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SpaceX Falcon 9 v1.1 - SES-8 Launch Updates
Launch Vehicle Information, Countdown Timeline, SpaceX Archive
Tuesday's launch marks another major step SpaceX is taking on becoming a competitor to the established launch providers, but the company has a few more steps to complete. A key to becoming a leading commercial launch provider will be establishing a quick turnaround in between flights from both coasts.
Following Thursday's launch scrub, SpaceX specialists reviewed telemetry data collected during the engine start-up that was aborted by the onboard computer due to a slow thrust build-up on a number of first stage Merlin 1D engines. The slow engine start was traced back to contaminated TEA-TEB igniter fluid. As a precautionary measure, the gas generators of all nine Merlin engines were cleaned and the center engine had its Gas Generator replaced. Pressing into the launch countdown, SpaceX was confident that all known rocket anomalies had been resolved. Heading into the first few hours of the Falcon 9 launch countdown, final hands-on work at the launch site as well as thorough systems checks on the Falcon 9 were performed. Those tests included extensive checks of the electrical system and the launcher's avionics and flight computers to verify all those systems were ready to support the mission. Also, the Falcon 9 was put through S-Band and C-Band Communication Checks and the Flight Termination System was checked out. When initial checkouts were complete, teams at the pad finished closing out the launch vehicle and pad structures before evacuating the launch area to get ready for propellant loading. Propellant Loading procedures began with the chilldown of Liquid Oxygen Ground Support Equipment and Transfer Lines before Falcon 9 tank chilldown commenced.
By T-7 minutes, the SES-8 spacecraft had transitioned to its flight mode – being switched to internal power and starting its launch sequence. At T-6:15, the two stages of the Falcon 9 transferred to internal power.
At T-6 Minutes, pressurization for Strongback retraction began. The two cradles of the Strongback structure that stabilized the Falcon 9 started opening. Once both were open at T-4:25, the Strongback Structure started its retraction to the launch position, clearing the way for Falcon 9 to lift off. The Strongback was secured in position by T-2:45. Meanwhile, the second stage completed Nitrogen loading. The TEA-TEB (Triethylaluminum-Triethylborane) engine ignition system was configured for launch at T-3:40 and 25 seconds later, the Flight Termination System went to internal power and was armed for flight. Liquid Oxygen Topping was terminated and at T-2:20, propellant tank pre-press started. The Range was declared clear for launch at T-2 Minutes. At the same time, the flight computers of the Falcon 9 were aligned and placed in auto alignment mode to configure the system for launch. Helium Loading ended at T-95 seconds with all bottles at flight level and flight pressure to be used for propellant tank pressurization in flight. One minute before liftoff, the launch vehicle’s computers assumed control of the countdown for the final steps until launch. The first stage went through a thrust vector actuator test before the Falcon 9 pressurized its propellant tanks for liftoff starting at T-40 seconds. Within 20 seconds, all tanks had reached flight pressure. By that time, the Niagara system was dumping thousands of liters of water on the launch pad for sound suppression during liftoff.
Five seconds after first stage cutoff, the Falcon 9 separated its two stages using mechanical collets that were pneumatically actuated. Once the first stage was gone, the second stage ignited its Merlin 1D Vac engine at T+3 minutes and 10 seconds.
Merlin 1D Vac features an extended nozzle to optimize it for operation in vacuum conditions. It delivers a total thrust of 81,700 Kilograms and also has throttle and re-start capability. Shortly after second stage ignition, at around T+3:40, the protective payload fairing was jettisoned. The Falcon 9 fairing is 5.2 meters in diameter and 13.1 meters long to offer enough space to large Geostationary Communications Satellites many of which are lined up on the company's busy launch manifest. After burning for just under 6 minutes, the second stage shut down, having arrived in a Low Earth Parking Orbit. At the conclusion of its first burn, the stack entered an 18-minute coast phase to set up the proper position for the second burn to raise the apogee of the orbit and reduce its inclination. During the coast, attitude maneuvers were performed using the reaction control system of the second stage that was also used to re-orient the stage for its second burn.
No information was released on the post-separation procedure of the second stage. Options that SpaceX could have chosen include a simple CCAM maneuver & passivation, an orbit-lowering or deorbit burn, or a burn to depletion in order to be able to assess the excess performance on the second stage so that the precise Falcon 9 performance could be tested in flight. Tracking information will be provided in the coming days showing the final orbit of the second stage.
