Spaceflight Insider

SES-9 communications satellite launched atop SpaceX Falcon 9

SpaceX Falcon 9 NASA CRS 6 Cape Canaveral Air Force Station Space Launch Complex 40 photo credit: Michael Howard SpaceFlight Insider

Archive Photo Credit: Michael Howard / SpaceFlight Insider

The fifth time was the charm for SpaceX. The company launched the SES-9 communications satellite into orbit at 6:35 p.m. EST (23:35 GMT) on Friday, March 4. This evening’s launch was the 22nd flight of a Falcon 9 and the first from Florida since the Orbcomm OG2 mission took to the skies on Dec. 22, 2015. 

The launch comes after four prior attempts were called off last week due to problems with regulating the temperature of the liquid oxygen during loading. This upgraded Falcon 9, dubbed “Full Thrust”, utilizes colder-than-normal liquid oxygen (LOX) and rocket-grade kerosene (RP-1), chilled to near their freezing point. This densifies the propellant, allowing more fuel to fit in the same volume – something needed to both send a payload to geostationary transfer orbit (GTO) and recover first-stage boosters downrange.

702 satellite Intelsat Boeing image posted on SpaceFlight Insider

SES-9 is based on the 702 HP platform. Archive Photo Credit: Boeing

The 11,700-pound (5,300-kilogram) SES-9 was constructed by Boeing Satellite Systems off of the aerospace firm’s 702HP platform. The spacecraft is designed to last for 15 years in geosynchronous orbit.

On board are 57 high-power Ku-band transponders – the equivalent of 81–36 MHz transponders. Power is maintained by four lithium-ion battery bays manufactured by Saft. Altogether, SES-9 is the largest satellite dedicated to severing customers in more than 20 countries in the Asia-Pacific region. This is the 11th satellite Boeing has constructed for SES.

SES-9 replaces some capacity on orbit while drastically expanding television capabilities in both standard and high definition (HD). The newly expanded capacity will allow broadcasters to stream more local stations to their areas of coverage. SES-9 will be the seventh satellite fielded by SES for this region which covers Northeast Asia, South Asia, and Indonesia.

“The satellite’s Indian Ocean and South East Asian coverage is ideal for providing seamless in-flight connectivity for domestic Asian flights operating in countries like Indonesia and the Philippines,” said SES’ Senior Vice President, Commercial Asia-Pacific and the Middle East Deepak Mathur. “With 3.6 billion people expected to fly globally in 2016, SES-9 mobility beams will help to meet part of the increasing demand for in-flight connectivity from airline passengers.”

Mathur said SES-9 will deliver high-speed broadband services and mobile backhaul to remote regions to enable the deployment of communication networks, such as banking and e-government services.

The satellite has suffered through numerous delays. The latest of which, according to a report on, occurred when a “generic anomaly” was discovered in the second stage. Before that, SES-9 was scheduled to fly in December of 2015, but SES traded the flight opportunity with Orbcomm.

However, in terms of getting to orbit, an array of recent delays caused the spacecraft to stay at SLC-40 for far longer than anticipated.

  • SpaceX Falcon 9 rocket launches from Cape Canaveral Air Force Station's Space Launch Complex 40 with the SES-9 communications satellite photo credit Michael Howard SpaceFlight Insider

    Photo Credit: Michael Howard / SpaceFlight Insider

    Feb. 24 – The launch was postponed 24 hours due to issues with the rocket’s cryogenic fuel, the hold was called about 30-minutes prior to the opening of the launch window.

  • Feb. 25 – About one minute and 41 seconds prior to the opening of the day’s launch window opening, another hold was called. The cause again appears to be the super-cooled fuel the rocket uses.
  • Feb. 28 – The third launch attempt first encountered an issue when a wayward tugboat entered the security box and had to be escorted out. The second attempt of the evening was called by the rocket’s computers due to low thrust.
  • March 1 – This past Tuesday, SpaceX had planned to try again but opted to hold off until today due to extreme wind sheer.

All of that patience paid off this evening when the Falcon roared off of SLC-40 and into the skies above.

The Dec. 2015 flight of Orbcomm OG2 was the first successful flight of a Falcon 9 since the loss of the CRS-7 International Space Station resupply mission in June of last year.

The relatively rapid return-to-flight for the Falcon 9 highlighted the ability of the company to evaluate, identify, and correct issues in a very short amount of time and then return their launch vehicle to service.

This modified Falcon 9 uses a super-cooled propellant to increase the total thrust of the vehicle, providing enhanced performance. The increase allows SpaceX a wider latitude in terms of the payloads the booster can carry aloft. It also gives the craft more residual energy for return to launch site capabilities. This was the second time SpaceX used this variant, having flown the Orbcomm mission using this design.

On Feb. 23, SpaceX told SpaceFlight Insider that the aerospace firm was planning on carrying out an ocean-based landing on one of the Autonomous Spaceport Drone Ships (ASDS) that the company has fielded on several past attempts. The NewSpace firm has downplayed the chances of success for that endeavor owing to the energy needed to get SES-9 on its required trajectory.

