The RTV-G-4 Bumper was a
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 used to ...
built by the United States. A combination of the
German V-2 rocket and the
WAC Corporal
The WAC Corporal was the first sounding rocket developed in the United States and the first vehicle to achieve hypersonic speeds. It was an offshoot of the Corporal program, that was started by a partnership between the United States Army Ordn ...
sounding rocket, it was used to study problems pertaining to two-stage high-speed rockets. The Bumper program launched eight rockets between May 13, 1948, to July 29, 1950.
The first six flights were conducted at the
White Sands Missile Range
White Sands Missile Range (WSMR) is a United States Army military testing area and firing range located in the US state of New Mexico. The range was originally established as the White Sands Proving Ground on 9July 1945. White Sands National P ...
; the seventh launch, Bumper 8 on July 24, 1950, was the first rocket launched from
Cape Canaveral
, image = cape canaveral.jpg
, image_size = 300
, caption = View of Cape Canaveral from space in 1991
, map = Florida#USA
, map_width = 300
, type =Cape
, map_caption = Location in Florida
, location ...
.
Bumper program
Background
![V2-Air-Force-Eastern-Test-Range-1950-2](https://upload.wikimedia.org/wikipedia/commons/d/dc/V2-Air-Force-Eastern-Test-Range-1950-2.jpg)
The Bumper program to produce and launch a two-stage combination of the
V-2
The V-2 (german: Vergeltungswaffe 2, lit=Retaliation Weapon 2), with the technical name ''Aggregat 4'' (A-4), was the world’s first long-range guided ballistic missile. The missile, powered by a liquid-propellant rocket engine, was develope ...
and
WAC Corporal
The WAC Corporal was the first sounding rocket developed in the United States and the first vehicle to achieve hypersonic speeds. It was an offshoot of the Corporal program, that was started by a partnership between the United States Army Ordn ...
rockets was conceived in July 1946 by
Colonel Holger N. Toftoy.
Both the WAC Corporal and the V-2 had been extensively tested at
White Sands Proving Grounds
White Sands Missile Range (WSMR) is a United States Army military testing area and firing range located in the US state of New Mexico. The range was originally established as the White Sands Proving Ground on 9July 1945. White Sands National P ...
, the WAC Corporal's launch series occurring in late 1945/early 1946 and the
V-2 launches beginning March 15, 1946.
Bumper was started on June 20, 1947, to:
* Investigate launching techniques for a two-stage missile and separation of the two stages at high velocity.
* Conduct limited investigation of high-speed high-altitude phenomena.
* Attain record-setting velocities and altitudes.
Bumper employed the V-2 as first stage and the WAC Corporal as second stage. In a typical flight, the V-2 engine would fire first, taking the Bumper combination to an altitude of , at which point the WAC Corporal would be released under its own power. This separation occurred before V-2
Brennschluss
Brennschluss (a loanword, from the German ''Brennschluss'') is either the cessation of fuel burning in a rocket or the time that the burning ceases: the cessation may result from the consumption of the propellants, from deliberate shutoff, or from ...
(engine cutoff) to ensure that the WAC Corporal had a stable, actively controlled platform to lift off from, and also so that the V-2 would impart close to maximum possible speed to the Bumper's second stage. The V-2 rocket had a maximum altitude of around , while the WAC Corporal without its solid rocket booster, had a theoretical maximum altitude of ( with). Together, Bumper could reach altitudes of more than twice those attainable by the V-2 alone.
[
Engineering and limited scientific results (for instance, air resistance at high altitude determined by the rocket's trajectory)][ would be obtained from the ]telemetry
Telemetry is the in situ data collection, collection of measurements or other data at remote points and their automatic data transmission, transmission to receiving equipment (telecommunication) for monitoring. The word is derived from the Gr ...
payload carried by the WAC Corporal second stage. Though the Bumper program was not, itself, a secret, aspects of it were classified, particularly the way the WAC Corporal was fitted into the nose of the V-2.
Planning
Overall responsibility for the Bumper program was given to the General Electric
General Electric Company (GE) is an American multinational conglomerate founded in 1892, and incorporated in New York state and headquartered in Boston. The company operated in sectors including healthcare, aviation, power, renewable energ ...
Company and was included in the Hermes project
Project Hermes was a missile research program run by the Ordnance Corps of the United States Army from November 15, 1944, to December 31, 1954, in response to Germany's rocket attacks in Europe during World War II. The program was to determine ...
. The Jet Propulsion Laboratory
The Jet Propulsion Laboratory (JPL) is a federally funded research and development center and NASA field center in the City of La Cañada Flintridge, California, United States.
