From Aerojet - The Creative Company, 1995:
The origins of Aerojet's sounding rockets lie in the development of the thrust chamber assembly for the Nike Ajax surface to air missile. Douglas Aircraft Co. (the vehicle contractor) let a contract to Aerojet on January 1, 1946 for a 21AL-2600, regeneratively cooled, pressure fed unit using RFNA and a 65%-35% mixture of aniline and furfuryl alcohol propellant. Development and early production of some 6600 thrust chambers and more than 100 complete engines was successful. However, the rest of the main production orders for the liquid rocket portions of the 16,000 operational missiles were given to Bell Aircraft. We did get to supply several thousand of the inertially activated pressure regulators. This was the first major operational surface to air missile in the United States, and was widely used by at least eleven other countries. The U. S. Army had converted to Nike Hercules by 1960, and some 7000 training flights of the Ajax worldwide, had been made by 1978.From NASA SOUNDING ROCKETS, 1958-1968 - A Historical Summary, NASA SP-4401, 1971, by William R. Corliss
During WW II, Aerojet also provided some support for early work by GALCIT on their Private and Corporal missiles. Some of these missiles were converted to sounding rocket service and WAC-Corporal sounding rockets were launched in late 1945. Dr James Van Allen, then supervisor of the High Altitude Research Group of the Applied Physics Laboratory (APL) at Johns Hopkins University, visited Dr. Rolf Sabersky at Aerojet in 1946 to survey its rocket capabilities, which of course, included Ajax. As a result, he persuaded the Navy to support development and initial production of what came to be known as the Aerobee family. Dr. Van Allen was also in charge of the sounding rocket part of the APL Bumblebee (tactical solid rocket) program … and coined the name Aerobee as a contraction of the Aerojet and Bumblebee names.
In December 1947 the Navy gave a contract to Aerojet for the development of the entire Aerobee sounding rocket, later known as the Aerobee 100. In those days, the preliminary design: activity was simple, direct, and effective - as described by Carson Hawk: "One day Young and I were assigned to prepare a preliminary design for a high altitude sounding rocket The next day we visited Caltech to review the data they had gathered on a similar rocket which they had tested in their wind tunnel. It was somewhat smaller as it was based on a 1500 lbf thrust chamber. We came back to Aerojet, and the next day laid out the Aerobee sounding rocket. We did a fairly complete weight analysis based on the known specific impulse for the 2600 lbf thrust chamber with RFNA and aniline/furfural alcohol propellants and the GALCIT drag data. We also did a prediction of burnout altitude and final altitude utilizing stepwise integration run on an electromechanical Marchant calculator. The first flights showed the design to be conservative by about 5%."
The contract included the 2.5KS-18000 solid booster, fins, nose cone, and all the other components needed to make a complete launch vehicle. Although the motor was a slightly modified Nike Ajax, it was now defined as a 45AL-2600, and with a new AJ10 series number. The same propellants were used, and the in-line, integral oxidizer, fuel and air pressurizing tanks constituted the main vehicle structure. In 1950, pressurization was changed to helium.
Initially the 2600 lbf thrust regeneratively cooled motor suffered a number of burnouts in the converging section of the nozzle. It used a spiral flow, fuel cooled configuration, with the fins that directed the flow being welded to the outside of the chamber wall and machined for a close fit with the inside of the cylindrical outer case and a smooth filler block in the nozzle area. A very simple change solved the problem permanently. It seemed likely that the chamber might be undergoing elongation and distortion from the thermal and pressure loads, and thus the filler block would lose contact with the tops of the fins. This allowed axial bypassing (and reduced velocity) of the coolant flow that might be causing the hot spots. The fix was to move the fins from the OD of the nozzle to the ID of the filler block, and to cut the block into two sections that were spring loaded in the fore and aft direction. This resulted in maintaining contact with both the converging and diverging portions of the nozzle wall, and no bypassing. It worked like a charm on all subsequent Aerobees and the B-47 motors.
