.jpg) SES-9 satellite encapsulated in the Falcon 9 payload fairing, but not yet mated with the launch vehicle, 20 February 2016. | |
| Mission type | Communications |
|---|---|
| Operator | SES[1] |
| COSPAR ID | 2016-013A |
| SATCATno. | 41380 |
| Website | https://www.ses.com/ |
| Mission duration | 15 years (planned) 9 years, 8 months, 24 days (elapsed) |
| Spacecraft properties | |
| Spacecraft type | Boeing 702 |
| Bus | BSS-702HP[1] |
| Manufacturer | Boeing |
| Launch mass | 5,271 kg (11,621 lb) |
| Start of mission | |
| Launch date | 4 March 2016, 23:35UTC |
| Rocket | Falcon 9 Full Thrust |
| Launch site | Cape Canaveral,SLC-40 |
| Contractor | SpaceX |
| Orbital parameters | |
| Reference system | Geocentric orbit |
| Regime | geostationary orbit |
| Longitude | 108.2° East |
| Transponders | |
| Band | 33Ku-band |
| Bandwidth | 36Mhz, 54 MHz |
| Coverage area | Northeast Asia,South Asia,Indonesia |
SES-9 is ageostationarycommunications satellite operated bySES It was launched fromCape CanaveralSLC-40 by aFalcon 9 Full Thrustlaunch vehicle on 4 March 2016.
SES-9 is a largecommunications satellite operating in geostationary orbit at the 108.2° East, providing communications services toNortheast Asia,South Asia andIndonesia, maritime communications forvessels in theIndian Ocean,[2] and mobility beams for "seamlessin-flight connectivity" for domestic Asianairlines of Indonesia and thePhilippines.[3]
The satellite was built byBoeing, using a modelBSS-702HPsatellite bus.[4]
SES-9 had a mass of 5,271 kg (11,621 lb) at launch,[5] the largest Falcon 9 payload yet to a highly-energeticgeosynchronous transfer orbit (GTO).[3]SES used the spacecraft's own propulsion capabilities to circularize the trajectory to ageostationary orbit.[6]
SES-9 has 57 high-power Ku-band transponders, equivalent to 81 transponders of 36MHz bandwidth and, co-located at 108.2°E alongside SES-7, it provides additional and replacement capacity forDTH broadcasting and data inNortheast Asia,South Asia andIndonesia, and maritime communications for theIndian Ocean. Broadcasts are on six Ku-band coverage beams:[7]
In addition to the earlierSES-8 mission ordered in 2011 and launched in 2013, SES contracted SpaceX for three additional launches starting with SES-9, originally planned for 2015. The deal was announced on 12 September 2012.[8] In early 2015,SES announced[9] that it would be the launch customer of the next rocket evolution by SpaceX:Falcon 9 v1.1 Full Thrust (also calledFalcon 9 v1.2,[10] and later, justFalcon 9 Full Thrust). At the time, SES expected SES-9 to be launched by September 2015.[11] Despite the failure of theCRS-7 mission in June 2015, SES re-confirmed in September 2015 their decision to provide the first payload for the new rocket variant; however the launch was postponed until late 2015.[12]
Eventually, after considering all options, SpaceX announced a change on 16 October 2015:Orbcomm's 11Orbcomm-OG2 satellites would be the payload on the return-to-flight mission of the redesigned rocket instead of SES-9.[11] The Orbcomm payload with itslower orbit would allow SpaceX to test relighting the second-stage engine, a capability required to successfully put the heavier SES-9 on ageostationary orbit.[11] The Orbcomm mission was subsequently delayed to mid-December 2015, while SES-9 was scheduled to follow "within a few weeks".[11] Finally, Falcon 9 Full Thrust performed itsmaiden launch on 22 December 2015, thefinal launch of the Falcon 9 v1.1 variant followed in January 2016, with SES-9 moving to February 2016. Consequently, this was the second launch of the Full Thrust variant.[4]
A successfulstatic fire test of the rocket was completed on 22 February 2016.[4]
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| Attempt | Planned | Result | Turnaround | Reason | Decision point | Weather go (%) | Notes |
|---|---|---|---|---|---|---|---|
| 1 | 24 Feb 2016, 11:46:00 pm | Delayed[13] | — | Issue loading cryogenic liquid oxygen | 60% | ||
| 2 | 25 Feb 2016, 11:47:00 pm | Aborted[14] | 1 day 0 hours 1 minute | Issue loading cryogenic liquid oxygen | (T-00:01:41) | 80% | |
| 3 | 28 Feb 2016, 11:47:00 pm | Aborted[15] | 3 days 0 hours 0 minutes | Fouled Range | 95% | ||
| 4 | 29 Feb 2016, 12:21:00 am | Aborted[15] | 0 days 0 hours 34 minutes | Low thrust alarm due to rising oxygen temps | 95% | ||
| 5 | 4 Mar 2016, 11:35:00 pm | Successful launch[16] | 4 days 23 hours 14 minutes | 90% | Launch window: 23:35 to 01:06 UTC |
The launch was initially scheduled for 24 February 2016 at 23:46 UTC, with a backup launch window the next day at the same time.[3] Neither day produced a launch however as both attempts were scrubbed: on 24 February 2016, prior topropellant loading "out of an abundance of caution, in order to get the rocket's liquid oxygen propellant as cold as possible"; and on 25 February 2016, just two minutes prior to launch "citing a last-minute problem with propellant loading".[17]
