Hermes

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Tactical ballistic missile. Family: V-2. Country: USA. Status: Retired 1954.

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.

The designs ran the gamut from short range solid propellant rockets through Mach 3 ramjets to intercontinental boost-glide vehicles. General Electric was also responsible for firing captured German V-2 rockets, training Army personnel in their use, and the Bumper project which created a two-stage vehicle using a V-2 and a WAC-Corporal. See individual entries for the Hermes A-1, Hermes A-3, Hermes B-1, and Hermes C.

On 20 November 1944 the Army's Ordnance Department issued a contract to General Electric for Project Hermes, the development of long-range missiles surface-to-surface and surface-to-air missiles. With the defeat of Germany on near horizon, this was intended primarily for Americanization and continued development of German technology. In a three-phase program, GE was first to prepare with a comprehensive search of the available literature; then send an engineering group to the future occupied Germany to become familiar with the German missile programs; and finally to develop Americanized experimental versions of the German weapons.

Three categories of missiles were to be developed:

Hermes A1, an antiaircraft missile based on the German Wasserfall. system. Following the establishment of the indigenous Nike project in February 1945, and after it was clear that the Germans had not in fact solved the surface-to-air missile guidance problem, the A1 was reduced to a propulsion test vehicle.
Hermes A2, which was to have been a wingless, surface-to-surface version of the Hermes Al. This never left the planning stage (the Russians did pursue their equivalent version of the Wasserfall, resulting in the Scud ballistic missile, still feared and in worldwide use 60 years later). In 1949 the Hermes A2 designation was applied to a proposed, low-cost, surface-to-surface missile capable of carrying a 680-kg warhead over a 120-km range. The propulsion system for this proposed missile was jointly developed by General Electric and Thiokol. But no funding was forthcoming from the Army to develop the missile itself.
Hermes A3 described, a tactical missile that was originally to deliver a 450-kg warhead 240 km with a circular probable error of 60 m. But these specifications were changed constantly by the Army, due to the rapid development of nuclear weapons and the changing Army doctrine of their use. The resulting annual redesigns of the missile during the 1940's meant that no progress could begin in actually developing the missile. Finally the A3 was reduced to test vehicle status in June 1953 and terminated in 1954.

In addition to these ultimate products, GE ended up running a large number of other projects under Hermes once the scope of the German rocket effort was understood:

Firing of captured V2 rockets from White Sands, running from 15 March 1946 to June 1951. GE was to use the scientific and engineering data it obtained from the V2 to design American rockets of the type. The firings were to verify available research data and to conduct new high-altitude research; to test American-developed control equipment, fuses, countermeasures, and instrumentation; and to gain experience in the handling and firing of high-velocity missiles. These firings cost the Ordnance Department $1 million annually - one of the most efficient and economical phases of the entire guided missile program.

Bumper, a project to launch a two-stage version of the V-2. The V-2 would serve as the first stage, a WAC Corporal the second. to extreme altitudes, speeds, and ranges. Eight of these missiles were built and flown. They proved the feasibility of two-stage, liquid-fueled rockets, solved the problem of separating two rockets while in flight, the ignition and operation of rocket motors at high velocities and altitudes. Basic design data for future missiles also evolved from studies of the problems of aerodynamic heating of these hypersonic missiles.

Hermes B, a Mach-4 missile based on German breakthroughs in ramjet propulsion. Work began in June 1946 when the Army recognized that GE was the "…only group in the country who believed they could develop a Mach 4 ramjet" . This ambitious project required basic research in propulsion, aerodynamics, structures, and trajectory-shaping. Hermes B was to carry a 450 kg warhead over a 1600 km range at 4200 kph. Wishing to make the missile nuclear-capable, the Chief of Ordnance later changed the specifications to require a 2300-kg warhead to be carried over a 2800-km range at 4500 kph. This resulted in GE proposing a test vehicle, the Hermes B1, to test technologies leading to a Hermes B2 missile meeting the full requirement. GE used the von Braun team at White Sands to fly the B1 four times in 1950-GE static fired engines for the Hermes B2, but the program was canceled in 1954, when the Air Force was assigned responsibility for such missiles. The Air Force Navaho, a long-range Mach-3 ramjet missile, flew in the late 1950's but was in turn canceled in favor of cheaper, less-vulnerable ballistic missiles.

