Encyclopedia Astronautica
Hermes B-1



hermesb1.jpg
Hermes B-1
Credit: © Mark Wade
hermes2.jpg
Hermes B-1
American tactical ballistic missile. Test vehicle for Hermes II Mach 3 ramjet cruise missile. The modified V-2 merely acted as a booster for the 'Ram' second stage.

The ramjet portion of the Army's Hermes programme, like all post-war ramjet efforts, remains shrouded in secrecy. A confusing maze of designations was applied at various points in the project. It was deeply classified at the time -- test launches do not appear in official V-2 launch lists -- and it seems to remain unknowable to what extent flight experiments progressed.

The concept of a ramjet-augmented A9 had already been sketched out at Peenemuende. German research into ramjet propulsion remains largely undocumented, but after the war German teams in Russia, Britain, France, and America all were put to work developing missiles using the new form of propulsion. In America and Russia the boost-glide concept of the A9 and Saenger Silverbird were both quickly dropped in favour of ramjet-powered Mach 3 cruise vehicles, indicating that this conclusion had already been reached in Germany before the end of the war.

Von Braun's team at White Sands made testing of a ramjet-powered missile one of their earliest priorities. The Hermes B, already proposed by Hermes contractor in 1946, was a conventional 12 m long cruise missile with a conventional cylinder + conical shock body inlet ramjet. The Germans wished to pursue the Hermes II, a more radical linear ramjet concept. In tests a V-2 would be used to get the second stage 'Ram' missile up to ramjet ignition speed.

The Ram second stage had a 4.65 m wingspan. The stub wings incorporated the 'Organ' linear ramjets. The missile's base nestled into a recess built into the top of the V-2's fuel tank. In a test flight, the V-2 would take the second stage to supersonic speed at 15,000 m altitude, then separate. The Ram would coast to 20,000 m, then the ramjet would be ignited and the stage would cruise at over 3500 kph. It was expected the ramjet would generate a thrust of 13.1 kN, and the stage carried 634 kg of 'zip fuel' (jet fuel with boron hydride additive), enough for 400 seconds of powered flight. It was expected an operational missile version would have a range of 800 km with a 230 kg payload. The Ram stage had a diameter of 1.29 m, a length of 5.44 m, a total mass of 2563 kg. Nearly as important as the radical propulsion was the inertial guidance system, which controlled operation of both the first and second stages.

On its very first test, which was with an instrumented but inactive ramjet, the V-2 veered off-course. Telemetry indicated expected air flow in the ramjet ducts, but the second stage provided aerodynamic lift and glided at Mach 3 out of the White Sands test range. It blew a 10 m diameter crater in a cemetary south of Juaerz, Mexico. The Peenemuende Germans joked 'We were the first German unit to not only infiltrate the United States, but to attack Mexico from US soil'. The Army was however not amused and two further tests planned for later that year were cancelled. Component tests of the conventional ramjet planned for the Hermes B were carried out on three V-2 flights in 1947-1949. However the next tests of the Ram stage did not come until 1949-1950. There is no record of the results or whether they carried live ramjets.

Work on Hermes ramjet vehicles continued after the German team was moved to Huntsville Alabama. It was by 1952 envisioned the Hermes II would travel at Mach 4.5 at 24 km altitude over a 2400 km range. But the decision was taken that the US Air Force would be solely responsible for long-range cruise missiles, and the Hermes II was cancelled in September 1953. The equivalent Air Force Navaho would reach flight test in 1957, only to be cancelled in turn in favour of simpler ballistic missiles.

Failures: 3. First Fail Date: 1947-05-30. Last Fail Date: 1949-10-06. Standard warhead: 230 kg (500 lb). Maximum range: 500 km (310 mi). Boost Propulsion: Lox/alcohol. Cruise engine: GE Ramjet. Maximum speed: 3,500 kph (2,100 mph).

The ramjet portion of the Army's Hermes programme, like all post-war ramjet efforts, remains shrouded in secrecy. A confusing maze of designations was applied at various points in the project. It was deeply classified at the time -- test launches do not appear in official V-2 launch lists -- and it seems to remain unknowable to what extent flight experiments progressed.

The concept of a ramjet-augmented A9 had already been sketched out at Peenemuende. German research into ramjet propulsion remains largely undocumented, but after the war German teams in Russia, Britain, France, and America all were put to work developing missiles using the new form of propulsion. In America and Russia the boost-glide concept of the A9 and Saenger Silverbird were both quickly dropped in favour of ramjet-powered Mach 3 cruise vehicles, indicating that this conclusion had already been reached in Germany before the end of the war.

