In a wide-ranging release of information, ATK have announced what is their complete crew transportation system. With the previously announced Liberty launch vehicle as the foundation, the company have now revealed that their own crewed spacecraft will fly atop of the vehicle, with the MLAS launch abort system. Test flights are set to begin in 2014 from the Kennedy Space Center.
Fighting For Liberty:
Although Liberty is less known than the Falcon 9/Dragon combination – a duo that have already launched into space – ATK are pushing forward at a pace to bring their commercial crew transportation system into the running for returning the US’ domestic launch capability, lost after the retirement of the Space Shuttle fleet.
Currently working with NASA via an unfunded Space Act Agreement (SAA) – as opposed to being funded by the Commercial Crew Development (CCDev) process – the pressure is firmly on the shoulders of all the suitors interested in transporting Americans to Low Earth Orbit (LEO) to produce an attractive package of hardware and schedules, pressure that has been increased, due to some political wishes to downselect to a single NASA partner.
When the Liberty launch vehicle was announced, it was noted the rocket would be capable of launching most of the spacecraft put forward for commercial LEO operations. However, it lacked a commitment from one of the other commercial companies, unlike the United Launch Alliance’s (ULA) Atlas V, a vehicle that has since been confirmed as the rocket of choice for SNC’s Dream Chaser, Boeing’s CST-100 and initially Blue Origin’s spacecraft.
Now the game has changed again, with ATK announcing it has found a spacecraft to pair up with Liberty, a capsule that is literally part of what is now a complete transportation system. That capsule is their own spacecraft, thus the entire stack will be known as Liberty.
This complete system, including the spacecraft, launch abort system, launch vehicle, and ground and mission operations, is being designed from inception to meet NASA’s human-rating requirements.
Liberty will hit the ground running, with the schedule showing the first of potentially several test flights will begin in 2014, launching from the Kennedy Space Center (KSC) with L2 information (L2 Link) claiming the test flights will take place from Pad 39B on a modified Mobile Launch Platform (MLP). As such, the test version of Liberty will be the first vehicle to launch from KSC since Atlantis rode uphill on STS-135.
The full scale Liberty is currently designed to launch off the former Ares I Mobile Launcher (ML). However, that has since been repurposed for use with the Space Launch System (SLS), meaning Liberty will either require an additional ML or a redesigned MLP from the former Space Shuttle Program (SSP).
In 2015, Liberty is scheduled to make its debut crew flight, a schedule ATK claim will support crewed missions for NASA and other potential customers by 2016, with a price-per-seat that is projected to be lower than the cost on the Russian Soyuz rocket.
Liberty – First Stage:
KSC will be no stranger to the first stage of the Liberty launch vehicle, given it utilizes a Solid Rocket Booster (or Motor in this scenario), a key element of Shuttle heritage, bar its additional muscle of being a five segment, as opposed to a four segment, motor.
(Image taken from the amazing 220mb super slow-mo DM-3 Five Seg Motor Ground Test Video – available in L2 – LINK).
With the appearance of an Ares I – given it works on the same aerodynamic design principle – the first stage is the same design that was tested during the DM-3 test in Utah, and is the same motor that will initially provide the bulk of the lift-off power for the SLS, with two five segment boosters set to debut with the Heavy Lift Launch Vehicle (HLV) in 2017.
“Our goal in providing Liberty is to build the safest and most robust system that provides the shortest time to operation using tested and proven human-rated components,” said Kent Rominger, vice president and program manager for Liberty.
“Liberty will give the U.S. a new launch capability with a robust business case and a schedule that we expect will have us flying crews in just three years, ending our dependence on Russia.
“Liberty will enable a successful commercial space program and result in a globally competitive capability that America doesn’t have today. This program is changing the way we do business and can also result in a positive change to government programs.”
During the Constellation Program, the five segment motor was observed as suffering from the phenomenon of Thrust Oscillation (TO) during the Ares I development process – requiring additional hardware to “dampen” the effects on the crew riding atop of the vehicle.
However, the DM ground tests – and their vast array of instrumentation, aimed at gathering more detailed data on RSRM (Reusable Solid Rocket Motor) behaviour during the first stage of launch, on the final shuttle missions – have proven TO to be less than expected.
Notably, the Liberty Upper Stage is also a different design when compared to the Ares I Upper Stage, further decoupling the potential TO effects, especially as TO was heavily related to the Ares I stack in the configuration with the Orion crew vehicle.
