The Scout family of rockets were American
launch vehicle
A launch vehicle is typically a rocket-powered vehicle designed to carry a payload (a crewed spacecraft or satellites) from Earth's surface or lower atmosphere to outer space. The most common form is the ballistic missile-shaped multistage ...
s designed to place small
satellite
A satellite or an artificial satellite is an object, typically a spacecraft, placed into orbit around a celestial body. They have a variety of uses, including communication relay, weather forecasting, navigation ( GPS), broadcasting, scient ...
s into orbit around the Earth. The Scout
multistage rocket
A multistage rocket or step rocket is a launch vehicle that uses two or more rocket ''stages'', each of which contains its own engines and propellant. A ''tandem'' or ''serial'' stage is mounted on top of another stage; a ''parallel'' stage is ...
was the first orbital launch vehicle to be entirely composed of
solid fuel
Solid fuel refers to various forms of solid material that can be burnt to release energy, providing heat and light through the process of combustion. Solid fuels can be contrasted with liquid fuels and gaseous fuels. Common examples of solid fu ...
stages. It was also the only vehicle of that type until the successful launch of the Japanese
Lambda 4S in 1970.
The original Scout (a
backronym
A backronym is an acronym formed from an already existing word by expanding its letters into the words of a phrase. Backronyms may be invented with either serious or humorous intent, or they may be a type of false etymology or folk etymology. The ...
for Solid Controlled Orbital Utility Test system) was designed in 1957 at the
NACA
The National Advisory Committee for Aeronautics (NACA) was a United States federal agency that was founded on March 3, 1915, to undertake, promote, and institutionalize aeronautical research. On October 1, 1958, the agency was dissolved and its ...
, at
Langley center. Scout launch vehicles were used from 1961 until 1994. To enhance reliability the development team opted to use "off the shelf" hardware, originally produced for military programs. According to the
NASA
The National Aeronautics and Space Administration (NASA ) is an independent agencies of the United States government, independent agency of the federal government of the United States, US federal government responsible for the United States ...
fact sheet:
"... the first stage motor was a combination of the Jupiter Senior and the Navy Polaris
Polaris is a star in the northern circumpolar constellation of Ursa Minor. It is designated α Ursae Minoris (Latinisation of names, Latinized to ''Alpha Ursae Minoris'') and is commonly called the North Star or Pole Star. With an ...
; the second stage came from the Army MGM-29 Sergeant; and the third and fourth stage motors were designed by Langley engineers who adapted a version of the Navy Vanguard
The vanguard (sometimes abbreviated to van and also called the advance guard) is the leading part of an advancing military formation. It has a number of functions, including seeking out the enemy and securing ground in advance of the main force.
...
."
The first successful orbital launch of a Scout, on February 16, 1961, delivered
Explorer 9, a satellite used for atmospheric density studies, into orbit.
The final launch of a Scout, using a Scout G-1, was on May 8, 1994, from
Vandenberg Air Force Base
Vandenberg may refer to:
* Vandenberg (surname), including a list of people with the name
* USNS ''General Hoyt S. Vandenberg'' (T-AGM-10), transport ship in the United States Navy, sank as an artificial reef in Key West, Florida
* Vandenberg S ...
. The payload was the Miniature Sensor Technology Integration Series 2 (''MSTI-2'') military spacecraft with a mass of . MSTI-2 successfully acquired and tracked a
LGM-30 Minuteman
The LGM-30 Minuteman is an American land-based intercontinental ballistic missile (ICBM) in service with the Air Force Global Strike Command. , the LGM-30G (Version 3) is the only land-based ICBM in service in the United States and represents th ...
missile.
The standard Scout launch vehicle was a solid propellant, four-stage booster system, approximately in length with a launch weight of .
Scout A
The Scout A was used for launches of the
Transit NNSS series (Transit-O 6 to 19), placing two satellites in orbit at the same time.
Twelve flights were conducted between 21 December 1965 and 27 August 1970.
It was also used to launch the British
Ariel 3 scientific satellite.
Standard payload capability was 122 kg into a low-Earth orbit.
Parameters

*Thrust at liftoff: 513.40
kN (52,352
kgf)
*Mass at launch: 17,850 kg
*Diameter: 1.01 m
*Length: 25.00 m
Stage 1: ''
Algol
ALGOL (; short for "Algorithmic Language") is a family of imperative computer programming languages originally developed in 1958. ALGOL heavily influenced many other languages and was the standard method for algorithm description used by the ...