The night’s activities began to pick up pace about thirty-four minutes to the planned liftoff time with the launch conductor conducting a readiness poll. Some four minutes later, RP-1 and liquid oxygen LOX loading got underway.

Ten minutes prior to launch, the Falcon 9 began engine chilldown. Eight minutes after this, the Cape’s Range Control Officer announced that the range was ready for launch. This was followed about 30 seconds later by SpaceX’s launch director confirming the same.

Weather predictions provided a 90 percent chance of favorable conditions for launch. Photo Credit: Jason Rhian / SpaceFlight Insider

Weather predictions provided a 90 percent chance of favorable conditions for launch. Photo Credit: Jason Rhian / SpaceFlight Insider

About a minute prior to launch, the rocket’s command flight computer began carrying out pre-flight checks and the two-stage rocket’s propellant tanks were pressurized.

At a mere three seconds before the Falcon 9 left the pad, the engine controller ordered the engine ignition sequence to start.

The SES-9 mission got underway at the very opening of this evening’s launch window, lifting off the pad at Cape Canaveral Air Force Station’s Space Launch Complex 40, and into the fading light of the skies above.

One minute after it had left SLC-40, the Falcon 9 entered the part of the flight known as maximum dynamic pressure – more commonly as “max-Q”. Here, the booster and its precious cargo were placed through the greatest amount of stress due to a combination of speed and atmospheric pressure.

First stage engine shutdown / main engine cutoff (MECO) occurred at approximately two minutes and 36 seconds into the flight, with stage separation occurring four seconds later.

Seven seconds after staging, the lone Merlin 1D in the Falcon 9’s upper stage ignited.

At three minutes and 42 seconds into the mission, the payload fairing, having achieved its job of shielding the SES-9 satellite through Earth’s turbulent atmosphere, was jettisoned.

The first second-stage engine shutoff (SECO) took place slightly more than nine minutes into the flight. At a little over 27 minutes into the mission, that engine reignited for a burn that lasted about 48 seconds.

Finally, 31 minutes and 24 seconds after having been launched, SES-9 was deployed into GTO. SpaceX CEO and Founder Elon Musk noted in a tweet that the first stage of the rocket landed hard on the “Of Course I Still Love You” Autonomous Spaceport Drone Ship.

Upon being sent into this orbit, the spacecraft’s bipropellant motors will carry the vehicle to its intended orbital slot of 108.2 degrees east, 36,000 miles (58,000 kilometers) above the Earth. Once on station, SES-9 used electric propulsion to remain in position and orient itself for the best possible performance. The spacecraft will share its orbital location with SES-7, currently providing similar services to the same region.

SES has more than 50 geostationary satellites – making it one of the largest operators worldwide. Their customers range from traditional television broadcasters to internet suppliers and government organizations. SES maintains headquarters in Luxembourg with offices around the globe including the United States and Singapore. Their systems provide more than 1,000 channels reaching over 44 million homes and 160 million subscribers.

Video courtesy of Ruptly TV / SpaceX


Joe Latrell is a life-long avid space enthusiast having created his own rocket company in Roswell, NM in addition to other consumer space endeavors. He continues to design, build and launch his own rockets and has a passion to see the next generation excited about the opportunities of space exploration. Joe lends his experiences from the corporate and small business arenas to organizations such as Teachers In Space, Inc. He is also actively engaged in his church investing his many skills to assist this and other non-profit endeavors.

Reader Comments

The thrust to weight with the center engine at minimum throttle setting is still greater than one. It cannot hover. Hover requires that your engine be able to throttle such that the thrust to weight ratio is one. But to land after hovering, you actually need a thrust to weight ratio less than one, otherwise you just hover until you run out of fuel.

The problem with hovering is that it is very propellant inefficient. The physics says the most efficient way to propulsive land is to use the maximum thrust at the last possible moment (Pulling the most G’s over the shortest time). To the extent the structures and control systems can handle this that is the best way to go. Sure, hovering makes the landing easier but they’ve already proven landing is doable with hover-slam for LEO missions where there is some fuel margin.

For GTO missions they may not have the luxury even if the the engine could throttle down, which it can’t. If SpaceX wants any chance of landing something like SES-9, heavy bird to supersync, they need to master multi-engine hover-slam.

Daniel Wisehart

That assumes you have enough fuel left to do all those things. How much delta-V were you thinking need at 1,000 feet and what is the mass of the first stage? I think you are going to find that the Falcon 9 achieved its primary mission perfectly, which was to launch a damn heavy satellite into Geotransfer orbit, with a heavily modified rocket. It is a huge success for SpaceX.

The secondary objective was an experimental landing with too little fuel and too much energy after deorbit. In that sense, it was probably a success too because what you want out of an experiment is good data, not necessarily a finished product. SpaceX is moving very wisely towards their goals: they are keeping their objectives in order and moving in careful steps. Way to go SpaceX!

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