Liberty – Upper Stage:
Liberty’s Upper Stage is the Core Stage (EPC) of the Ariane 5 launch vehicle used by Arianespace, which will be supplied under contract with EADS/Astrium North America.
The latest generation of the Ariane 5 is based on an evolution of the Vulcain engine that powers the cryogenic core stage. This evolution, called Vulcain 2, provides an increased thrust through an overall mixture ratio and liquid oxygen mass flow increase.
The EPC stage is 5.4 m in diameter and 31 m long on the Ariane 5. It is powered by one Vulcain 2 engine that burns liquid hydrogen (LH2) and liquid oxygen (LO2) stored in two tanks separated with a common bulkhead. The LO2 tank is pressurized by gaseous helium and the LH2 one by a part of gaseous hydrogen coming from the regenerative circuit.
The Vulcain 2 engine develops 1390 kN maximum thrust in vacuum. Its nozzle is gimballed for pitch and yaw control.
The engine is turbopump-fed and regeneratively cooled. The thrust chamber is fed by two independent turbopumps using a single gas generator. A cluster of GH2 thrusters are used for roll control. The engine utilizes two turbo-pumps, driven by a gas generator, and sports a GHe pressurization system for the LOX tank and GH2 for LH2 tank.
Ignition of the engine is obtained by pyrotechnic igniters and occurs nine seconds before lift-off in order to check that’s it’s functioning properly. It is understood that this core stage on the Liberty Upper Stage can be air-started, as would be required during its role with Liberty.
“Astrium is proud to be part of the ATK Liberty team and to provide our proven second stage, which is powered by the Vulcain 2 engine, as an integral part of this exciting next-generation launch system,” said John Schumacher, CEO of Astrium in North America, an EADS North America company.
“Initially, we will ship the second stage to the Kennedy Space Center where it will be integrated by the skilled workforce there. However, once Liberty’s business base is established in the U.S. market, we envisage Liberty upper stage manufacturing in the United States.”
The configuration of a solid first stage and liquid second stage lowers the likelihood of failure, claimed ATK, and enables a flight path with total abort coverage, maximizing survival for the crew in the unlikely event of an anomaly requiring an abort.
Liberty’s performance of 44,500 pounds to LEO enables the system to launch both crew and cargo and also serve non-crewed markets including ISS cargo up and down mass, commercial space station servicing, US government satellite launch, and future endeavors.
Liberty – Crew Capsule:
In announcing the Liberty spacecraft confirmation as part of the final design package, ATK claim their design leverages design work performed at NASA Langley Research Center (LaRC) on the composite crew module and launch abort system, for which ATK was a contractor, and also the service module design work performed by NASA Glenn Research Center.
Although its birth fell under the radar, ATK provided details on this spacecraft back in 2009, as the company delivered a full-scale, crew module structure made of composite materials to NASA for structural testing.
The Composite Crew Module (CCM) is a unique capsule design that has the potential to reduce the overall weight of future manned launch vehicles, a unique design in that it was specifically built to resemble a space capsule.
Full-scale structural testing was performed at NASA LaRC to determine the strength and viability of the composite structure. During the destructive testing, the CCM was placed under load conditions similar to those observed during launch, on-orbit, landing, and abort scenarios.
Led by the NASA Engineering and Safety Center (NESC), ATK was part of a team of NASA and industry experts who designed and fabricated the CCM to demonstrate how composite materials could be used to develop a pressurized space capsule.
Constructed in two primary sections, the upper and lower shells are joined together with a splice joint and cured using out-of-autoclave technology. The bonding of the composite assemblies and integration of metal hardware were achieved by combining existing technology and ATK’s innovative manufacturing processes.
“We believe that no other offering can match Liberty’s safety, spacious spacecraft, customer service and performance,” Mr Rominger added. “These traits enable the Liberty business to provide the best commercial space flight experience.”
Liberty – MLAS:
Although only referenced by name in ATK’s release on the Liberty announcement, the Max Abort Launch System – or MLAS (named after Maxime (Max) Faget) – is another element from the cancelled Constellation Program.
Although it was never publicly admitted, this system was often mentioned by sources as a potential solution towards a growing movement associated with cancelling Ares I and human rating the Ares V, as the Constellation Program began to falter.
It also had the backing of then-NASA administrator Mike Griffin, which would not have come as a surprise, given MLAS was an evolution of two of the original three LAS concepts studied by Constellation, one of which made the LAS trade study in 2007 via a rather amusing hand-drawn sketch, created in 2006.
