 Vanguard rocket on Pad LC-18A | |
| Function | Satellitelaunch vehicle |
|---|---|
| Manufacturer | Glenn L. Martin Company |
| Country of origin | United States |
| Size | |
| Height | 21.9 meters (72 ft) |
| Diameter | 1.14 meters (3 ft 9 in) |
| Mass | 10,050 kilograms (22,160 lb) |
| Stages | 3 |
| Capacity | |
| Payload toLEO | |
| Mass | 11.3 kg (25 lb) |
| Launch history | |
| Status | Retired |
| Launch sites | Cape Canaveral,LC-18A |
| Total launches | 11 |
| Success(es) | 3 |
| Failure | 8 |
| First flight | 23 October 1957 (Vanguard 1: 17 March 1958) |
| Last flight | 18 September 1959 |
| First stage – Vanguard | |
| Height | 13.4 m (44 ft) |
| Diameter | 1.14 m (3 ft 9 in) |
| Empty mass | 811 kg (1,788 lb) |
| Gross mass | 8,090 kg (17,840 lb) |
| Powered by | 1General Electric GE X-405 |
| Maximum thrust | 125,000 N (28,000 lbf) |
| Specific impulse | 248 s (2.43 km/s) |
| Burn time | 144 seconds |
| Propellant | LOX /Kerosene (RP-1) |
| Second stage –Delta | |
| Height | 5.8 m (19 ft) |
| Diameter | 0.8 m (2 ft 7 in) |
| Empty mass | 694 kg (1,530 lb) |
| Gross mass | 1,990 kg (4,390 lb) |
| Powered by | 1Aerojet GeneralAJ10-37 |
| Maximum thrust | 32,600 N (7,300 lbf) |
| Specific impulse | 261 s (2.56 km/s) |
| Burn time | 120 seconds |
| Propellant | UDMH /Nitric acid (IWFNA) |
| Third stage –Grand Central Rocket Company | |
| Height | 1.5 m (4 ft 11 in) |
| Diameter | 0.8 m (2 ft 7 in) |
| Empty mass | 31 kg (68 lb) |
| Gross mass | 194 kg (428 lb) |
| Powered by | 1 33KS2800 |
| Maximum thrust | 10,400 N (2,300 lbf) |
| Specific impulse | 238 s (2.33 km/s)[1]: 151 |
| Burn time | 33 seconds[1]: 151 |
| Propellant | Polysulfide/AP (APCP) |
| Third stage (SLV-7) –Allegany Ballistics Laboratory | |
| Height | 1.5 m (4 ft 11 in) |
| Diameter | 0.8 m (2 ft 7 in) |
| Empty mass | 23 kg (51 lb)[1]: 151 |
| Gross mass | 229 kg (505 lb)[1]: 151 |
| Powered by | 1X248 |
| Maximum thrust | 10,400 N (2,300 lbf) |
| Specific impulse | 251 s (2.46 km/s)[1]: 151 |
| Burn time | 38 seconds[1]: 151 |
| Propellant | Soliddouble base propellant |
TheVanguard rocket[1] was intended to be the firstlaunch vehicle the United States would use to place asatellite into orbit. Instead, theSputnik crisis caused by the surprise launch ofSputnik 1 led the U.S., after the failure ofVanguard TV-3, to quickly orbit theExplorer 1 satellite using aJuno I rocket, makingVanguard 1 the second successful U.S. orbital launch.
Vanguard rockets were used byProject Vanguard from 1957 to 1959. Of the eleven Vanguard rockets which the project attempted to launch, three successfully placed satellites into orbit. Vanguard rockets were an important part of theSpace Race between the United States and theSoviet Union.
In 1955, the United States announced plans to put a scientific satellite in orbit for theInternational Geophysical Year (IGY) in 1957–1958. The goal was to track the satellite as it performed experiments.[2] At that time, there were three candidates for the launch vehicle: The Air Force'sSM-65 Atlas, a derivative of theArmy Ballistic Missile Agency'sSSM-A-14 Redstone, and a Navy proposal for a three-stage rocket based on theRTV-N-12a Viking sounding rocket.[3][4]
TheRAND Corporation,Air Force andCIA had long pursued the idea of areconnaissance satellite.[5] Such a program was under way, Weapon System 117L, which was top secret compartmented.[6] One problem with reconnaissance was the question of legality: Was there "freedom of space" or did a nation's airspace end when space is entered?[2] TheNational Security Council backed the IGY satellite because it would make good cover for WS117L and set a precedent of freedom of space peaceful civilian satellite. At the same time the NSC stressed that the IGY satellite must not interfere with military programs.[7] TheArmy'sRedstone-based proposal would likely be the first one ready for a satellite launch. Its connection with German-born scientistWernher von Braun, however, was a public-relations risk.[8][4] In any case, theAtlas andRedstone ballistic missiles were top-priority military projects, which were not to be hindered by pursuing a secondary space launch mission.[9]Milton Rosen's Vanguard was a project at theNaval Research Laboratory (NRL), which was regarded more as a scientific than a military organization. Rosen and Richard Porter (IGY satellite chief and head of theAmerican Rocket Society) both lobbied for the Vanguard and against using the Atlas or von Braun's rockets.[10] They emphasized the non-military goals of the satellite program. Besides the public-relations aspect, a non-military satellite was considered important, because a discussion of whether overflights of foreign countries by satellites were legal or illegal was to be avoided.[11]
In August or September 1955, theDOD 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.[12] The Vanguard rocket was designed as a three-stage vehicle. The first stage was aGeneral ElectricX-405 liquid-fueled engine (designated XLR50-GE-2 by the Navy), derived from the engine of theRTV-N-12a Viking. The second stage was theAerojet GeneralAJ10-37 (XLR52-AJ-2) liquid-fueled engine, a variant of the engine in the RTV-N-10Aerobee. Finally, the third stage was a solid-propellant rocket motor. All three-stage Vanguard flights except the last one used a motor built by theGrand Central Rocket Company. Vanguard had no fins, and the first and second stages were steered bygimbaled engines. The second stage housed the vehicle's telemetry system, the inertial guidance system and the autopilot. The third stage wasspin-stabilized, with the spin imparted by a turntable on the second stage before separation.
