Highly Elliptical Orbit

Posted : admin On 1/3/2022

Orbital Variations
Changes in orbital eccentricity affect theEarth-sun distance. Currently, a difference of only 3 percent (5million kilometers) exists between closest approach (perihelion), whichoccurs on or about January 3, and furthest departure (aphelion), whichoccurs on or about July 4. This difference in distance amounts to abouta 6 percent increase in incoming solar radiation (insolation) from Julyto January. The shape of the Earth’s orbit changes from beingelliptical (high eccentricity) to being nearly circular (loweccentricity) in a cycle that takes between 90,000 and 100,000 years. When the orbit is highly elliptical, the amount of insolation receivedat perihelion would be on the order of 20 to 30 percent greater than ataphelion, resulting in a substantially different climate from what weexperience today.

Elliptical

The shape of the Earth’s orbit changes from being elliptical (high eccentricity) to being nearly circular (low eccentricity) in a cycle that takes between 90,000 and 100,000 years. When the orbit is highly elliptical, the amount of insolation received at perihelion would be on the order of 20 to 30 percent greater than at aphelion, resulting. Highly elliptical orbit. Satellites in highly elliptical orbits move more slowly in high-altitude parts of the orbit than in low-altitude parts, thus maximising viewing times over high latitudes. (Earth image: EUMETSAT) At a recent EUMETSAT HEO meeting, the participants agreed to support an HEO mission. However, further investigations are.

OrbitsHighly Elliptical Orbit

Obliquity (change in axial tilt)
As the axial tilt increases,the seasonal contrast increases so that winters are colder and summersare warmer in both hemispheres. Today, the Earth's axis is tilted 23.5degrees from the plane of its orbit around the sun. But this tiltchanges. During a cycle that averages about 40,000 years, the tilt ofthe axis varies between 22.1 and 24.5 degrees. Because this tiltchanges, the seasons as we know them can become exaggerated. More tiltmeans more severe seasons—warmer summers and colder winters; less tiltmeans less severe seasons—cooler summers and milder winters. It's thecool summers that are thought to allow snow and ice to last fromyear-to-year in high latitudes, eventually building up into massive icesheets. There are positive feedbacks in the climate system as well,because an Earth covered with more snow reflects more of the sun'senergy into space, causing additional cooling.

Heo Satellites

  1. It would be desirable to include a new definition in the Radio Regulations that would state that: “A satellite in a highly elliptical orbit has a repeating ground track, only operates in a portion of its orbit, the active arc, and is switched off elsewhere. At all times there is only one satellite in the active arc.
  2. A highly elliptical orbit (HEO) is an elliptic orbit with a low-altitude (often under 1,000 kilometres (540 nmi)) perigee and a high-altitude (often over 35.