MarketRTV-G-4 Bumper
Company Profile

RTV-G-4 Bumper

The RTV-G-4 Bumper was a sounding rocket built by the United States. A combination of the German V-2 rocket and the WAC Corporal 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 and July 29, 1950. The first six flights were conducted at the White Sands Missile Range; the seventh launch, Bumper 8 on July 24, 1950, was the first rocket launched from Cape Canaveral.

Bumper program
Background The Bumper program to produce and launch a two-stage combination of the V-2 and WAC Corporal rockets was conceived in July 1946 by Colonel Holger N. Toftoy. 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 (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. 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 Company and was included in the Hermes project. The Jet Propulsion Laboratory was assigned to perform the theoretical investigations required, design the second stage, and create the basic design of the separation system. The Douglas Aircraft Company was assigned to fabricate the second stage, and do detailed design and fabrication of the special V-2 rocket parts required. 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. Down range tracking was provided by the USS Sarsfield, 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. From the tracking ship Sarsfield, the WAC Corporal's nose was observed to fail 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 ==
Launch history
Bumper was launched eight times between 1948 and 1950. == See also ==
tickerdossier.comtickerdossier.substack.com