Hermes C1 was the subject of a feasibility study for a long-range ballistic missile authorized in June 1946. The original recommended Hermes C1 was a two-stage, 113 tonne missile powered by 450-kN rocket engines, with a range of over 3200 km. Six engines in clusters of two would make up the first stage, providing a total of 2700 kN of thrust at lift-off and burning for 60 seconds. The second stage would have one motor, and burn for 60 seconds. The 450 kg warhead would separate after burnout of the second stage and glide at hypersonic speed to its target. However GE was ordered to give the other Hermes projects more priority, and didn't turn in the feasibility study for the C1 to the Army until October 1950. The Chief of Ordnance found it valuable, and ordered that it be further refined, while stopping short of authorizing active development of the concept by GE. Instead von Braun's team, just moved to the Redstone Arsenal in Huntsville, Alabama, were asked to pursue in-house development of a single-engine, single-stage version, the Hermes C, as a tactical ballistic missile. This would begin flying three years later as the Redstone missile. Interestingly, the clustered-engine concept would emerge again in April 1957 as the Saturn I.

Hermes II, which began in April 1946 when GE was given a contract supplement for improved exploitation of the von Braun rocket team held at Fort Bliss, Texas. In order to stimulate their creative juices and observe their methods, the German group were given specific design and development projects. The objective of the Hermes II was development of a ramjet research test vehicle, which would carry a 230-kg payload over an 800-km range at Mach 3.3. Hermes II consisted of a modified V2 booster with a winged, ramjet second stage. On 31 October 1951, the Hermes II was given the official RV-A-3 designation. Work continued on the project until its cancellation in September 1953.
The Department of the Army invested well over $100 million in the Hermes projects during their 10-year life span. Yet, at the end of that decade there was no Hermes missile system available for production or tactical deployment. As this had been one of the original objectives (the development of a tactical weapon system), how did the Ordnance Department justify this expenditure of research and development funds? The answer may well be found in the contributions it made to the advancing state of the art. Because the General Electric Company began the Hermes project when there was a dearth of basic design information for guided missiles, it performed research as a prerequisite to achieving its goals. In so doing, it discovered and extended basic knowledge in areas such as propulsion systems, rocket fuels, aerodynamics, guidance equipment, and testing equipment. It compiled basic statistics on motor design. It pioneered in producing higher impulse and more efficient rocket fuels. It contrived a method of including, in propellants, silicone additives that deposited protective coatings on the interiors of rocket motors against the corrosive effects of high velocities and temperatures.
Another of its achievements in rocket motors was the hybrid motor which was the first in which the thrust could be controlled by the regulation of the flow of the oxidizing agent into the motor. Through exhaustive aerodynamic studies and tests, it also accumulated technical data used in designing missile airframe structures. Furthermore, the General Electric Company pioneered in the development of guidance equipment to insure greater accuracy of a missile's flight path. It invented a coded, command-guidance radar that was adapted for use in the Corporal system. The first inertial guidance equipment used in any missile system was devised for the Hermes A3. A similar guidance system was later used, effectively, in the Redstone.
Thus, the Ordnance Department could very well have looked upon the Department of the Army's investment in the Hermes projects as one that had paid dividends in knowledge, equipment, and experience even though the desired tactical missile failed to materialize.
Manufacturer: GE. Launches: 26. Failures: 6. Success Rate: 76.92%. First Launch Date: 1947-05-30. Last Launch Date: 1954-11-16. Launch data is: complete. Development Cost $: 96.400 million. in: 1949 average dollars. Version:
Hermes A-1.
Hermes A-1
Other Designations: RV-A-5. Department of Defence Designation: SSM-A-15. Popular Name: CTV-G-5. Alternate Designation: SSM-G-15.
The Army Hermes A-1 single stage test rocket was an American version of the German Wasserfall anti-aircraft rocket.
Historical Essay © Andreas Parsch
After several configurations for the Hermes A-1 surface-to-air missile had been studied, it was decided in 1946 to base the missile on the war-time German Wasserfall SAM. However, after the SAM-N-7/MIM-3 Nike project had been started in the same year, the Hermes A-1 was redefined as a pure test vehicle for guidance and control systems. During 1947 and 1948, component flight testing took place on V-2s, but problems with the rocket engine delayed the launch of the first Hermes A-1 (designated CTV-G-5 in early 1948) until 1950. After two failures in May and September 1950, the first fully successful flight occurred on 2 February 1951, followed by two more tests in March and April that year. This concluded the flight test program of the CTV-G-5, which was formally redesignated as RV-A-5 in mid-1951.