''
* Derived from
Polaris
Polaris is a star in the northern circumpolar constellation of Ursa Minor. It is designated α Ursae Minoris (Latinisation of names, Latinized to ''Alpha Ursae Minoris'') and is commonly called the North Star or Pole Star. With an ...
missile
* Gross Mass: 11,600 kg
* Empty Mass: 1,650 kg
* Vacuum thrust: 564.25 kN (57,537 kgf)
* Burn time: 47 s
* Diameter: 1.01 m
* Span: 1.01 m
* Length: 9.09 m
Stage 2: ''
Castor''
* Derived from
Sergeant
Sergeant (Sgt) is a Military rank, rank in use by the armed forces of many countries. It is also a police rank in some police services. The alternative spelling, ''serjeant'', is used in The Rifles and in other units that draw their heritage f ...
missile
* Gross Mass: 4,424 kg
* Empty Mass: 695 kg
* Vacuum thrust: 258.92 kN (26,402 kgf)
* Burn time: 37 s
* Diameter: 0.79 m
* Span: 0.79 m
* Length: 6.04 m
Stage 3: ''
Antares
Antares is the brightest star in the constellation of Scorpius. It has the Bayer designation α Scorpii, which is Latinisation of names, Latinised to Alpha Scorpii. Often referred to as "the heart of the scorpion", Antares is flanked by ...
''
* Gross Mass: 1,400 kg
* Empty Mass: 300 kg
* Vacuum thrust: 93.09 kN (9,493 kgf)
* Burn time: 36 s
* Diameter: 0.78 m
* Span: 0.78 m
* Length: 2.90 m
Stage 4: ''
Altair
Altair is the brightest star in the constellation of Aquila (constellation), Aquila and the list of brightest stars, twelfth-brightest star in the night sky. It has the Bayer designation Alpha Aquilae, which is Latinisation of name ...
''
* Gross Mass: 275 kg
* Empty Mass: 37 kg
* Vacuum thrust: 22.24 kN (2,268 kgf)
* Burn time: 28 s
* Diameter: 0.64 m
* Span: 0.64 m
* Length: 2.53 m
Scout-X1 (NASA)
In the late 1950s, NASA established the Scout program to develop a multistage solid-propellant space booster and research rocket. The U.S. Air Force also participated in the program, but different requirements led to some divergence in the development of NASA and USAF Scouts.
The basic NASA Scout configuration, from which all variants were derived, was known as Scout-X1. It was a four-stage rocket, which used the following motors:
* 1st stage:
Aerojet General
Aerojet was an American rocket and missile propulsion manufacturer based primarily in Rancho Cordova, California, with divisions in Redmond, Washington, Orange and Gainesville in Virginia, and Camden, Arkansas. Aerojet was owned by GenCorp, ...
Algol
ALGOL (; short for "Algorithmic Language") is a family of imperative computer programming languages originally developed in 1958. ALGOL heavily influenced many other languages and was the standard method for algorithm description used by the ...
* 2nd stage:
Thiokol
Thiokol was an American corporation concerned initially with rubber and related chemicals, and later with rocket and missile propulsion systems. Its name is a portmanteau of the Greek words for sulfur () and glue (), an allusion to the company ...
XM33
Castor
* 3rd stage:
Allegany Ballistics Laboratory
Allegany Ballistics Laboratory (ABL) located in Rocket Center, West Virginia, is a diverse factory, industrial complex employing some 1,000 people across . The facility is a member of the Federal Laboratory Consortium and is operated by Northr ...
X-254 Antares
* 4th stage: Allegany Ballistics Laboratory
X-248 Altair
Scout's first-stage motor was based on an earlier version of the Navy's Polaris missile motor; the second-stage motor was developed from the Army's Sergeant surface-to-surface missile; and the third- and fourth-stage motors were adapted by NASA's Langley Research Center; Hampton, VA, from the Navy's Vanguard launch vehicle.
Unlike the
Thor
Thor (from ) is a prominent list of thunder gods, god in Germanic paganism. In Norse mythology, he is a hammer-wielding æsir, god associated with lightning, thunder, storms, sacred trees and groves in Germanic paganism and mythology, sacred g ...
or
Atlas-Agena
The Atlas-Agena was an American expendable launch system derived from the SM-65 Atlas missile. It was a member of the Atlas (rocket family), Atlas family of rockets, and was launched 109 times between 1960 and 1978. It was used to launch the first ...
the Scout was non-military and could be sold to foreign customers.
