Three weeks from now, the first human-capable vehicle for Beyond Earth Orbit (BEO) exploration in more than four decades is scheduled to roar away from Space Launch Complex (SLC)-37B at Cape Canaveral Air Force Station, Fla., on its first voyage. NASA’s Orion spacecraft will ride a Delta IV Heavy, the largest and most powerful rocket currently in active operational service, anywhere in the world, on the Exploration Flight Test (EFT)-1 mission. Following a planned liftoff at 7:05 a.m. EST on Thursday, 4 December, the Heavy will boost Orion to a peak altitude of 3,600 miles (5,800 km), whereupon the spacecraft will complete two orbits in 4.5 hours, then plunge back to Earth in excess of 20,000 mph (32,000 km/h), testing its heat shield at lunar-return velocities and temperatures of up to 2,200 degrees Celsius (4,000 degrees Fahrenheit). Without doubt, EFT-1 represents the most significant advance in human space exploration of the second decade in the 21st century.
As described in yesterday’s AmericaSpace article, the Orion spacecraft consists of two primary components, a conical Crew Module and a cylindrical Service Module, and is designed to eventually support deep-space missions of up to 21 days in duration, plus another six months in “quiescent” mode. The shape of the Crew Module was deemed the safest and most reliable means of re-entering Earth’s atmosphere at the extreme velocities—far in excess of 20,000 mph (32,000 km/h)—required for direct return trajectory profiles from the Moon. It stands 10 feet (3.3 meters) tall and measures 16.5 feet (5 meters) across its base, as opposed to 12.8 feet (3.9 meters) for the Apollo command module, thereby providing an interior volume of 690 cubic feet (19.5 cubic meters), significantly larger than its 1960s-era ancestor.
Moreover, the Crew Module is equipped with “smart cockpit” digital controls, derived from the Boeing 787 Dreamliner, which will provide its future crews with enhanced situational awareness. “Whereas the shuttle’s cockpit screens are filled with data that astronauts have to interpret and act upon,” Flight International explained in October 2006, “Orion’s displays will use graphics along with enhanced synthetic vision and additional flight-related symbology.” At the apex of the Crew Module will be the NASA Docking System (NDS), which has compatibility with the two International Docking Adapters (IDAs), to be launched to the International Space Station (ISS) aboard a pair of SpaceX Dragon resupply missions in June and August 2015. Orion’s cabin atmosphere is an oxygen-nitrogen mixture at close to terrestrial sea-level pressure.
Mounted at the base of the Crew Module is the cylindrical Service Module, which marks out Orion as the first piloted spacecraft in U.S. history—excluding space stations—to carry solar arrays. In the original design, the arrays took the form of two circular panels, deployed from the main body of the Service Module shortly after launch, which would give the spacecraft a total span of about 55.7 feet (17 meters). The Service Module stands 15.5 feet (4.8 meters) in height and measures 16 feet (5 meters) in diameter, with an empty mass of 8,000 pounds (3,700 kg). At its base is the Aerojet-built main engine, capable of 7,500 pounds (3,400 kg) of thrust, with a Reaction Control System (RCS) providing maneuverability and backup capability to execute the critical Trans-Earth Injection (TEI) “burn” from deep space. Inside the bowels of the Service Module, a pair of liquid oxygen tanks and smaller nitrogen tanks will maintain Orion’s habitability, whilst lithium hydroxide cartridges will scrub the crew’s exhaled carbon dioxide with oxygen and nitrogen and recycle them back into the life-support loop. The Service Module for EFT-1 has been fabricated by Lockheed Martin, with batteries in place of solar arrays, although that of the next flight in 2018 will be developed by the European Space Agency (ESA) and will feature an X-shaped layout of four electricity-generating “wings”.
By the summer of 2006, after more than a year of initial design and definition, Orion had received its program name and on 31 August NASA revealed that Lockheed Martin would be the prime contractor to design, develop and build the spacecraft. “Manufacturing and integration of the vehicle components will take place at contractor facilities across the country,” it was reported. “Lockheed Martin will perform the majority of the Orion vehicle engineering work at NASA’s Johnson Space Center, Houston, and complete final assembly of the vehicle at the Kennedy Space Center, Fla.” The initial Design, Development, Testing and Evaluation (DDT&E) phase of the contract totaled $3.9 billion and extended for seven years from September 2006. Several months later, in April 2007, the contract was further modified to $4.3 billion, with two years added to the design phase and two test flights of Orion’s Launch Abort System (LAS) incorporated into the schedule. “This spacecraft will be a cornerstone of America’s human exploration of the Solar System by a new generation of explorers,” explained Jeff Hanley, manager of the Constellation Program at the Johnson Space Center (JSC) in Houston, Texas, “and these changes and additional tests will ensure that it is robust enough to accomplish its missions.”
