Injun 1

Injun 1 [UoI]

Injun 1 (under Grab 2 (Solrad 3)) [UoI]

The satellite Injun 1 was the first of a series of spacecraft designed and built by the University of Iowa to study the natural and artificial trapped radiation belts, auroras and airglow, and other geophysical phenomena.

Injun 1 was launched simultaneously with Transit 4A and Solrad 3 / Grab 3. For launch, the cylindrical Injun 1 was contained in a cage-like structure between Transit 4A and Solrad 3. Transit 4A successfully separated from Injun 1, but Grab 2 (Solrad 3) did not. Injun 1 was designed to be magnetically aligned. However, due to the presence of Solrad 3 / Grab 3 (which blocked the view of the photometer), it was impossible to keep the satellite constantly oriented on the terrestrial magnetic field throughout an orbit. A single axis fluxgate magnetometer was used to monitor the orientation of the spacecraft with respect to the local magnetic field. Injun 1 had a complex spin-and-tumble motion with an ill-defined and variable period of several minutes. The satellite sent back radiation data until March 6, 1963, and is expected to be in orbit for about 900 yr.

It carried following instruments:

• Geiger-Mueller Counter
• Cadmium Sulfide Detector
• Electron Differential Energy Spectrometer
• Auroral and Airglow
• Fluxgate Magnetometer
• Solid-State Proton Detector
• 2- to 8-A and 8- to 20-A X-Ray Detectors