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The MIDAS 6 (MIssile Defense Alarm System) satellite was designed primarily to detect the exhaust heat from a recently launched ICBM by use of infrared sensors. A secondary objective was to eject small copper needles into Earth orbit (Project West Ford). The needles were to serve as an artificial scattering medium for radio signals in the centimeter band. The spacecraft was cylindrically shaped measuring approximately 6 m in length and 1.5 m in diameter. Once in orbit, the spacecraft was stabilized in a nose-down attitude so that the IR sensors and telemetry antenna were always facing earthward. The satellite continued in orbit until April 1977.

Project West Ford

Flying as a payload on the Midas 4 and 6 missions was a controversial experiment, run by Lincoln Labs and the Department of Defense, called Project West Ford (or Project Needles). The payload consisted of a "dispenser", a cylinder of naphthalene with millions of tiny wires, or "needles", embedded in it. The payload would be ejected into Earth orbit, and as it sublimed it would release the needles into an Earth-orbiting cloud, which would spread into a continuous torus. The objective of the project was to use this short-lived orbiting torus of conducting dipoles as an artificial scattering medium to test a passive communication technique of bouncing radio signals off the torus to other locations on Earth. The needles were small copper wires, 1.78 cm (0.7 inches) long. The length was chosen to be half the wavelength of an 8.4 GHz frequency radio signal. The first West Ford experiment, launched on Midas 4 in 1961, used approximately 350 million of these needles with diameters of 0.00254 cm (0.001 in). The 28 kg of copper needles were embedded in roughly 2 kg of naphthalene, forming a cylinder 14 cm in diameter and 32 cm long with a mass of 30 kg. Total mass of the cylinder and deployer system was 42 kg.

The cylinder was released on ground command after Midas 4 had achieved orbit, into a 3500 x 3750 km altitude, 95.9 degree inclination orbit. The cylinder was supposed to have a 6 revolution per second spin imparted to it upon release, but this did not occur. Furthermore, the naphthalene did not heat up and disperse the needles as planned, but instead ended up forming "clumps", seven of which have been tracked (radar cross sections of 0.06 to 0.6 square meters) and are still in orbit as of 2013. It is estimated that tens of thousands of clusters, too small to be tracked, may have formed.

The second West Ford experiment, on this mission, was more successful. The 1.78 cm long needles were thinner, with diameters of 0.00178 cm (0.0007 in). 480 million of these were embedded in 1.5 kg of naphthalene, forming five disks, joined to form a roughly 11 cm diameter, 36 cm long cylindrical dispenser with a mass of 20.5 kg, 19 kg of which was the needles. The cannister also had a 7 kg telemetry transmitter, operating at 240 MHz and 350 mW, to monitor the spin rate, and an 11 kg deployer system.

Midas 6, on ground command at 23:57 UT on May 10, 1963, ejected the cannister with an imparted spin rate of 8 revolutions per second. The five cylinders ended up in a 3600 x 3680 km altitude orbit at 87.4 degrees inclination. Uneven heating resulted in the cylinders breaking apart after releasing roughly 15% to 40% (70 - 190 million) of their needles. The rest of the material apparently stayed in coherent clumps, similar to the first experiment. By June 1963, 40 days after launch, the needles that were successfully released formed an orbiting toroidal belt with a circumference of 63,000 km (mean altitude 3650 km) and a variable cross section of about 15 km with a mean depth of about 30 km. Depending on how many needles were actually released, the mean density within this belt would be from about 3 to 9 needles per cubic kilometer.

Communications between Millstone Hill in Massachusetts and Camp Parks in northern California were successfully achieved using the needles. The orbits of these needles decayed and the individual needles were gone from orbit by 1965 or early 1966. The clumps, however, remain in orbit, 144 individual small objects have been identified associated with this experiment, 46 remain in Earth orbit as of 2013, most of these in orbits with perigees above 2000 km. Perhaps another thousand clumps were formed, too small to be detected.

Alternate Names

  • 00574
  • MIDAS6
  • Missile Defense Alarm System 6
  • Project Needles
  • West Ford (2)

Facts in Brief

Launch Date: 1963-05-09
Launch Vehicle: Atlas-Agena B
Launch Site: Point Arguello, United States
Mass: 2000 kg

Funding Agency

  • Department of Defense-Department of the Air Force (United States)


  • Surveillance and Other Military
  • Space Physics

Additional Information

Questions and comments about this spacecraft can be directed to: Dr. David R. Williams



NameRoleOriginal AffiliationE-mail

Selected References

  • Heart, F. E., et al., Measured physical characteristics of the West Ford belt, IEEE Proc., 52, No. 5, 519-533, doi:10.1109/PROC.1964.2993, May 1964.
  • Maclellan, D. C., et al., Effects of the West Ford belt on astronomical observations, IEEE Proc., 52, No. 5, 564-570, doi:10.1109/PROC.1964.2996, May 1964.
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