For the star Alpha Draconis, see
Thuban
.
Experimental ballistic missile
Alpha Draco
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![](//upload.wikimedia.org/wikipedia/commons/thumb/f/f6/Alpha_Draco_under_maintenance.jpg/300px-Alpha_Draco_under_maintenance.jpg) The Alpha Draco test vehicle
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Type
| Experimental
ballistic missile
|
---|
Place of origin
| United States
|
---|
|
In service
| 1959
|
---|
Used by
| United States Air Force
|
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|
Designed
| 1957-1958
|
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Manufacturer
| McDonnell
|
---|
No.
built
| 3
|
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|
Length
| 46.1 feet (14.05 m)
|
---|
Diameter
| 31 inches (790 mm)
|
---|
Wingspan
| 7.1 feet (2.16 m)
|
---|
|
Engine
| First stage,
Thiokol TX-20
50,000 lb
f
(222 kN)
Second stage,
Thiokol TX-30
12,300 lb
f
(54.8 kN)
|
---|
Propellant
| Solid fuel
|
---|
Operational
range
| 240 miles (390 km)
|
---|
Flight ceiling
| 100,000 feet (30,000 m)
|
---|
| Mach
5+
|
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The
Alpha Draco
missile, also known as
Weapons System 199D
(
WS-199D
), was an experimental
ballistic missile
developed by
McDonnell Aircraft
in the late 1950s to investigate the aerodynamic physics of the
boost-glide
reentry
trajectory. Three test flights were conducted in 1959, of which two were successful.
Design and development
[
edit
]
As part of the
WS-199
project to develop new strategic weapons for the
United States Air Force
's
Strategic Air Command
, McDonnell Aircraft developed the Alpha Draco missile between 1957 and 1959, under a contract to launch three vehicles to determine the feasibility of the boost-glide reentry vehicle (BGRV) concept.
[1]
The purpose of the rocket was to establish whether a strategic missile using the "boost-glide" principle of propulsion could be practically used.
[2]
The idea had been proposed by
Walter Dornberger
, who had moved to McDonnell after working for a short time at
Bell Aircraft
. Dornberger had originally worked on the idea as part of efforts to extend the range of the
V-2 missile
late in
World War II
.
The Alpha Draco missile was a two-stage vehicle, the first stage comprising a
Thiokol
TX-20 solid-fuel rocket of the type used in the
MGM-29 Sergeant
theater ballistic missile
, and the second stage using a Thiokol TX-30 solid-fuel rocket. The payload vehicle was aerodynamically shaped, using the
lifting body
principle to provide aerodynamic lift;
[4]
following burnout of the first stage, the vehicle would coast for a short time before ignition of the second stage,
[2]
burnout of the second stage was followed by the vehicle entering the glide phase of flight, which would be terminated by a dive upon the target.
[5]
The vehicle would enter a roll during its glide period to distribute aerodynamic heating. Guidance was provided by a
Honeywell
inertial guidance
unit.
[6]
Operational history
[
edit
]
Following modification of the launch pad at the
Cape Canaveral Air Force Station
's
Launch Complex 10
to include a concrete
flame deflector
[7]
and a gantry modified from that used by the
Honest John battlefield missile
,
[6]
three test launches of the Alpha Draco vehicle were conducted during 1959.
[4]
The initial flight, on February 16, was successful; the second flight, one month later, also fulfilled its test goals. The final launch of the Alpha Draco on April 30, however, suffered a flight-control failure and was destroyed by
range safety
command.
[5]
With the expenditure of the third and final vehicle, the program was concluded,
[2]
the project's cost having come to a total of approximately $5 million
USD
($54 million today).
[5]
The program demonstrated that the vehicle was able to generate
lift/drag ratio
of 3.5 to 1, allowing it to greatly extend its range;
it was also the first missile to achieve
hypersonic
flight inside of an atmosphere.