With SES-8 safely in orbit, the satellite will begin commissioning and transfer to Geostationary Orbit while SpaceX heads on to the next launch that is planned before the end of the year. Also launching from Cape Canaveral, a Falcon 9 v1.1 will launch with the Thaicom-6 commercial communications satellite, targeting an orbit similar to SES-8. “The successful insertion of the SES-8 satellite confirms the upgraded Falcon 9 launch vehicle delivers to the industry’s highest performance standards,” said Elon Musk. “As always, SpaceX remains committed to delivering the safest, most reliable launch vehicles on the market today. We appreciate SES’s early confidence in SpaceX and look forward to launching additional SES satellites in the years to come.” SpaceX hopes to become a game-changer on the commercial satellite launch market – offering its Falcon 9 for $56.5 million dollars per launch and the upcoming Falcon Heavy for $135 million which is less than the two main competitors of Falcon 9 as Ariane 5 comes at a price of $200 million per launch and a commercial Proton launch has a price tag of around $100 million. United Launch Alliance, Sea/Land Launch and the Chinese Long March Rocket only play a minor role in the commercial launch business. With Ariane 5 booked for several years and Proton-M/Briz-M struggling with reliability issues, the door is open for SpaceX, but to be able to perform launches in addition to the standing SpaceX manifest, the company has to increase launch vehicle production and shorten its turnaround in between launches. Elon Musk said that he is confident that the current production rate of one Falcon 9 per month can be boosted to 18 per year in the coming months and to 24 rockets per year by the end of 2014.
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SES- 8 is a commercial communications satellite built by Orbital Sciences Corporation and operated by SES World Skies. The spacecraft is based on Orbital’s GEO STAR-2.4 satellite platform that has extensive flight heritage in Geostationary Satellites. SES-8 has a launch mass of 3,200 Kilograms carrying a hybrid Ku- and Ka-Band payload. The satellite is equipped with two power-generating solar arrays featuring Ultra-Triple Junction Gallium Arsenide solar cells, and two 4,850-watt-hour Li-Ion batteries for power storage in order to supply about 5 Kilowatts of power to the satellite payload. SES-8 is equipped with 24 active Ku-band transponders of 36 or 54 Mhz capacity switchable among 33 channels and two beams. A number of channels provide cross-strapping capability to multiple frequency bands to increase flexibility. The satellite also carries a Ka-Band communications payload. |
Image: Orbital Sciences
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The spacecraft features two 2.5 by 2.7-meter single shell super elliptical deployable reflectors and a 1.45-meter fixed antenna pointing nadir. The 24 transponders are divided into two groups, one group of 18-for-15 and one group of 12-for-9 traveling-wave tube amplifiers. SES-8 is three-axis stabilized with excellent pointing capability. A Monopropellant propulsion system is used for insertion in to Geostationary Orbit and stationkeeping in GEO.
SES-8 has a planned service life of 15 years, but carries fuel for at least 16 years of operation in Geostationary Orbit at 95 degrees East to provide communication services to South Asia and Indo-China (Thailand, Vietnam, Laos), primarily direct-to-home services. The satellite will also support VSAT services and industry and government applications.
SES-8 has a planned service life of 15 years, but carries fuel for at least 16 years of operation in Geostationary Orbit at 95 degrees East to provide communication services to South Asia and Indo-China (Thailand, Vietnam, Laos), primarily direct-to-home services. The satellite will also support VSAT services and industry and government applications.
SpaceX Falcon 9 Launch moved to Tuesday |
December 2, 2013 |
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SpaceX will make the next attempt to launch its Falcon 9 rocket carrying the SES-8 satellite on Tuesday with a backup day on Wednesday. SpaceX CEO and Chief Designer Elon Musk confirmed via Twitter that all anomalies that came up on the first two launch attempts had been resolved and teams will spend Monday re-checking their findings. On Thursday, Falcon 9 shut down its engines one second before the planned liftoff because the onboard computer detected a slow thrust ramp-up on a number of first stage engines. After the launch attempt was scrubbed and Falcon 9 was de-tanked, detailed analysis of the data collected during engine start was performed in parallel with inspections of the engines. SpaceX determined that the slow thrust ramp-up was caused by contamination of the igniter fluid. Merlin 1D engines use TEA-TEB – a pyrophoric mixture of Triethylaluminum-Triethylborane for ignition. TEA-TEB and Oxygen are hypergolic – they ignite on contact. |
Photo: SpaceX
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For ignition, LOX is flowed into the engine and TEA-TEB is injected to begin the combustion process and release enough energy to ignite the Rocket Propellant 1 that is then flowed into the engine. For mass reduction, the first stage uses a ground-based TEA-TEB system with tanks and plumbing located within the pad structure.
