What is an inclined satellite?
A satellite is in an inclined orbit if the orbit exhibits an angle other than zero degrees with the equatorial plane. These types of satellites are ideal for Remotely Piloted Aircraft (RPA), mobile platforms and Communications On The Move (COTM) applications as they require tracking antennas. These satellites offer additional access to bandwidth where capacity is limited and approaching saturated fill rates. Planning and procurement of Inclined Satellite capability presents substantial cost savings in an austere budgetary environment.
The difference between station-kept and inclined satellites
- GEO: All SES satellites are geosynchronous satellites, or GEO, operating from about 23,000 miles above the equator.
- Station-Kept: Each GEO orbital spot represents a box of approximately 45 miles by 45 miles square – a satellite operating within this box is described as “station-kept”. This allows an antenna on the ground to be pointed at the satellite in a fixed place.
- Inclined Satellites: In the latter stages of a satellite’s life, the operator can save fuel by reducing station-keeping adjustments and extend the life by allowing the spacecraft to drift in the north/south direction. The square box becomes a rectangle, approximately 45 miles wide as much as 1,400 miles long. Adjustments via firing of thrusters are still required to keep the satellite within the bigger rectangular box. The satellite drifts in an elongated figure 8 pattern within the rectangular box and is then known to be in inclined orbit.
How inclined satellites are different
Putting a satellite in inclined orbit conserves fuel and extends a satellite’s life
- No Additional Hardware Required For COTM Applications: As a mobile satellite user you can use your tracking antenna for inclined satellite solutions.
- Low Price: The price per megahertz is substantially lower than station-kept satellites because as inclined assets are available for use only for specific applications (such as RPAs which already have tracking antennas).
- High Availability: Due to the fact that the majority of antennas are not tracking antennas, this results in large amounts of bandwidth available on inclined assets.
- Turnkey Solutions: Any required tracking antennas at the hub or teleport can be bundled into the bandwidth price, avoiding the need for separate acquisition efforts.
Why Inclined Satellites Cost Less:
There are two main reasons why inclined orbit capacity is less expensive:
- Technical – The need for a tracking antenna reduces the number of missions that are applicable for the use of inclined capacity.
- Business – These satellites are no longer used for their original DTH mission and now kept on orbit to support only COTM applications. SES has a responsibility to maximize the use of each satellite by doing the following:
- Leasing the satellite to another operator
- Raising the satellite into graveyard orbit, or
- Continue to operate the satellite at an inclined orbit
When evaluating these options, SES must select the option that yields the best return with the least risk.
Approvals and Field Trials for Inclined Capacity
- Global Hawks – Air Combat Command has already approved Global Hawks for operation on inclined orbit capacity.
- Predators – Flight testing of Predators on inclined orbit capacity was successfully completed by ACC in late 2012. TTPs (tactics, techniques and procedures) are now under review with final approval expected shortly.
- Win-T – Field trials for WIN-T terminals were conducted at Fort Drum in late 2012 and early 2013. Operations were successful and a final test report is under development.
- VSATs – SES inclined satellites can be tracked by Very Small Aperture Terminals (VSATs).
SES GS Inclined Satellites: