History
International Falls is a small town in the northern side of the Minnesota state, located a few kilometers afar from the Canada border. In the early 50's the main airfield in the town was the Einarzen Flight Station which on those times was a mandatory stop for refuelling or to expect good weather for those few intrepid pilots who ventured fly to the lone Canadian plains.
The airfield was first used as a launch site for stratospheric balloons between August and September 1955, during an expedition of the Holloman AFB balloon division, conducted under the auspices of the Aero Medical Field Laboratory.
With the close cooperation of Winzen Research Inc. (main contractor and balloon supplier) were carried out a total of 10 flights carrying various loads, from mice and human skin samples to monkeys and emulsion plates with the common objective of to study the influence of the cosmic rays in living beings who were exposed to them for a long time. The Holloman staff provided the expedition with the land vehicles, a van for telemetry and communications, as well as a C-47 aircraft, all of them assigned to track the balloons while in flight and to recover the gondolas.
The site was chosen because of its northern latitude because Earth's magnetic shield deflects less the incoming cosmic radiation allowing it to penetrate the atmosphere to levels much closer to the ground than in latitudes closer to the equator. These studies were of a very important nature for pionnering efforts to reach near space altitudes in manned programmes like "MANHIGH".
After that series of launches, and during the remainder of the decade, there were some isolated missions launched there. Since then the airfield has not be used for this activity again.
List of Balloons launched there
| Date | Hour | Flight Duration | Experiment | Payload landing place or cause of the failure |
|---|---|---|---|---|
| 8/1/1955 | 5:32 CST | 25 h | ANIMAL CAPSULE | 4 Miles NW of Fortuna, North Dakota, US |
| 8/1/1955 | --- | ---No Data--- | --- No Data --- | |
| 8/5/1955 | 5:30 CST | 26 h | ANIMAL CAPSULE | 5 Miles N of Mohall, North Dakota, US |
| 8/8/1955 | 5:12 CST | 27 h | ANIMAL CAPSULE | 10 Miles NE of Medicine Lake, Montana, US |
| 8/11/1955 | 5:31 CST | 25 h | ANIMAL CAPSULE | 4 Miles N of Pilot Mound, Manitoba, Canada |
| 8/22/1955 | 5:45 local | 25 h 21 m | ANIMAL CAPSULE | 2 miles SE of Middle River, Minnesota, US |
| 8/31/1955 | 5:52 CST | 23 h 10 m | ANIMAL CAPSULE | 4 Miles NE of Pine Island, Minnesota, US |
| 9/1/1955 | 5:50 CST | + 4 d | ANIMAL CAPSULE | Failure of the separation system. Never recovered. |
| 9/6/1956 | --- | ---No Data--- | --- No Data --- | |
| 9/7/1956 | --- | ---No Data--- | --- No Data --- | |
| 7/19/1958 | 6:57 cst | --- | ANIMAL CAPSULE (JIG I) | No Flight. Balloon destroyed at launch. |
| 8/19/1959 | 12:00 utc | F 2 h 45 m | SCINTILLATION COUNTER | --- No Data --- |
| 7/5/1963 | 2:14 UTC | 10 h 23 m | ION CHAMBER + SINGLE GEIGER COUNTER + GEIGER TELESCOPE | --- No Data --- |
| 7/6/1963 | 2:00 UTC | 10 h 28 m | ION CHAMBER + SINGLE GEIGER COUNTER + GEIGER TELESCOPE | --- No Data --- |