In 1955 the 4000 lbf thrust model was introduced as the AJ10-24, and later as the AJ11-21. Chemical pressurization was developed for both the 2600 and 4000 lbf models, but Helium was generally preferred. This thrust chamber assembly was used in all subsequent 150, 150A and 170 vehicles. In the 1952-53 time period a larger vehicle with greater propellant capacity and increased thrust and nozzle expansion ratio motor was developed, and was known as the Aerobee 300. The 4000 lbf unit with a nozzle expansion ratio of only 4.6 actually produced. 4100 lbf thrust at sea level, and 4728 lbf at altitude. The 300 series (using the AJ60-92 motor) with the 10 to 1 nozzle produced a vacuum thrust of 5074 lbf. During 1965-66 the Aerobee 350 was developed, and this used a cluster of four 150 motors with a Nike solid rocket booster: Other variations included the Aerobee-Hi, the 200, and the 350A. Customers included the Army, Navy, Air Force, NASA, and a variety of other government agencies, as well as foreign users, and 1025 complete vehicles were produced.
The succession of rocket motor developments and growth was no less important than the similar activities conducted on the associated vehicle, launcher, and support parts of the system. Aerojet did the design, development, and much of the fabrication of essentially all of the Aerobee liquid second stages of the 100, 150, 150A, 170, 200, 300, and 350 units. In most cases we either supplied the Aerojet solid propellant first stages, or else specified and integrated solid first stages from other suppliers. All of the propellant feed systems used the simple pressure feed configuration with the pressurant, fuel and oxidizer tanks in line and welded into a single unit. Controls per se were non-existent, but the system was arranged to provide a smooth slow start of combustion. This provided a highly desirable "easy ride" for delicate payloads. Vehicle directional control was accomplished by simple fixed fins, which required correctly estimating the wind directions and adjusting the tower tilt accordingly. Aerojet supplied the payload mounting and related componentry, as well as the nose cone, fairings, and fins (via purchase from Douglas). Aerojet even supplied a few early payloads, and developed an attitude control system that could accurately point the payload in a selected direction - which is still being manufactured and sold to other launch vehicle users.
Aerojet's AETRON Division designed almost all of the launch towers, and handled the lubrication and erection of many of them. Locations ranged from Fort Churchill in Canada to Woomera Australia, and included at least one shipboard installation, and one pair of towers for simultaneous launches.
Support requirements were minimal - two men could do all the fueling, mounting and spaceflight preparations. Payloads were of course, dependent on their complexity, and recovery operations often took on the appearance of a "hounds and hare" chase across the desert to find and recover the payloads. In later years, some flights parachuted the entire vehicle back for refurbishment and reuse.
Sounding rockets were crucial to our early understanding of the upper atmosphere, and near space environment. They also provided invaluable information on the lower atmosphere and surface environment, oceans, winds, weather, and many phenomenon of interest to the military. Their third major area of use was the early examination of outer space, the sun, planets and other astral bodies. A large part of this understanding was obtained using sounding rockets, in most cases launched by Aerojet. In fact, Aerojet sounding rockets made up 51% of all U. S. sounding rocket launches (184) and reached the highest altitude (290 km) in the period before satellites, if the captured V-2s are excluded.
Aerojet and Bristol Aerospace Ltd of Winnipeg Canada formed a joint venture to share sounding rocket technology, and this lasted from 1958 to 1974. The first sounding rocket resulting from this cooperation, the Black Brant, was launched in 1965. Bristol gradually got more and more of the orders, and essentially displaced Aerojet from the business. They have produced more than 800 Black Brants since that time, and about two thirds, of their current production is for NASA. Aerojet's Aerobee project moved from the Azusa Plant to Space launch systems in 1961, and began the attempted expansion into supplying more complex complete launch systems (some with guidance), and a much broader range of vehicle sizes and capabilities. These included the Astrobee series and a variety of configurations based on various solid propellant rockets supplied by other companies. The last of the formal Aerobee program flights was in 1984.
