 1955, White House Press Secretary James C. Hagerty announced the United States would launch a satellite during the upcoming International Geophysical Year (IGY.) The IGY was set for July 1, 1957 - December 31, 1958. Both the Army and Navy submitted satellite proposals.

The Army's proposal, called "Project Orbiter," used a Redstone tactical ballistic missile for a first stage topped with three solid-fuel upper stages. (For more information about Orbiter and the Army proposal, see the "Explorer 1" article on this web site.) The Navy submitted Vanguard. President Eisenhower did not wish to use a converted military missile to launch the first American satellite, so he opted for Vanguard. At the time, Eisenhower wanted to establish a precedent to allow satellites to overfly other nations without diplomatic protests, particularly from the Soviet Union. Establishing such a precedent was critical to America's long-range defense plans because ultimately reconnaissance satellites would be the only way to peer behind the Iron Curtain. The President felt using a rocket with no weapon connection to launch a scientific satellite would be less provocative to the Soviets and would establish the precedent he needed. The White House and the National Academy of Sciences also wanted to avoid charges that the United States was using the IGY to further military research.

The Glen L. Martin Company in Baltimore, Maryland, received the contract to build the Vanguard rocket. Martin also built Viking. As the design progressed, the Martin engineers realized the XLR10-RM-2 was not powerful enough, so they switched to the General Electric X-405 engine, which generated a 27,000-pound thrust. The X-405 burned kerosene and liquid oxygen. Vanguard's first stage was 45 inches in diameter, just like the second Viking series. Similarly, the Aerobee did not have the necessary performance for the second stage. Vanguard's second stage was built upon Aerobee technology - it burned a hypergolic combination of white inhibited fuming nitric acid (IWFNA) and unsymmetrical dimethylhydrazine (UDMH.) Like Aerobee, these propellants were pressure-fed to the combustion chamber. Aerojet, the California-based company that built Aerobee, also built Vanguard's second stage. The third stage, which was built by the Grand Central Rocket Company, looked like the easiest section, but it wasn't. Designers had a difficult time finding the right propellant combination that gave the desired thrust, burn time, and overall performance. Overall, the Vanguard rocket barely had enough power to reach orbit, which drove a need to miniaturize components and minimize structural weights.

Martin proposed two phases to the project, an initial series of five test vehicles followed by six operational launch vehicles. All launchings were to be from Cape Canaveral, Florida. (The earlier Viking launches took place at White Sands Proving Ground in New Mexico.) The first flight, TV-0, was actually a Viking that was launched on December 8, 1956. TV-0 tested the range instrumentation system and provided valuable experience for the Florida-based launch crew. Vanguard TV-1 was a two-stage rocket. It comprised a Viking with a solid-fuel upper stage. This stage was the prototype for what would become the Vanguard solid-fuel third stage. Vanguard TV-2 was the first launch of an actual Vanguard first stage with dummy upper stages. This flight proved so successful that another flight with the back up rocket (TV-2BU) was deemed unnecessary. (The TV-2BU was eventually donated to the Smithsonian Institution, where it is on display in the National Air and Space Museum.) Original plans called for another suborbital test mission, TV-3, followed by the first attempt to launch a minimal satellite with Vanguard TV-4.

The Soviets also announced satellite plans for IGY and even published the frequencies their spacecraft would use. Western experts dismissed the Soviet proclamation because they thought the Russians did not have the technology to perform such a feat. On October 4, 1957, the Soviets proved the Western experts wrong with the launch of Sputnik 1. A month later, they followed up with Sputnik 2. Suddenly there was a great deal of pressure on the Vanguard team to hurry up and launch a satellite in response to the Soviet successes. Although it was intended as a booster development flight, TV-3 became the first American attempt to launch a satellite into orbit, thanks to a statement issued to the press by the White House.

One of the biggest differences between the American and Soviet space programs was the former's openness. Soviet officials only announced their Sputniks once the satellites were in orbit. The American program, by comparison, was conducted openly, in full view for all to see. On December 6, 1957, the world's media focused on the launch of Vanguard TV-3 at Cape Canaveral. TV-3 carried a minimal satellite; a small sphere with a radio beacon. Solar cells and batteries powered the transmitter. To track the satellite, the NRL developed a series of 14 tracking stations around the world to receive signals from Vanguard. These receiving stations were known as the Minitrack system. Minitrack had been another factor affecting the President's decision to select Vanguard over Orbiter. The Army proposal did not present any plans for tracking their satellite, while Vanguard presented an entire system of booster, launch facilities, and tracking stations.

Live television carried the final minutes of the countdown. When the count reached zero, the X-405 engine ignited and Vanguard began its slow climb towards space - for two seconds. When it was barely four feet off the ground, TV-3's engine faltered. It settled back on the pad and collapsed in a massive fireball. A few days later, cleanup crews found the battered and burned satellite among the debris. "Most humiliating," was how Senator Lyndon B. Johnson of Texas described the failure.

