Vanguard rocket

Infobox rocket


caption =Launch of Vanguard rocket. (U.S. Navy)
name =Vanguard
country-origin = United States
function =Satellite launch vehicle
manufacturer =Martin
height =75 feet
alt-height =
diameter =3.74 feet
alt-diameter =
mass =22,156 lb
alt-mass =10,050 kg
stages =3
LEO-payload =20 lb
alt-LEO =
payload-location =
payload =
alt-payload =
status =Retired
sites =LC-18A, Cape Canaveral
launches =12
success =3
fail =8
partial =1
first=October 23, 1957
firstorbited =Vanguard 1
April 17, 1958
last=September 18, 1959
stage1name =Vanguard
stage1engines =1 X-405
stage1thrust =30,303 lbf
alt-stage1thrust =134.79 kN
stage1SI =248 lbf·s/lb
stage1time =2 min 25 s
stage1fuel =LOX/kerosene
stage2name =Delta
stage2engines =1 AJ10-118
stage2thrust =7,599 lbf
alt-stage2thrust =33.80 kN
stage2SI =261 lbf·s/lb
stage2time =1 min 55 s
stage2fuel =Nitric acid/UDMH
stage3name =Grand Central or ABL
stage3engines =1 Solid
stage3thrust =2,599 lbf
alt-stage3thrust =11.56 kN
stage3SI =230 lbf·s/lb
stage3time =31 s
stage3fuel =Solid

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. to quickly orbit the Explorer 1 satellite using a Juno I rocket, making Vanguard I the second 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 1957/58. At that time there were three possible candidates for the launch vehicle: the Air Force's SM-65 Atlas, a derivative of the Army's SSM-A-14 Redstone, and a Navy proposal for a three-stage rocket based on the RTV-N-12a Viking sounding rocket. However, the Atlas and Redstone ballistic missiles were top-priority military projects, which were not to be slowed by pursuing a secondary space launch mission. Therefore the Navy's project, named Vanguard, was selected in September 1955 as the first satellite launch vehicle of the USA. The Martin company, which had also built the Viking, became prime contractor for the launch vehicle.

Politics also played a major role in the selection of Vanguard. The Army's Redstone-based proposal would likely be ready earlier for a first satellite launch. However, Vanguard was a project of the NRL (Naval Research Laboratory), 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 whether overflights of foreign countries by satellites were legal or not was to be avoided.

The Vanguard rocket was designed as a three-stage vehicle. The first stage was a General Electric y-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 controlled by gimballed nozzles. 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 1st/2nd-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. When TV-3 exploded a few seconds after lift-off on December 6, 1957, this was accordingly viewed, at least in the eye of the general public, as a major embarrassment and a disaster for the U.S. space program.

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 (406 miles)) 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.

Mission

In August 1955, the DOD Committee on Special Capabilities chose the NRL proposal as it appeared most likely, by spring 1958, to fulfill the following:

# Place a satellite in orbit during the IGY
# Accomplish a scientific experiment in orbit
# Track the satellite and ensure its attainment of orbit

Project Vanguard was chosen from three proposals presented by the United States Air Force, the United States Army, and the United States Navy. The Army's ABMA under Dr. Wernher von Braun had suggested using a modified Redstone rocket (see: Juno I) while the Air Force had proposed using the untested Atlas rocket.

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

pecifications

*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
**Span: 1.14 m
**Length: 12.20 m
**Propellants: Lox/Kerosene
**Engines: 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
**Span: 0.84 m
**Length: 5.36 m
**Propellants: Nitric acid/UDMH
**Engines: AJ10-118

*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
**Span: 0.50 m
**Length: 2.00 m
**Propellants: Solid
**Engines: GCRC

See also

* Vanguard 1 Satellite
* Vanguard 2 Satellite
* Vanguard 3 Satellite
* Explorer program
* Sputnik program
* Viking rocket

External links

* [http://www.hq.nasa.gov/office/pao/History/SP-4202/toc2.html Vanguard - A History - NASA SP-4202 online]
* [http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19740072500_1974072500.pdf The Vanguard Satellite Launching Vehicle: An Engineering Summary - NASA (PDF)]
* [http://www.geocities.com/nielspapermodels/Models.htm Free paper models of vanguard rockets]