The Aerobee, a high altitude sounding rocket, was sponsored in 1947 by the Naval Research Laboratory. The complete vehicle was a 19 ft. long, two stage, missile configured with an ogive nose and fixed stabilizing fins. It was boosted to about 1000 ft/sec by a 2KS-22,000 solid rocket. The sustainer rocket, a 2,600 lbf thrust nitric acid/aniline and furfural alcohol unit increased the velocity of the main stage to about 5,800 ft/sec. This vertical velocity was enough to allow the stage, with its 100 lb pay load, to reach an altitude of 150 miles. The payloads were scientific instruments, housed in the nose cone. The nose cone was separated at altitude and parachuted to earth for recovery. The unit also had a telemetry link which was used for vehicle destruction, in the case of an errant flight, as well as the signal to separate the nose cone from the main vehicle.
The Aerobee was launched from a tower, approximately 100 ft high. The tower was slightly canted in the up range direction to give the vehicle a measure of direction within the Range. The first tower was designed by the architect-engineer Division (Aetron), and built at White Sands Proving Grounds. Chan Ross participated heavily in the detail design of the vehicle with Bob Young. Some novel design features were developed for the high pressure fuel and oxidizer tanks. Significant was the submerged arc welding of a special cold-rolled stainless steel (19-9DL) to withstand over 100,000 psi tensile stress across the welded section. Also the use of machined ring forgings to form the knuckle radii and skirt attachment section was considered a first. These features allowed the entire vehicle to be smaller in size than would have been possible otherwise. Bob Young, Chan Ross, and Thorpe Walker, the Project Engineer, spent many days at White Sands during the early firings.
The Aerobee Program produced a fascinating folklore of its own, which Aerojet veterans still like to recall. For instance: in the early flight tests there was considerable trouble with exactly where the vehicle was going to impact when it landed. Many of the stories concern this problem. After the vehicle reached its zenith and started back towards Earth, the aerodynamics of the fins would give it a nose down attitude. If there was any wind at all, the unit would take a slight heading into the wind, the angle depending on the wind velocity. Thus, if one were to calculate an impact point, it required a rather precise knowledge of the ballistic wind situation. This is something that could only be estimated, as it was changeable. On this one occasion at White Sands, the wind direction changed soon after launch and was blowing rather severely from the South. The tracking equipment was not in a link that could predict impact changes and, as a consequence, the destruct system was not activated. The Aerobee headed for Mexico, about fifty miles to the South. It landed a few miles outside the city limits of Juarez, killing a lone cow in a field. It was an international incident requiring an apology by the State Department. To correct the problem of Aerobees impacting out of the Range boundaries, we worked with Van Allen's people at the University of Iowa and devised a moving set of arms which remained in the field of view of one of the theodolites tracking the vehicle. The motion of the arms was such that the Aerobee would be destructed on command of the operator if the line of sight fell outside of the arm position.
Aerobee pioneered the use of high altitude photography to study meteorological phenomena including cloud patterns. From this work the concept of weather satellites and some of the sensors were derived. The first maps of the earth's atmosphere, showing variations of temperatures and pressures with altitude and variations of composition, density and turbulence between the many layers, were from sounding rocket data; much of that was from the Aerobee. Aerobee was the first U. S. space vehicle to carry mammals 2200 mph into space (1954) and return them safely --- monkeys (Patricia and Mike) and mice (Mildred and Albert). The mice became attractions at the National Zoo and Mike lived nine more years. In mid 1970's Aerobee's were built to be recovered by parachute. They were then refurbished — ready to be turned around to fly again.
The largest of the Aerobee family is the Aerobee 350 (i.e. 100 lb. payload to 350 miles) sponsored by NASA. It is 50 ft long, 22 in. diameter and over 3 tons gross weight. Most Aerobees included a payload recovery system employing a parachute and using telemetry to release the payload and the parachute. Most Aerobees were launched from towers over 100 ft high designed by Aerojet's AETRON Division. The towers allow for a nearly vertical launch.
