Hobbies And Interests
Location
Because Russia is so far north, a tundra-type satellite orbit is ideal because most of the country is located within the northern part of the world. Molniya satellites cover a relatively small geographical area, therefore making these orbits particularly attractive to scientists.
Because the orbit of the satellite is at an angle to the equator, the ground footprint of the satellite traces a figure-eight pattern above the area in question. When a satellite is launched in a circle, these satellites travel at equal distances above the Earth; the time at which the satellite is close to the Earth is much longer than when the orbit pattern is an ellipse. However, these orbit patterns tend to travel much farther away from the geographical area in question, because the angles of circuit are not as oblique to the equator.
Satellite Period
The scientists who designed the tundra-type orbit calculated the frequency at which the satellite would return close to the Earth during its observable period. (The low point of the satellite's orbit, about 600 meters above the Earth, is during this observable period, called perigee.) Because of the efficiency of the tundra orbit, generally fewer than four working satellites in tandem are needed to cover any 24-hour period. The relatively long perigee of the satellite means that fewer satellites total are needed to cover the area of broadcast needed.
Angle of Launch
The tundra orbit has almost no cost in terms of corrective energy needed to keep the satellite in its correct orbit. These satellites are launched at an angle of 63.4 degrees from the equator. This angle has been found to be the most efficient orbiting angle for launching the satellite; it doesn't require corrections by jet-pack, which the satellites of geosynchronous and other angled orbits require.
Other Orbit Types
Equatorial orbits navigate around the center of the Earth and are not as ideal to Russia as the tundra orbit because of the short period of time during which the satellite passes near the country. Equatorial mounts are the extra-cost special equipment needed to follow this type of orbit because the satellite moves so rapidly over the observable area.
Geosynchronous-type orbits are a specific type of equatorial orbit; these orbits are more attractive to scientists because they allow the satellites to spin at the same speed at which the Earth spins, which makes them seem like the satellite is standing still. Although geosynchronous orbits keep the satellites in one place above the Earth (by moving eastward, in the direction of the spin of the Earth), they are costlier in terms of the power required to keep the satellites circling. Additionally, geosynchronous orbits are generally too far south for use in northern countries.
Another type of orbit is called the sun-synchronous orbit. Although the orbit is easy in terms of energy to maintain, it's unattractive to the northern scientist because the satellite doesn't remain in proximity to the polar region long enough for the reception of adequate information.
Considerations
It has been posited that the Molniya orbits would be ideal for human space travel; however, this supposition has been concluded as untenable, because a high level of radiation coming from the Earth̵7;s atmosphere has coincided with this type of orbit and would prove this kind of mission either dangerous or impossible. Additionally, the radiation belts block data transmission during some portion of the satellite's travel.