Intelsat 29e Launch: Orbit Raising Underway
By Richard Laurie, Senior Program Manager, Space Systems Acquisition
The first of Intelsat’s new high throughput Intelsat EpicNG satellites was launched on an Ariane 5 vehicle on the evening of 27 January. It was a picture-perfect launch, blasting off right on time. Within 30 minutes of lift-off, Intelsat 29e (IS-29e) was in a geostationary transfer orbit (GTO) heading into view of the Kumsan, South Korea ground station. That’s when those of us on the ground in El Segundo, California began to see satellite telemetry. A few minutes later, when we were able to successfully send a command, we declared signal acquisition.
Then, just when the celebrations got underway in French Guiana, the work for those of us in El Segundo really began!
Here at the Boeing offices in El Segundo, a team of Intelsat and Boeing engineers are working together to raise the orbit of IS-29e and put it into service at its orbital location at 310° East. Boeing has a 25-person team working round-the-clock in the Mission Operations Center with an Intelsat team – of which I am a part – also on hand for decision-making and reviews.
In the first two days after launch, we evaluated the health of the satellite and determined the orbit that it was placed into by the launch vehicle. The desired target orbit was an ellipse whose apogee (the farthest point from the Earth) was 35,546 km and whose perigee (the closest point from the Earth) was 240 km. The target orbit was selected so that, at apogee, the desired orientation with respect to the Sun to satisfy power and thermal constraints was the same as the desired orientation for firing the main thruster. If the actual injection orbit were off nominal we might have had to reorient the satellite from the Sun attitude to the burn attitude and back before and after every burn. Fortunately, the injection orbit was close enough to the target orbit that reorientations were unnecessary. Another sigh of relief!
Next up, are a series of main thruster firings whose primary purpose is to raise the perigee from the 240 km to the geostationary altitude of 35,786 km. For IS-29e, the first of these firings began about midnight in El Segundo on 29 January and will continue for approximately 10 days. After each burn, the resulting orbit is tracked for several orbits around the earth to determine the new orbit, which is used to plan the next burn. Our goal is to put IS-29e into a designated test orbit at 310.3° East where we will deploy the stowed reflectors and solar array wings.
I’ll write again soon on our progress.