The Scout X-1 first flew successfully on 10 October 1960, after an earlier failure in July 1960. The rocket's first stage had four stabilizing fins, and the vehicle incorporated a gyro-based guidance system for attitude stabilization to keep the rocket on course.
Satellites orbited
*
San Marco 1, the first Italian satellite (in 1964), launched by an Italian crew.
* San Marco 2, the second Italian satellite (in 1967) and first in the world launched from a sea platform. Three more
San Marco
San Marco is one of the six sestiere (Venice), sestieri of Venice, lying in the heart of the city as the main place of Venice. San Marco also includes the island of San Giorgio Maggiore. Although the district includes Piazza San Marco, Saint Mar ...
satellites would use Scout rockets. Italy owned
San Marco platform launched in 1967-1984 Scout rockets only.
*
AEREOS and AEROS B atmospheric research
[p.12 AEROS]
*
Ariel 3, the first satellite designed and constructed in the United Kingdom, and four other
Ariel satellites (Ariel 2, 4, 5 and 6) including first satellite for radioastronomy -
Ariel 2.
*
Magsat, the first globally complete 3D map of Earth's magnetic fields.
*
Transit
Transit may refer to:
Arts and entertainment Film
* ''Transit'' (1980 film), a 1980 Israeli film
* ''Transit'' (1986 film), a Canadian short film
* ''Transit'' (2005 film), a film produced by MTV and Staying-Alive about four people in countrie ...
satellites,
a prototype satellite Transit 5A was launched 1962-12-19 by a Scout X-3. On four different flights, Scout rockets placed two Transit satellites in orbit with a single launch. The last of these, on 1988-08-25, launched Transit-O 31 and Transit O-25 on a Scout G rocket.
*
OFO-A, launched bullfrogs into space for biological experiments (1970)
* FR-1, a French satellite used to study VLF propagation (1965)
*
Astronomical Netherlands Satellite, ANS was the first Dutch satellite (30 August 1974). (ANS; also known as Astronomische Nederlandse Satelliet) was a space-based
X-ray
An X-ray (also known in many languages as Röntgen radiation) is a form of high-energy electromagnetic radiation with a wavelength shorter than those of ultraviolet rays and longer than those of gamma rays. Roughly, X-rays have a wavelength ran ...
and
ultraviolet telescope.
* Miniature Sensor Technology Integration Series 2 (MSTI-2), launched into low earth orbit on 8 May 1994 local time aboard the last NASA SCOUT booster.
* Explorer 9, 13(S 55), 13(S 55a), 16, 19, 20, 22, 23, 24, 27, 30, 37, 39, 42, 45, 46, 48, 52, 53, 56, and 57
*
Uhuru, the first XRay orbital observatory, which confirmed the first black hole detected
Cygnus X-1
* ESRO 1 A/B, 2A/B,
* Miranda
* ANS 1
* San Marco 4, 5
* Triad 2
*
Gravity Probe A
* Triad 3
* Transat
* AEM 1, 2
* Nova 1
* Nova 2
* HILAT
* Nova 3
* ITV 1, 2
*
Polar BEAR
The polar bear (''Ursus maritimus'') is a large bear native to the Arctic and nearby areas. It is closely related to the brown bear, and the two species can Hybrid (biology), interbreed. The polar bear is the largest extant species of bear ...
* REX 1
*
SAMPEX
* Radical
* DSAP 1 F1, F2, F3, F4, F5
* RFD 1, 2.
* OTV3 1, 2, 3, 4, 5.
*
Scout X-1A
Scout X-1A was an American
sounding rocket
A sounding rocket or rocketsonde, sometimes called a research rocket or a suborbital rocket, is an instrument-carrying rocket designed to take measurements and perform scientific experiments during its sub-orbital flight. The rockets are often ...
which was flown in 1962. It was a five-stage derivative of the earlier
Scout X-1
Scout X-1 was an American expendable launch system and sounding rocket which was flown seven times between August 1960 and October 1961. Four orbital and three suborbital launches were made, with four of the launches resulting in failures.
The ...
, with an uprated first stage, and a
NOTS-17 upper stage.
