Orbits 'R' Us!

 Orbits 'R' Us!

The speed of the Earth's rotation from west to east at the equator is 1675 km/h (1041 mph). The satellite receives a significant boost if it is launched in the same direction as Earth's rotation. It cannot benefit from this boost whether it is launched in the north or south. It also consumes a lot of fuel for the spacecraft's engines to alter the inclination, or tilt, of the satellite's orbit if it is launched toward the east. An orbit around the poles is highly inclined.

The function of the satellite will determine which orbit is best.

suspension of disbelief

For instance, the two GOES* weather satellites are tasked with monitoring the weather across North America. Any developing situation, such as tropical storms forming in the Atlantic Ocean or storm fronts moving across the Pacific Ocean toward the west coast of the United States, must be "never taken their eyes off." They are, therefore "parked" in an orbit known as a geostationary orbit (gee-oh-STAY-shun-air-ee). They complete one orbit every day, precisely over the equator of the planet. The GOES satellite appears to be hovering over the same location on Earth constantly because Earth spins once on its axis every day. *GOES is an acronym for Geostationary Operational Environmental Satellite.

However, satellites that are tasked with mapping or studying every inch of the planet's surface require an orbit that gets as close to crossing both the North and South Poles as is physically conceivable. In this manner, Earth rotates beneath the satellite's orbit and completes the majority of the traveling! In order for the satellite's imaging and measurement equipment to work well, it should be situated quite close to Earth's surface.

The lower the satellite's orbit, the shorter its orbital period and the faster it must travel. Because of this, a geostationary orbit needs to be quite high. It must travel far enough in order for it to move slowly enough to circle the planet only once a day.

Polar-orbiting Operational Environmental Satellites is the abbreviation for this term.

 Consider launching two satellites to the same altitude. But only one will orbit the equator, and the other will enter a polar orbit. Which spacecraft will require the most fuel to enter its orbit? Can you guess which one?

You are correct if you guessed the polar orbiting satellite. 

The speed of the Earth's rotation from west to east at the equator is 1675 km/h. The satellite receives a significant boost if it is launched in the same direction as Earth's rotation. It cannot benefit from this boost whether it is launched in the north or south. It also consumes a lot of fuel for the spacecraft's engines to alter the inclination, or tilt, of the satellite's orbit if it is launched toward the east. An orbit around the poles is highly inclined.

 

 

 

We are looking down at the North Pole in the cartoon on the right. Naturally, this cartoon is not accurate to scale. Given that it would be 22,300 miles away, it would be difficult for Rusty to see a geostationary satellite overhead if he were standing somewhere on the equator, but if he could, the spacecraft would appear to be dangling above him always. To see a cartoon of what this would look like, click on it.

 

 

 

 

 

The satellite nearly crosses directly over both the North and South Poles in the cartoon on the left. In ouranimation, it completes two full days of rotations. In actuality, the satellite may circle the planet several times throughout the day, orbiting once every hour and a half or so. The three POES* satellites are a prime example of satellites in polar orbit. It just takes six hours to photograph nearly every square inch of Earth using the combined images from the three satellites. With the aid of this data, scientists are able to better comprehend global trends in the weather, temperature, oceans, volcanoes, and flora. The data also aids in forest fire detection and search and rescue operations.