IGY Bulletin, Number 8, February 1958 - Thule neutron monitor station

One last short article from this issue of the IGY Bulletin.

The Thule (Greenland) neutron monitor station was built for the IGY in 1957 by the Bartol Research Foundation. It was operated by the U.S. Army Signal Corps, which is in charge of communications and information systems support for the armed forces. Martin Pomerantz, president of the Bartol at the time, provided the material for this article.

The Bartol Research Institute is a research center in the Department of Physics and Astronomy at the University of Delaware (a 90-minute drive from my location in Lancaster, PA). The Bartol Research Institute currently operates 10 neutron monitor stations as part of the Neutron Monitor Program. Thule, which was put into operation on 27 Aug. 1957 during the IGY, is still running.

Thule neutron monitor, oldest of the monitors operated by Bartol Research Institute. The neutron detector tubes are inside the four white boxes (photo by J Roth, Bartol).

As a reminder of what was in an earlier post, the Bartol says: A neutron monitor is an instrument that measures the number of high-energy particles impacting Earth from space. For historical reasons these particles, mostly protons and helium nuclei, are called "cosmic rays." Because the intensity of cosmic rays hitting Earth is not geographically uniform, it is important to place neutron monitors at multiple locations in order to yield a complete picture of cosmic ray influxes. The neutrons are secondary spallation products derived from cosmic rays interacting with molecules in the atmosphere.

The article goes on to say that the Thule station, 1500 miles from the North Pole, was important because it was closer to the geomagnetic pole than any other neutron monitor. Cosmic rays can more easily funnel in towards the Earth's surface through the openings at the magnetic poles.

The secondary protons and neutrons produced in the atmosphere by cosmic rays are stable, so they provide much information about the distribution of cosmic rays and the geomagnetic field. The neutron fluxes vary with cosmic ray intensity; on the one hand they correlate with flares on the sun which emit cosmic rays, but on the other hand are inversely related to the solar cycle and solar magnetic fields when high (low) heliomagnetic fields shield (don't shield) galactic cosmic rays from reaching the Earth. Bartol gives a thorough explanation.

Thule has a fascinating history as: the home to indigenous Inughuit; the site of a secret U.S. airbase; the main staging point for the construction of Camp Century; the site of a Ballistic Missile Early Warning System (BMEWS) outpost, with radar in order to warn North America of a transpolar missile attack from either the USSR mainland or of submarine-launched missiles from the Arctic and North Atlantic oceans.

A philatelic aside on Thule: I was looking at eBay to see if I could find any relevant stamps or covers. I found listings of five 1937 stamps from Thule. Apparently, stamps for regular mail were not issued from the town of Thule (now Qaanaaq) until 1938. The 1937 "local" stamps were privately printed by the Thule Committee in memory of polar explorer Knud Rasmussen (1879-1933) on the 25th anniversary of the establishment of the most northerly trading post in the world, the Thule Trading station. These stamps are not listed in the Scott catalogue, but you can find them in Colnect.

Thule stamps, not in my collection (Quora)

First successful Vanguard satellite launch into orbit, March 17, 1958

Let's commemorate the second successful U.S. satellite launch, Vanguard 1, on this date in 1958.

The U.S. had two competing satellite programs during the IGY, Explorer and Vanguard.

Project Vanguard was a program managed by the United States Navy Naval Research Laboratory (NRL), which intended to launch the first artificial satellite into low Earth orbit using a Vanguard rocket. The Navy proposal included all three aspects of the mission: launch vehicle, payload satellite, and ground tracking stations. 

In response to the launch of Sputnik 1 on 4 Oct. 1957, the U.S. revived the Explorer program, directed by Wernher von Braun under the aegis of the the Army Ballistic Missile Agency (ABMA). 

Ironically, the Air Force proposal was not pursued.

As discussed in an earlier post, the first three-stage Vanguard test rocket, TV-3, was launched on 6 Dec. 1957, but lost thrust, settled back on the launch pad, and exploded. The next Vanguard launch on 5 Feb 1958 flew for just 1 minute the vehicle lost control and then  broke up.

Meanwhile, ABMA, together with the Jet Propulsion Laboratory (JPL), built Explorer 1 and successfully launched the first U.S. satellite on 1 Feb. 1958, as discussed in this post.

On 17 March 1958, Vanguard 1, aka TV-4, became the second artificial satellite successfully placed in Earth orbit by the United States. Three times a charm! It was the first solar cell powered satellite. Just 6" in diameter and weighing 3 lb., Vanguard 1 was much smaller than Sputniks 1 and 2, hence dubbed as the "grapefruit satellite" by Soviet Premier Nikita Khrushchev. Vanguard 1, and the upper stage of its launch vehicle, are the oldest artificial satellites still in space, as Vanguard's predecessors, Sputnik 1, Sputnik 2, and Explorer 1, have decayed from orbit. Primary scientific objectives of this mission were to determine atmospheric density and the shape of the earth. The solar powered transmitter operated until May, 1964.

Below is a cover from my collection postmarked from Cape Canaveral on the 15th anniversary of Vanguard 1's launch. The cahet shows images of the rocket and satellite. The stamp is Scott #1402 (1971), bearing the image of Dwight Eisenhower, who had been president during the IGY. It is signed by John P. Hagen, director of the Vanguard program.

Cover from my collection for the 15th anniversary of the Vanguard 1 launch

Scott Manley has a nice YouTube video on these two programs and their launches:

My first real job out of college with Fairchild Space and Electronics Co. was in the space power subsystems group. We designed and sometimes fabricated solar cell array-battery power subsystems for satellites, a legacy of the Vanguard 1 mission.

IGY Bulletin, Number 8, February 1958 - IGY satellite program notes

Just a 1-page article to summarize today. It is a reprint of a short piece by Hugh Odishaw, titled "Soviet satellite carrier rocket," from Science magazine, vol. 126, no. 3287, 27 Dec. 1957, p. 1334.

It reports that on 8 Dec. 1957 a cable was sent by A. N. Nesmeyanov, chief scientific secretary of the Soviet Union, to Detlev Bronk, the president of the U.S. National Academy of Sciences. The letter stated that some unburnt parts of the rocket that carried Sputnik 1 into space might have been scattered on a line between Alaska and the west coast of the United States (Alaska was not yet a state.) Nesmeyanov asked that any recovered pieces be returned to the USSR Academy of Sciences. Bronk responded that no such finds had been made.

According to NASA, the Sputnik 1 rocket body, a Semyorka R-7 ICBM, was the second stage, or "core booster", that carried the Sputnik satellite into orbit. The rocket body itself (about 55' high by 10' across) also reached orbit and was visible from the ground as a magnitude 1 object. In fact, this was actually the "Sputnik" people saw from the ground over the next few months. The much smaller (2' diameter) Sputnik 1 satellite was barely visible at magnitude 6, one hundred times fainter than the rocket.

Below are two depictions of the Sputnik 1 rocket from my collections.

Schematic of the Sputnik 1 rocket (source is a booklet in my collection: Soviet Sputniks, 1959, p. 28)

The Sputnik rocket and satellite depicted on North Korean stamp from my collection (Scott #134, issued 26 March 1958)