This review is of the new radios from Frsky, the best price for this kind of technology so far. The FrSky Tandem X20 Series is a dual-band telemetry radio system, its development has drawn on valuable ...

When an explosion rocked Apollo 13's service module on April 13, 1970, the vehicle's vital role, and that of the attached command module spacecraft, suddenly became crystal clear. The astronauts lost ...