The CTV-G-5's aerodynamic characteristics, its propulsion system, and its radio-command guidance system were considered satisfactory. During 1950, improved versions of the CTV-G-5 were studied (as Hermes A-1E1 and Hermes A-1E2), and the designation SSM-G-15 (formally changed to SSM-A-15 in mid-1951) was reserved for a tactical surface-to-surface version of the Hermes A-1. However, the SSM-G-15 proposal was very short-lived, and in May 1950 the Hermes A-1 was again and finally reduced to a pure research program. No XSSM-G-15 missile was built as such, but it appears that one Hermes A-1E1 was assembled but not flown. The whole Hermes A-1 program was officially terminated in October 1951, when the focus for liquid-fueled rocket-powered Hermes development had shifted to the Hermes A-3.

Launches: 5. Failures: 2. First Launch Date: 1950-05-19. Last Launch Date: 1951-04-26. Apogee: 25 km (15 mi). Liftoff Thrust: 71.000 kN (15,961 lbf). Total Mass: 3,025 kg (6,668 lb). Core Diameter: 0.86 m (2.82 ft). Total Length: 7.77 m (25.49 ft). Span: 2.49 m (8.16 ft). Maximum range: 65 km (40 mi).
- Stage1: 1 x Hermes A-1-1. Gross Mass: 5,000 kg (11,000 lb). Motor: 1 x Hermes A-1. Thrust (vac): 71.000 kN (15,961 lbf). Length: 7.80 m (25.50 ft). Diameter: 0.86 m (2.82 ft). Propellants: Nitric acid/Tonka.
Version:
Hermes A-2. Department of Defence Designation: SSM-G-13. Popular Name: RTV-G-10. Alternate Designation: SSM-A-13.
The Army Hermes A-2 single stage test rocket proved the technology of large solid rocket motors as developed by H L Thackwell at Thiokol. But the Army preferred to have further development done in-house and JPL was selected to develop the Sergeant rocket. In addition to the flight tests, a total of 22 motors were static fired, including one after seven years of storage.
Historical Essay © Andreas Parsch
The original Hermes A-2 was a wingless surface-to-surface derivative of the Hermes A-1, but this project died early in the planning stage around 1947. The A-2 designator was revived in 1948, when it was assigned to a proposed low-cost short-range (120 km (75 miles)) surface-to-surface missile to be powered by a solid-propellant rocket motor. Because large solid rocket motors were essentially an unexplored field at that time, the Hermes A-2 project's initial focus was on the RV-A-10 propulsion test vehicle (most probably designated RTV-G-10 before mid-1951; see note (2) on designation table below). However, a tactical missile (to be armed with a 40 kT W-7 nuclear fission warhead) was also projected as SSM-G-13 (SSM-A-13 after mid-1951).

In 1950, Thiokol began the development of the United States' first large solid-fueled rocket motor. After numerous tests with subscale motors and static firings, the first flight of the RV-A-10 occurred in February 1953. It was successful and was followed by three more successful tests in March that year, which ended the program. The RV-A-10 was a completely unguided rocket, but it validated the concept of solid-fuel propulsion for large missiles. However, the tactical XSSM-A-13 Hermes A-2 had already been cancelled in October 1952, and the development of a solid-fueled short-range ballistic missile was assigned by the Army to the JPL (Jet Propulsion Laboratory), leading to the SSM-A-27/MGM-29 Sergeant.

Manufacturer: Thiokol. Launches: 4. First Launch Date: 1953-02-11. Last Launch Date: 1953-03-25. Apogee: 58 km (36 mi). Liftoff Thrust: 142.000 kN (31,922 lbf). Total Mass: 3,530 kg (7,780 lb). Core Diameter: 0.79 m (2.59 ft). Total Length: 6.17 m (20.24 ft). Span: 2.41 m (7.90 ft). Maximum range: 109 km (67 mi). Number Standard Warheads: 1. Standard warhead: W-7. Standard warhead yield: 40 KT. Boost Propulsion: Solid.
- Stage1: 1 x RV-A-10-1. Gross Mass: 3,500 kg (7,700 lb). Empty Mass: 800 kg (1,760 lb). Thrust (vac): 140.000 kN (31,470 lbf). Burn time: 30 sec. Length: 4.00 m (13.10 ft). Diameter: 0.79 m (2.59 ft).
Version:
Hermes A-3.
Hermes B-1

