Arcas (originally "All-Purpose Rocket for Collecting Atmospheric Soundings", also designated Big Boy Rocket or "PWN-6") was the designation of an American

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 often ...

, developed by the Atlantic Research Corp. (now Atlantic Richfield Company (ARCO)), Alexandria, Va. The Arcas sounding rocket was an unguided vehicle with a diameter of 4.5 inches designed to carry payloads of or less to heights in excess of when launched from sea level.Bruce Bollerman
''A Study of 30 km to 200 Km Meteorological Rocket sounding systems,'' Volume 1
Chapter 6.3.2, "Arcas,"' NASA Report CR-1529, May 1970, page 248-258. Retrieved 2018-03-22. The Arcas had a maximum flight altitude of , a takeoff thrust of 1.5 kN, a takeoff weight of , and a diameter of . The Arcas was long and had a fin span of . Including variants, it was launched at least 1,441 times between November 4, 1958, and August 9, 1991. Arcas launch sites included White Sands, Vandenberg, Fort Churchill, Point Mugu, San Nicolas, Cape Canaveral LC43, Eglin, Kronogård, Kindley,

McMurdo Station McMurdo Station is an American Antarctic research station on the southern tip of Ross Island. It is operated by the United States through the United States Antarctic Program (USAP), a branch of the National Science Foundation. The station is ...

, Barking Sands, CELPA (Mar Chiquita), Ascension, Birdling's Flat, Wallops Island LA2, Thumba,

Barbados Barbados, officially the Republic of Barbados, is an island country in the Atlantic Ocean. It is part of the Lesser Antilles of the West Indies and the easternmost island of the Caribbean region. It lies on the boundary of the South American ...

, Keweenaw, Thule AFB, Barreira do Inferno Launch Center,

Antigua Antigua ( ; ), also known as Waladli or Wadadli by the local population, is an island in the Lesser Antilles. It is one of the Leeward Islands in the Caribbean region and the most populous island of the country of Antigua and Barbuda. Antigua ...

Fort Greely Fort Greely is a United States Army launch site for anti-ballistic missiles located about southeast of Fairbanks, Alaska, Fairbanks, Alaska. It is also the home of the Cold Regions Test Center (CRTC), as Fort Greely is one of the coldest areas ...

Grand Turk Island Grand Turk is an island in the Turks and Caicos Islands, a British Overseas Territory, tropical islands in the Lucayan Archipelago of the Atlantic Ocean and northern West Indies. It is the largest island in the Turks Islands (the smaller of th ...

, Tartagal,

Fort Sherman Fort Sherman is a former United States Army base in Panama, located on Toro Point at the Caribbean (northern) end of the Panama Canal, on the western bank of the Canal directly opposite Colón, Panama, Colón (which is on the eastern bank). It w ...

and Primrose Lake.

History

A 1957

Stanford Research Institute SRI International (SRI) is a nonprofit organization, nonprofit scientific research, scientific research institute and organization headquartered in Menlo Park, California, United States. It was established in 1946 by trustees of Stanford Univer ...

study proposed a small single-stage sounding rocket to measure high-altitude winds to determine the spread of radioactive fallout. The U.S. Office of Naval Research and the Air Force Research Center awarded Atlantic Research Corporation a contract to develop this sounding rocket, known as "Kitty" in January 1958. ARC designed the Arcas rocket, the first of which was ready for flight tests in late 1958. By the end of 1960, more than 400 Arcas rockets had been launched.

Engine

The Arcas was powered by a slow-burning SR45-AR-1 solid-propellant motor with an end-burning grain, generating an average thrust of for 30 seconds. Total impulse was 9,089 lbf⋅s (40,430 N⋅s). Since the rocket diameter was larger than the nozzle diameter of the engine, the aft end of the rocket ended in a tapered "boat tail", to decrease the subsonic drag. Arcas was launched from a tubular closed-breech launcher, which provided a faster boost by the piston action of trapping the engine gasses. The rocket was kept centered in the tube by four plastic spacers.

Variants

Arcas use with DMQ-6 telemetry

When used for radar calibration in the 1960s, the Arcas rocket configuration consisted of a closed breech launcher, a sounding rocket, and two payload configurations, one a parachute recovery system with a DMQ-6 telemetry transmitter compatible with standard meteorological ground station receiving equipment, the other a one-meter metalized balloon for radar calibration. The Arcas characteristics for this type operation were: DMQ-6 :Nominal payload: :Maximum altitude: :Time to maximum altitude: 128 seconds Balloon :Nominal payload: :Maximum altitude: :Time to maximum altitude: 134 seconds Rocket: :Altitude at burnout: :Launch velocity: . :Total rocket weight: :Outside dimension of tail: Transmitter: :Robin balloon cross section :DMQ-6 transmitter cross section

Kitty

A variants of the basic Arcas were the Atlantic Research PWN-6A and 6B "Kitty".Andreas Parsch
"PWN-6"
Directory of U.S. Military Rockets and Missiles. Retrieved 2018-03-22. These had a ceiling of .

Rooster

Another variant of the basic Arcas was the PWN-7 "Rooster". It had a ceiling of 65 km.

Sidewinder Arcas

The Sidewinder Arcas was a two-stage

, consisting of a Sidewinder starting stage and an Arcas upper stage. The Sidewinder Arcas had a ceiling of , a takeoff

thrust Thrust is a reaction force described quantitatively by Newton's third law. When a system expels or accelerates mass in one direction, the accelerated mass will cause a force of equal magnitude but opposite direction to be applied to that ...

of 26 kN, a takeoff weight of , a diameter of and a length of .

Super Arcas

A higher power version of the Arcas, Super Arcas, was used extensively around the world from a wide variety of platforms on land and at sea. With a boost from a

gas generator A gas generator is a device for generating gas. A gas generator may create gas by a chemical reaction or from a solid or liquid source, when storing a pressurized gas is undesirable or impractical. The term often refers to a device that uses a ...

-fed launch tube, Super Arcas was capable of reaching altitudes as high as . There were many time-based weather experiments launched on this rocket due to the ability of the launch tube to be rapidly turned around for another launch. One of those experiments launched one rocket per hour for 24 hours straight in

Antarctica Antarctica () is Earth's southernmost and least-populated continent. Situated almost entirely south of the Antarctic Circle and surrounded by the Southern Ocean (also known as the Antarctic Ocean), it contains the geographic South Pole. ...

Boosted Arcas

Another variation of Arcas was called the Boosted Arcas, which was a 2-stage rocket; one Arcas second stage and one booster.

Sparrow Arcas

Sparrow Arcas was a two stage vehicle, composed of a Sparrow first stage and an Arcas second stage.

Frangible Arcas

Frangible Arcas was an experimental variation launched four times between 1964 and 1965. Rocket was designed to fragment after payload separation, reducing the risk to populated areas from falling spent rocket motor.

References

External links

*https://web.archive.org/web/20050412122516/http://astronautix.com/lvs/arcas.htm {{DEFAULTSORT:Arcas (Rocket) Sounding rockets of the United States