Falcon 9 v1.1 successfully lofts SES-8 in milestone launch
SpaceX launched their Falcon 9 v1.1 rocket on Tuesday, ahead of successfully lofting the SES-8 satellite into its Geostationary Transfer Orbit. In what was the debut of SpaceX’s upgraded Falcon 9 rocket from SLC-40 at Cape Canaveral, the third launch attempt enjoyed a smooth countdown, launching at the start of the launch window at 17:41 local time.
Monday SCRUB DETAILS:
Thursday SCRUB DETAILS:
SpaceX’s Falcon 9 v.1.1 rocket scrubbed for the second time during its Thanksgiving launch attempt. The countdown suffered from two holds during its available launch window.
Initial information noted hold one (an abort at ignition) was caused by low ramp of up thrust on Merlin 1D engines, as the countdown was at around T-1 second. Following a recycled countdown, hold two was called by the Prop console just after T-60 seconds, as the team ran out of time to be fully confident with their review of the engines after the first abort.
The issue with hold one was related to the ground side TEA-TEB, which uses a triethylaluminum-triethylborane mixture as a first-stage ignitor. Oxygen had apparently contaminated the mix, causing the issue.
The vehicle has had its engines inspected, with the next launch originally classed as no sooner than “a few days time” (aligned to Saturday). However, L2 information noted the next attempt would be NET (No Earlier Than) Monday, later confirmed by SpaceX, allowing for the cleaning of the gas generator turbines on the engine set.
That has since been completed, along with the replacement of gas generator hardware on Engine 9 (center engine), which was seen as likely to allow for the next attempt to take place at the start of the week.
However, per L2 information – later made official by SpaceX – the teams were informed that due to ongoing review work relating to the engines, and to a lesser extent concerns over the weather during the window, the company sent out notice that they would not be pressing ahead with a launch on Monday.
With the next opportunity – on Tuesday – secured with the Eastern Range, improved weather conditions are expected throughout the launch window. SpaceX have also secured a backup opportunity on Wednesday, should it have been required, which – in the end – it wasn’t, following the launch at 17:41 local time.
*Please refer to live update pages and L2 for ongoing information*
Falcon 9/SES-8 Mission Overview:
Constructed by Orbital Sciences Corporation, SES-8 is a 3,200-kilogram (7,100 lb) satellite based upon the GEOStar-2.4 satellite bus.
Bound for a geostationary orbit at a longitude of 95 degrees east, it is expected to provide Ku band communications to Southern Asia, India and China. The satellite carries 24 Ku band transponders and a small Ka band communications payload broadcasting through three reflector dishes.
SES-8 will be powered by a pair of deployable four-panel gallium arsenide solar arrays which generate 5,000 watts of electrical power. Backup power is provided by a pair of approximately 4,800 watt-hour lithium ion batteries.
The spacecraft’s propulsion system consists of a BT-4 monopropellant engine developed by Japan’s IHI Corporation. SES-8 has a design life of 15 years.
SES-8 is part of SES’ eponymous SES series of satellites, which was introduced in 2010 after the company was restructured.
Formed in the mid-1980s, the company’s first satellite was Astra 1A, launched by an Ariane 4 in December 1988. After SES purchased American operator GE Americom in 2001 the organisation was renamed SES Global, with its existing fleet becoming SES Astra, and GE Americom becoming SES Americom.
Two years later the company acquired Nordic Satellite AB, which it renamed SES Sirius, and in 2006 it purchased New Skies Satellites, a former subsidiary of Intelsat, as SES New Skies.
In 2009 SES began to rationalise its subsidiaries, with SES Americom and SES New Skies merging to form SES World Skies. Sirius was also merged into World Skies the following year. While satellites already in orbit have retained their existing name, all of its satellites still awaiting launch were renamed as part of the SES series.
SES-1, a former SES Americom ground spare, was the first satellite to be launched in this series, riding a Proton-M to orbit in April 2010. It was followed by SES-2 and SES-3 in 2011 and SES-4 and SES-5 in 2012.