Subsequently, the launch was rescheduled for the evening of 28 February 2016 at 23:47 UTC, with a fallback slot same time next day.[18] On 28 February 2016, launch attempt was aborted less than two minutes before scheduled liftoff due to a tugboat entering the area of the offshore safety zone.[19] A second attempt on 28 February 2016 was made about 35 minutes later, after the downrange zone had been cleared, however, the rocket shut-down a moment after ignition due to low thrust flag from one engine. Rising oxygen temperature due to the hold for the tugboat to clear and a suspected helium bubble, the two are related: the helium bubble in the warmer LOX was affected by the earlier launch attempt, when the stage was pressurized (with helium) for some time, increasing the saturation of helium gas into the liquid oxygen, which could then bubble out when the turbopumps began rapidly drawing oxidizer from the tank for the launch (and lowering tank pressure in the zone around the turbopump inlet), were suggested by Elon Musk as the likely reasons for the alarm being triggered.[20] The next launch attempt on 1 March 2016 was postponed to 4 March 2016 due to high winds.[21]
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The launch was finally attempted, and succeeded, on 4 March 2016 at 23:35:00 UTC.[6]
The originalapogee for thetransfer orbit contracted by SpaceX was 26,000 km (16,000 mi), asubsynchronoushighly-elliptical orbit that SES would thencircularize andraise over several months before the satellite would be ready foroperational service at 36,000 km (22,000 mi). SESCTOMartin Halliwell indicated in February 2016 that SpaceX had agreed to add additionalenergy to the spacecraft with the launch vehicle and that a new apogee of approximately 39,000 km (24,000 mi) was the objective, in order to assist SES in the satellite becoming operational many weeks earlier than otherwise possible,
| External videos | |
|---|---|
 SES-9 Technical Webcast: Experimental Landing |
Following word from SES that SpaceX had allocated some of the normal propellant reserve margins for landing to placing the SES-9 satellite in a higher (and moreenergetic) orbit than originally planned,[22]
SpaceX confirmed in February 2016 that they would still attempt a secondary goal of executing a controlled-descent andvertical landingflight test of thefirst stage on the SpaceXeast-coastAutonomous spaceport drone ship (floating landing platform) namedOf Course I Still Love You.[4][23][3] Although SpaceX successfullyrecovered a first booster on land following theDecember launch to a less-energetic orbital trajectory,[24][25] they had not yet succeeded in booster recovery from any of the previous attempts to land on a floating platform.[23] Because the SES-9 satellite was very heavy and was going to such a high orbit, SpaceX indicated prior to launch that they did not expect this landing to succeed.[22]
As expected, booster recovery failed: the spent first stage "landed hard", damaging the drone ship,[26] but the controlled-descent andatmospheric re-entry, as well as navigation to a point in theAtlantic Ocean over 600 km (370 mi) away[27] from the launch site, were successful and returned significant test data on bringing back a high-energy Falcon 9.[6]
The controlled descent through theatmosphere and landing attempt for each booster is an arrangement that is not used on otherorbitallaunch vehicles.[28] SES CTO Martin Halliwell had informed SpaceX that they were willing to use the same rocket twice to power another satellite to orbit.[29] This idea became reality in March 2017 with theSES-10 mission flying with the reused booster fromCRS-8.
By 21 March 2016, the hole in the deck of the drone ship had been nearly repaired.[30]
This mission is going to a Geostationary Transfer Orbit. Following stage separation, the first stage of the Falcon 9 will attempt an experimental landing on the "Of Course I Still Love You" droneship. Given this mission's unique GTO profile, a successful landing is not expected.
SES 9's launch weight is 5271 kg, [...] heavier than the Falcon 9 rocket's advertised lift capacity to geosynchronous transfer orbit, an elliptical path around Earth that serves as a drop-off point for communications satellites heading for positions 22,300 miles (35,900 kilometres) above the equator, a popular location for powerful broadcast platforms.Geosynchronous transfer orbits targeted by satellite launchers typically have an apogee, or high point, of at least 22,300 miles and a low point a few hundred miles above Earth. [...] SES's contract with SpaceX called for the rocket to deploy SES 9 into a "sub-synchronous" transfer orbit with an apogee around 16,155 miles (25,999 kilometres) in altitude. Such an orbit would require SES 9 to consume its own fuel to reach a circular 22,300-mile-high perch, a trek that Halliwell said was supposed to last 93 days. The change in the Falcon 9's launch profile [is planned to] put SES 9 into an initial orbit with an apogee approximately 24,419 miles (39,299 kilometres) above Earth, a low point 180 miles (290 kilometres) up, and a track tilted about 28° to the equator.
After a variety of problems delayed four previous launch attempts, a SpaceX Falcon 9 successfully launched the SES-9 communications satellite March 4, although an attempted landing of the rocket's first stage on a ship was not successful, as expected.
This mission also marks SpaceX's return-to-flight as well as its first attempt to land a first stage on land. The landing of the first stage is a secondary test objective.
Media related tothe launch of SES-9 at Wikimedia Commons