On 24 May 2016 at 10:48 CEST, another two Galileo satellites are scheduled to launch from Europe’s Spaceport in French Guiana. They will join the existing constellation of 12 navigation satellites orbiting our Earth.
Navigation is highly important for institutional, private and commercial users on our planet; accurate positioning is useful for all types of transportation, agriculture, and also the casual athlete on their Sunday run. But we need to know one thing first to determine our position on the Earth: where the satellites actually are!
Navigation for Navigation
We spoke to two of our Telespazio VEGA colleagues in the Navigation Support Office at the European Space Operations Centre (ESOC) in Darmstadt, who can answer this question. Telespazio VEGA is one out of several companies involved in the Navigation Support Office activities.
“We are looking forward to the time after the launch,”
explains Gwendolyn Läufer, Navigation Engineer in the ESOC Navigation Support Office. “Our work starts during the commissioning phase, the moment the satellite starts transmitting signals, a couple of weeks after launch Users are waiting to see how the navigation solutions improve with two more satellites added to the constellation. And we want to be the first to impress them with centimetre-level orbit predictions of the satellites, predictions that are necessary for the most exciting and exact uses of navigation signals
Looking forward to the launch and first position determination: Gwen and our Telespazio VEGA colleagues in the Navigation Facility. - Photo: Jürgen Mai.
These accurate orbit predictions are possible because of one special fact about navigation satellites: they are constantly broadcasting a signal specifically designed for positioning! This signal can be received by Galileo receivers all around the Earth; in turn, these receivers provide a constant flow of highly accurate position information used to measure and predict the precise Galileo satellite orbits. In contrast, the orbits of other spacecraft, for example interplanetary probes, must be determined using only their own instruments and information from short uplink and downlink sessions with the ground.
Something to be proud of
“The Navigation Support Office was the first analysis centre to perform precise orbit determination for newly launched Galileo satellites,” adds Adam Vigneron, Software Engineer and also Telespazio VEGA colleague. “It's something we're quite proud of! Imagine this: We calculate a prediction of the satellite’s position with an accuracy of up to 5 centimetres, with the satellite moving at a distance of 23.222 km from Earth. That’s comparable of knowing the position of one human hair currently moving around Wiesbaden while we are on Darmstadt’s Mathildenhöhe!”
Gwen and Adam confirmed they would both be watching the Galileo launch on 24 May to have a first look which challenges lie ahead. We wish them and the Navigation team an exciting run for the first orbit determination!
Telespazio VEGA and Galileo
Telespazio VEGA is highly involved in Galileo in many aspects. Throughout our company, around 35 people are contributing to the programme, among others in the ESOC Navigation Facility.
In the Software Solutions area, Telespazio VEGA is or has been in charge of different ground systems for Galileo, constantly evolving with the system’s needs:
- For the development of the Constellation Simulator (CSIM) for the entire Galileo constellation, and related trainings of the Flight Control Team
- As Prime-Contractor for the development of the hardware-in-the-loop simulator
- As the company in charge of the Assembly, Integration & Validation Platform (AIVP) for the Ground Mission Segment
- During the In-Orbit-Validation-Phase (IOV), we supported the testing and validation of the very first four Galileo Satellites
- We developed the Galileo System Simulation Facility (GSSF): a tool to assess the functional and performance behaviour of the Galileo satellite navigation system
- Several colleagues have been involved in the Mission Segment Validation through the Thales Alenia Space team in Ditzingen, Germany.
Prior to the launch, our colleagues in the ICT Team located at ESOC in Darmstadt have ensured that the networks and ICT systems are optimised for the LEOP. With this in mind, we are ready for operations!
And we are also proud that a large number of our staff are or will be part of operations during the Launch and Early Orbit Phase (LEOP) and then later for routine operations.
- At the Galileo Control Centre in Oberpfaffenhofen, Telespazio VEGA forms a large part of the permanent Flight Control Team and is providing also the Mission Director for the LEOP through spaceopal.
- And since the LEOP will be supported also from the ESOC in Darmstadt, the Flight Control Team there can also count on Telespazio VEGA spacecraft operations engineers in charge of data handling, AOCS as well as Power and Thermal.
- At the same time, the Telespazio VEGA GIMUS Team (Ground Infrastructure Maintenance and User Support) will provide additional support for the Ground Station Software Systems during LEOP.
The launch will be covered via live video stream on www.esa.int.
Galileo is Europe’s own global navigation satellite system, providing a highly accurate, guaranteed global positioning service under civilian control.
ESA: Navigation Facility - Galileo
DLR: Galileo Control CentreOberpfaffenhofen
Telespazio: The Group's involvement - spaceopal - Galileo Control Centre Fucino