SpaceX's Third SES Mission Marks Record-Setting Launch Cadence for Historic Pad 39A

SpaceX seeks to set a raft of new records on Thursday, 30 March, as its launch cadence out of historic Pad 39A at the Kennedy Space Center (KSC) in Florida ramps up for a third mission of 2017. Significantly, the pad—which saw service for more than four decades in support of the Apollo and Space Shuttle programs—will be re-used a mere 14 days after SpaceX successfully delivered the heavyweight EchoStar-23 communications satellite aloft on 16 March, establishing a new record for the shortest interval between flights out of 39A. And perhaps of greater significance from the perspective of reusability and driving down the cost of getting payload to orbit, Thursday’s launch marks the first re-use of an already-flown Upgraded Falcon 9 first stage. The 2.5-hour “window” extends from 6 p.m. EDT through 8:30 p.m. EDT.

Primary payload for the mission will be the SES-10 communications satellite, flying on behalf of Luxembourg-based operator SES. This marks the third SES bird to be launched by SpaceX, following SES-8—its first customer to Geostationary Transfer Orbit (GTO), back in December 2013—and more recently last March’s SES-9, with at least three more SES satellites to follow over the course of the next year. These include SES-11, whose transponders will be marketed as EchoStar-105 from the 105 degrees West orbital slot, plus SES-14 and SES-16. With SES-11 and SES-14 targeted to cover the Americas, including Mexico and the Caribbean, SES-16 (also known as “GovSat-1”) will be dedicated to military and national security applications for the Government of Luxembourg.

Weighing around 11,700 pounds (5,300 kg), SES-10 is built on Airbus Defence & Space’s three-axis-stabilized Eurostar-3000 “bus”, which carries frequency-agile remote-controlled Flexible Command Receivers to effect a more robust operations control link. Its twin solar arrays provide an electricity-generating capability of 13 kilowatts and the Eurostar-3000 was the first commercial satellite family to employ lithium-ion batteries in the place of older nickel-based ones for power during orbital eclipse. The bus also benefits from a bi-propellant chemical thruster system for initial orbit-raising and maneuvers and an electric plasma propulsion system for station-keeping. It is anticipated that the satellite will remain fully operational at a GTO altitude of 22,300 miles (35,800 km) for about 15 years.

Contracts to build SES-10 were signed between SES and Airbus Defence & Space in February 2014. It was revealed at the same time that SpaceX would serve as the launch provider, with initial speculation that it would ride the Falcon Heavy, due to perceived payload-to-GTO limitations on the “standard” Falcon 9. However, it subsequently became clear that the satellite could fly within the envelope of a standard Falcon 9, although Thursday’s flight remains one of the heaviest payloads ever delivered to GTO by SpaceX.

From the outset, it was intended that the new satellite’s three high-powered beams and optical elevation angle would expand SES capabilities across Mexico, Central and South America and the Caribbean region, providing Direct-to-Home (DTH) television broadcasting and other telecommunications services. In particular, SES-10 will allow broadcasters to meet a growing demand for enhanced picture quality, with more than 80 Ultra-High Definition (UHD) channels anticipated in Latin America by 2025.

As well as reaching an estimated 21 million homes in Spanish-speaking Latin America—with a “footprint” extending from the Gulf of California in Mexico to Cape Horn at the southernmost tip of Tierra del Fuego—it is expected that SES-10’s 55 dedicated Ku-band transponders will support business enterprise, enhanced broadband connectivity and offshore oil and gas exploration. Moreover, the satellite will provide connectivity to support the Caribbean cruise tourism industry, which presently accounts for about 40 percent of total worldwide cruise shipping. It will also enable airlines in Latin America to achieve a jump from 44 in-flight “connected” aircraft in 2015 to more than 1,500 by 2020.

“SES-10 will provide our customers in Latin America with fresh, high-power satellite capacity for multiple applications at an established orbital slot,” said SES President and CEO Romain Bausch at the time of the February 2014 contract award.

Prior to last spring’s launch of SES-9, it was noted that the SES television channel count had grown by 11.3 percent by the end of 2015, with an expectation of further enhancing capacity by 21 percent across emerging markets by the fall of 2017. A key driver of this enhanced capacity—and a total of around 80 new transponders—were to be provided by SES-9 and 10. At present, SES operates a fleet of more than 50 geostationary satellites in over 30 orbital “slots”, providing 7,200 television and radio channels and satellite communications services to worldwide business entities and government agencies. These reportedly reach around 99 percent of the world’s population. SES’s primary focus is upon Europe and the contiguous United States, with additional coverage of Latin America, Africa, the Middle East and the Asia-Pacific region.

