GEneric Launch Window Optimisation
easy to use and highly configurable application
for launch window determination
© SciSys (click to enlarge)
SciSys' GELO (GEneric Launch window Optimisation) product offers satellite operators a sophisticated application that automates the task of selecting optimal parameters for launching any mission using any launch vehicle into any Geosynchronous Orbit (GEO).
A Geosynchronous Orbit (GEO) is a zero inclination high Earth orbit (approximately 35,700 km altitude) in which the satellite's orbital period is equal to the Earth's rotation period - and so the satellite orbits over a fixed position on the Earth's surface. This type of orbit is commonly used by telecommunications and meteorological satellites.
GELO significantly reduces the complexity of important launch decisions by providing the operator with all the required outputs in a stand alone package that can be used to rapidly generate results for any number of scenarios - enabling full flexibility in launch planning.
GELO provides comprehensive constraint checking functionality. This takes into account parameters such as:
- Fuel lifetime
- Eclipse
- Altitude constraints
- Sensor visibility
- Station TM/TC (Telemetry/Telecommand) visibilities
4F1 satellite into Super Synchronous orbit
on board a Lockheed Martin Atlas 5 booster
© ILS (click to enlarge)
GELO optimises:
- Initial launch elements
- LEOP (Launch and Early Orbit Phase) burn times and attitudes for multiple burns
- Target inclination vector
- Spacecraft lifetime
These optimisations are validated against the constraints to calculate the available launch windows within a fully configurable mission timeline.
GELO is an operationally proven product. Global satellite operator Inmarsat used GELO for its recent successful launch of the Inmarsat 4F1 satellite. This was launched into Super Synchronous orbit* aboard an Atlas 5 rocket on March 11 2005. Inmarsat will continue to use GELO for all future Inmarsat 4 launches, including Inmarsat 4F2 due to be launched in September 2005.
The European Space Agency (ESA) are currently validating GELO against MSG-2 (Meteosat Second Generation) mission analysis reports.
GELO has been validated against independent mission analysis reports for Super Synchronous launches, Geosynchronous Transfer Orbits** and launches with no inclination plane changes required.
*A Super Synchronous Orbit is a special type of Geosynchronous Transfer Orbit (GTO) in which the highest point of the orbit (the 'apogee') is significantly further from the Earth than the desired Geosynchronous Orbit (GEO). This type of orbit is often used as an energy saving device for satellites with non-zero launch inclinations.
**A Geosynchronous Transfer Orbit (GTO) is used to transfer to Geosynchronous Orbit (GEO). It is an elliptical orbit with its highest point ('apogee') at geosynchronous height.
