After more than a decade of planning and preparation, excitement, and frustration, NASA is ready to launch the first human-capable vehicle for Beyond Earth Orbit (BEO) exploration in more than four decades on Thursday, 4 December. Liftoff of the inaugural Orion spacecraft on the long-awaited Exploration Flight Test (EFT)-1 is targeted to occur from Space Launch Complex (SLC)-37B at Cape Canaveral Air Force Station, Fla., at 7:05 a.m. EST. The “launch window” extends for two hours and 39 minutes. The mission will be boosted aloft by the most powerful rocket currently in active operational service, anywhere in the world—United Launch Alliance’s (ULA) Delta IV Heavy—which is tasked with delivering the spacecraft to a peak altitude of 3,600 miles (5,800 km). Orion will then complete two orbits in 4.5 hours, before plunging back to Earth in excess of 20,000 mph (32,000 km/h) to test the hardiness of its heat shield at near-lunar-return velocities and temperatures of close to 2,200 degrees Celsius (4,000 degrees Fahrenheit).
As described in AmericaSpace’s Orion history series of four articles, which concluded last weekend, the spacecraft rose from the ashes of tragedy, following the loss of Shuttle Columbia and her STS-107 crew in February 2003. A year after the disaster, President George W. Bush proposed the Vision for Space Exploration (VSE), which called for the retirement of the inherently flawed shuttle fleet by 2010 and the development of an entirely new spacecraft, capable of delivering astronauts to BEO locations for the first time since the end of the Apollo era. Initially known as the Crew Exploration Vehicle (CEV), the spacecraft gained the name “Orion” in August 2006 and under the guidance of both NASA and prime contractor Lockheed Martin steadily rose from the drawing boards into design, development, and construction. As part of the Constellation Program, it was anticipated that Orion would fly a piloted mission as soon as 2015 and return humans to the Moon by 2020.
However, inadequate funding and a distinctly lukewarm response to the program from President Barack Obama—who entered the White House in January 2009—led to the bitterly disputed cancellation of Constellation. Nevertheless, work on Orion continued, and in May 2011 it was unveiled in the incarnation of the Multi-Purpose Crew Vehicle (MPCV), targeted to explore myriad BEO targets, including Near-Earth Asteroids (NEAs). Shortly afterwards, a new booster for exploration, known as the Space Launch System (SLS), began development, and in November 2011 NASA announced plans for the unpiloted EFT-1 mission, to fly atop a Delta IV Heavy, which currently provides the greatest heavy-lift capacity available to the United States. Originally planned for March 2014, EFT-1 slipped until September and eventually December, as ULA’s launch manifest contorted in response to delays and the needs of its other military customers.
Preparations for the ambitious mission entered high gear, and in July 2012 the actual Orion spacecraft arrived at the Operations and Checkout Building at the Kennedy Space Center (KSC), Fla., for final processing. The titanium “skeleton” of its heat shield was attached to its carbon-fiber skin, and the spacecraft’s airframe underwent static loads tests to evaluate its capability to handle up to 240,000 pounds (108,860 kg) of force at various stages during its mission phases. This year, 2014, efforts to stage the EFT-1 mission entered high gear. The Orion spacecraft moved swiftly through an integrated systems test in April, during which its myriad components ran for 26 uninterrupted hours in order to verify that the conical Crew Module could route power and send commands to allow for the management of the computers, software and data loads, propulsion valves, temperature sensors, and other instrumentation. Next came Crew Module vibration testing, the installation of the heat shield in May, and the stacking of the capsule atop the Service Module on 9 June inside the Final Assembly and System Testing (FAST) Cell.
By this stage, the mammoth Delta IV Heavy, which constitutes the largest and most powerful launch vehicle currently in active operational service, anywhere in the world, was deep into processing for what will be its eighth flight since its maiden voyage in December 2004. The Heavy was most recently used to launch the NROL-65 classified payload on behalf of the National Reconnaissance Office in August 2013 and during its decade of service has been employed almost exclusively for heavyweight military satellites. The EFT-1 mission marks the vehicle’s first dedicated use for a civilian NASA exploration flight. Capable of delivering up to 63,470 pounds (28,790 kg) into a 125-mile (200-km) low-Earth orbit or up to 31,350 pounds (14,220 kg) into a 22,300-mile (35,900-km) geosynchronous transfer orbit, the Heavy consists of a trio of 134-foot-tall (40.8-meter) Common Booster Cores (CBCs), one of which serves as the first stage “core” and two as side-mounted strap-on rockets. Topping the stack is the 16-foot-wide (5-meter) Delta Cryogenic Second Stage (DCSS) and the dedicated Orion payload fairing, the latter of which underwent structural load tests in January 2014. The entire Heavy weighs an estimated 1.6 million pounds (725,750 kg).