As these decisions were being made, initial testing of parachute systems for the new spacecraft and rockets got underway at the U.S. Army’s Yuma Proving Ground, near Yuma, Ariz. By mid-September 2006, Boeing had been selected to support the design of Orion’s primary lunar-return-capable heat shield, with options including Phenolic Impregnated Carbon Ablator (PICA) and alternate technologies explored in subsequent contracts. For more than three years, NASA’s Orion Thermal Protection System Advanced Development Project worked on eight candidate materials, before finally narrowing them down to the previously flight-proven PICA and Avcoat, the latter of which had been utilized in the Apollo command module’s heat shield and on parts of the shuttle. At length, in April 2009, NASA selected Avcoat—a material composed of silica fibers with an epoxy-novalic resin, filled in a fiberglass-phenolic honeycomb and manufactured directly onto Orion’s heat shield substructure and installed as a complete unit onto the crew module—which was described as “the more robust, reliable and mature system”.
During this period, other aspects of Orion’s development continued. The spring of 2007 was an “eventful” time, according to Jeff Hanley. Reviews of launch vehicle and spacecraft systems requirements, including more than 1,700 issues pertaining to performance, design and qualification, were completed by the end of May to clear the way for a summer of system definition reviews, leading up to the Preliminary Design Review (PDR) process in mid-2008 and the Critical Design Review (CDR) stage in early 2010. Dovetailed into this manifest, it was anticipated that the Constellation Program would also undergo a Lunar Architecture System Requirements Review in the spring of 2009.
Elsewhere, the effort to build the critical LAS was also gaining momentum. In April 2007, NASA partnered with the Air Force’s Space Development and Test Wing at Kirtland Air Force Base, near Albuquerque, N.M., to stage a series of tests between 2008-2011 of an escape rocket mechanism to pull the crew capsule to safety in the event of a launch malfunction. “A total of six tests are planned, pending environmental assessments,” NASA reported. “Two will simulate an abort from the launch pad and will not require a booster. The rest will use abort test boosters and simulate aborts at three stressing conditions along the Ares launch vehicle trajectory.”
Groundbreaking operations for the construction of the abort test pads got underway at the Army’s White Sands Missile Range, near Las Cruces, N.M., in November 2007, and in the spring of the following year a full-scale, 20,000-pound (9,000 kg) Orion crew capsule test structure was shipped from NASA’s Langley Research Center in Hampton, Va., to the Dryden Flight Research Center at Edwards Air Force Base, Calif., to participate in the “Pad Abort-1” test. Concurrently, in April 2008, the solid-fueled motor to jettison the LAS during ascent was successfully static-fired by Aerojet at its facility in Sacramento, Calif. Meanwhile, ATK Thiokol performed tests of the LAS igniter system and test-fired the motor itself at its own site in Promontory, Utah, in November 2008. Burning for 5.5 seconds, the successful motor test cleared the way for Pad Abort-1.
After several delays, the full-scale Pad Abort-1 test took place at White Sands on 6 May 2010. An abort motor, with a momentary 500,000 pounds (226,800 kg) of thrust, burned for six seconds to boost the Orion capsule away from the pad. It reached a peak velocity of 540 mph (870 km/h). Simultaneously, a 7,000-pound-thrust (3,170 kg) attitude control motor was also ignited to provide steering, whilst a jettison motor pulled the LAS away from the capsule to permit parachute deployment and a safe landing. Overall, Pad Abort-1 lasted 135 seconds and Orion was brought to a touchdown about a mile (1.6 km) north of the pad.
The performance of the spacecraft in other critical areas was also being steadily proven and brought closer to flight readiness. In March 2009, a full-scale mockup, known as the Post-Landing Orion Recovery Test (PORT), was successfully placed in a test pool at the Naval Surface Warfare Center’s Carderock Division in West Bethesda, Md., as part of efforts to understand the kind of motions the astronauts might experience after a water splashdown. Orion swept through its Preliminary Design Review (PDR) with flying colors in August 2009, following six months of focused subsystems evaluations across all ten NASA field centers and its success prompted Cleon Lacefield, vice president and Orion Project Manager at Lockheed Martin, to remark that its design was “much more mature than you might see on many programs at the PDR checkpoint”. He paid tribute to the close partnership between Lockheed Martin and NASA during the design of the spacecraft, which involved 300 technical reviews, 100 peer reviews and 18 subsystem design reviews.