According to SES, Internet traffic is expected to reach 15 gigabits per capita, as well as 645.7 million Machine-to-Machine (M2M) connections, by 2020. The new satellite will aid telecommunications (telco) operators, service providers and businesses to handle an increasing need for data and bandwidth in remote, mountainous and other difficult-to-reach areas, including Amazonia, Tierra del Fuego and Patagonia. “Allowing coverage of multiple countries from a single hub for Very Small Aperature Terminal (VSAT), mobile backhaul and trunking applications, SES-10 will offer an opportunity for service providers and telco operators to quickly expand their reach across the continent,” it was explained.

Last August, it was revealed that SES-10 would be SpaceX’s first customer to launch atop a “re-flown” Upgraded Falcon 9 booster. Since SpaceX was formed in May 2002, founder Elon Musk has made no secret of his intent to deliver humans into deep space, colonizing Mars and other destinations in the Solar System. As part of this architecture, SpaceX has focused on reusability technologies: most visibly the capability to return spent first stages of its Falcon 9 booster to soft landings on either the Autonomous Spaceport Drone Ship (ASDS) in the Atlantic and Pacific Oceans or on solid ground at Landing Zone (LZ)-1 at Cape Canaveral Air Force Station, Fla. Between December 2015 and February 2017, SpaceX successfully guided eight Falcon 9 first stages back to Earth and landed them in an intact configuration, for potential refurbishment and re-use.

The first stage to be used on Thursday to boost SES-10 to orbit will be the same vehicle which delivered the CRS-8 Dragon cargo ship to the International Space Station (ISS) in April 2016. “We believe reusable rockets will open up a new era of spaceflight and make access to space more efficient in terms of cost and manifest management,” said SES Chief Technology Officer Martin Halliwell, speaking last August. “The due diligence the SpaceX team has demonstrated throughout the design and testing of the SES-10 mission launch vehicle gives us full confidence that SpaceX is capable of launching our first SES satellite dedicated to Latin America into space.” SpaceX President Gwynne Shotwell added: “Re-launching a rocket that has already delivered spacecraft to orbit is an important milestone on the path to complete and rapid reusability.”

Originally tracking a launch in the timeframe from mid-October through mid-November 2016, the SES-10 mission met with significant delay, in the wake of last September’s on-the-pad explosion of an Upgraded Falcon 9 booster. This failure resulted in the destruction of the vehicle itself and its primary payload, the Amos-6 communications satellite, and enforced a hiatus of several months, before SpaceX returned to flight in mid-January 2017.

Efforts to prepare for the historic SES-10 mission got underway at around the same time. On 16 January, Airbus Defence & Space delivered SES-10 from its clean room facility in Toulouse, France, to Cape Canaveral for pre-launch preparations. A week later, and several thousand miles away, at SpaceX’s Rocket Development Facility in McGregor, Texas, the refurbished CRS-8 first stage underwent a static-fire of its nine Merlin 1D+ engines on the test stand. It was subsequently transported to Florida.

Since this mission will head for geostationary altitude—some 22,300 miles (35,800 km) above Earth—substantially higher energy and velocity demands will be brought to bear on the Upgraded Falcon 9, in comparison to launches into low-Earth orbit. This precludes the possibility of bringing the SES-10 first stage back to a landing on solid ground, at Landing Zone (LZ)-1 at Cape Canaveral. Instead, the first stage will attempt a controlled touchdown on the East Coast-based ASDS, nicknamed “Of Course I Still Love You”. The ASDS was drawn out of Port of Jacksonville on Saturday afternoon, by means of the Elsbeth III tug, bound for a position about 420 miles (680 km) offshore in the Atlantic Ocean.

It will be the first such foray for “Of Course I Still Love You” in several months, since it supported the return of an Upgraded Falcon 9 first stage in August 2016, at the end of the JCSAT-16 mission. Following the multi-month hiatus in the wake of the Amos-6 failure, January’s launch of a batch of Iridium NEXT satellites from Vandenberg Air Force Base, Calif., saw its first stage alight on the West Coast-based ASDS in the Pacific Ocean, whilst February’s ISS-bound CRS-10 Dragon accomplished a smooth touchdown on solid ground at LZ-1 at the Cape. Most recently, the heavyweight EchoStar-23 launch two weeks ago required all of the energy performance of its Upgraded Falcon 9 to achieve orbit and was not recovered. If Thursday’s launch goes ahead as expected, this will be the sixth fully successful ASDS landing in SpaceX history.

