For the first time, SpaceX’s Upgraded Falcon 9 booster—which delivered 11 Orbcomm Generation-2 (OG-2) satellites into low-Earth orbit, just before Christmas—will transport its first payload from Space Launch Complex (SLC)-40 at Cape Canaveral Air Force Station, Fla., toward a 22,370-mile (36,000-km) Geostationary Transfer Orbit (GTO) on Wednesday, 24 February, when it lofts the heavyweight SES-9 communications satellite on behalf of the Luxembourg-based satellite operator, SES. The first stage of the booster is then expected to attempt an oceanic touchdown on the Autonomous Spaceport Drone Ship (ASDS), nicknamed “Of Course I Still Love You.” When operational at 108.2 degrees East longitude, SES-9 will mark SES’ largest-ever satellite dedicated to communications services in the Asia-Pacific region and represents the company’s first spacecraft to utilize electric propulsion. Speaking last year, SES President and CEO Karim Michel Sabbagh stressed that SES-9 will help to “add significant growth capacity to serve the strong demand for video in international markets.”
Although SpaceX has to date successfully delivered seven communications satellites to GTO—beginning with SES-8, back in December 2013, and most recently TurkmenÄlem52E/MonacoSat in April 2015—the Hawthorne, Calif.-headquartered launch servicers provider has yet to do so atop its Upgraded Falcon 9. The latter, as detailed in a previous AmericaSpace article, is also known as “Full Thrust,” because its nine Merlin 1D+ first-stage engines and its single Merlin 1D+ Vacuum second-stage engine will operate at their full, 100-percent power level. This is in contrast to the 80 percent of rated performance seen by the Falcon 9 v1.1, which flew its final mission last month, and the Upgraded Falcon 9 also benefits from a further 13 percent of additional performance, accrued through a range of structural enhancements to the vehicle’s airframe and a process of “densifying” and increasing the liquid oxygen propellant load. All told, this produces a performance “gain” of 33 percent in the Upgraded Falcon 9 over the v1.1. The new also stands about 5.6 feet (1.6 meters) taller than its predecessor, topping-off at 229.6 feet (70 meters).
Under original plans, SES-9 was slated to be SpaceX’s first Upgraded Falcon 9 payload, targeted to launch no later than September 2015, but these efforts were thwarted and placed on indefinite hold as the company wrestled with restoring its fleet of boosters to flight status, having catastrophically lost the Commercial Resupply Services (CRS)-7 Dragon mission on 28 June. However, as outlined by AmericaSpace’s Mike Killian last fall, SpaceX and SES agreed to switch SES-9 with the OG-2 payload. Since the OG-2 satellites were headed for low-Earth orbit and did not require a second “burn” of the Upgraded Falcon 9’s second stage to achieve their desired position, it made sense to fly this mission, then test the re-light capability of the Merlin 1D+ Vacuum engine, before committing with confidence to the higher-energy, GTO-bound SES-9 mission.
Previously described by Space News as a “high priority” payload, the delays to SES-9 are reportedly one reason why SES trimmed its 2016 revenue projections. Last month, SES outlined an 11.3-percent growth on television channels in 2015 and noted that the SES-9 and SES-10 satellites “will drive growth by delivering a total of 80 additional transponders in Asia and Latin America, with important pre-fill rates underwritten by customer agreements.” SES presently operates a fleet of more than 50 geostationary satellites in over 30 orbital “slots,” which provide in excess of 7,200 television channels, as well as radio channels and satellite communications services to worldwide business and government agencies, and reportedly can reach 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. In fact, SES-9 will mark SES’s largest-ever satellite to handle Asia-Pacific communications traffic.
It officially came into being in October 2012, when Boeing was selected to build the satellite “to serve the fast-growing markets in Asia,” with the intention that it would be placed at 108.2 degrees East longitude “and provide incremental as well as replacement capacity” in an orbital slot co-located with the SES-7 satellite. Specifically, it was expected that SES-9 would provide direct-to-home broadcasting and other services to 22.29 million households in north-eastern Asia, south Asia, and Indonesia, as well as maritime communications in the Indian Ocean.