Alongside the Orion, the vehicle which would transport it into space was also well into its own development. From February 2006, engineers at NASA’s Marshall Space Flight Center in Huntsville, Ala., performed initial wind tunnel testing of what came to be known as the Ares I Crew Launch Vehicle (CLV). This two-stage rocket had an anticipated payload capacity of 50,000 pounds (22,300 kg). It would feature a first stage fabricated by ATK Thiokol, builder of the shuttle’s Solid Rocket Boosters, which would be based upon an expanded, five-segment SRB. This would be topped-off by a Boeing-built second stage, to be fed by Pratt & Whitney Rocketdyne’s oxygen/hydrogen J-2X engine. The latter was an evolved and modernized version of the very same engine employed by the Saturn IB and Saturn V boosters in the Apollo era and would be utilized to power the second stage of the Ares I CLV and a larger Ares V Cargo Launch Vehicle (CaLV). The “Ares” name honored the Greek variant of the ancient Roman god of war, Mars, whose planetary namesake formed the major celestial target of exploration for the VSE.
Construction of a 300-foot-tall (90-meter) test stand at the Stennis Space Center in Hancock County, Miss., commenced in mid-2007, in order to perform full-scale firings and evaluations of J-2X hardware, including its powerpack and gas generator. The engine itself passed its Critical Design Review (CDR) in November 2008, which allowed it to progress into the manufacturing phase. Meanwhile, Boeing was selected to build Ares I’s avionics system, responsible for developing the mechanized “brains” of the vehicle for guidance, navigation and control until it delivered Orion safely into low-Earth orbit.
Elsewhere, ATK Thiokol, which had signed a $1.8 billion contract with NASA in August 2007 to build the five-segment SRB for the Ares I and Ares V first stages, was required to perform a test flight, known as “Ares I-X”. In effect, this would be an evaluation of many of the key systems of the first stage of the Ares I, with a standard four-segment SRB and a dummy, “ballasted” fifth segment to make it aerodynamically accurate. The performance of the hardware was critical, for its 2.6 million pounds (1.2 million kg) of thrust would power the vehicle to an altitude of 25 miles (40 km) during the first two minutes of each flight. Hardware for Ares I-X began to arrive at the Kennedy Space Center (KSC) for processing in the Vehicle Assembly Building (VAB) from November 2008, with the Solid Rocket Motors (SRMs) themselves arriving in March 2009. Concurrently, testing of the rocket’s parachute and igniter systems was also completed. Ares I-X was originally targeted for July 2009—although KSC’s historic Pad 39B was not handed over by the Shuttle Program to the Constellation Program for appropriate modification until 31 May—and the launch in any case slipped until late October. “The Ares I-X rocket is a combination of existing and simulator hardware that will resemble the Ares I crew vehicle in size, shape and weight,” NASA explained. “It will provide valuable data to guide the final design of the Ares I, which will launch astronauts in the Orion Crew Exploration Vehicle.”
Although the “Orion” for Ares I-X actually took the form of a “boilerplate” crew module, topped by a 46-foot-tall (14-meter) LAS, it was instrumented with 150 sensors to measure aerodynamic pressures and temperatures in order to contribute to an understanding of the performance of the vehicle. A further 550 sensors were also mounted on the body of Ares I-X itself to monitor its flight. “This launch will tell us what we got right and what we got wrong in the design and analysis phase,” said Jonathan Cruz, deputy project manager for the Ares I-X crew module and LAS, based at the Langley Research Center. “We have a lot of confidence, but we need those two minutes of flight data before NASA can continue to the next phase of rocket development.”
By August 2009, the Ares I-X vehicle—which stood 327 feet (100 meters) high, far taller than the 149-foot (45-meter) shuttle-era SRBs—had been fully stacked inside the VAB and was transported to Pad 39B on 20 October. By this stage, confidence had been further bolstered by ATK Thiokol’s successful full-duration test firing of the five-segment SRB in Promontory, Utah, on 10 September, with a second ground test planned for the summer of 2010. Liftoff on 27 October was postponed by 24 hours, due to concern over the “triboelectrification rule”, one of the weather-related aspects of Launch Commit Criteria (LCC). At length, Ares I-X roared aloft at 11:30 a.m. EDT on 28 October. The mission spanned six minutes, from launch through to parachute deployment and splashdown, and was declared an unbridled success. In the words of Doug Cooke, NASA’s Associate Administrator for the Exploration Systems Mission Directorate at NASA Headquarters in Washington, D.C., the test represented “a huge step forward” for the agency’s exploration goals.
Sadly, the following year, 2010, would bring the Constellation Program to the nadir of cancellation and a whole new architecture for BEO exploration would take center stage. Although the Pad Abort-1 test of the Orion/LAS hardware was successfully performed in May and ATK Thiokol supported a second ground firing of the five-segment SRB at its Utah test site on 31 August, the new president, Barack Obama, had directed NASA to cancel the Constellation Program, terminate work on Orion and the Ares I and Ares V boosters, and recommended a new human space exploration architecture. It was a decision which would win the president praise and vilification in equal measure.
This series of Orion history articles will conclude next weekend.
Missions » SLS » EFT-1 »