Prototype of a single-stage liquid propellant tactical Army missile. Two versions test flown but abandoned in favour of the Redstone in-house design.
Historical Essay © Andreas Parsch
In late 1947, the U.S. Army established preliminary characteristics for the Hermes A-3 program, calling for a liquid-fueled rocket-powered surface-to-surface missile to carry a 450 kg (1000 lb) warhead to 240 km (150 miles) with an accuracy of 60 m (200 ft) CEP. In early 1948, the designation SSM-G-8 was assigned, but the project progressed very slowly in the first years. This was mainly because of frequent changes in the requirements, which repeatedly necessitated a complete redesign of the projected XSSM-G-8 missile. However, the Hermes A-3 program accelerated somewhat in 1951, when it was split into the RV-A-8 Hermes A-3A interim test vehicle and the SSM-A-16 (briefly SSM-G-16) Hermes A-3B operational missile with a W-5 nuclear warhead (47 kT).

The first flight attempt of an RV-A-8 failed in March 1953, but the second test succeeded in June that year. Until January 1954, a total of seven Hermes A-3As were launched, but only two flights were fully successful. Nevertheless, the RV-A-8's reliable (for its time) high-performace liquid-fueled rocket engine and its inertial guidance system significantly advanced the state-of-the-art in ballistic missile design. Although the Hermes A-3 program was reduced to a pure research effort in June 1953, six XSSM-A-16 Hermes A-3B missiles were launched between May and November 1954. However, only one of these (in October) was fully successful. The XSSM-A-16, originally designed as the prototype for the operational missile, was of similar design but slightly larger than the RV-A-8, and featured a further improved radio/inertial guidance system.

The Hermes A-3B was actually the last surviving element of the Hermes program, and the latter was finally terminated at the end of 1954. Although Hermes did not result in any operational missile, the Army's successful SSM-A-14/PGM-11 Redstone and SSM-A-27/MGM-29 Sergeant missiles owed much to the technology studied and tested during the Hermes program.

Apogee: 30 km (18 mi). Liftoff Thrust: 80.000 kN (17,984 lbf). Total Mass: 3,800 kg (8,300 lb). Core Diameter: 1.02 m (3.34 ft). Total Length: 8.70 m (28.50 ft). Version:
Hermes A-3A. Department of Defence Designation: RV-A-8. Alternate Designation: SSM-G-8.

Launches: 7. First Launch Date: 1953-03-13. Last Launch Date: 1954-01-15. Apogee: 30 km (18 mi). Liftoff Thrust: 80.400 kN (18,075 lbf). Total Mass: 3,780 kg (8,330 lb). Core Diameter: 1.02 m (3.34 ft). Total Length: 8.74 m (28.67 ft). Span: 2.29 m (7.51 ft). Maximum range: 105 km (65 mi). Boost Propulsion: Liquid propellant.
- Stage1: 1 x Hermes A-3A-1. Gross Mass: 3,800 kg (8,300 lb). Motor: 1 x Hermes A-3A. Thrust (vac): 80.000 kN (17,984 lbf). Length: 8.70 m (28.50 ft). Diameter: 1.02 m (3.34 ft). Propellants: Nitric acid/Tonka.
Version:
Hermes A-3B. Department of Defence Designation: SSM-A-16.

Launches: 6. Failures: 1. First Launch Date: 1954-05-11. Last Launch Date: 1954-11-16. Apogee: 37 km (22 mi). Liftoff Thrust: 100.500 kN (22,593 lbf). Total Mass: 5,370 kg (11,830 lb). Core Diameter: 1.19 m (3.90 ft). Total Length: 10.16 m (33.33 ft). Span: 2.54 m (8.33 ft). Maximum range: 105 km (65 mi). Number Standard Warheads: 1. Standard warhead: W-5. Standard warhead yield: 47 KT. Boost Propulsion: Liquid propellant.
- Stage1: 1 x Hermes A-3B-1. Gross Mass: 5,300 kg (11,600 lb). Empty Mass: 2,000 kg (4,400 lb). Motor: 1 x Hermes A-3B. Thrust (vac): 100.000 kN (22,480 lbf). Length: 10.10 m (33.10 ft). Diameter: 1.19 m (3.90 ft). Propellants: Nitric acid/Tonka.
Version:
Hermes B-1.
Hermes B-1
Credit - © Mark Wade
Other Designations: RTV-G-3. Department of Defence Designation: SSM-A-9. Manufacturer's Designation: Hermes II. Popular Name: SSM-G-9. Alternate Designation: RTV-G-6.
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.
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.

