Though this reduced SOLRAD 3's data-transmission ability by half, the satellite still returned valuable information regarding the Sun's normal levels of X-ray emissions.

The SOLRAD experiment package also established that, during solar flares, the higher the energy of emitted X-rays, the more disruption caused on the Earth's thermosphere (and radio transmissions therein).

The GRAB mission was also highly successful, returning so much data on Soviet air defense radar facilities that an automated analysis system had to be developed to process it all.

The United States Navy's Naval Research Laboratory (NRL) established itself as a player early in the Space Race with the development and management of Project Vanguard (1956–1959),[2] America's first satellite program.

The Earth's atmosphere blocks large sections of sunlight's electromagnetic spectrum, making it impossible to study the Sun's X-ray and ultraviolet output from the ground.

[12] As was the case with most early automatic spacecraft, SOLRAD 2, though spin stabilized,[3] lacked attitude control systems and thus scanned the whole sky with no source in particular.

[6]: 13  So that scientists could properly interpret the source of the X-rays detected by SOLRAD 2, the spacecraft carried a vacuum photocell to determine when the sunlight was striking its photometers and the angle at which it hit them.

[14] SOLRAD 3/GRAB 2 was launched on 29 June 1961 at 04:22 GMT on a Thor-Ablestar rocket, along with Transit 4A and the University of Iowa's Van Allen radiation belt Injun 1 satellite from Cape Canaveral, LC-17B.

The satellite also found that the higher the hardness (energy level) of X-rays emitted during solar flares, the greater the disturbances and microwave bursts in the thermosphere, both affecting radio communications.