Vanguard (rocket)

The Vanguard rocket was intended to be the first launch vehicle the United States would use to place a satellite into orbit. Instead, the Sputnik crisis caused by the surprise launch of Sputnik 1 led the U.S., after the failure of Vanguard TV3, to quickly orbit the Explorer 1 satellite using a Juno I rocket, making Vanguard I the second successful U.S. orbital launch.

Vanguard rockets were used by Project Vanguard from 1957 to 1959. Of the eleven Vanguard rockets which the project attempted to launch, three successfully placed satellites into orbit.

Overview
In 1955, the USA announced plans to put a scientific satellite in orbit for the International Geophysical Year (IGY) in 1957-1958. The goal was to track the satellite as it performed experiments. At that time there were three candidates for the launch vehicle: The Air Force's SM-65 Atlas, a derivative of the Army Ballistic Missile Agency's SSM-A-14 Redstone, and a Navy proposal for a three-stage rocket based on the RTV-N-12a Viking sounding rocket.

The Army's Redstone-based proposal would likely be first ready for a first satellite launch. Its connection with German-born scientist Wernher von Braun, however, was a public relations risk. In any case, the Atlas and Redstone ballistic missiles were top-priority military projects, which were not to be slowed by pursuing a secondary space launch mission. Vanguard was a project of the Naval Research Laboratory (NRL), which was regarded more as a scientific than a military organization. This helped to emphasize the non-military goals of the satellite program. This was considered important, because a discussion of whether overflights of foreign countries by satellites were legal or illegal was to be avoided.

In August or September 1955, the DOD Committee on Special Capabilities chose the NRL proposal, named Vanguard, for the IGY project. The Martin company, which had also built the Viking, became prime contractor for the launch vehicle. The Vanguard rocket was designed as a three-stage vehicle. The first stage was a General Electric X-405 liquid-fueled engine (designated XLR50-GE-2 by the Navy), derived from the engine of the RTV-N-12a Viking. The second stage was the Aerojet General AJ10-37 (XLR52-AJ-2) liquid-fueled engine, a variant of the engine in the RTV-N-10 Aerobee. Finally, the third stage was a solid-propellant rocket motor. All three-stage Vanguard flights except the last one used a motor built by the Grand Central Rocket Company. Vanguard had no fins, and the first and second stages were steered by gimbaled engines. The second stage also housed the vehicle's telemetry system, the inertial guidance system and the autopilot. The third stage was spin stabilized, the spin being imparted by a turn-table on the second stage before separation.

Launch summary
The first two flights of the Vanguard program, designated Test Vehicle (TV)-0 and -1, were actually the last two remaining RTV-N-12a Viking rockets. TV-0, launched on December 8, 1956, primarily tested new telemetry systems, while TV-1 on May 1, 1957 was a two-stage vehicle testing separation and ignition of the solid-fueled upper stage of Vanguard. TV-2, launched on October 23, 1957 after several abortive attempts, was the first real Vanguard rocket. The second and third stages were inert, but the flight successfully tested first/second-stage separation and spin-up of the third stage. However, by that time, the Soviet Union had already placed the "Sputnik" satellite into orbit, and therefore project Vanguard was more or less forced to launch its own satellite as soon as possible. Therefore, a very small experimental satellite (called the "grapefruit" and weighing only 1.8 kg (4 lb)) was added to TV-3, which was to be the first test of an all-up Vanguard rocket. Although the NRL and Martin tried to emphasize that the TV-3 mission was a pure test flight (and one with several "firsts"), everyone else saw it as the first satellite launch of the Western world. Wernher von Braun angrily said about the Sputnik launch: "We knew they were going to do it. Vanguard will never make it. We have the hardware on the shelf. We can put up a satellite in 60 days".

On 6 December the US Navy launched a Vanguard rocket, carrying a 1.3 kg (2.9 lbs) satellite, from Cape Canaveral. It only reached an altitude of 1.2 meters (4 ft), fell and exploded. The satellite was blasted off the top of the rocket where it landed in bushes near the pad and began transmitting signals, leading to New York Journal-American columnist Dorothy Kilgallen remarking "Why doesn't somebody go out there, find it, and shoot it?" The American press called it Kaputnik.