Scout X-2
Scout X-2 was an American
expendable launch system
An expendable launch system (or expendable launch vehicle/ELV) is a launch vehicle that can be launched only once, after which its components are destroyed during reentry or impact with Earth, or discarded in space. ELVs typically consist of s ...
and
sounding rocket
A sounding rocket or rocketsonde, sometimes called a research rocket or a suborbital rocket, is an instrument-carrying rocket designed to take measurements and perform scientific experiments during its sub-orbital flight. The rockets are often ...
which was flown twice in 1962. It was a four-stage rocket, based on the earlier
Scout X-1
Scout X-1 was an American expendable launch system and sounding rocket which was flown seven times between August 1960 and October 1961. Four orbital and three suborbital launches were made, with four of the launches resulting in failures.
The ...
, introducing the Algol 1D
and
Antares 2B stage upgrades. On 1962-08-23 a Scout X-2 was used for the first successful launch of a
DMSP satellite, lifting off from
Point Arguello near
Vandenberg Air Force Base
Vandenberg may refer to:
* Vandenberg (surname), including a list of people with the name
* USNS ''General Hoyt S. Vandenberg'' (T-AGM-10), transport ship in the United States Navy, sank as an artificial reef in Key West, Florida
* Vandenberg S ...
.
Scout X-3
The Scout X-3 flew after 1962 and introduced the Algol IIA upgrade.
Scout X-4
The Scout X-4 flew after 1963 and introduced Altair 2 upgrade.
Scout A-1
The Scout A-1 flew in 1973 and introduced the Castor IIA upgrades.
Scout B-1
The Scout B-1 flew after 1971 and introduced the Altair III upgrades.
Scout D-1
The Scout D-1 flew in 1972 and introduced the Algol III upgrade.
Scout F-1
The Scout F-1 flew twice in 1975, and was composed of a
Algol-3A first stage, a
Castor-2A second stage, a Antares-2B third stage and a
Star-20 fourth stage. It successfully launched
Small Astronomy Satellite 3
The Small Astronomy Satellite 3 (SAS 3, also known as SAS-C before launch) (Explorer 53) was a NASA X-ray astronomy space telescope. It functioned from 7 May 1975 to 9 April 1979. It covered the X-ray range with four experiments on board. The ...
from the San Marco Launch Complex, but failed on launching the
Dual Air Density Explorer satellites from Vandenberg.
[ ][ ]
Scout G-1
The Scout G-1 flew from 1974 until the Scout's retirement in 1994. It was rated to orbit a 210 kg payload.
XRM-89 Blue Scout I (USAF)

The USAF Scout program was known as HETS (Hyper Environmental Test System) or System 609A, and the rockets were generally referred to as Blue Scout. The prime contractor for the NASA Scout was LTV, but the Blue Scout prime contractor was Ford Aeronutronics.
By using different combinations of rocket stages, the USAF created several different Blue Scout configurations. One of these was the XRM-89
Blue Scout I, which was a three-stage vehicle, using Castor 2 and an Antares 1A stages, but omitting the basic Scout's Altair 4th stage. The first launch of an XRM-89 occurred on 1961-01-07, and was mostly successful. On that flight, the XRM-89 carried a variety of experiments to measure rocket performance and high-altitude fields and particle radiation. The payload was located in a recoverable reentry capsule, but the capsule sank before it could be recovered from the water. The only other XRM-89 launches (in May 1961 and April 1962) were unsuccessful, and the Blue Scout I program was terminated in 1962.
XRM-90 Blue Scout II (USAF)
The XRM-90
Blue Scout II was a rocket of the U.S. Air Force's System 609A Blue Scout family. The XRM-90 was a four-stage rocket, which used the same stages as the basic NASA Scout. It was nevertheless not identical to the latter, because the 4th stage was hidden in a payload fairing with the same diameter as the 3rd stage, and the first stage nozzle used a flared tail skirt between the fins. Externally, the XRM-90 was indistinguishable from the XRM-89 Blue Scout I.
The first XRM-90 launch occurred on 1961-03-03, followed by a second one on 1961-04-12. Both sub-orbital flights were successful, and measured radiation levels in the
Van Allen belts
The Van Allen radiation belt is a zone of energy, energetic charged particles, most of which originate from the solar wind, that are captured by and held around a planet by that planet's magnetosphere. Earth has two such belts, and sometimes ot ...