Each CBC carries approximately 440,000 pounds (200,000 kg) of liquid hydrogen and oxygen, and each utilizes a single RS-68 cryogenic engine, developed by Pratt & Whitney Rocketdyne. When this engine was introduced back in 2002, it became the first large, liquid-fueled powerplant to be developed in the United States since the Space Shuttle Main Engine (SSME). Hardware for both stages of the Heavy were fabricated by ULA at Boeing’s 1.5-million-square-foot (140,000-square-meter) facility in Decatur, Ala., after which they were transferred to Cape Canaveral Air Force Station, Fla., aboard the M/C Delta Mariner cargo vessel in the February-March 2014 timeframe. Upon arrival at the launch site, the stages underwent final assembly within the seven-story Horizontal Integration Facility (HIF), ahead of rollout to Space Launch Complex (SLC)-37B.
However, it soon became clear that EFT-1 would slip from September to December, due to delays within ULA’s existing launch manifest. According to an AmericaSpace article by Mike Killian in mid-March, the specific reason was to offer priority to several U.S. military payloads, including the critical Geosynchronous Space Situational Awareness Program (GSSAP)—part of the Air Force Space Command (AFSPC)-4 mission—which eventually launched on 28 July, after many weather-related delays.
Notwithstanding these delays, the protective ogive-shaped panels for Orion’s Launch Abort System (LAS) arrived at the Cape in April. The LAS itself was rotated into a vertical position in late July, ready for the arrival of Orion, which by now was heading into the homestretch of its processing regime. The cone-shaped “back shell” of the Crew Module, coated with 970 black protective tiles of shuttle-era heritage, was installed in mid-August. “One of the lesser-known tests … will demonstrate Orion’s ability to operate after sustaining damage from a micrometeoroid hit,” explained Mike Killian at the time. “Orion’s violent return to Earth in December will give engineers the chance to verify new models to better understand the heating environment for damage on Orion’s heat shield, which will inform future decisions about what kind of damage may require a repair. Before installing the protective back shell, engineers purposely drilled 1-inch-wide holes into two tiles on the opposite side of the back shell from Orion’s windows and reaction control system jets. One of the holes is 1.4 inches deep and the other is 1 inch deep, and both are meant to mimic damage from a micrometeoroid hit. Sensors on the vehicle will record how high temperatures climb inside the holes during Orion’s return.” Shortly after the installation of the back shell, the complete EFT-1 spacecraft—Crew Module and Service Module, united at last—were moved from the newly-renamed “Neil Armstrong Operations and Checkout Building” to the Payload Hazardous Servicing Facility (PHSF) for fueling. From there, on 28 September, Orion was transferred to the Launch Abort System Facility (LASF) for the installation of the LAS itself.
The Delta IV Heavy was by this stage structurally complete, save its precious payload, and following a 24-hour delay was rolled out from the HIF to SLC-37B by means of the diesel-powered Elevating Platform Transporter on 1 October, whereupon it was hoisted by the Fixed Pad Erector into a vertical orientation within the 260-foot-tall (79.2-meter) Mobile Service Tower (MST). In the meantime, the ogive-shaped panels were installed around the Orion/LAS stack on 30 October, with rollout from the LASF to SLC-37B originally planned for 10 November. This was postponed by 24 hours, due to poor weather, and NASA’s newest spacecraft for human deep-space exploration began its stately 5 mph (8 km/h) roll to the pad at 8:54 p.m. EST on the 11th. As described by Mike Killian in AmericaSpace’s Photo Feature of the rollout, the EFT-1 stack passed the historic Vehicle Assembly Building (VAB) and Pad 39B en-route and Orion reached SLC-37B at 3:07 a.m. on 12 November.
A week later, engineers installed the spacecraft’s batteries, thereby completing a critical step in the final preparations for launch. Since they have a limited life span, the batteries needed to be brought online as late as possible, and on 19 November an all-up communications run was performed between Orion and the geosynchronous-orbiting Tracking and Data Relay Satellite System (TDRSS), in an evaluation known as “Live Sky Test.” The next major milestone took place on the 21st, when NASA and Lockheed Martin managers concluded the Flight Readiness Review (FRR) and unanimously authorized a “Go” to proceed with an opening launch attempt on 4 December.
The second part of this EFT-1 preview article will appear tomorrow.
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