Aerobee's conception dates back to the mid 1930s when Theodore von Karman, Frank Malina and many of the Caltech staff started rocket work at the Guggenheim Aeronautical Laboratory at Caltech. Malina's memoirs show early sponsorship by the National Academy of Sciences and the interest in operation in space well before World War II brought the need for aircraft propulsion augmentation. The early work on the missiles Private and Corporal at Caltech's Jet Propulsion Laboratory (JPL) led to the WAC-Corporal sounding rocket firings in 1945. Dr. James Van Allen of the Applied Physics Laboratory (APL) at Johns Hopkins University was supervisor of the High Altitude Research Group and directed operation of the APL Bumblebee series of sounding rockets. Van Allen visited Dr. Rolf Sabersky at Aerojet in 1946 to survey rocket capability. He subsequently obtained Navy Bureau of Ordnance support for an order for 20 of the Aerojet Aerobee sounding rockets.
The Aerobee name, given by Van Allen, is a contraction of AEROjet and BumbleBEE, the latter referring to the early rocket family of Van Allen's. Aerojet had supplied propulsion for both the WAC-Corporal and the Bumblebee according to an Aerojet 1948 brochure.
Development of the Nike-Ajax surface-to-air missile engine in 1946 was a major factor in Aerojet starting the Aerobee. Douglas Aircraft built the Nike-Ajax and contracted with Aerojet on New Years Day 1946 for 21 AL-2600 regetvetativebf cooled, pressure-fed rocket engines using RFNA and alcohol propellants. This was the first operational surface-to-air missile in the U. S. and Aerojet made 6000 of the engines. Bell Aircraft made subsequent production runs also. This engine was the basis for the first Aerobee 100.
The early development did not go completely smoothly. The engine suffered a series of burnouts due to thermal and pressure distortions which opened gaps in the coolant flow and reduced the effective velocity over the chamber wall. The fix entailed sectioning the outer walls of the cooling passages and spring loading the sections to keep gaps from opening. It worked and was used successfully on both Aerobee and B-47 projects. In about 1950 the need for higher performance and payload resulted in the development of an engine to replace the original 2600 lbf unit. Design features were essentially identical. Optional nozzle expansions were available giving either 4728 or 5074 lbf. The same propellants and almost identical feed systems were used.
During the International Geophysical Year (IGY 1957-8) for a concentrated 18 month period scores of Aerobees were launched to collect data to help meet the IGY objectives. A variation of the Aerobee 150, called Aerobee-Hi was selected for a number of flights from near the Arctic Circle at Fort Churchill near Manitoba, Canada using an Aerojet Aetron-built launch tower. It was a part of the IGY Project Arctic Circle. Aerobee-Hi got its strange name a year earlier for reaching an altitude record of 163 miles. Some of the other IGY contributions of Aerojet included building the second stage of the Vanguard space launch vehicle which launched IGY scientific earth satellites.
Photographs of star fields were being made from space decades before the Hubble Space Telescope. Although simple and small by comparison, they could train on a predetermined spot in the sky and take photographs in various spectral ranges. One example is the first wide angle ultraviolet photographs of star fields taken from an Aerobee in flight. New data was obtained on the variations in star temperatures. That same system was later used on the Apollo missions. The Aerobee's low cost and high reliability (about 97%) allowed scientists to collect vast amounts of data relatively easily as early as ten years before the Sputnik satellite. Data was obtained on the ascent and descent of the Aerobee. Data could be collected over a period of several minutes.
Sounding rocket launches were made from ground, aircraft (F-4) and also from a ship --- the USS Norton Sound. Widely dispersed launch sites ranged from near the Arctic Circle to Australia and South Africa. Aerobee was launched wherever the scientific data needed to be collected. Often data on astronomy, magnetic fields, radiation fields and other areas of interest require special locations for best readings. Ship launches were made from many locations. The ground launches were made from locations including: Wallops Island, Virginia; White Sands and Holloman AFB, New Mexico; Eglin AFB, Florida; Fort Churchill, Canada; Walker Cay; and Woomera, Australia.
It is easy to see that the Aerobee was one of the first icons that represented Aerojet to the world, especially to the scientists and professors. Dr. James Van Allen flew many experiments on Aerobee in his work on the cosmic ray phenomenon and his complete solution of that long standing problem. He discovered the radiation belt (later named the Van Allen Belt) that circles the earth from Aerobee collected data. The Norton Sound was fitted with a tower to extend Van Allen's work, and others, around the world with the Aerobee. In Van Allen's Origins of Magnetospheric Physics, Smithsonian Institution Press, 1983, he said, "The immense opportunity for finally being able to make scientific observations through and above the atmosphere of the earth drove us to heroic measures and into a new style of research, very different from the laboratory type in which many of us had been trained." Aerojet's Aerobee team was certainly a part of those heroic measures.