Elon Musk Tweeted that the “abort was caused by oxygen in ground side TEA-TEB.” Introducing even minor quantities of oxygen into the TEA-TEB system for example when re-filling or due to a small leak causes the TEA-TEB to react. A small oxygen source will not cause a hypergolic reaction, but the TEA-TEB becomes contaminated with oxidation products as the oxygen reacts with the mixture. As a result, the overall TEA-TEB concentration was reduced and the reaction during engine start was not as powerful as usual which caused the slow thrust build-up.
According to SpaceX, the source of the contamination has been determined. Also, teams cleaned the turbopump gas generators of all first stage engines as a precautionary measure to have the opportunity of a number of engine re-starts on subsequent launch attempts. Additionally, the gas generator on the Center engine was replaced to ensure a clean ignition.
With all anomalies understood and solved, SpaceX will be ready to perform their first Geostationary Launch on Tuesday. The launch window opens at 22:41 UTC and closes at 0:07 UTC – the satellite operator agreed to a 20-minute extension of the window. Launch weather will be favorable for Tuesday’s opportunity and the backup day on Wednesday with a 90% chance of favorable conditions on both days, clouds being the primary concern.
Elon Musk Tweeted that the “abort was caused by oxygen in ground side TEA-TEB.” Introducing even minor quantities of oxygen into the TEA-TEB system for example when re-filling or due to a small leak causes the TEA-TEB to react. A small oxygen source will not cause a hypergolic reaction, but the TEA-TEB becomes contaminated with oxidation products as the oxygen reacts with the mixture. As a result, the overall TEA-TEB concentration was reduced and the reaction during engine start was not as powerful as usual which caused the slow thrust build-up.
According to SpaceX, the source of the contamination has been determined. Also, teams cleaned the turbopump gas generators of all first stage engines as a precautionary measure to have the opportunity of a number of engine re-starts on subsequent launch attempts. Additionally, the gas generator on the Center engine was replaced to ensure a clean ignition.
With all anomalies understood and solved, SpaceX will be ready to perform their first Geostationary Launch on Tuesday. The launch window opens at 22:41 UTC and closes at 0:07 UTC – the satellite operator agreed to a 20-minute extension of the window. Launch weather will be favorable for Tuesday’s opportunity and the backup day on Wednesday with a 90% chance of favorable conditions on both days, clouds being the primary concern.
Falcon 9 Launch Scrubbed after Last-Second Countdown Abort |
November 28, 2013 |
Photo: SpaceX Launch Webcast
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The second launch attempt of a SpaceX Falcon 9 rocket on the company’s first GEO Transfer Mission was scrubbed on Thursday after the rocket’s engines were shut down just split seconds before liftoff. SpaceX says the next launch attempt will not take place for several days to allow engineers to complete inspections on the launch vehicle to determine the cause of a slow thrust build-up condition that was observed during ignition. Thursday’s launch countdown was started 13 hours and 2 minutes ahead of the opening of the launch window which stretched from 22:39 to 23:44 UTC. After checkouts and initial reconfigurations of the rocket, the Falcon 9 was loaded with Liquid Oxygen and Rocket Propellant-1, going through an uneventful countdown sequence. As teams were approaching terminal countdown, all Stations were polled for a GO or No GO for launch. |
All was in readiness including the Falcon 9 launch vehicle, the SES-8 spacecraft, the Eastern Range and the launch weather that had not been an issue throughout the day. Pressing into the Terminal Countdown Sequence at T-10 minutes, the Falcon 9 started final reconfigurations to prepare for liftoff. The launch vehicle transitioned to internal power, the first stage ignition system was armed and Liquid Oxygen Loading was terminated to allow tank pressurization to start ahead of the retraction of the Strongback to clear the way for liftoff.