Fabricated at Boeing’s Satellite Development Center in El Segundo, Calif., SES-9 is based upon the proven 702HP spacecraft “bus.” With a mass of 11,750 pounds (5,330 kg), its tailored payload module interfaces with the main bus at four locations, and with just six electrical connectors, for simplicity and cost efficiency. It also utilizes an advanced Xenon Ion Propulsion System (XIPS), which reportedly provides 10 times more efficiency than liquid fuels, with a quartet of station-keeping thrusters. Six early 702 missions suffered problems with their solar array concentrators, whose cells tended to outgas at a higher-than-predicted rate and caused them to become “fogged” and reduced the satellites’ operational lifetimes. This problem was later corrected a pair of six-paneled triple-junction gallium arsenide cells. SES-9’s 12.7-kilowatt communications payload includes 57 high-power Ku-band transponders, and the satellite is expected to remain operational for 15 years. The satellite was delivered to Cape Canaveral in December 2015, with launch initially targeted for late January 2016.
With SpaceX’s successful return to flight—and a triumphant “shakedown” of the Upgraded Falcon 9 on 21 December—it was announced in early February that the 24th had been established for an opening launch attempt for SES-9. The Eastern Range had provided a backup opportunity on 25 February, to guard against weather or technical issues. At the same time, SES revealed that—in order to mitigate the negative impact of several months of delays—SpaceX had agreed to support “a mission modification” to reduce the amount of time needed for the satellite to reach its orbital slot. SES-9’s heavy weight places it beyond the nominal capabilities the Upgraded Falcon 9 and it was intended that SpaceX would boost it to a “sub-GTO orbit,” after which the satellite would employ its own chemical and electric propulsion assets to achieve its final slot about four to six months later. However, it was subsequently decided that modifying the mission profile “will reduce the time needed for SES-9 to reach its orbital slot, keeping the Operational Service Date (OSD) in the third quarter of 2016, as previously foreseen.”
In readiness for the opening launch attempt, the meteorological forecast from the 45th Weather Squadron at Patrick Air Force Base has predicted a 60-percent likelihood of acceptable conditions at T-0 for Wednesday. Citing the development of a low-pressure system along the Gulf Coast and associated clouds and isolated showers over the Space Coast, it was pointed out that atmospheric conditions are expected to become “more unstable” by Tuesday, “as the low-pressure area strengthens and moves east, creating gusty winds, more widespread rain showers and adding the threat of isolated thunderstorms.” Moreover, by Wednesday, the low-pressure system will pull north-east, dragging a cold front which will slowly progress across the Cape, yielding gusty winds, rain showers, and a chance of thunder during the day. However, the front should push south of SLC-40 during Wednesday’s countdown, although the 45th cautioned that clouds may linger until midnight. Consequently, the key Launch Commit Criteria (LCC) for Wednesday are expected to risk violation of the Cumulus and Thick Cloud Rules, as well as Liftoff Winds.
In recent days, processing of the Upgraded Falcon 9 and encapsulation of SES-9 into its two-piece (or “bisector”) Payload Fairing (PLF) has proceeded smoothly, with a satisfactory Static Fire Test of the nine Merlin 1D+ first-stage engines performed on Monday, 22 February. “Full-duration static fire completed,” SpaceX tweeted late Monday. “Targeting Wednesday for launch of SES-9 satellite.”
Following the completion of the test, the standard Launch Readiness Review (LRR)—which typically occurs at L-1 day for commercial missions—should take place during Tuesday. At the same time, the Autonomous Spaceport Drone Ship (ASDS) departed Port of Jacksonville with the Elsbeth III tug at 7:55 p.m. EST on Friday, 19 February, bound for a position in the Atlantic Ocean to await the recovery of the Upgraded Falcon 9’s first stage.