Sounding rockets are complete rocket vehicles with multiple stages, propulsion systems, stabilizing fins, guidance and control systems, aerodynamic structures, launcher interface, payload containment, parachute recovery systems, nose cones, data recording systems, range safety destruct systems and essentially all the elements of any spaceflight rocket irrespective of the size. Launcher and range support were simple and a launch could be handled by two or three people.
These Aerobees were generally two stage rockets in series, the first stage being a solid propellant motor and a liquid propellant second stage on top. There were different family groups of Aerobees with each group given a number designation 100, 150, 170, 200 and 350. An Aerobee 150 could take a 100 lbm payload to 150 miles altitude. The Aerobee 350 could lift 150 lbm to 280 miles or 1000 lbm (half ton) to 130 miles. All but the 350 were 15 in. diameter. The 350 employed four clustered liquid engines and a solid booster stage and is 22 in. diameter. Aerobees were known for their smooth acceleration and soft ride from special propulsion and clean aerodynamic design --- a crucial factor in protecting the special pay loads. Aerobee work was moved to Space General in El Monte about 1961 and integrated with the sounding rocket guidance work brought in by acquisition of Space Electronics. Initially the Aerobees were operated as expendable vehicles with only the payload recovered. In the 1970s provisions were added to also recover the main vehicle itself for reflight. This was long before the reusable Space Shuttle. The first Aerobees were flying only two years after World War II and five years from Aerojet's inception. The last of the formal program flights was in 1984. Al Olson has been associated with the program since 1960 and although the Aerobee's are no longer flying, a small part of his responsibility is building and selling a Mk VI Attitude Control System for rockets around the world. This was one of the Aerobee subsystems developed at Space General and refined over the years with newer technology. It remains in demand and provides a profitable and steady but relatively small income for Aerojet. The unit allows for instruments to be pointed with relative precision to obtain special data on preselected guide stars.
Al Olson said recently, "I'd like to think the Aerobee made a real difference to the company, the country and even the world from all that data and from the way the sounding rocketeering led the way to the larger rockets and larger payloads. If so, then people including Cliff Chalfant, Charlie Roth, Nick Migdal, Reed Jenkins, and Jim Taylor can know all those ruined weekends and tough travel schedules were worth it." Al has kept a tally of all the Aerojet sounding rocket flights and is one of the last of the old sounding rocketeers at Aerojet. He is a program manager on some of the latest missile defense divert and attitude control systems. Tom Sprague documented that Space General President Jack Heckel (later Aerojet President) showed his engineering talent and teamwork spirit at one of his company's Aerobee launches when some smart elbow grease was needed — in that case "Rank Has Its Priorities."
The Aerobee flight log of Al Olson's shows there were 1030 flights and only 23 failures, which is an excellent record of 97.8% reliability. Tom Sprague documented a story of a recovery failure that sounds like a soap opera but was quite serious to the scientists involved. An Aerobee recovery failure caused the film of the 1971 solar eclipse to be lost in 6,000 ft of water. Gloom. Miraculously, the payload was located and recovered by a Navy deep diving vessel Euphoria! But then a mistake in the film processing lab rendered the photos useless. Double Gloom.
One Aerobee is displayed in a place of honor at the Smithsonian National Air and Space Museum near the Capitol Building in Washington D. C. Others are at the Air Force Museum in Dayton, Ohio and at White Sands Missile Range in New Mexico. Rocket modeling enthusiasts have favored the Aerobee as a prototype for decades and Aerojet provided drawings to help. Life magazine photographer J. R. Eyerman and Aerojet technicians rigged a Life magazine camera on an Aerobee and the January 6, 1958 edition showed the earth's curvature from 107 miles high, giving the world its first view of the earth from space.