. The second Blue Scout II also carried a micrometeorite sampling experiment, but the recovery of the reentry capsule failed. The third XRM-90 was used by NASA in November 1961 for
Mercury-Scout 1. This was an attempt to orbit a communications payload for
Project Mercury
Project Mercury was the first human spaceflight program of the United States, running from 1958 through 1963. An early highlight of the Space Race, its goal was to put a man into Earth orbit and return him safely, ideally before the Soviet Un ...
, but the rocket failed after 28 seconds of flight. The USAF subsequently abandoned the XRM-89 Blue Scout I and XRM-90 Blue Scout II vehicles, and shifted to the RM-91/SLV-1B Blue Scout Junior instead.
XRM-91 Blue Scout Junior / Journeyman B (USAF)
The XRM-91
Blue Scout Junior (sometimes called Journeyman B) was a rocket of the U.S. Air Force's System 609A Blue Scout family. Although the Blue Scout Junior had sufficient impulse to have put a small satellite in low Earth orbit, it was not used as an orbital launch vehicle. The XRM-91 did not resemble the other Scout variants externally, because the usual first Scout stage (an Aerojet General Algol) was not used. Instead, the four-stage Blue Scout Junior used Scout's 2nd and 3rd stages (Castor and Antares) as the first two stages, and added an Aerojet General
Alcor and a spherical NOTS Cetus in a common nose fairing. The XRM-91 also lacked the gyro-stabilization and guidance system of the RM-89 Blue Scout I and RM-90 Blue Scout II, making it a completely unguided rocket. It relied on second-stage fins and two spin motors to achieve a stable flight trajectory.
The first launch of an XRM-91 occurred on September 21, 1960, making it actually the first Blue Scout configuration to fly. The flight was planned to make radiation and magnetic field measurements at distances of up to 26 700 km (16 600 miles) from earth, and while the rocket did indeed achieve this altitude, the telemetry system failed so that no data was received. The second launch in November ended with a failure during second stage burn. The third flight was to measure particle densities in the Van Allen belts and reached a distance of 225 000 km (140 000 miles), but again a telemetry failure prevented the reception of scientific data. The fourth and final XRM-91 mission in December 1961 also carried particle detectors, and was the only completely successful flight of the initial Blue Scout Junior program.
The Blue Scout Junior was regarded by the USAF as the most useful of the various Blue Scout configurations. It was used (in slightly modified form) between 1962 and 1965 by the Air Force as the SLV-1B/C launch vehicle for suborbital scientific payloads. The SLV-1C was also chosen as the rocket for the MER-6A interim ERCS (
Emergency Rocket Communications System) vehicle; this provided a reliable and survivable emergency communications method for the
United States National Command Authority, using a
UHF
Ultra high frequency (UHF) is the ITU designation for radio frequencies in the range between 300 megahertz (MHz) and 3 gigahertz (GHz), also known as the decimetre band as the wavelengths range from one meter to one tenth of a meter ...
repeater that would transmit pre-recorded messages to all units within line-of-sight of the rocket's
apogee
An apsis (; ) is the farthest or nearest point in the orbit of a planetary body about its primary body. The line of apsides (also called apse line, or major axis of the orbit) is the line connecting the two extreme values.
Apsides perta ...
.
NASA used a three-stage Blue Scout Junior configuration (omitting the Cetus 4th stage) as the RAM B.
San Marco Project
The Italian space research program began in 1959 with the creation of the CRA (Centro Ricerche Aerospaziali) at the University of Rome. Three years later, on 7 September 1962, the university signed a memorandum of understanding with NASA to collaborate on a space research program named San Marco (St. Mark). The Italian launch team was trained by NASA.
The San Marco project was focused on the launching of scientific satellites by Scout rockets from a mobile rigid platform located close to the equator. This station, composed of 2 platforms, 1 3-leg control platform called Santa Rita where the launch center and radar was located, and another platform called San Marco, housing the movable shelter for the missile and the launcher. These platforms were installed off the Kenya coast, close to the town of Malindi. During launch, the San Marco platform was vacated of all persons. Two support boats ferried the crews daily to the platforms from the land base.
Launches
Debris
The Scout rockets have contributed to several pieces of debris over the years, some of which is still orbiting as of 2023.
See also
*
Comparison of orbital launchers families
This article compares different orbital launcher families (launchers which are significantly different from other members of the same 'family' have separate entries). The article is organized into two tables: the first contains a list of currentl ...
References
External links
Profileof the Blue Scout Junior
of the Scout series
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