Overly conservative red-line limits have caused a number of countdown aborts in Falcon 9’s short history. In the past, the launch team was able to confirm that no hardware problems were present and adjust the limits before trying again. That was also the thinking on Thursday and teams set up for another launch attempt at the end of the 65-minute window while working on data analysis in parallel, developing a plan to modify the engine start sequence to ensure the engines would reach the proper thrust levels at the expected time. The Merlin 1D engines use high-pressure Helium to spin-up their turbopumps during the ignition sequence. According to Elon Musk, teams decided to increase the Helium pressure during start-up for the second attempt to see if that would allow the vehicle to pass all abort limits. A Tweet sent by Musk indicated that teams were not fully convinced that this modification would work, but decided to press on. While setting up for a new launch attempt, the Propulsion Team was still analyzing the data acquired during the engine start and cutoff to ensure that no actual hardware problem was present on any of the nine engines. The end of the 65-minute launch window was targeted as T-0, keeping the option of a late abort in the Terminal Countdown in case the data analysis could not be completed in time.
First Falcon 9 GEO Transfer Launch Scrubbed due to Technical Problems
Falcon 9 Propellant Loading is a rather quick process as the first stage is loaded via interfaces located at the base of the rocket and the second stage propellants are fed to the second stage via the Strongback Umbilical tower. After about 50 minutes, LOX entered replenish and the RP-1 tanks were filled within half an hour.
When the safing sequence was complete, the team recycled the countdown to T-13 minutes and holding.
After investigating the problem, the team identified a conservatively set telemetry limit for a Stage 1 Power Supply that was tripped during the transfer to internal power. With no problem in the hardware, the limit was adjusted for another launch attempt. Coordinating a new T-0 of 23:30 UTC, the SpaceX team had one more attempt for the day’s window. Again were all stations polled and reported GO for Terminal Count that began at 23:20 UTC. Going through the nominal steps, Falcon 9 made a successful transfer to internal power at T-6:10 and the countdown continued into the final five minutes to launch.
Image: SpaceX/SpaceFlight101
When the Countdown was still underway, the Payload Fairing Umbilical became detached because it got caught in the Strongback Structure during retraction. Normally, the umbilical separates after liftoff, when the vehicle pulls away from the pad. The fairing umbilical ensures good purge flow to the payload which is required for thermal control. Whether this umbilical also includes electrical and data connections is unknown. Without purge flow over an extended period of time, thermal limits of the payload could be violated which could cause damage to the satellite if it is subjected to an extreme thermal environment. Running out of window time, the launch team pressed into de-tanking operations to set up for possible repairs and data analysis over the coming days as the next launch attempt can not take place until Thursday. On Tuesday and Wednesday, the Federal Aviation Administration that licenses all orbital launches from the US has prohibited SpaceX from launching due high air traffic heading into Thanksgiving Weekend in the United States. Weather would be 80% GO for Thursday. A new launch date will officially be set after reviews and assessments of Monday’s scrubbed launch attempt. |
SpaceX ready for First GEO Transfer Mission on Monday |
November 24, 2013 |
Image: SpaceX
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SpaceX is ready for its next ambitious mission that is set for launch on Monday. Making its first launch from Cape Canaveral, the new Falcon 9 v1.1 launch vehicle will also perform the first-ever mission to Geostationary Transfer Orbit for SpaceX. Liftoff from Space Launch Complex 40 is planned for the window-opening time of 22:37 UTC to start a 33-minute ascent mission delivering the SES-8 communications satellite to orbit. SpaceX performed the Launch Readiness Review that gave the formal approval to press into launch operations on Monday, not identifying any show stoppers, just minor items that are being closed out over the weekend. Those items include minor reconfigurations and equipment replacements at the launch pad that were identified during the Static Fire Test on Thursday. The test was completed satisfactory as all nine Merlin 1D engines of the first stage showed nominal performance during the two-second test firing. The excessive venting during the countdown to the Static Fire was caused by a combination of weather conditions and a change in LOX loading procedures due to a benign Ground Support Equipment issue that was not of any major concern, but is being closed-out for the launch. |
Following the completion of the Static Fire Test, the Falcon 9 was de-tanked and transported back to the hangar for integration with its payload, the SES-8 commercial communications satellite.
Countdown operations will begin on Monday, 13 hours and 30 minutes before launch with the activation of the Falcon 9 v1.1 launch vehicle for pre-launch checkouts and reconfigurations. The initial hours of the Countdown are dedicated to a series of checkouts on the launch vehicle - including extensive communication checks, flight termination system testing and flight computer & navigation system verifications.
As part of final preparations at Space Launch Complex 40, technicians will close out the Falcon 9 rocket and launch pad facilities before evacuating the launch pad for propellant loading. As clocks tick down, the Air Force will start monitoring the Eastern Range as well as weather conditions. The forecast for Monday calls for an 80% chance of favorable weather conditions.
Countdown operations will begin on Monday, 13 hours and 30 minutes before launch with the activation of the Falcon 9 v1.1 launch vehicle for pre-launch checkouts and reconfigurations. The initial hours of the Countdown are dedicated to a series of checkouts on the launch vehicle - including extensive communication checks, flight termination system testing and flight computer & navigation system verifications.
As part of final preparations at Space Launch Complex 40, technicians will close out the Falcon 9 rocket and launch pad facilities before evacuating the launch pad for propellant loading. As clocks tick down, the Air Force will start monitoring the Eastern Range as well as weather conditions. The forecast for Monday calls for an 80% chance of favorable weather conditions.
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Once all systems are configured for propellant loading, the complex tanking sequence will be initiated - starting with the chilldown of Liquid Oxygen ground support equipment before the first and second stage oxidizer tanks are being chilled down by the -183-degree Celsius LOX. At L-3 Hours 50 Minutes, Liquid Oxygen will start flowing inside the tanks of the two stages. Ten minutes later, Rocket Propellant-1 fuel will be filled into the first and second stage tanks. As part of propellant loading, the first stage of the rocket is filled with approximately 382,000 Kilograms and the second stage is filled with around 70,800 Kilograms of propellants. Propellant loading will wrap up before L-3 hours as the RP-1 tanks reach flight level and LOX enters replenish that will be active until late in the terminal countdown. In addition to LOX and RP-1 propellants, the Falcon 9 is loaded with Helium that is used as pressurant gas to pressurize and maintain the propellant tanks at flight pressure during the mission. Nitrogen is loaded to serve as propellant for the vehicle's cold gas attitude control systems. When tanking is complete, the launch team will repeat communication checks and flight termination system testing to verify all systems are in proper condition for the mission. The launch team will be watching over the systems of the launcher throughout the countdown, making sure that no parameters exceed given limits. Overall, the two-stage Falcon 9 v1.1 stands 68.4 meters tall, is 3.66 meters in diameter with a liftoff mass of 480,000 Kilograms. The launcher can deliver payloads of up to 13,150 Kilograms to Low Earth Orbit and 4,850kg to Geostationary Transfer Orbit. >>>Detailed Falcon 9 v1.1 Overview One hour ahead of launch, the launch team will receive a weather briefing and an update on range safety rules to assess whether a launch at the opening of the window will be possible. |
Photo: SpaceX
Falcon 9 at VAFB
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As the countdown enters its final hour, the launch team will start final reconfigurations for the Terminal Countdown Sequence. At L-13 minutes, the launch team will be polled for a GO/No GO to press into the final countdown sequence.
The Terminal Countdown Sequence gets underway at T-10 minutes and features the final set of reconfigurations to transition the Falcon 9 to its launch configuration. The flight control system will be enabled and the nine Merlin 1D engines on the first stage will start their Chilldown Sequence at T-9:43 to start conditioning the engines for blastoff as pre- and bleeder-valves are opened. By T-7 minutes, the SES-8 spacecraft will have switched to internal power and transition to their flight configuration. At T-6 minutes, the automated countdown sequencer is being started up.
Next, the Flight Computers are aligned for flight and placed in auto alignment mode. Nitrogen Loading is terminated at T-5 minutes. Shortly thereafter, the Falcon 9 launcher starts its Auto Sequence.
>>>Falcon 9 Countdown Timeline
At T-4 minutes and 30 seconds, the Falcon 9 launch vehicle is transitioned to internal power. 20 seconds later, the Launch Vehicle Release System begins its own countdown auto sequence. At T-3:40, the TEA-TEB Ignition System of the first stage is activated followed by transferring the Flight Termination System to internal power and its transition to auto mode. At T-3:02, Liquid Oxygen Topping is terminated followed by a Thrust Vector Control System test on the second stage. At T-2 minutes 30 seconds, the launch team completes a final status check and the Range is verified clear for launch at T-2 minutes
Helium Loading is terminated at T-95 seconds, final engine chilldown starts at T-90 seconds and the purge of the nine Merlin 1D engines starts at T-80 seconds. One minute before liftoff, the Flight Computer starts-up and assumes control over all the vehicle's functions.
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The nine Merlin Engines on the first stage complete a Thrust Vector Control System test at T-50 seconds and all propellant tanks begin their pressurization to flight level at T-40 seconds. As part of the final steps before ignition, the tanks reach flight pressure and the pyrotechnics of the vehicle are armed for flight. Three seconds ahead of launch, the nine Merlin 1D engines are ignited and soar up to full thrust. Each of the nine Merlin 1D engine provides 654 Kilonewtons of thrust for a collective liftoff thrust of 600,200 Kilograms. Computers will monitor engine start-up and verify that all nine engines reach operational conditions before the vehicle is committed to launch. When clocks reach zero, the 68.4-meter Falcon 9 will blast off and slowly clear its tower as it has a relatively low initial thrust-to-weight ratio of 1.25 and its size provides the appearance of a slower initial climb. After the vehicle clears the tower, it makes a short vertical ascent before beginning its pitch&roll. On its way uphill, Falcon 9 burns nearly 2.2 metric tons of propellants per second. Falcon 9 passes Mach 1 a little more than one minute into the flight and passes Maximum Dynamic Pressure one minute and 20 seconds after liftoff. After passing the two-minute mark into the flight, the rocket will enter its throttle segment - slowly throttling down its first stage engines to limit acceleration as the rocket approach shutdown. Merlin 1D offers throttle capability from 70 to 100% of rated performance while its predecessor, Merlin 1C, could not the throttled down and Falcon 9 v1.0 had to shut two of its engines down ten seconds ahead of MECO. First Stage Cutoff occurs at T+2 minutes and 58 seconds as all nine Merlin 1D engines are shut down. The two stages of the Falcon 9 separate at T+3:03 as the pneumatic separation system is initiated and the first stage is pushed away. Seven seconds after staging, the Merlin 1D Vac engine of the second stage is ignited, soaring up to full thrust of 81,700 Kilograms for a 5-minute 20-second burn to boost the stack into a Low Earth Parking Orbit. |
Photo: SpaceX
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While the second stage is burning, the Falcon 9 will separate its huge composite payload fairing which is 5.2 meters in diameter and 13.2 meters long - offering enough payload volume to a number of different satellites including Geostationary Comm satellite such as SES-8.
Spending the final 45 seconds of its burn in Terminal Guidance Mode, the second stage shuts down at T+8 minutes and 30 seconds. At that point, the vehicle begins an 18-minute coast phase in an orbit inclined 28 degrees to reach the proper location in its orbit for the critical second burn. While coasting, the second stage uses its reaction control system to maintain a stable attitude and re-orient for the next burn.
Spending the final 45 seconds of its burn in Terminal Guidance Mode, the second stage shuts down at T+8 minutes and 30 seconds. At that point, the vehicle begins an 18-minute coast phase in an orbit inclined 28 degrees to reach the proper location in its orbit for the critical second burn. While coasting, the second stage uses its reaction control system to maintain a stable attitude and re-orient for the next burn.
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The critical re-start of the Merlin 1D vacuum engine on the second stage will occur about 27 minutes after launch - an exact time has not been given by SpaceX. Burning for just over one minute (again, no exact time provided by SpaceX), the second stage will raise the apogee of the orbit to a Supersynchronous Altitude and reduce the orbital inclination to 20.75 degrees. SES-8 is targeting an insertion orbit of 295 by 80,000 Kilometers. To ensure a good engine re-start, SpaceX modified the second stage by adding insulation on the TEA-TEB (Triethylaluminium-Triethylborane) igniter fluid lines. Exposure to supercold oxygen caused the TEA-TEB lines to freeze during the September 29 maiden flight of the Falcon 9 v1.1 and prevented the second stage engine re-light. The second stage uses a redundant igniter system to ensure a good re-ignition which is critical for a launch into a GEO transfer trajectory. SES-8 is being inserted into a Super-Synchronous orbit to reduce the total velocity change required by the satellite to reach Geostationary Orbit. A conventional insertion into GEO from an elliptical transfer orbit would require a delta-v of 1,800m/s while the SSTO design reduces the total dV requirement to 1,500m/s. The reduction of inclination from 28 to under 21 degrees also contributes to the lower delta-v requirement. |
Once the second stage arrives in its insertion orbit, it will again re-orient and release the SES-8 spacecraft at T+32 minutes and 53 seconds to complete its flight.
Falcon 9 completes Static Fire Test ahead of SES-8 Launch |
November 21, 2013 |
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SpaceX has completed the first Static Fire Test of its new Falcon 9 v1.1 Launch Vehicle at Space Launch Complex 40 at Cape Canaveral Air Force Station ahead of the planned launch of the SES-8 satellite atop that Falcon 9 rocket – currently planned for NET November 25, pending good hot-fire results of the rocket and the upgraded launch pad. Following the debut flight of the Falcon 9 v1.1 conducted from Vandenberg Air Force Base, California, in late September, SpaceX switched its focus from the west coast to the east coast for two upcoming launches of the SES-8 and Thaicom-6 commercial communications satellites. To facilitate the larger v1.1 launch vehicle, the pad at SLC-40 required a number of modifications after hosting the first five launches of the Falcon 9 in its v1.0 configuration. The main differences between the v1.0 and v1.1 include the use of the more powerful Merlin 1D engine, a new engine layout on the first stage and stretched propellant tanks on the first and second stage as well as the use of upgraded avionics and controllers. Falcon 9 v1.1 stands 68.4 meters tall, is 3.66 meters in diameter with a liftoff mass of 480,000 Kilograms. The v1.1 first stage switches from the 3x3 tic tac toe engine pattern to an "Octaweb." Eight engines are arranged in a circle - clustered around a single Merlin 1D. |
Photo: KSC Media Feed
Strong release of oxygen from the launcher had observers worried during the Countdown
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These nine Merlin 1D engines provide a total liftoff thrust of 600,200 Kilograms. The goal of Falcon 9 v1.1 is improving Falcon’s payload capacity, increasing reliability and further decreasing launch cost by implementing easier manufacturing processes.
For Falcon 9 v1.1 to be able to launch from Florida, the pad needed a number of modifications to accommodate the Falcon 9 v1.1 propellant, electrical and purge interfaces. A new Transporter-Erector was built to transport the larger rocket to the pad and place it in its horizontal launch configuration. Unlike the pad and T/E at Vandenberg, the current setup in Florida can only accommodate the Falcon 9 v1.1 and not the Falcon Heavy that features three cores.
For Falcon 9 v1.1 to be able to launch from Florida, the pad needed a number of modifications to accommodate the Falcon 9 v1.1 propellant, electrical and purge interfaces. A new Transporter-Erector was built to transport the larger rocket to the pad and place it in its horizontal launch configuration. Unlike the pad and T/E at Vandenberg, the current setup in Florida can only accommodate the Falcon 9 v1.1 and not the Falcon Heavy that features three cores.
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While teams were busy with the pad work, preparations for the SES-8 mission started in earnest in early September with the delivery of the first and second stage of the rocket after the two stages completed clean test firings at the McGregor site, Texas. At the same time, the launch campaign for the first-ever Falcon 9 v1.1 launch from Vandenberg was in full swing, providing SpaceX with valuable lessons that were learned during Wet Dress Rehearsals and the Static Fire Test carried out at VAFB. Some of those lessons were implemented at Cape Canaveral, both on the launch vehicle and the pad to avoid running into the same problems during the first Cape launch campaign. On September 29, Falcon 9 v1.1 made its premier launch, blasting off from Vandenberg on an ambitious test flight carrying the Canadian Cassiope Satellite and a number of secondary payloads. The mission achieved its primary objective of deploying all payloads into the correct orbit, however, the Falcon ran into some problems with the secondary test objectives of the flight. |
Photo: Elon Musk via Twitter
Falcon 9 v1.1 launches from Vandenberg
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The first was a soft splashdown landing attempt of the first stage utilizing the excess performance this launch had due to the low payload mass and the low-energy target orbit.
After launching and delivering the second stage onto its trajectory to continue powered ascent, the first stage completed a re-orientation and re-ignited three engines to slow down ahead of re-entry. Stage 1 successfully completed the braking burn and survived re-entry for a second burn using only the center Merlin 1D engine to slow down for a soft landing in the Pacific. During atmospheric flight, the first stage exhibited a roll that caused propellants to be centrifuged in the tanks causing the second burn to be cut-short, leading to a harder impact in the ocean.
Although the first stage could not be recovered intact, the test provided valuable data on the performance of the first stage that will allow SpaceX to tweak the return sequence for the next attempt. The deployable landing legs of the F9R will provide additional stability during atmospheric flight and prevent an uncontrollable roll as seen on the Cassiope launch.
After launching and delivering the second stage onto its trajectory to continue powered ascent, the first stage completed a re-orientation and re-ignited three engines to slow down ahead of re-entry. Stage 1 successfully completed the braking burn and survived re-entry for a second burn using only the center Merlin 1D engine to slow down for a soft landing in the Pacific. During atmospheric flight, the first stage exhibited a roll that caused propellants to be centrifuged in the tanks causing the second burn to be cut-short, leading to a harder impact in the ocean.
Although the first stage could not be recovered intact, the test provided valuable data on the performance of the first stage that will allow SpaceX to tweak the return sequence for the next attempt. The deployable landing legs of the F9R will provide additional stability during atmospheric flight and prevent an uncontrollable roll as seen on the Cassiope launch.
Photo: Twitter
SES-8 inside Falcon's Payload Fairing - Photo: @LH2Padrat on Twitter
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The SES-8 and Thaicom-6 missions will not feature first stage landing or splashdown attempts because the entire performance of the Falcon 9 is required to deliver the spacecraft to their target Super-Synchronous Transfer Orbits. The next launch featuring a first stage recovery attempt will be the Dragon SpX-3 mission set for launch in February 2014, possibly using a first stage with landing legs if it is ready in time. The second issue that came up during the Cassiope launch in September was the re-ignition of the second stage after payload separation that was supposed to be used as a demonstration of re-ignition capability and to precisely calculate the exact performance of the launch vehicle after burning the second stage to depletion. After separating Cassiope and the secondary payloads, the second stage initiated its ignition sequence, reaching an engine pressure of 2.7MPa before a shutdown was triggered when the onboard computer detected an anomaly. After the launch, Elon Musk, SpaceX CEO and chief designer, said that the problem was understood and that a simple solution existed to prevent the problem from occurring again. The root cause of the problem has been traced back to frozen TEA-TEB lines after LOX exposure requiring additional insulation to be installed. It has been reported that the fix was implemented on the second stage at Cape Canaveral following a detailed analysis of telemetry gathered during the September launch. For Geostationary Transfer Orbit launches, a second stage re-light is an essential requirement. To get ready for launch, the SES-8 payload was delivered to Florida in early October, being transported via truck from Orbital Sciences' facilities in Virginia. At the launch site, SES-8 completed final testing and checkouts as well as propellant loading before being encapsulated in the large Falcon 9 payload fairing. For the Static Fire Test, the payload was not installed on the launch vehicle. |
The Static Fire and launch date slipped several times in November as work on the launch pad had not finished and required a few additional days. On Wednesday, teams performed the first Static Fire attempt that had to be scrubbed and re-set for another attempt on Thursday.
Coming back on Thursday, teams began the next Static Fire Attempt which basically is a full launch countdown that involves loading the Falcon 9 with Liquid Oxygen and Kerosene propellants and the usual testing activities that are also performed on launch day. This allows teams to fully test the launcher and rehearse procedures needed for launch.
Coming back on Thursday, teams began the next Static Fire Attempt which basically is a full launch countdown that involves loading the Falcon 9 with Liquid Oxygen and Kerosene propellants and the usual testing activities that are also performed on launch day. This allows teams to fully test the launcher and rehearse procedures needed for launch.
Photo: KSC Media Feed
Normal venting earlier in the countdown
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A video feed provided by the Kennedy Space Center showed the Falcon 9 excessively venting gaseous or liquid Oxygen during the countdown. The venting started about 19:02 UTC and gave the impression of a persistent release of large quantities of oxygen that was still ongoing when the video feed was cut at 19:16 UTC. The strong venting from the 1-2 interstage area down to the LOX tank of the 1st stage raised questions among observers, but was apparently not an issue as the countdown continued towards the the hot fire. After entering the terminal countdown, clocks ticked down all the way to engine ignition. The Merlin 1D engines on the first stage ignited and built- up thrust for a brief moment before being shut down. Subsequently, the launch team went through vehicle safing before de-tanking the vehicle. Data from the Static Fire will be analyzed to confirm that all engines reached operational conditions and all other subsystems performed properly as well. The launcher is taken back to the hangar to remove instrumentation that was in place for the Static Fire and install the payload stack on the vehicle to get ready for launch. |
Currently, launch is planned for NET (No Earlier Than) Monday, November 25 during a six-minute launch window opening at 22:37 UTC. Falcon 9 will blast off from SLC-40 and depart the Space Coast on a launch azimuth of 90 degrees. The first stage will complete a nominal ascent profile for stage separation about three minutes into the flight. The second stage will then ignite its Merlin 1D vacuum engine to boost the stack into a Parking Orbit. Following a Coast Phase, the second stage has to perform the critical re-ignition in order to boost the SES-8 spacecraft into a Super-Synchronous Transfer Orbit of approximately 300 by 80,500 Kilometers, also accomplishing a reduction of inclination to about 21 degrees to benefit the SES-8 spacecraft for an energy-efficient insertion into Geostationary Orbit.
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