Founded in the 1930s by Caltech researchers, JPL is owned by NASA an ...
was assigned to perform the theoretical investigations required, design the second stage, and create the basic design of the separation system. The Douglas Aircraft
The Douglas Aircraft Company was an American aerospace manufacturer based in Southern California. It was founded in 1921 by Donald Wills Douglas Sr. and later merged with McDonnell Aircraft in 1967 to form McDonnell Douglas; it then operated as ...
Company was assigned to fabricate the second stage, and do detailed design and fabrication of the special V-2 rocket parts required.
No German engineers were directly involved with Project Bumper, though some worked on the initial studies regarding the mating of the V-2 and WAC corporal. Two women, Mary Taggard and Bea Sylvester, were on the Bumper team providing rocket (but not launch) support.[
]
Operations
Six Bumper launches were made from White Sands Proving Grounds. The first four, launched in 1947/48 were test flights of varying degrees of success.[ The first fully successful Bumper flight was the fifth in the series, launched at 3:14 P.M. (]MST
The Master of Studies or Master in Studies (M.St. or MSt; ) is a postgraduate degree at the University of Oxford, University of Cambridge, University of St Andrews, the Australian National University, University of Dublin and the University of Ne ...
), February 24, 1949.[
Bumper 5 was the first in the Bumper series to be launched with a fully fueled second stage.][ One minute after blast-off, at an altitude of and a speed of just under per second, the WAC Corporal detached from the V-2 first stage and fired its own engine. Forty seconds later, at second stage Brennschluss, the WAC Corporal had reached its maximum speed of per second.][ It reached its peak altitude of , a world record,] six and a half minutes after launch.
The V-2 first stage crashed into the New Mexico desert five minutes after launch north of its firing site. The WAC Corporal hit the ground 12 minutes after take-off from its launch pad. So great was its velocity upon impact, higher than any rocket to date, that the wreck was not found for analysis until January 1950.[
In 1949, the ]Joint Long Range Proving Ground
Cape Canaveral Space Force Station (CCSFS) is an installation of the United States Space Force's Space Launch Delta 45, located on Cape Canaveral in Brevard County, Florida.
Headquartered at the nearby Patrick Space Force Base, the station ...
was established at Cape Canaveral Air Force Station
Cape Canaveral Space Force Station (CCSFS) is an installation of the United States Space Force's Space Launch Delta 45, located on Cape Canaveral in Brevard County, Florida.
Headquartered at the nearby Patrick Space Force Base, the statio ...
on the east coast of Florida
Florida is a state located in the Southeastern region of the United States. Florida is bordered to the west by the Gulf of Mexico, to the northwest by Alabama, to the north by Georgia, to the east by the Bahamas and Atlantic Ocean, and to ...
, where the last two Bumper launches would take place. On July 24, 1950, Bumper 8 became the inaugural launch of "the Cape", still in use as of 2021. Both Bumpers 8 and 7 (fired in that sequence, a week apart). These flights were much ballyhooed in the American press.[
Bumper 8 and 7 saw significant modifications to the WAC Corporal. The nose cone was coated in teflon, while the WAC Corporal body was coated in perlite to resist heating caused by atmospheric friction.] Down range tracking was provided by the USS Sarsfield (DD-837), which was positioned beneath the point where staging was to occur.[ Bumper 7 suffered the first pad abort at Cape Canaveral causing Bumper 8 to be launched first.][ Bumper 8 pitched over to an angle only 10 degrees above the horizon instead of the planned 22 degrees. The WAC Corporal nose was observed to fail from the tracking ship USS Sarsfield following second stage separation.][ There was no telemetry received following the separation and disintegration of the WAC Corporal.][ Despite the failure of the WAC Corporal the flight was declared a success as the missile range facilities had all functioned as intended.][ As the WAC Corporal was still highly classified, its failure was not reported.][ Bumper 7 was launched a week later. Bumper 7's V-2 saw thrust decay while only 14 miles east of the Cape at an altitude of only 8.5 miles. As intended following V-2 thrust decay the WAC Corporal then fired for 40 seconds achieving only 3,286 mph, slightly over half the speed expected.][ Joint Long Range Proving Ground Commander Col. Harold R. Turner announced that the test was "a complete success in every way."][ The myth that the Bumper program at the Cape was a success, when in fact there were significant failures of the missiles, has continued to this day.][
]
Launch history
[
]
See also
Spaceflight before 1951
Spaceflight as a practical endeavor began during World War II with the development of operational liquid-fueled rockets. Beginning life as a weapon, the V-2 was pressed into peaceful service after the war at the United States' White Sands Missi ...
References
{{DEFAULTSORT:Bumper (Rocket)
Spaceflight before 1951
United States Army equipment
Experimental rockets of the United States
Sounding rockets of the United States