...the Aerobee is a hybrid resulting from Navy development funds and Army technology (the Wac Corporal). In 1946, the scientific drawbacks of the V-2 were generally well known, as was the fact that the extant Wac Corporal was too small for much of the anticipated space research. The Aerobee program had its genesis when Merle A. Tuve and Henry H. Porter, of the Applied Physics Laboratory (APL) of the Johns Hopkins University, suggested to James A. Van Allen that he survey the rockets available for scientific research within the United States. An important event during Van Allen's survey was the visit to APL by Rolf Sabersky of Aerojet Engineering Corp., the manufacturers (along with Douglas Aircraft Co.) of the Wac Corporal, in early January 1946.
Van Allen's conclusions were submitted to Tuve (then Director of APL) on January 15 in a memo entitled "Liquid Powered Sounding Rockets for High Atmospheric Studies." Essentially, Van Allen's conclusions were that no fully satisfactory sounding rockets existed and that APL should act as an agent for the Navy Bureau of Ordnance in the development and procurement of new scientific sounding rockets. Also on January 15, APL directed a letter to Aerojet requesting a detailed proposal for the delivery of 20 sounding rockets capable of carrying 68 kg (150 lb) to 60 960 m (200 000 ft). Following a conference at APL on February 2, Aerojet submitted a letter proposal on February 22 bearing the lengthy title: "Proposal to Develop Sounding Rockets Capable of Attaining Altitudes in Excess of 600 000 Feet (182 880 m) and Carry a Payload from 300 to 1500 Pounds (136 to 680 kg), This to Include Liquid Rocket Motor and Fuel Development and Also to Develop Efficient High Thrust Launching Rockets."
Meanwhile the Naval Research Laboratory, which had provided many experiments for the V-2s, was consulted. On March 1, 1946, Van Allen recommended that the Navy Bureau of Ordnance negotiate a contract with Aerojet for the procurement of 20 liquid-propellant sounding rockets, 15 of which would go to APL and 5 to NRL. The contract was formally awarded to Aerojet on May 17 for 20 XASR-1 sounding rockets. The rocket performance stipulated was the delivery of 68 kg (150 lb) of payload to over 91 440 m (300 000 ft) - obviously, the Aerobee would have to be considerably larger than the Wac Corporal. At APL, which was assigned the task of technical direction by the Navy, James A. Van Allen took charge of the Aerobee program.
The Aerobee industrial team was essentially the same as that which built the Wac Corporal. Aerojet Engineering was the prime contractor while Douglas Aircraft Co. performed aerodynamic engineering and some manufacturing. The original Aerobee was about 6 m (19 ft) long and weighed roughly 725 kg (1600 lb). It featured the same propellants as the Wac Corporal (furfuryl alcohol and red fuming nitric acid) and a 1.8-m (6-ft) solid-propellant booster that accelerated the basic vehicle to about 300 m/sec (1000 ft/sec) before dropping off.
The first Aerobee test took place at White Sands on September 25, 1947, when a dummy Aerobee was launched with a live booster to check out stage separation. Two similar tests followed in October. Then, on November 24, 1947, the first full-scale Aerobee was launched. Although the flight had to be terminated after 35 seconds because of excessive yaw, so many subsequent flights were successful that the rocket was soon renowned for its reliability - particularly in comparison with the V-2. Orders for more Aerobees from Government agencies began to arrive at Aerojet. Aerojet has made various versions of the Aerobee ever since.
Some 40 of the original Aerobee design (XASR-1) were fired.
Payload: 68 kg (149 lb) to a 130 km altitude. Failures: 70. Success Rate: 93.34%. First Fail Date: 1947-11-24. Last Fail Date: 1978-02-04. Launch data is: complete.
Status: Retired 1985.
Gross mass: 727 kg (1,602 lb).
Payload: 68 kg (149 lb).
Height: 7.80 m (25.50 ft).
Diameter: 0.38 m (1.24 ft).
Thrust: 18.00 kN (4,046 lbf).
Apogee: 130 km (80 mi).
First Launch: 1957.07.16.
Last Launch: 1959.11.30.
Number: 36 .