Dec. 6, 1957. The U.S. Navy test of a Vanguard rocket, along with its satellite payload, ends in disaster as the first stage of the rocket fails.
Photo: U.S. Navy

Whether they realized it or not, the Soviets gave President Eisenhower the precedent he wanted for having spacecraft overfly international borders, so the issue of not using a military missile for the first satellite became moot. Following the second Sputnik, the United States Army received permission to launch their satellite. (President Eisenhower actually issued the order a few days after Sputnik 1, but it took nearly a month to find its way through bureaucratic channels.) With American prestige on the line, attention shifted to the Army and their upcoming launch of a Jupiter C rocket bearing the Explorer 1 satellite. The Jupiter C was based on Project Orbiter. On January 31, 1958, the Army fired the first American satellite into orbit with the Jupiter C.

This was a good thing for the fledgling American space program because it deflected some of the attention away from Vanguard, which continued to have difficulties. The second orbital launch attempt, on February 5, 1958, with the TV-3 backup rocket (TV-3BU) also failed to reach orbit. This time the control system failed when the rocket was about 1,500 feet up.

Undaunted by two successive failures, the Martin Company and NRL prepared the TV-4 rocket for flight. On March 17, 1958, TV-4 successfully orbited the second American satellite, Vanguard 1. The 3.25-pound satellite had two radio transmitters, one powered by batteries and the other powered by solar cells. The battery-powered transmitter broadcast for 29 days while the one powered by solar cells worked for several years. This was the first time solar cells were used to power a satellite. Although Vanguard 1 did not carry any scientific instruments, careful analysis of the satellite's orbit let scientists measure the Earth's true shape and areas of mass concentrations. Among other things, they found the Earth is slightly pear-shaped. There was a backup rocket for TV-4; it was shipped back to Glen L. Martin in Baltimore for modification to Vanguard Space Launch Vehicle (SLV) standards.

The next rocket, TV-5, was the first to carry an "operational" Vanguard satellite. These were 20 inches in diameter and carried scientific instruments. It failed. Three more failures followed until booster SLV-4 orbited Vanguard 2 on February 17, 1959. Vanguard 2 was the first successful "operational" mission in the program. The 20-inch diameter satellite weighed 21 pounds. It carried photocells that measured the Earth's albedo or sunlight reflected by the surface or cloud layers. Vanguard 2 wobbled in its orbit and scientists had a hard time interpreting the data, but once they did, they managed to create a map of the Earth's cloud cover. Because of this, Vanguard 2 may be regarded as the first meteorological satellite.

Two more failures followed, owing to malfunctions in the second stage. Boosted by the refurbished TV-4BU, Vanguard 3 reached orbit on September 18, 1959. Like its predecessor, Vanguard 3 was based on a 20-inch diameter sphere. This spacecraft, however, contained a magnetometer mounted on the end of a conical housing attached to the top of the satellite. Other instruments on Vanguard 3 comprised a solar X-ray detector and four different types of micrometeoroid detectors. Micrometeoroid risks worried early spacecraft designers and they needed to collect data on the frequency of hits and the size of particles encountered by an object in space.

The first detector was a microphone that turned impact vibrations into electrical pulses. The second micrometeoroid detector consisted of an opaque shield over an optical cell. As micrometeoroids punctured the shield, more light reached the cell, varying the signal it generated. By measuring the signal from the photocell, scientists could determine the size and number of holes punched in the shield. The third detector used pressure filled cells of varying thickness. As micrometeoroids punctured the cells, the scientists could determine their relative energies by noting which cells were punctured. The final detector package comprised a foil strip whose electrical resistance increased when it was punctured by micrometeoroids. Overall, scientists found punctures were more prevalent than expected.

With its suite of instruments, the third Vanguard satellite weighed 53 pounds. Vanguard 3 broadcast data for 84 days. This concluded the Vanguard program on a successful note.

When the National Aeronautics and Space Administration came into being in October 1958, two hundred members of the NRL Vanguard team went to the new civilian agency. They formed the nucleus of what became the Goddard Space Flight Center in Greenbelt, Maryland. After Vanguard, the Goddard Space Flight Center became NASA's lead center for space science research. Although it has long been silent, Vanguard 1 continues to orbit the Earth, making it the oldest manmade object in space. Estimates are that it will remain in orbit for 2,000 years! Who knows, perhaps someday a space crew will retrieve the little satellite and bring it back to Earth for exhibition as an example of the earliest days of the space program.

Vanguard Launch SummaryVehicle Launch Date Results
TV-0 December 8, 1956 "Viking 13" rocket test launch
TV-1 May 1, 1957 "Viking 14" with second stage
TV-2 October 23, 1957 First launch of Vanguard first stage
TV-3 December 6, 1957 Failed; first stage failure
TV-3BU February 5, 1958 Failed; control system malfunction
TV-4 March 17, 1958 Orbited Vanguard 1
TV-5 April 28, 1958 Failed; third stage malfunction
SLV-1 May 27, 1958 Failed; improper third stage trajectory
SLV-2 June 26, 1958 Failed; second stage cut off early
SLV-3 September 26, 1958 Failed; second stage thrust too low
SLV-4 February 17, 1959 Orbited Vanguard 2
SLV-5 April 13. 1959 Failed; second stage damaged
SLV-6 June 22, 1959 Failed; second stage malfunction
TV-4BU September 18, 1959 Orbited Vanguard 3