Launches: 4. Failures: 3. First Launch Date: 1947-05-30. Last Launch Date: 1950-11-09. Apogee: 200 km (120 mi). Liftoff Thrust: 267.000 kN (60,023 lbf). Total Mass: 14,400 kg (31,700 lb). Core Diameter: 1.65 m (5.41 ft). Total Length: 15.70 m (51.50 ft). Span: 5.41 m (17.74 ft). Standard warhead mass: 230 kg (500 lb). Maximum range: 500 km (310 mi). Boost Propulsion: Lox/alcohol. Boost engine: V-2. Cruise Propulsion: Jet fuel+Boron hydride. Cruise engine: GE Ramjet. Guidance: Inertial. Maximum speed: 3,500 kph (2,100 mph). Ceiling: 30,000 m (98,000 ft).
- Stage1: 1 x A-4. Gross Mass: 12,805 kg (28,230 lb). Empty Mass: 4,008 kg (8,836 lb). Motor: 1 x A-4. Thrust (vac): 311.800 kN (70,095 lbf). Isp: 239 sec. Burn time: 68 sec. Length: 12.00 m (39.00 ft). Diameter: 1.65 m (5.41 ft). Propellants: Lox/Alcohol.
Version:
Hermes C-1. Other Designations: RV-A-10. Department of Defence Designation: SSM-G-13. Popular Name: RTV-G-10. Alternate Designation: SSM-A-13.
The Hermes C1 was a clustered-engine intercontinental ballistic missile proposed by General Electric in June 1946. It was eventually down-scoped to a single-engine tactical missile, which flew as the Redstone in 1953.
Hermes C1 was the subject of a feasibility study for a long-range ballistic missile authorized in June 1946. The original recommended Hermes C1 was a two-stage, 113 tonne missile powered by 450-kN rocket engines, with a range of over 3200 km. Six engines in clusters of two would make up the first stage, providing a total of 2700 kN of thrust at lift-off and burning for 60 seconds. The second stage would have one motor, and burn for 60 seconds. The 450 kg warhead would separate after burnout of the second stage and glide at hypersonic speed to its target. However GE was ordered to give the other Hermes projects more priority, and didn't turn in the feasibility study for the C1 to the Army until October 1950. The Chief of Ordnance found it valuable, and ordered that it be further refined, while stopping short of authorizing active development of the concept by GE. Instead von Braun's team, just moved to the Redstone Arsenal in Huntsville, Alabama, were asked to pursue in-house development of a single-engine, single-stage version, the Hermes C, as a tactical ballistic missile. This would begin flying three years later as the Redstone missile. Interestingly, the clustered-engine concept would emerge again in April 1957 as the Saturn I.
Manufacturer: Thiokol. Apogee: 24 km (14 mi). Liftoff Thrust: 2,670.000 kN (600,230 lbf). Total Mass: 110,000 kg (240,000 lb). Maximum range: 60 km (37 mi). Boost Propulsion: Liquid Propellant. Boost engine: 6 engines. Cruise Propulsion: Liquid Propellant. Cruise engine: 1 engine. Stage 3 Engine: Glide vehicle.
Hermes Chronology