The MLAS concept combines the boost protection cover of the service module mounted escape system with the command module mounted motors, in turn reducing the overall height of the vehicle – something desired by the Ares V HR advocates, who were worried about being able to stack and rollout the vehicle – with a LAS tower – under the height restrictions of the Vehicle Assembly Building (VAB) doors.
The MLAS utilizes a ‘bullet’ boost protection cover over the capsule to house four Mk 70 Terrier solid motors separation motors – as opposed to locating them on a tower above the capsule.
Two orientation parachutes are attached to the top of the fairing to re-orient the vehicle, with the blunt heat shield to aid in fairing separation.
The design resulted in the aborting vehicle re-orienting immediately after abort motor cut off during a pad abort, but would fly with its nose “into the wind” on a mid-altitude abort. The orientation parachutes would then activate quickly before the fairing separation.
In the event of a high altitude abort, the fairing would come off immediately, in order to allow the Command Module Reaction Control System (RCS) to stabilize the vehicle for entry.
The design of MLAS changed several times during its development, gaining fins for stability during later cycles, becoming more in line with another hand drawn sketch.
This time the artist was former Constellation head Scott “Doc” Horowitz – as seen in the second of two MLAS presentations acquired by L2 (Link to Presentations) – over a year after Mr Griffin’s conceptual design.
The final version of the MLAS flight test vehicle weighed in at over 45,000 lbs and was over 33 feet tall – and this vehicle actually got to fly for real, after being shipped to Wallops for its one and only hop off the ground.
The pad abort test proper began seven seconds after burnout of some specially attached solid motors, as the vehicle rose into the Virginia morning sky at 6:25am local time on July 8, 2009.
Video of the launch showed a perfect test, as the vehicle rose on a stable flight path, before reorientation and further stabilization, followed by crew module simulator separation from the MLAS fairing, and parachute recovery of the crew module simulator.
Other tests were planned for MLAS, including a high altitude abort = which will involve the fairing being released immediately after abort is called, in order to allow the Command Module Reaction Control System (RCS) to stabilize the vehicle for entry. However, the program was put on the backburner, as the Constellation Program found itself cancelled.
It is not yet known if the Liberty program will carry out further MLAS tests, given NASA’s exploration effort relating to the system is now over – with the Space Launch System (SLS) that will launch Orion set to use the previously chosen Line Tandem Tractor (Tower) design as its LAS.
Liberty – Jobs:
Liberty’s announcement also noted its industry base, a key selling point in this post-Shuttle era where thousands of skilled engineers lost their jobs. As such, the ATK release claimed the Liberty system would sustain thousands of jobs across the United States including Alabama, California, Colorado, Florida, Maryland, New York, Ohio, Texas, Utah, and Virginia.
Citing the system’s “low remaining development cost” will accelerate the time to market, in turn meeting NASA’s requirements, the system will provide a quicker return on investment to outside entities
One of the major players in Liberty – Lockheed Martin – is providing crew interface systems design, subsystem selection, assembly, integration and mission operations support for the Liberty spacecraft. These subsystems could include avionics, guidance navigation and control, propulsion systems, environmental control system, docking system and other components.
“Combining Lockheed Martin’s and ATK’s decades of human spaceflight experience to create the Liberty space vehicle will help ensure America’s crew access to the International Space Station – sooner rather than later,” said Scott Norris, Lockheed Martin Lead, Liberty Program.
“We look forward to our role supporting Liberty as it delivers on a highly-effective cost solution for NASA crew and for commercial missions.”
Continuing to work under the ongoing SAA, as part – albeit unfunded – of the CCDev-2 program, the team has successfully completed four milestones. The next major milestone is a structural test of the second stage tank, to be conducted at Astrium in June.
“Working with the NASA team under the SAA has provided significant benefit to the development of the Liberty crew transportation system,” added Mr Rominger.
The Liberty team will be working with NASA centers to further leverage lessons learned, engineering expertise test, launch facilities and mission operations, including Kennedy, Johnson, Marshall, Langley, Glenn, Ames and Stennis.
Additional subcontractors for Liberty include Safran/Snecma, which provides the Vulcain 2 engine; Safran/Labinal, which provides second stage wiring; L-3 Communications Cincinnati Electronics, which provides first stage, abort and telemetry system avionics, as well as second stage telemetry and abort system integration prior to launch at KSC; and Moog Inc, which provides thrust vector control and propulsion control.
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