What are Polar Orbits?

1 Answer
Can you answer this question?
Sep 8, 2022

Polar orbits are earth-centered orbit that passes through the north-south poles with an altitude of 200-1000 Km above the earth’s surface and have an inclination of about 60-90 degrees above the earth’s equator. They are used for earth-mapping, reconnaissance, and weather satellite applications.

A satellite in a polar orbit completes around 15-20 orbits per day from the north to south poles which indicates that they move at an incredibly fast rate around the earth. As the satellite in a polar orbit, passes through a specific region multiple times throughout a day, repeated images of the same region can be taken in short intervals making the mapping of the earth very convenient over the polar and other subsequent regions which are useful for observations. By using 2-3 Satellites in the polar orbit, a particular earth strip can be observed continuously, without intervals in a more detailed manner.

For a satellite to remain in this orbit, it needs to travel at a speed of 17,500 miles per hour (7.8 Kilometers per second). This speed which is required for a satellite to maintain its orbit around the earth is known as orbital velocity. 

If the satellite’s orbital velocity is higher than the optimal value, it faces the risk of flying out of orbit and into space, rendering the satellite out of bounds. Additionally, if the orbital velocity is kept too low, the satellite will be pulled back to earth due to gravity causing it to crash and burn. If correct orbital velocity is maintained the gravity of the earth balances the inertia of the satellite, pulling it down to the earth’s surface just enough to enable the satellite to traverse in its intended orbit. At higher altitudes, the speed required to keep a satellite in an orbit changes. The speed of the satellite in an orbit is inversely proportional to the altitude from the earth’s surface.

Key parameters of a Polar Orbit

Parameters

Polar Orbit Attributes

The altitude of Polar orbits From Earth

200 - 1000 Km

Orbital Velocity for a satellite in a Polar orbit

17,500 mph (7.8 km/s)

Orbits Completed in a Day for a Satellite

15-20 Orbits per day

Satellites Needed

2-3 for Continuous Coverage

Satellite Life

3-7 Years

Propagation Loss

Low

Network Complexity

Complex

Broadband Capability

Poor


Space Missions - A list of all Space Missions

esa

Name Date
Altius 01 May, 2025
Arctic Weather Satellite (AWS) 01 Mar, 2024
Eutelsat Quantum 30 Jul, 2021
Sentinel 6 21 Nov, 2020
Cheops 18 Dec, 2019
EDRS 06 Aug, 2019
BepiColombo 20 Oct, 2018
Aeolus 22 Aug, 2018
Sentinel 3B 25 Apr, 2018
Sentinel 5 13 Oct, 2017

isro

Name Date
INSAT-3DS 17 Feb, 2024
XPoSat 01 Jan, 2024
Aditya-L1 02 Sep, 2023
DS-SAR 30 Jul, 2023
Chandrayaan-3 14 Jul, 2023
NVS-01 29 May, 2023
TeLEOS-2 22 Apr, 2023
OneWeb India-2 26 Mar, 2023
EOS-07 10 Feb, 2023
EOS-06 26 Nov, 2022

jaxa

Name Date
XRISM 07 Sep, 2023
SLIM 07 Sep, 2023
ALOS-3 07 Mar, 2023
ISTD-3 07 Oct, 2022
HTV9 21 May, 2020
HTV8 25 Sep, 2019
HTV7 23 Sep, 2018
HTV6 09 Dec, 2016
HTV5 19 Aug, 2015
HTV4 04 Aug, 2013

nasa

Name Date
NEO Surveyor 01 Jun, 2028
Libera 01 Dec, 2027
Europa Clipper 10 Oct, 2024
SpaceX CRS-29 09 Nov, 2023
Psyche 13 Oct, 2023
DSOC 13 Oct, 2023
Psyche Asteroid 05 Oct, 2023
Expedition 70 27 Sep, 2023
SpaceX Crew-7 25 Aug, 2023
STARLING 18 Jul, 2023