SES-6 was launched earlier this year, while SES-7 was purchased from bankrupt American operator ProtoStar in 2009, having originally been launched as ProtoStar 2. The majority of satellites in this series have been launched by Proton rockets.
SES World Skies and SES Astra were merged into their parent company in 2011; however the two satellite fleets continue to be operated separately.
SpaceX performed the launch of SES-8 using a Falcon 9 rocket. Founded by billionaire Elon Musk in March 2002, SpaceX developed the small Falcon 1 rocket which first flew unsuccessfully in 2006.
Following three consecutive launch failures the rocket made its first successful launch in September 2008.
Ten months later a Falcon 1 successfully delivered its first functional payload, RazakSat, into orbit, however that launch also marked the rocket’s final flight with SpaceX opting to concentrate its efforts onto the larger Falcon 9.
In addition to launch services, SpaceX also participated in NASA’s Commercial Orbital Resupply Services programme, developing the Dragon spacecraft which is now used to resupply the International Space Station.
In 2008 SpaceX was awarded a Commercial Resupply Services contract for twelve ISS resupply flights, at a cost of 1.6 billion dollars. Two of these missions have been conducted to date, with the next one scheduled for early in 2014.
The launch of SES-8 marks the first time SpaceX will deliver a satellite into geostationary transfer orbit, although it is not the first contract they have received to launch such a payload. Avanti Communications had previously ordered a Falcon 9 to deploy its Hylas-1 satellite, however following delays with the Falcon 9’s development this payload switched to an Ariane 5.
SpaceX’s first geostationary comsat launch comes in year which has seen contracts signed for communications satellites to launch on unusual rockets; an Atlas V has been booked to launch Mexico’s Morelos 3 satellite, while Japan has been contracted to perform its first commercial launch with an H-IIA orbiting Canada’s Telstar 12V.
The shift towards less conventional providers comes as a result of Arianespace’s launch manifest being full for several years, with reliability issues affecting all of their main rivals. Sea Launch experienced a Zenit-3SL launch failure in February, while the Proton rocket offered by International Launch Services suffered a failure during a mission for the Russian military in July.
In addition to the July failure, there has been speculation that the orbit achieved by the Proton-M/Briz-M launch earlier in November with a Raduga satellite may have been somewhat more eccentric and inclined than had been planned.
Briz stages have also malfunctioned during two Rokot launches this year, including Friday’s launch of three Swarm satellites for ESA. Fortunately the anomaly in Friday’s flight occurred during the disposal burn; after all three spacecraft had separated.
SpaceX’s Falcon 9 is a two-stage rocket, with both stages burning RP-1 propellant with liquid oxygen used as an oxidiser. The launch marks the type’s seventh flight, and the second for the v1.1 configuration which will be used. The rocket is 68 metres (220 ft) long, with a diameter of 3.7 metres (12 feet).
The Falcon’s first stage is powered by nine Merlin-1D engines, arranged in an octagonal pattern which SpaceX have named the “octaweb”. This engine configuration was introduced in the previous launch, which carried Canada’s CASSIOPE satellite; Falcon 9 v1.0 launches used a square arrangement.
The rocket’s second stage is powered by a tenth Merlin engine, which has been optimised for operations in a vacuum.
Following its construction at SpaceX’s factory in Hawthorne, California, the Falcon 9 was test-fired in Texas before being shipped to the launch site.
In preparation for its launch the Falcon 9 arrived at Cape Canaveral in September, followed by its payload which arrived by road in early October; however the launch was delayed a few weeks after an anomaly was noted on the rocket which launched CASSIOPE.
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Although the rocket deployed its payloads successfully, the upper stage failed to ignite when a restart test was attempted after spacecraft separation to demonstrate that capability, which is required for the SES mission.
The countdown for the third launch picked up at around 4am local time (9am UTC) with the power-up of the rocket thirteen and a half hours in advance of liftoff.
No major milestones in the count were to occur until about three hours and fifty minutes before liftoff, at which point oxidiser tanking began. Ten minutes later propellant loading also started.
Three quarters of an hour after oxidiser tanking began, both the fuel and oxidiser were fully loaded. However, oxidiser topping continue throughout the countdown to replenish oxygen that boils off.
