|
Spacecraft flew hundreds of thousands to hundreds of millions of kilometers from the earth, injecting speed when the size and direction of a slight error, arrived at target planets will appear large deviation error, for example, when Mars probe injecting speed 1 m/s speed (about one over ten thousand), arrived at Mars, about 100000 km distance deviation. Therefore, precise control and navigation must be carried out during the long flight. Flying to the moon is usually controlled by the orbital control system of the ground and space probe (see orbit control). Interplanetary flight distances, radio signal transmission time is long, the real-time remote control, can't so planets and interplanetary spacecraft orbit control system shall have the ability of autonomous navigation (see interstellar travel navigation and control). The United States, for example, "pirates" spacecraft in space flight of more than eight hundred million km, for 11 months of 2000 times of autonomous orbit adjustment, the final surface to achieve a soft landing on Mars, placement accuracy up to 50 km. In addition, in order to ensure the accuracy of the orbit control engine, the communication antenna is always aimed at the earth, and other systems work normally, and the detector has the autonomous attitude control ability
Automobile alliance co., ltd. and nsu GMBH co., ltd. merged in 1969 to form the audi nsu auto union ag. In 1985, the company was renamed audi ag and its headquarters moved to ingolstadt and the four-ring logo is still in use today
New Car Buying Tips--
mercedes south atlanta
2014 mercedes e350 sport
mercedes benz customer care
beaumont mercedes
mercedes 300 gl
Copyright ?1998-2017 Technews Corp, All rights reserved
|