Von Braun's team at White Sands made testing of a ramjet-powered missile one of their earliest priorities. The Hermes B, already proposed by Hermes contractor in 1946, was a conventional 12 m long cruise missile with a conventional cylinder + conical shock body inlet ramjet. The Germans wished to pursue the Hermes II, a more radical linear ramjet concept. In tests a V-2 would be used to get the second stage 'Ram' missile up to ramjet ignition speed.

The Ram second stage had a 4.65 m wingspan. The stub wings incorporated the 'Organ' linear ramjets. The missile's base nestled into a recess built into the top of the V-2's fuel tank. In a test flight, the V-2 would take the second stage to supersonic speed at 15,000 m altitude, then separate. The Ram would coast to 20,000 m, then the ramjet would be ignited and the stage would cruise at over 3500 kph. It was expected the ramjet would generate a thrust of 13.1 kN, and the stage carried 634 kg of 'zip fuel' (jet fuel with boron hydride additive), enough for 400 seconds of powered flight. It was expected an operational missile version would have a range of 800 km with a 230 kg payload. The Ram stage had a diameter of 1.29 m, a length of 5.44 m, a total mass of 2563 kg. Nearly as important as the radical propulsion was the inertial guidance system, which controlled operation of both the first and second stages.

On its very first test, which was with an instrumented but inactive ramjet, the V-2 veered off-course. Telemetry indicated expected air flow in the ramjet ducts, but the second stage provided aerodynamic lift and glided at Mach 3 out of the White Sands test range. It blew a 10 m diameter crater in a cemetary south of Juaerz, Mexico. The Peenemuende Germans joked 'We were the first German unit to not only infiltrate the United States, but to attack Mexico from US soil'. The Army was however not amused and two further tests planned for later that year were cancelled. Component tests of the conventional ramjet planned for the Hermes B were carried out on three V-2 flights in 1947-1949. However the next tests of the Ram stage did not come until 1949-1950. There is no record of the results or whether they carried live ramjets.

Work on Hermes ramjet vehicles continued after the German team was moved to Huntsville Alabama. It was by 1952 envisioned the Hermes II would travel at Mach 4.5 at 24 km altitude over a 2400 km range. But the decision was taken that the US Air Force would be solely responsible for long-range cruise missiles, and the Hermes II was cancelled in September 1953. The equivalent Air Force Navaho would reach flight test in 1957, only to be cancelled in turn in favour of simpler ballistic missiles.

Designations Discussion (© Andreas Parsch)

The Hermes B program was begun in 1946 with the ambitious goal to develop a ramjet-powered surface-to-surface cruise missile to carry a 450 kg (1000 lb) warhead over a range of 1600 km (1000 miles) at a speed of Mach 4. The payload and range requirements were subsequently increased to 2260 kg (5000 lb) and 2400 km (1500 miles). Because Mach 4 ramjets were way beyond the state-of-the-art in 1946, the Hermes B would require a long-term research effort. Therefore the project was split into the Hermes B-1 ramjet test vehicle and the Hermes B-2 operational missile. In 1946, the U.S. Army also established the Hermes II project, which was a broadly-defined general missile research effort to be conducted by a group of German scientists at the U.S. Army's Ordnance Research and Development Division at Ft. Bliss, TX. The first task of the Hermes II group was to design and fly a ramjet test vehicle in support of the Hermes B program. Later, in early 1948, the U.S. Army assigned the formal designations RTV-G-3, RTV-G-6 and SSM-G-9 to the Hermes II, Hermes B-1 and Hermes B-2 missiles, respectively.

The Hermes II test vehicle was actually the first flight-test article of the whole Hermes program. The missile consisted of a V-2, which had a ramjet-powered second stage (called "Ram") mounted semi-recessed on top. The "Ram" was a small vehicle with large wedge-shaped wings, which actually housed small rectangular-section ramjet units. This peculiar device was also called the "Organ". The V-2 first stage had enlarged fins to improve stability of the whole Hermes II missile. The Hermes II was launched into an arched trajectory, and after burnout of the V-2 engine, the "Ram" was to be separated from the V-2 by diffential aerodynamic drag. As soon as the "Ram" was no longer climbing, the ramjet units were to ignite and propel the vehicle to a speed of about 1000 m-s (3200 ft-s). The "Ram" was to carry a newly developed advanced gyro-inertial stabilization and guidance system. The first flight of a Hermes II occurred in May 1947, and used only a mockup "Ram" with dummy (non-burning) ramjets to measure dynamic pressures in the ramjet ducts. Although the flight was unsuccessful (the missile veered off course, crashing in Mexico(!)), some preliminary data was obtained.


