EASO - Efficient Automation of Satellite Operations


The EASO project aimed to:

  • Develop the bus and payload SPELL procedures for SES satellite fleet;
  • Develop the automatic translator software tools (PIL2SPELL, TAS2SPELL, 7022SPELL).

These automatic converters were required to automatically translate bus procedures from 3 prime satellite manufacturers (Airbus Defence and Space, Thales Alenia Space, and Boeing) into SPELL:

  • PIL2SPELL for Airbus Defence and Space’ Eurostar 3000 Platform;
  • TAS2SPELL for Thales Alenia Space’s SpaceBus 4000 Platform;

7022SPELL for Boeing’s 702HP Platform.



The main challenge of the EASO project was to evaluate if it is possible to develop 100% automatic and error free translators. The experience with the PIL2SPELL, 7022SPELL and TAS2SPELL converters has largely demonstrated that this approach is extremely efficient compared to manual development, in cases where the procedure baseline is mature and consistent. The converted SPELL procedures are then used in an operational environment with reduced validation effort.

The design of automatic translators is based on innovative technologies such as Algebraic Graph Transformation (AGT) and Triple Graph Grammar (TGG) in order to convert structure patterns into the corresponding SPELL patterns. The PIL2SPELL automatic translator was designed and implemented in collaboration with the University of Luxembourg (SnT). Due to the promising results of PIL2SPELL automatic translator software, the original project’s scope was extended with the inclusion of the development of automatic translator software for additional satellite manufacturers’ bus procedures, i.e., 7022SPELL and TAS2SPELL converters.

Another key challenge was to use these XXX2SPELL automatic converters in order to generate a large number of SPELL bus procedures validated and used in SES satellite operations.



Thanks to the EASO project, SES has been able to:

  • Increase the productivity and efficiency of SES satellite controllers up to ~20% by 2018;
  • Increase the use of SPELL in SES satellites fleet, where SPELL is used to control 37 in-orbit satellites in SES’s fleet (70% of SES satellites) as per July 2016;
  • Reduce the engineering overhead per spacecraft;
  • Demonstrate that automatic translators can generate SPELL bus procedures fully compliant with the satellite bus procedures available from the satellite manufacturer;
  • Demonstrate the homogeneity of SPELL, which can be used in operational environments for different satellite platforms from different satellite manufacturers, and based on different ground control systems;
  • Increase the level of standardization and safety as well as reduce the risk in satellite operations through automation and improving readability of SPELL automated procedures and their operational efficiency;
  • Promote further the use of SPELL as an industry de-facto standard for the automation of satellite operations across the worldwide user community, including both satellite manufacturers and other satellite operators.


The EASO product features can be summarised as follows:

  • Set of XXX2SPELL software tools that allow 100% automatic conversion of bus procedures from 3 prime satellite manufacturers (Airbus Defence and Space, Thales Alenia Space, and Boeing) into SPELL bus procedures.
  • SPELL payload procedures for 15 SES satellites from Airbus Defence and Space, Space System Loral, Orbital Sciences Corporation, Thales Alenia Space and Boeing;
  • SPELL bus procedures for 7 SES satellites from Space System Loral, Orbital Sciences Corporation and Thales Alenia Space, which have been manually developed, and also for 8 SES satellites from Airbus Defence and Space, which have been automatically generated with the PIL2SPELL automatic translator software tool.

The standard SES process of SPELL procedures’ Specification, Development, Verification and Validation has been adopted to guarantee the fidelity and correctness of the manually-developed bus and payload SPELL procedures.

All three PIL2SPELL, TAS2SPELL and 7022SPELL automatic converters developed as part of EASO were successfully validated with the support of the respective manufacturers’ and SES’ satellite engineers and are based on the manufacturers’ input Bus procedures available in their respective native input formats.


SPELL bus and payload procedures are executed by satellite controllers within the SPELL suite of applications.

SPELL Development Environment

The automatic translator software tools are offline components within the SPELL Development Environment (SPELL-Dev). Operation Architects, the ones in charge of developing SPELL procedures and converters, use the automatic translator software through the SPELL Development Environment. After the 100% automatic conversion achieved through the XXX2SPELL converters, the SPELL satellite procedure is stored in the SPELL procedure repository for the operational use of satellite controllers.

SPELL Execution Environment

Satellite controllers operate the satellites through the SPELL GUI, which interacts with the SPELL Server. Finally, the SPELL Server acquires telemetry and issues telecommands to the GCS through the Driver, a middleware software component created to communicate to a specific GCS.


The EASO project was kicked-off in July 2012. Six (6) milestones have been spread over the entire project duration: Milestone 1 (December 2012), Milestone 2 (November 2013), Milestone 3 (May 2014), Milestone 4 (November 2014), Milestone 5 (November 2015) and Milestone 6/Final Review (July 2016).

The work was planned so that SES satellites launched in 2012 and afterwards will be directly operated using SPELL bus and payload procedures. The previously launched satellites would have their bus and payload procedures developed into SPELL towards the EASO project end.


Current status

The EASO project was successfully completed in July 2016 having achieved all initial objectives. All EASO activities have been successfully completed and the validated project outputs (i.e., SPELL procedures and XXX2SPELL automatic converters) are actually used in in-orbit satellite operations today (as per July 2016).

The experience with the PIL2SPELL, 7022SPELL and TAS2SPELL automatic converters and the use of SPELL has been very successful showing the path to be followed in the future.

As per July 2016, SES uses SPELL to control 37 satellites of its fleet (70% of SES satellites). This percentage is expected to increase even further in the near future with the addition of new satellites (all SPELL-operated) in the SES satellite fleet.

SPELL has become an industry de-facto standard for the automation of satellite operations across the worldwide user community, including both satellite manufacturers and other satellite operators.

As a result of the key benefits brought in by EASO, the EASO project was selected by ESA as an ARTES Success Story in which two entities within SES, namely SES TechCom and SES Technology, have been successfully collaborating for the benefit of SES and the wider satellite community.   


ESA Contacts

Status date

Wednesday, January 18, 2017 - 12:57