A memoir is a type of autobiography wherein the main content of a written material is about the writer.It is a genre of literature that involves writing about certain aspects and concerns of a personâs life. memoir is a type of autobiography wherein the main content of a written material is about the writer.
There have been about 8000 man made objects launched into space - only a handful left Earth orbit. Some have decayed and reentered. There are about 3000 satellites currently in orbit. Only about 1000 of those are active. But there are other objects, too, such as spent rockets. Some objects have broken apart because of collisions. There are about 20,000 objects in orbit that are 10 cm in diameter, or larger.
Depending on the job they have to do, we put satellites into different orbits. Some orbit the Sun, but most orbit the Earth. Three very useful types of orbit are a polar orbit, a geostationary orbit (GEO) and a low Earth orbit (LEO). These satellites are in orbit above the Earth's equator. They stay above the same location on Earth. They are used for telecommunications, television transmission and for navigation. Low Earth orbit (LEO) A satellite has a Low Earth Orbit when it orbits somewhere between 300 and 800 km above the Earth's surface. These satellites only take about 90 minutes to go around the Earth. They are ideal for making observations of the Earth's resources.