*Note: Drawing shows original V-2 fins (RTV-G-3 as flown had larger ones)


Although further Hermes II flights were originally planned for 1947, these were postponed. The three remaining RTV-G-3 flights eventually occurred in January 1949, October 1949 and November 1950, but it is unclear whether the three latter flights carried a "Ram" with live ramjets and-or released the "Ram" into free flight. However, this seems relatively unlikely given the apparently reduced priority of Hermes II and the fact that the original schedule had planned free-flying inertially-guided live "Rams" only for flight #6 and later. The RTV-G-3 Hermes II was redesignated RV-A-3 in mid-1951.

Whether there were any RTV-G-6 Hermes B-1 vehicles (redesignated RV-A-6 in mid-1951) is a matter of debate. There are many sources which refer to the Hermes II missile described and illustrated in the preceding paragraphs as "RTV-G-6", "RTV-A-6" (which is incorrect in any case; see note (4) on designation table below) and-or "Hermes B-1". This is actually not surprising, because the RTV-G-6-RV-A-6 was planned to be the ramjet test vehicle of the Hermes B program, and the RTV-G-3-RV-A-3 Hermes II effectively was exactly that! Furthermore, by 1951 the U.S. Army apparently used the same project number for the RV-A-3 and RV-A-6, and there is also a common project summary report for RV-A-3-RV-A-6. There are several possibilities (the first one is in my opinion by far the most likely, and the last two are almost certainly incorrect):

  • The RV-A-6 was to be a completely new ramjet-powered missile, possibly closer to the projected Hermes B-2 tactical missile. If so, no RV-A-6 was ever built.
  • The RV-A-6 designation was transferred to the Hermes II, when it became clear that the latter would remain the only ramjet test vehicle for the Hermes B program. If so, the RV-A-3 and RV-A-6 are actually identical.
  • The RV-A-6 designation was applied to the "Ram" upper stage of the RV-A-3.
  • There were three launches of V-2s with (non-burning) cylindrical ramjet ducts on top to test Hermes B propulsion technology. The RV-A-6 designator might have been applied to these tests.

The history of the projected tactical SSM-G-9 Hermes B-2, redesignated SSM-A-9 in mid-1951, is a bit unclear. Source [1] says it was cancelled in June 1950, and this is confirmed by a U.S. Army document from 1951, which lists the SSM-A-9 program as "completed". On the other hand, source [3] (an official U.S. Army history document) quotes a termination date of 1954 for the Hermes B program. However, all relevant sources agree that work on an operational ramjet-powered missile was continued after the completion of the RTV-G-3 flight tests until September 1953 under the Hermes II-RV-A-3 program. The final specifications called for a rather impressive cruise missile, flying over a range of 2400 km (1500 miles) with a speed of Mach 4.5 at 24000 m (80000 ft). These studies apparently included static firings of ramjets (quite possibly related to a projected RV-A-6 vehicle), but no all-up missile flight tests. Whatever the details are, no actual XSSM-G-9 (XSSM-A-9) Hermes B-2 missiles were ever built.

AKA: RTV-G-3; Hermes II; SSM-A-9; SSM-G-9; RTV-G-6.
Gross mass: 14,400 kg (31,700 lb).
Payload: 230 kg (500 lb).
Height: 15.70 m (51.50 ft).
Diameter: 1.65 m (5.41 ft).
Span: 5.41 m (17.74 ft).
Thrust: 267.00 kN (60,023 lbf).
Apogee: 200 km (120 mi).
First Launch: 1947.05.30.
Last Launch: 1950.11.09.
Number: 4 .

More... - Chronology...


Associated Countries
Associated Engines
  • A-4 Thiel Lox/Alcohol rocket engine. 311.8 kN. Isp=239s. Used on V-2 missile. Work began June 1936. Interim design, but went into production. Used 18 x 1.5 tonne thrust chambers, feeding common mixing chamber. Tested from 1939, mass production 1943-1945. More...

