| SES-8 | |
| Mission Type: | Communication |
| Operator: | SES |
| Cospar Id: | 2013-071A |
| Satcat: | 39460 |
| Website: | https://www.ses.com/ |
| Mission Duration: | 15 years (planned) (elapsed) |
| Spacecraft Type: | GEOStar-2 |
| Spacecraft Bus: | STAR-2.4 |
| Manufacturer: | Orbital Sciences Corporation |
| Power: | 5 kW |
| Launch Date: | 3 December 2013, 22:41:00 UTC |
| Launch Rocket: | Falcon 9 v1.1 |
| Launch Site: | Cape Canaveral, SLC-40 |
| Launch Contractor: | SpaceX |
| Entered Service: | February 2014 |
| Orbit Reference: | Geocentric orbit |
| Orbit Regime: | Geostationary orbit |
| Orbit Longitude: | 95° East |
| Apsis: | gee |
| Trans Band: | 33 Ku-band |
| Trans Bandwidth: | 36 MHz |
| Trans Coverage: | South Asia, India, Indo-China, Thailand, Vietnam, Laos |
| Programme: | SES constellation |
| Previous Mission: | SES-7 |
| Next Mission: | SES-9 |
SES-8 is a geostationary Communications satellite operated by SES SES-8 was successfully launched on SpaceX Falcon 9 v1.1 on 3 December 2013, 22:41:00 UTC.[1]
It was the first flight of any SpaceX launch vehicle to a supersynchronous transfer orbit, an orbit with a somewhat larger apogee than the more usual geostationary transfer orbit (GTO) typically utilised for communication satellites.[2]
The SES-8 satellite is built on the STAR-2.4 satellite bus by Orbital Sciences Corporation (OSC). It is the sixth satellite of that model to be built for SES.[3]
The communications satellite is initially co-located at 95° East [4] with NSS-6 in order to provide communications bandwidth growth capacity in the Asia-Pacific region, specifically aimed at high-growth markets in South Asia and Indo-China, "as well as provide expansion capacity for satellite television (direct-to-home - DTH), Very-small-aperture terminal (VSAT) and government applications".[3] [5]
The launch of SES-8 was the seventh launch of the Falcon 9 launch vehicle, and the second launch of the Falcon 9 v1.1. SES paid a discounted price — "well under US$60 million" — for the launch since it was the inaugural geostationary launch on the Falcon 9. When originally contracted, in 2011 the putative launch date was early 2013.[2]
The launch was the second launch of the Falcon 9 v1.1 version of the rocket, a longer rocket with 60% more thrust than the Falcon 9 v1.0 vehicle, and the first launch of the larger v1.1 rocket using the rebuilt erector structure at SpaceX' Cape Canaveral SLC-40.[6] As a result, a number of systems on the launch vehicle was flown for only the second time, while several parts of the ground infrastructure at Cape Canaveral were used in a launch for the first time. These include:[7]
In order to maximize the propellant available for the launch of SES-8 into geostationary transfer orbit (GTO), SpaceX did not attempt a controlled descent test of the first-stage booster as they did on the previous Falcon 9 v1.1 flight in September 2013.[10]
In the previous launch of the Falcon 9 v1.1 — the first launch of the much larger version of the rocket with new Merlin 1D engines — on 29 September 2013, SpaceX was unsuccessful in reigniting the second stage Merlin 1D vacuum engine once the rocket had deployed its primary payload (CASSIOPE) and all of its nanosat secondary payloads.[11] The restart failure was determined to be frozen igniter fluid lines in the second-stage Merlin 1D engine. A minor redesign was done to address the problem by adding additional insulation to the lines.[12]
A second burn of the upper stage was required, and was completed successfully, during the SES-8 mission [13] in order to place the SES-8 telecommunications satellite into the highly elliptical supersynchronous orbit for satellite operator SES to effect a plane change and orbit circularisation.[12] [11]
The Falcon 9 upper stage used to launch SES-8 was left in a decaying elliptical low Earth orbit which, by September 2014, had decayed and re-entered the atmosphere of Earth.[14]
Both stages of the Falcon 9 arrived at Cape Canaveral for processing before 2 October 2013, after both had trouble-free test firings at the SpaceX Rocket Development and Test Facility at McGregor, Texas.[3] A launch attempt on 25 November 2013, with a planned liftoff at 22:37:00 UTC was scrubbed following a reported off-nominal condition in the liquid oxygen tank and supply lines of the first-stage booster that could not be resolved within the approximately one-hour launch window. A launch date of 28 November 2013 was announced, three days later, being the next opportunity for the launch site on Earth to be in alignment to achieve the target orbit.