The 230-foot-tall (70-meter) Upgraded Falcon 9 booster was transferred from the Horizontal Integration Facility (HIF) to Pad 39A and elevated to the vertical on Saturday, 25 March, by means of the Transporter-Erector (TE). SpaceX teams then pressed ahead with customary pre-launch procedures, with a brief Static Fire Test of the nine Merlin 1D+ engines of the first stage scheduled for Sunday afternoon. This was delayed by 24 hours and eventually took place without incident on Monday, 27 March. This correspondingly led to a 24-hour delay to the launch date from Wednesday to Thursday. Launch is presently targeted to occur during a 2.5-hour “window”, extending from 6 p.m. EDT through 8:30 p.m. EDT. New rules, implemented after the Amos-6 failure, require a customer’s payload to be installed atop the booster after the completion of the Static Fire Test. As a result, the first stage went horizontal after the Static Fire Test and was returned to the HIF for the installation of the SES-10 payload.

According to the 45th Space Wing at Patrick Air Force Base in its L-3 forecast, the weather outlook for Thursday calls for 70-percent-favorable conditions. “On Wednesday, a weak surface boundary will drape across the Mid-Atlantic states and trail back into a developing storm system over Texas,” it was noted. “On Thursday, the strengthening Texas storm system begins to track northeasterly into the Tennessee Valley.” Although neither the system or its frontal boundary are expected to directly impact the KSC area until late Friday and Saturday, the 45th highlighted a possible elevated risk from “upper-level cloudiness and added instability”. Primary issues on Thursday include a risk of violating the Cumulus Cloud Rule and Thick Cloud Rule. Should SpaceX miss the opportunity to launch on Thursday, Friday’s outlook deteriorates to 60-percent-favorable, as the surface boundary associated with the system pushes into the Florida Panhandle. “Surface winds along the Space Coast will turn more southerly,” it was stressed, “and speeds will increase into the 20-25 mph range”. In addition to a potential violation of the Cumulus Cloud and Thick Cloud Rules, there also exists the risk of infringing the Liftoff Winds Rule.

In keeping with procedures implemented since the Amos-6 failure, the Upgraded Falcon 9 has benefited from a somewhat longer fueling regime on its three previous missions. Loading of rocket-grade kerosene (known as “RP-1”) and “densified” cryogenic oxygen is expected to begin around an hour before T-0. This is quite different from previous practice with the booster, which saw fueling commence about 35 minutes before T-0. The longer fueling regime is expected to be a temporary measure, until a further enhanced Falcon 9 upgrade enters service, later in 2017.

Passing T-10 minutes, the terminal countdown autosequencer will be initiated and the nine Merlin 1D+ engines of the first stage—which are configured in a circle of eight, with the ninth at the center—are chilled down, ahead of ignition. The vehicle will transition to internal power and assume primary command of all critical functions, going into “Startup” a minute before launch. At T-3 seconds, the nine Merlins will roar to life, pumping out a combined thrust of 1.5 million pounds (680,000 kg). Following liftoff, the first stage will power uphill for the opening minutes, before the second stage and its restartable Merlin 1D+ Vacuum engine picks up the baton to deliver SES-10 to orbit. Landing of the first stage is anticipated on the ASDS within ten minutes of liftoff. If successful, it remains to be seen if this stage will be recycled to fly a third time. “As with every first-stage recovery, we will inspect the flight hardware after landing and assess,” SpaceX told AmericaSpace, earlier this week. “Remember, this has never been done before.”

As well as bringing Pad 39A back to operational service, almost six years after the end of the Space Shuttle program, SpaceX has already established an impressive cadence of back-to-back launches. Having despatched the ISS-bound CRS-10 Dragon mission on 19 February, a mere 25 days elapsed before EchoStar-23 departed the pad on 16 March. This was the shortest interval between a pair of launches since April 1985, when shuttles Discovery and Challenger rocketed into orbit within 17 days of each other. If SES-10 rises to orbit as planned on Thursday, it will secure a new empirical record of just 14 days between launches, as well as an all-time record of only 39 days between three launches.

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