See also
  • A4 The V-2, known as the A4 to its developers, was the basis for most of the rocketry that exists in the world today. It was ineffective as a weapon of war, but represented a quantum leap in technology. The A1, A2, A3, and A5 were steps in the development of the missile. Later versions - the A6 through A12 - were planned to take the Third Reich to the planets. More...
  • Hermes Hermes was a major US Army project to implement German rocket technology after World War II. Development started in 1944 with award to General Electric as the prime contractor. The program was cancelled in 1954 after $ 96.4 million had been spent. Most of this was for nought since the Air Force received the long-range missile assignment in the end. More...
  • missile Guided self-propelled military weapon (as opposed to rocket, an unguided self-propelled weapon). More...

Associated Manufacturers and Agencies
  • GE American manufacturer of rockets, spacecraft, and rocket engines. General Electric Corporation, USA. More...

Associated Launch Sites
  • White Sands White Sands Missile Range occupies an area 160 x 65 km in the Tularosa Basin of southern New Mexico, across the Sacramento Mountain range from Roswell. In the 1930's, Robert Goddard, after surveying weather conditions and population densities, had selected Roswell for his pioneering rocket tests. White Sands, a true desert area, was even more unpopulated than Roswell. German advances in rocketry during World War II impelled the US Army to begin programs to exploit this technology. The White Sands Proving Ground was established for testing German and American long-range rockets on 9 July 1945. Seven days later the first atomic bomb was exploded at Trinity Site, near the north boundary of the range. The first launch of a Tiny Tim rocket was on 26 September 1945. On 11 October a Tiny Tim boosted a WAC Corporal rocket from the tower. This was the first use of Launch Complex 33, later to be used for V-2, Nike, Viking, Corporal, Lance and Multiple Launch Rocket System testing. More...
  • White Sands LC33 Wac, Viking, V-2, Nike, Javelin, Hermes, Corporal, Atlas, Apache launch complex. LC 33 was the United States' first major rocket launch facility. The original Army Launch Area 1 complex consisted of a blockhouse, several concrete launching pads for captured German V-2 rockets, a 30-m tall launch tower for Aerobee rockets, a gantry and blast pit. More...

Associated Stages
  • A-4 Lox/Alcohol propellant rocket stage. Loaded/empty mass 12,805/4,008 kg. Thrust 311.80 kN. Vacuum specific impulse 239 seconds. V-2 production version. More...

Hermes B-1 Chronology


1947 May 30 - . Launch Site: White Sands. Launch Complex: White Sands LC33. LV Family: Hermes. Launch Vehicle: Hermes B-1. LV Configuration: Hermes B-1 B-1 No. 0. FAILURE: Failure.
  • Hermes II test - . Nation: USA. Agency: USA. Apogee: 50 km (31 mi). Hermes B-1 impacts a graveyard 18.5 km south of Juarez, Mexico on its first test flight. This and the out-of-range V-2 impact on 15 May resulted in new safety measures at WSPG. 'We were the first German unit to not only infiltrate the United States, but to attack Mexico from US soil'. This vehicle was deeply classified at the time. Hermes experiments were conducted with modified V-2 rockets to test the configuration of a ramjet propulsion system. Four Hermes B-1 rockets were flown from Complex 33, none of which were noted in the contemporary records.

1949 January 13 - . 20:26 GMT - . Launch Site: White Sands. Launch Complex: White Sands LC33. LV Family: Hermes. Launch Vehicle: Hermes B-1. LV Configuration: Hermes B-1 B-1 No. 1. FAILURE: Failure.
  • Hermes II test - . Nation: USA. Agency: USA. Apogee: 1.00 km (0.60 mi).

1949 October 6 - . Launch Site: White Sands. Launch Complex: White Sands LC33. LV Family: Hermes. Launch Vehicle: Hermes B-1. LV Configuration: Hermes B-1 B-1 No. 2. FAILURE: Failure.
  • Hermes II test - . Nation: USA. Agency: USA. Apogee: 4.00 km (2.40 mi).

1950 November 9 - . Launch Site: White Sands. Launch Complex: White Sands LC33. LV Family: Hermes. Launch Vehicle: Hermes B-1. LV Configuration: Hermes B-1 B-1 No. 2A.
  • Hermes II test - . Nation: USA. Agency: USA. Apogee: 150 km (90 mi).

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