ABOUT HIGHLY ELLIPTICAL ORBIT (HEO)
A Highly Elliptical Orbit is any orbit with high eccentricity, featuring a low perigee and very high apogee. HEOs are used when extended dwell time over a particular region is needed. The satellite moves slowly near apogee and rapidly through perigee, spending most of its orbital period over the target area.
ORBITAL PARAMETERS
| Altitude (Min) | 200 km |
| Altitude (Max) | 50,000 km |
| Inclination | 0-90° |
| Orbital Period | 600-1440 minutes |
| Orbital Velocity | 1.5-10.5 km/s |
| Delta-V Required | 9.5-10.5 km/s |
| Eccentricity | 0.5-0.9 |
| Category | Highly Elliptical |
EQUATION / FORMULA
e = (r_a – r_p) / (r_a + r_p)
ADVANTAGES & DISADVANTAGES
ADVANTAGES
Extended dwell time over target region, flexible design, can cover polar areas
DISADVANTAGES
Radiation belt crossings, complex thermal environment, orbital debris risk at perigee
HISTORY
| Discoverer / Pioneer | General orbital mechanics principle |
| First Use | January 1, 1960 |
ALTITUDE CONVERSIONS (MIN)
| Kilometers | 200 km |
| Miles | 124 mi |
| Nautical Miles | 108 nmi |
TYPICAL PAYLOADS (3)
SATELLITE CONSTELLATIONS (3)
