Status date

The overall objective of the HEO for ATM Study is the analysis of satellite communications system options focused on the provisioning of Air Traffic Communication services (ATS/AOC) dedicated mainly to helicopter and small aircraft traffic on the north and polar routes for the following flight categories:

  • Scheduled Flights
  • Non Scheduled flights

The study aims at defining a reference system architecture and preliminary system design, in order to accomplish the requirements pertaining to the HEO S-ATM Communication service over the polar area (including north of ECAC) and define the reference system configuration for the Business Case activities. The project established a permanent link with the activities carried out in the frame of ESA IRIS project mainly concerning the communication protocol design.

HEO for ATM Study Work Activity is divided in two themes: System Definition and Business Analysis.

A coverage analysis was performed comparing the performance achievable between Molnyia and Tundra Constellation options.

The Study also includes the Integration between the GEO System and HEO System, referring to the current IRIS project in order to harmonise the relevant Interfaces from the functional and operating points of view.

The Project will carry out a business case for the provision of services in order to propose a solution which best meets the user requirements.

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The HEO satellite system will be designed to respond to the challenging requirements imposed by the provision of safety of life service over the polar region and North of Europe, supporting the Geo system in the overlapping coverage area. At the same time the system shall provide a highly reliable communication service minimizing the cost of the AES (Aeronautical Earth Station) equipment for both operational procedures and service provision.


The HEO for ATM satellite communication could be a system dedicated to the provision of ATS/AOC services for scheduled and non scheduled flights over the polar region. It would be a complementary system to the Geostationary Satellite based system over the North European continent (ECAC) with some restrictions concerning some services characterized by significant latency requirements.


The main characteristics of the HEO for ATM system baseline concept are:

  • A Molnyia constellation embarking an ATM Payload for ATS/AOC services communication adapted for different scenarios. The Platforms will be object of trade-off analyses studying existing HEO solutions and, if necessary, the sustainable applicable adaptation.
  • The HEO satellites, by means of ATM Payload, shall be able to cover the north polar area (comprising an area dedicated to handover process between GEO and HEO systems) with bi-directional Ku-Band feeder links (between GES located over 68 ° Northern Latitude and Satellites), and a bi-directional L-Band link between HEO satellites and AESs. Trade-off analyses are performed in the frame of the study considering different FWD and RTN carriers allocations.
  • A suitable Ground Control Segment will be able to operate either the satellites or the ATM Payloads depending on the mission phase.

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The Project Milestones are the following:

KOM (Kick-Off Meeting) T0
PM 1 - First Progress meeting T0+1.5 months
PM 2 - Second Progress Meeting T0+3.5 months
FP - Final presentation T0+7 months


Current status

The PM 2 has been performed.
HEO for ATM System definition activity has been completed.
The Business Case analysis with the Roadmap is currently ongoing.

The following results have been reached:

  • User Requirements were identified,
  • Channel Propagation model was delivered,
  • A HEO satellite system has been defined comprising Ground and Space Segment and User terminal architecture,
  • Different payloads sizing have been proposed based on different carrier allocation proposed by ESA according to the User requirements identification.,
  • The Ground control Segment architecture has been proposed,
  • A service Provision model was defined.