Multimedia Gallery
- Media Type: Illustration
Pioneer 4 achieved enough velocity to escape Earth’s gravity, but its trajectory past the Moon was off by a wide margin.
A sketch by Charles Wilkes during the U.S. Exploring Expedition.
Pontella, Indian Ocean (Pontella speciosa, Pontella detonsa ?, Pontella princeps, Pontella fera, Pontella valida)
The quartz clock keeps better time than the best mechanical clocks.
Aircraft equipment locates signals from a ground station. Typically, a needle points toward a station, giving a bearing relative to the direction the aircraft is headed.
Radio navigation relies on the transmission and reception of electromagnetic signals to determine position or course.
Antennas create four “beams” that aviators locate by listening to audio signals. When the signals overlap into a constant tone, the aviator is “flying the beam.”
Navigators used radio time signals to accurately set their second-setting watches. Stations around the world broadcast these time signals hourly.