The terminal count was marked at T-six minutes ahead of liftoff, with the rocket switching to its automated on-board sequence.
Unlike the previous two attempts, a nominal sequence of events were observed during the Tuesday countdown, resulting in the final clearance to launch at T-2 minutes along with activation of the pad water system sixty seconds later.
The rocket pressurised its propellant tanks forty seconds before launch.
The launch sequence involved – at T-3 seconds – the nine Merlin engines on the first stage being commanded to ignite.
When Falcon 9 Mission:
Falcon 9’s mission after launch involved the rocket pitching, rolling and yawing to the correct attitude for its journey into orbit. It encountered the region of maximum dynamic pressure approximately eighty seconds after lifting off. First stage flight ended with main engine cutoff, or MECO, at a mission elapsed time of two minutes, 58 seconds.
Five seconds into the twelve-second coast between first stage cutoff and second stage ignition, the spent first stage was jettisoned.
Unlike on the CASSIOPE launch in September, the first stage burned to depletion in order to maximise the vehicle’s performance. Because of this, no first stage engine restart tests were possible.
Approximately a minute into second stage flight, the payload fairing separated from around the SES-8 satellite at the nose of the rocket. The second stage made two burns during launch. The first burn lasted for five minutes and 20 seconds and was followed by an 18-minute coast phase.
Once the coast ends, the engine successfully restarted – a key first for SpaceX – to make a one-minute burn. Spacecraft separation followed, five minutes after the end of the second burn.
SES-8 was launched from Space Launch Complex 40 at the Cape Canaveral Air Force Station. A former Titan III and Titan IV pad, the complex was used for Titan launches up until the penultimate Titan IV launch in 2005.
Since SpaceX took up residence at the launch complex it has been used for Falcon 9 launches, with all five v1.0 rockets launching from SLC-40. The launch is the first time the larger Falcon 9 v1.1 has used the pad.
The SES-8 launch was the first commercial comsat launch to occur from SLC-40 in 20 years, and the fourth such launch from the complex overall.
The three previous commercial launches were all made by Commercial Titan III (CT-III) rockets; a hybrid of the Titan III(34)D and Titan IV aimed at the commercial geostationary launch market.
The first launch occurred in the early hours of 1 January 1990, or late on 31 December 1989 local time, carrying the Skynet 4A and JCSAT-2 communications satellites.
The second and third Commercial Titan III launches carried single Intelsat VI communications satellites. The first, Intelsat VI F-3, failed to separate from the carrier rocket. It was eventually freed by means of jettisoning its perigee motor, leaving it stranded in low Earth orbit.
Space Shuttle Endeavour retrieved the spacecraft during the STS-49 mission – a task which required three astronauts to perform a spacewalk – and attached a replacement kick motor before sending the satellite on its way to geostationary orbit.
Later renamed Intelsat 603, the spacecraft was only retired from service earlier this year.
The most recent commercial geostationary launch from SLC-40 was in June 1990, when the third Commercial Titan III orbited Intelsat VI F-4. Unlike the previous Intelsat launch, this mission was successful.
One further CT-III launch was made from SLC-40, however it carried a NASA payload; the Mars Observer mission to the red planet in September 1992.
SES-8 was the seventy-fourth orbital launch attempt of the year, and the third to be conducted by SpaceX.
One more Falcon 9 launch is currently planned before the end of the year, with a Falcon 9 v1.1 scheduled to deploy the Thaicom 6 communications satellite. That flight is currently scheduled for no earlier than 20 December – along this date is highly like to slip.
Had SES-8 launched on its original date, it could have resulted in the rare occurrence of three orbital launches on the same day; something which last happened on 17 May 2012 when Russian Soyuz-U and Proton-M rockets deployed the Kosmos 2480 and Nimiq 6 spacecraft, while Japan’s H-IIA launched an earth science satellite.
That, however, is not SpaceX’s concern, as they now press on with their busy upcoming manifest.
(Images: SpaceX, NASA, Orbital, Arianespace and L2).
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