It has previously been stressed by SpaceX that future first-stage recoveries will see a mixture of ASDS landings and “land” landings, dictated by available vehicle performance. Attempts to land Falcon 9 hardware on the ASDS has met with mixed success in recent years. A series of “controlled oceanic touchdowns” in April, July, and September 2014 were followed by three attempts to land on the ASDS: the first, in January 2015, saw the first stage reach the deck, but impact at a 45-degree angle and explode, whilst the second, in April 2015, landed with excessive lateral velocity and toppled over upon impact. More recently, in January 2016, the final Falcon 9 v1.1 came close to a bull’s-eye landing on the ASDS, but was ultimately thwarted by the failure of one of its landing legs to properly latch into position. That said, the Upgraded Falcon 9 succeeded in spectacular fashion in bringing its first stage back to Landing Zone (LZ)-1 at the Cape in December, raising hopes that this enhanced version of SpaceX’s workhorse may yield similar success Wednesday.
Unlike the earlier Falcon v1.1, whose propellants were typically loaded several hours in advance of T-0, the Upgraded Falcon 9 can take advantage of a new fueling regime, which kicks off barely 35 minutes before liftoff. With the opening of Wednesday’s launch window due to open at 6:46 p.m. EST, this regime will see liquid oxygen flowing into the booster’s tanks, chilled to a level much closer to its freezing point than on v1.1 missions. The countdown will reach its final “Go/No-Go” polling point of all stations at T-13 minutes, after which the Terminal Countdown will get underway at T-10 minutes.
During this period, the Merlin 1D+ engines will be chilled, ahead of their ignition sequence. All external power utilities from the Ground Support Equipment (GSE) will be disconnected from the stack, the SES-9 payload will be placed onto internal power, and at T-5 minutes the 90-second process of retracting the “strongback” from the vehicle will get underway. The Flight Termination System (FTS)—tasked with destroying the vehicle in the event of a major accident during ascent—will be placed onto internal power and armed. Fueling will then conclude and the first stage’s propellant tanks will attain their proper flight pressures. The Merlin 1D+ engines will be purged with gaseous nitrogen, and, at T-60 seconds, the SLC-40 complex’s “Niagara” deluge system of 53 nozzles will be activated, flooding the pad surface and flame trench with 30,000 gallons (113,500 liters) of water per minute to suppress acoustic energy radiating from the engine exhausts.
At T-3 seconds, the nine upgraded Merlin 1D+ engines will roar to life, ramping up to a combined thrust of 1.5 million pounds (680,000 kg). This represents a significantly enhanced propulsive yield over the 1.3 million pounds (590,000 kg) pumped out by the earlier Falcon 9 v1.1. Following computer-commanded health checks, this will produce the correct conditions to release the stack from SLC-40. Although T-0 on Wednesday is set for 6:46 p.m. EST—about 27 minutes after local sunset—the mission benefits from a relatively spacious launch window, which closes at 8:23 p.m.
Immediately after clearing the tower, the booster will execute a combined pitch, roll, and yaw program maneuver, establishing itself onto the proper flight azimuth to inject the SES-9 payload into orbit. Eighty seconds into the uphill climb, the vehicle will exceed the speed of sound and experienced a period of maximum aerodynamic duress—colloquially dubbed “Max Q”—on its airframe. At about this time, the Merlin 1D+ Vacuum engine of the second stage will undergo a chill-down protocol, ahead of its own ignition later in the ascent. Later, two of the first-stage engines will throttle back, under computer command, in order to reduce the rate of acceleration at the point of Main Engine Cutoff (MECO). Finally, at T+2 minutes and 58 seconds, the seven remaining engines will shut down and, a few seconds later, the first stage will separate from the rapidly ascending stack. The turn will then come for the restartable second stage, whose Merlin 1D+ Vacuum engine will ignite and continue the boost into orbit.
In the event of a 24-hour scrub on Wednesday, the weather prospects are expected to improve slightly by Thursday, to 80-percent favorable. Key concerns center upon a possible violation of Liftoff Winds. “On Thursday, skies clear rapidly as brisk winds bring much colder air to the Spaceport,” the 45th Weather Squadron explained in its synoptic analysis. “Winds will decrease near sunset as high pressure builds in and continues to push the frontal system south. The primary weather concern is strong winds remaining throughout the launch window.”
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