1944 December 1 - V-2 technology targeted for Hermes. Army Ordnance made plans under the Hermes program to study the German V-2 missile.
1946 January 11 - Hermes Mach 3 ramjet proposed. Von Braun briefs Hermes; V-2 first stage, ramjet second stage, cruise at 3400 kph at 19 km altitude.
1947 May 30 - White Sands LC33. Hermes B-1 B-1 No. 0 FAILURE: Failure. Hermes II test 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 - White Sands LC33. Hermes B-1 B-1 No. 1 FAILURE: Failure. Hermes II test Agency: USA. Apogee: 1.00 km (0.60 mi).
1949 October 6 - White Sands LC33. Hermes B-1 B-1 No. 2 FAILURE: Failure. Hermes II test Agency: USA. Apogee: 4.00 km (2.40 mi).
1950 May 19 - White Sands LC33. Hermes A-1 1 FAILURE: Failure. Agency: USA. Apogee: 0 km ( mi). First Army Hermes A-1 test rocket fired at WSPG.
1950 September 14 - White Sands LC33. Hermes A-1 2 FAILURE: Failure. Test mission Agency: USA. Apogee: 0 km ( mi).
1950 November 9 - White Sands LC33. Hermes B-1 B-1 No. 2A Hermes II test Agency: USA. Apogee: 150 km (90 mi).
1951 February 8 - White Sands LC33. Hermes A-1 4 Test mission Agency: USA. Apogee: 24 km (14 mi).
1951 March 15 - White Sands LC33. Hermes A-1 5 Test mission Agency: USA. Apogee: 24 km (14 mi).
1951 April 26 - White Sands LC33. Hermes A-1 6 Test mission Agency: USA. Apogee: 24 km (14 mi).
1953 February 11 - Cape Canaveral -. LV Model: Hermes A-2 . RV-A-10 1 Test mission Agency: USA. Apogee: 50 km (31 mi).
1953 March 4 - Cape Canaveral -. LV Model: Hermes A-2 . RV-A-10 2 Test mission Agency: USA. Apogee: 50 km (31 mi).
1953 March 13 - White Sands LC33. Hermes A-3A 1 RV-A-8 test Agency: USA. Apogee: 30 km (18 mi).
1953 March 25 - Cape Canaveral -. LV Model: Hermes A-2 . RV-A-10 4 Test mission Agency: USA. Apogee: 50 km (31 mi).
1953 March 25 - Cape Canaveral -. LV Model: Hermes A-2 . RV-A-10 3 Test mission Agency: USA. Apogee: 50 km (31 mi).
1953 June 18 - White Sands LC33. Hermes A-3A 2 Test mission Agency: USA. Apogee: 30 km (18 mi).
1953 August 13 - White Sands LC33. Hermes A-3A 3 Test mission Agency: USA. Apogee: 30 km (18 mi).
1953 October 5 - White Sands LC33. Hermes A-3A 4 Test mission Agency: USA. Apogee: 30 km (18 mi).
1953 October 21 - White Sands LC33. Hermes A-3A 5 Test mission Agency: USA. Apogee: 30 km (18 mi).
1953 November 20 - White Sands LC33. Hermes A-3A 6 Test mission Agency: USA. Apogee: 30 km (18 mi).
1954 January 15 - White Sands LC33. Hermes A-3A 7 Test mission Agency: USA. Apogee: 30 km (18 mi).
1954 May 11 - White Sands LC33. Hermes A-3B 1 Test mission Agency: GE. Apogee: 32 km (19 mi).
1954 July 20 - White Sands LC33. Hermes A-3B 2/A-16 Test mission Agency: GE. Apogee: 35 km (21 mi).
1954 August 26 - White Sands LC33. Hermes A-3B 3 FAILURE: Failure. Test mission Agency: GE. Apogee: 3.00 km (1.80 mi).
1954 September 21 - White Sands LC33. Hermes A-3B 4 Test mission Agency: GE. Apogee: 36 km (22 mi).
1954 October 19 - White Sands LC33. Hermes A-3B 5 Test mission Agency: GE. Apogee: 36 km (22 mi).
1954 November 16 - White Sands LC33. Hermes A-3B 6 Test mission Agency: GE. Apogee: 34 km (21 mi).
Bibliography:
- McDowell, Jonathan, Jonathan's Space Home Page (launch records), Harvard University, 1997-present. Web Address when accessed: http://www.planet4589.org/jsr.html.
- Emme, Eugene M, Aeronautics and Astronautics: An American Chronology of Science and Technology in the Exploration of Space 1915-1960, NASA, 1961. Web Address when accessed: http://www.hq.nasa.gov/office/pao/History/timeline.html.
- Ordway, Frank, and Sharpe, Mitchell, The Rocket Team, Collector's Guide Publishing, Ontario, Canada, 2000.
- Alway, Peter, Rockets of the World, Saturn Press, Ann Arbor, 1995.
- Parsch, Andreas, DesignationSystems.Net, Web Address when accessed: http://www.designation-systems.net/.
- Carpenter, Joel, ufx.org, Web Address when accessed: http://www.ufx.org/.
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