Flight TV-3BU (BU = Backup) on February 5, 1958 broke up after 57 seconds because of a control system malfunction, but TV-4 on March 17, 1958 finally succeeded in placing a "Grapefruit"-type satellite into orbit. By that time, however, the Army's Juno (Jupiter-C) had already launched the United States' first satellite. The TV-4 satellite, labeled Vanguard 1, reached a relatively high orbit (3966 km (2465 miles) x 653 km) and is currently the oldest human artifact in space. The following four flights, TV-5 and SLV (Satellite Launch Vehicle)-1 through -3 all failed, but on February 17, 1959, SLV-4 launched Vanguard 2 (weighing 10.8 kg (23.7 lb)) into orbit. The SLVs were the "production" Vanguard rockets. SLV-5 and -6 also failed, but the final flight on September 18, 1959 successfully orbited the 23.6 kg (52 lb) Vanguard 3 satellite. That last mission was designated TV-4BU, because it used a remaining test vehicle, which had been upgraded with a new third stage, the Allegheny Ballistics Lab X-248A2 Altair. This more powerful motor enabled the launch of the heavier payload. The combination of the AJ10 liquid engine and X-248 solid motor was also used, under the name Able, as an upper stage combination for Thor and Atlas space launch vehicles.

Launches
Vanguard launched 3 satellites out of 11 launch attempts:
 * Vanguard TV3 - December 6, 1957 - Failed to orbit 1.36 kg (3 lb) satellite
 * Vanguard TV3 Backup - February 5, 1958 - Failed to orbit 1.36 kg (3 lb) satellite
 * Vanguard 1 - March 17, 1958 - Orbited 1.47 kg (3.25 lb) satellite
 * Vanguard TV5 - April 28, 1958 - Failed to orbit 10.0 kg (22 lb) satellite
 * Vanguard SLV 1 - May 27, 1958 - Failed to orbit 10.0 kg (22 lb) satellite
 * Vanguard SLV 2 - June 26, 1958 - Failed to orbit 10.0 kg (22 lb) satellite
 * Vanguard SLV 3 - September 26, 1958 - Failed to orbit 10.0 kg (22 lb) satellite
 * Vanguard 2 - February 17, 1959 - Orbited 9.8 kg (21.6 lb) satellite
 * Vanguard SLV 5 - April 13, 1959 - Failed to orbit 10.3 kg (22.7 lb) satellite
 * Vanguard SLV 6 - June 22, 1959 - Failed to orbit 10.3 kg (22.7 lb) satellite
 * Vanguard 3 - September 18, 1959 - Orbited 22.7 kg (50 lb) satellite

Specifications

 * Stage Number: 1 - Vanguard
 * Mass: 7,661 kg
 * Empty Mass: 811 kg
 * Thrust (vac): 134.7 kN
 * Isp: 270 s (2.6 kN·s/kg)
 * Burn time: 145 s
 * Isp (sea level): 248 s (2.4 kN·s/kg)
 * Diameter: 1.14 m
 * Length: 12.20 m
 * Propellants: Lox/Kerosene
 * Engines: General Electric X-405


 * Stage Number: 2 - Delta A
 * Mass: 2,164 kg
 * Empty Mass: 694 kg
 * Thrust (vac): 33.8 kN
 * Isp: 271 s (2.7 kN·s/kg)
 * Burn time: 115 s
 * Diameter: 0.84 m
 * Length: 5.36 m
 * Propellants: Nitric acid/UDMH
 * Engines: Aerojet AJ10-37
 * Stage Number: 3 - Vanguard 3
 * Mass: 210 kg
 * Empty Mass: 31 kg
 * Thrust (vac): 11.6 kN
 * Isp: 230 s (2.3 kN·s/kg)
 * Burn time: 31 s
 * Isp (sea level): 210 s (2.1 kN·s/kg)
 * Diameter: 0.50 m
 * Length: 2.00 m
 * Propellants: Solid
 * Engines: Grand Central 33KS2800