Checkout systems are used for the pre-launch testing of spacecraft, payloads, and instruments. The Central Checkout System (CCS) is connected to other equipment (SCOEs, FEEs) that make up the entire Electrical Ground Support Equipment (EGSE).
Checkout systems – as a central part of the EGSE - are used at all levels of assembly, integration and test (AIT) of space systems - including instrument, platform, payload, and satellite level. Terma has been providing these systems for more than 30 years.
Today, Terma is able to offer three different systems:
- A multi-user system based on a modified version of the ESA SCOS-2000 software
- A single user system aimed at Instrument Level testing
- A next-generation multi-user system
All the systems are compatible with the ESA Mission Control Infrastructure to allow a smooth transition from test to operations.
In the last 30 years, Terma has supplied checkout systems for many spacecraft, payloads and instruments covering:
- Scientific spacecraft such as BepiColombo, Herschel, Planck, Rosetta, MarsExpress, Venus Express, Cluster, SOHO, ISO
- Earth observation spacecraft - Sentinel-5P, Sentinel-1, Sentinel-2, EarthCare, SWARM, Aeolus, CBERS, GOCE, Cryosat, Meteosat Second Generation, ENVISAT, ERS
- Communication spacecraft - SmallGEO
- Navigation – Galileo IOV, Galileo FOC
- Launchers – IXV
Terma is also part of a team, led by Astrium/ST, for development of the next generation Ariane EGSE.
MarsExpress (image courtesy: ESA-D.DUCROS)
Planck (image courtesy: ESA)
The Terma family of systems are designed to be compatible with each other and many other systems such as the control centre infrastructure used by a satellite operator. For example, our single user system can be used for testing instruments/payloads. The data generated (primarily TM/TC definitions, but also test sequences and synoptics) will also run on our multi-user systems used at satellite/system level testing. Then the TM/TC data can then be transferred to the satellite operator. This means that a lot of effort in re-definition and validation of this data can be avoided bringing advantages in cost, schedule and risk to a programme.
This concept has been proven on a number of major ESA missions – the first was Herschel and Planck and continues today with newer missions such as BepiColombo, SmallGEO and Galileo.
Standards are an important aspect of the system design - these include international standards, space industry standards, and de-facto standards. The use of space industry and international standards ensures that the system is compatible with many spacecraft systems. Use of de-facto standards also ensures that the systems can have a long lifetime without the risk of high maintenance costs – today many customers require lifetimes of 10 years or more.
For space standards, the systems support the ESA/CCSDS Telemetry and Telecommand Packet Standards and the ESA Packet Utilization Standard.
Terma is also able to fully support the product in the field and has developed high quality user training material and user documentation.
The central checkout system is built from a suite of software tools and can run on a single workstation or a network of workstations and servers without software modifications – allowing any system to be “right-sized” for a specific case.
The software is made of three main components:
- Preparation software - a set of tools to prepare the test/operations – defining the TM/TC DataBase, Test Sequence and Synoptic Pictures
- Execution software - a set of tools to run the test/operations
- Evaluation software - a set of tools to evaluate the results of test/operations.
Envisat (image courtesy: ESA)
The Preparation Software and the Execution Software are linked by a database known as the Preparation DataBase. The Execution Software and the Evaluation Software are linked by a database known as the Results DataBase.
Communication with other elements of the EGSE (SCOEs, FEEs) is done by communication protocols with TCP/IP as the underling layer.
For the single user system, a much more performant API can be used for connecting to other equipment – useful for high data rate instruments which tend to be very common these days.