Big or small, future satellites must be able to communicate efficiently with Earth-based stations. Historically, NASA has relied onradiofrequency (RF) communication, but RF is reaching its limit as demand for m
How are Satellites Used? Artificial satellites are used by humans in myriad ways. Some are used to send and receive signals without directly observing anything on the ground. This is the case with communication satellites for example. How We Observe the Earth ...
北斗卫星导航系统Nowadays, we are used to using our phones to get our location. But how do our phones know where we are in the world and in which direction we are going? It is all thanks to the satellites in space that help our phones calculate our position.Depending on where you are ...
The rockets take astronauts and man-made satellites into space. The satellites are used for communication weather monitoring and research. But how do satellites stay up without falling down? There are two opposite forces (力量) acting on the satellite. One of them is the force of gravitation (...
In our modern age, we do not think much about how our technology works. We are so used to tapping on our phone screen to get a map of our location. But how do our phones know where in the world we are and in which direction we are going? It is all thanks to the satellites in...
The satellites are used for communication, weather monitoring and research. But how do satellites stay up without falling down? There are two opposite forces (力量) acting on the satellite. One of them is the force of gravitation (地心引力), which tries to pull the satellite towards the ...
Known fully as the Global Positioning System (GPS), it is composed of dozens of satellites, which provide geographic coordinates for various earthly features. Originally put into orbit by the U.S. Department of Defense, they've been available for civilian benefit since the 1980s, and since ...
SETI researchers investigated how detectable Earth is to alien civilizations, finding that our most visible technosignatures are radio emissions and atmospheric pollutants. If observed from nearby space, lasers, satellites, and city lights would also signal our presence. This study provides a new pers...
A comprehensive system will require different sets of satellites for communication, sensing incoming missiles, and launching interceptors, Montgomery told CNN. Those types of systems are long-term projects, he said, requiring existing defenses to fill the gap in the meantime. ...
题目The rockets take astronauts and man-made satellites(卫星)into space. The satellites are used for communication, weather checking and research.But how do satellites stay up without falling down? There are two opposite forces influencing the satellite. One of them is the fo...