The Vanguard's second stage served for decades as the Able and Delta second stage for satellite launch vehicles.[13] TheAJ10 engine which made up those stages was adapted into theAJ10-137, which was used as theApollo Service Module engine. TheAJ10-190, adapted from theApollo spacecraft was used on theSpace Shuttle for orbital maneuvers.[14] As of 2025[update] an AJ10 is used on eachEuropean Service Module for NASA'sOrion spacecraft.
The first two flights of the Vanguard program, designatedVanguard TV-0 andVanguard TV-1, were actually the last two remaining RTV-N-12aViking rockets modified. Vanguard TV-0, launched on 8 December 1956, primarily tested new telemetry systems, while Vanguard TV-1 on 1 May 1957, was a two-stage vehicle testing separation and ignition of the solid-fueled upper stage of Vanguard.Vanguard TV-2, launched on 23 October 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 theSputnik 1 satellite into orbit, and so project Vanguard was more or less forced to launch its own satellite as soon as possible. Therefore, a very small experimental satellite (derisively called the "grapefruit" byNikita Khrushchev, and weighing only 1.5 kilograms (3.3 lb)) was added toVanguard TV-3, which was to be the first test of an all-up Vanguard rocket. Although theNRL andGlenn L. Martin Company tried to emphasize that the Vanguard 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, billed as "America's answer to Sputnik".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".[15]
On 6 December 1957, theUS Navy launchedVanguard TV-3 rocket, carrying a 1.5-kilogram (3.3 lb) satellite, fromCape Canaveral. It only reached an altitude of 1.2 meters (3.9 ft) before it fell and exploded. The satellite was thrown clear from the top of the rocket, landed in bushes near the pad, and began transmitting signals, leadingNew York Journal-American columnistDorothy Kilgallen to remark "Why doesn't somebody go out there, find it, and shoot it?"[16] The American press called itKaputnik.[17]
Investigation into the accident concluded that inadequate fuel tank pressure had allowed hot exhaust gases to back up into the injector head and destroy it, causing complete loss of engine thrust. After the failure of Vanguard TV-3, the backup vehicle,Vanguard TV-3BU ("BU" for backup), was prepared for another attempt. Pad crews hastened to repair the damage done toLC-18A by Vanguard TV-3's explosion, and in the third week of January 1958, the job was completed. Vanguard TV-3BU was erected on the pad, but continuous delays frustrated the launch attempt. Heavy rains shorted some electrical cables on the ground and necessitated their replacement. The second stage had also been sitting on the pad with a full load ofnitric acid for several weeks, which eventually corroded the fuel tank and valves. It had to be removed and replaced by a different stage. Finally, the launch got under way on the night of 5 February 1958. The Vanguard lifted smoothly into the sky and performed well until 57 seconds into launch, when the booster pitched over almost 40°. The skinny second stage broke in half from aerodynamic stress four seconds later, causing the Vanguard to tumble end-over-end beforerange safety officer sent the destruct command. Cause of the failure was attributed to a spurious guidance signal that caused the first stage to perform unintended pitch maneuvers. The guidance system was modified to have greater redundancy, and efforts were made to improve quality control. On 17 March 1958, Vanguard TV-4 finally succeeded in orbiting theVanguard 1 satellite. By that time, however, theArmy'sJuno (Jupiter-C) had already launched the United States' first satellite,Explorer 1. The Vanguard TV-4 rocket had put the satellite Vanguard 1, to a relatively high orbit of (3,966 by 653 kilometers (2,464 mi × 406 mi)). Vanguard 1 and its third stage remain in orbit as the oldest man-made artifacts in space.[18][19] The following four flights,TV-5 and SLV (Satellite Launch Vehicle)Vanguard SLV-1,Vanguard SLV-2 andVanguard SLV-3 all failed, but on 17 February 1959,Vanguard SLV-4 launchedVanguard 2, weighing 10.8 kilograms (24 lb), into orbit. The SLVs were the "production" Vanguard rockets.Vanguard SLV-5 andVanguard SLV-6 also failed, but the final flight on 18 September 1959, successfully orbited the 24-kilogram (53 lb)Vanguard 3 satellite. That last mission was designated Vanguard TV-4BU, because it used a remaining test vehicle, which had been upgraded with a new third stage, theAllegany Ballistics LaboratoryX-248A2 Altair. This more powerful motor enabled the launch of the heavier payload. The combination of theAJ10 liquid engine andX-248 solid motor was also used, under the nameAble, as an upper stage combination for Thor and Atlas space launch vehicles.
Vanguard launched 3 satellites out of 11 launch attempts:
This article incorporates text from this source, which is in thepublic domain. This article incorporates text from this source, which is in thepublic domain.Scripps-Howard's WASHINGTON DAILY NEWS: SAMNIK IS KAPUTNIK
