Monday, 9 July 2012

Starfish Prime - Nuclear Test July 9, 1962

In July of 1962, visitors to the Island of Honolulu, Hawaii where treated to the visual show of a lifetime. It was in July of 1962, when the U.S. decided to perform a exoatmospheric (in space) Nuclear Test, in response to the Soviet Unions decision to end a three year ban on nuclear testing.

Code named, Starfish Prime, it was to be one of five planned high altitude nuclear tests as part of Operation Fishbowl, within the larger Operation Dominic. These Operations where designed to test the viability of nuclear weapons in space. 

In 1958 the U.S. had conducted other high altitude nuclear testings, but decided that "Previous high-altitude nuclear tests: Yucca, Teak, and Orange, as well as the three Argus tests were poorly instrumented and hastily executed."  (Defence Atomic Support Agency. Project Officer's Interim Report: STARFISH Prime. Report ADA955694. August 1962 )

Before the successful Starfish Prime test, the U.S. had some minor complications with Operation Fishbowl. The first planned high altitude test, Bluegill, was on a perfect trajectory when it was lost by the radar tracking facility, and was ordered destroyed on June 2, 1962. On June 19, the second test proceeded, codenamed Starfish. The Thor rocket launched went according to plan, when the missile stopped at between 30,000 and 35,000 feet and began to break apart. The missile was ordered destroyed.

On July 9, the W49 thermonuclear warhead was loaded on to a third Thor missile, and launched and exploded at 9am (CUT) Starfish Prime was launched. It was 11pm local time (on July 8th) in Honolulu, where hotel patrons raced to the rooftops of their hotels, or the beaches. Wherever they could get a sight of the night sky over Johnston Island, despite the fact that they were a mere 1,400 km away.

At 400 kilometres above the island, the explosion caused an aurora effect on the night sky, and created an electromagnetic pulse (EMP), a pulse much larger than anticipated, and caused the measurement equipment to fail, as well as thousands of electronics on the surrounding islands, including TVs, radios, home alarms, and street lights.  The 1.4 Megaton detonation caused the immediate failure of several low orbit satellites, and within the coming days, the radiation Field would cause the malfunction of 1/3 of low orbit satellites.

 The aurora was visible for approximately ten minutes, before beginning to fade, and was silent. There was no fireball or mushroom synonymous with nuclear explosions created by the Starfish Prime test, as there was no oxygen for the weapon to ignite.

The lasting effects of the test, created a series of man made radiation belts circling the earth, causing further problems for the low orbit satellites. The radiation affected their solar panels, and electronic components.  It was estimated by Journal of Geophysical Research that these radiation belts remained for at least 5 years.

It was not all for nothing, the Thor rocket also carried a cadmium (109) tracer that helped scientists predict the seasonal mixes of polar and tropical air, as well as led to better understanding of the EMP effect of nuclear weapons.

Operation Fishbowl would see another 2 failed attempts at atmospheric tests, before finishing on a high note, with 4 successful tests.

Remembering History - Starfish Prime Nuclear Test