[8]
Although this was not put to immediate use, the tests provided valuable data that was used for later programs like the Boost Glide Reentry Vehicle and the ASSET and PRIME programs. Better understanding of the hypersonic lift process also led to the
lifting body
designs of the 1960s.
McDonnell Aircraft proposed a development of the Alpha Draco concept for the USAF requirement that evolved into the
Minuteman missile
program, but the boost-glide concept was considered too immature for operational development.
[9]
To be on the safe side, Minuteman silos were built deeper than required in case a boost-glide weapon would be fitted in the future. Although this never came to be, the extra depth proved invaluable as it allowed the missile to grow in length to the Minuteman III design without having to build new silos.
Launch history
[
edit
]
Date/Time (GMT)
|
Launch site
|
Outcome
|
Remarks
[10]
|
1959-02-16
|
Launch Complex 10
|
Success
|
Apogee 30 kilometres (19 mi), impact 224 nautical miles (415 km; 258 mi) downrange
[11]
|
1959-03-16
|
Launch Complex 10
|
Success
|
Apogee 30 kilometres (19 mi), impact 212 nautical miles (393 km; 244 mi) downrange
[8]
|
1959-04-27
|
Launch Complex 10
|
Failure
|
Destroyed due to flight path excursion following second stage ignition.
[8]
|
See also
[
edit
]
- Related development
- Comparable weapons
References
[
edit
]
- Notes
- ^
Brulle 2008, p. 89.
- ^
a
b
c
Parsch 2005.
- ^
a
b
Yenne 2005, p. 67.
- ^
a
b
c
Yengst 2010, pp. 38-39.
- ^
a
b
Brulle 2008, p. 94.
- ^
"Launch Complexes 9-10"
. Air Force Space & Missile Museum. Archived from
the original
on 2017-11-30
. Retrieved
2017-11-30
.
- ^
a
b
c
Brulle 2008, p. 105.
- ^
Brulle 2008, p. 106.
- ^
"Draco"
.
Encyclopedia Astronautica
. Archived from
the original
on 2011-10-11
. Retrieved
2011-01-19
.
- ^
Brulle 2008, p. 101.
- Bibliography
- Brulle, Robert V. (2008).
Engineering the Space Age: A Rocket Scientist Remembers
. Maxwell AFB, Alabama: Air University Press.
ISBN
978-1-58566-184-8
.
- Parsch, Andreas (1 November 2005).
"WS-199"
.
Directory of U.S. Military Rockets and Missiles
. designation-systems.net.
Archived
from the original on 15 December 2010
. Retrieved
20 January
2015
.
- Yengst, William (2010).
Lightning Bolts: First Manuevering [
sic
] Reentry Vehicles
. Mustang, OK: Tate Publishing & Enterprises.
ISBN
978-1-61566-547-1
.
- Yenne, Bill (2005).
Secret Gadgets and Strange Gizmos: High-Tech (and Low-Tech) Innovations of the U.S. Military
. St. Paul, MN: Zenith Press.
ISBN
978-0-7603-2115-7
.
External links
[
edit
]
Media related to
Alpha Draco
at Wikimedia Commons
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Air-to-air missiles
| 1955?1961 sequence
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1961?1963 sequence
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Other types
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Undesignated types
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100?199
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200?299
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300?399
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400?499
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500?599
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- 501?519
1
- 520
- 521?529
1
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- 531?541
1
- 542
- 543?549
1
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- 551?559
1
- 560
- 561?569
1
- 570
- 571?579
1
- 580
- 581?589
1
- 590
- 591
- 592
- 593?599
1
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600?699
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700?799
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800?899
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- 800
1
- 801
1
- 802
- 803
1
- 804
1
- 805
1
- 806
- 807
- 808?816
1
- 817
- 818
1
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1
- 820
1
- 821
1
- 822
1
- 823
- 824?831
1
- 832
- 833
1
- 834
- 835?845
1
- 846
- 847?899
1
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900?999
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- 900?951
1
- 952
- 853
1
- 854
1
- 855
1
- 956
- 957?967
1
- 968
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1
Unknown or not assigned
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