If all goes well, at 8:33 a.m. EDT Monday—on the opening of a two-hour “launch window”—the world’s most powerful rocket will take flight. Pummeling the ground with a combined 8.8 million pounds (3.9 million kilograms) of thrust from her four shuttle-heritage RS-25 Core Stage engines and a pair of five-segment Solid Rocket Boosters (SRBs), the mighty Space Launch System (SLS) will depart historic Pad 39B at the Kennedy Space Center (KSC) in Florida on the long-awaited Artemis I mission. It will deliver an uncrewed Orion spacecraft on a 42-day voyage around the Moon to evaluate systems and technologies for an eventual return of humans to lunar distance later this decade.
But Orion’s formative years were mired in political, financial and technical challenges. By early 2010, six years after President George W. Bush initiated the program, it had begun to bear fruit. Lockheed Martin had been selected as Orion’s prime contractor, parachute trials were well underway and rocket engine hardware for a powerful Ares I Crew Launch Vehicle (CLV) and Ares V Cargo Launch Vehicle (CaLV) approached maturation. In October 2009, a four-segment SRB—equipped with a “dummy” fifth segment and boilerplate Orion spacecraft—was lofted from Pad 39B for the Ares I-X test flight.
Yet the arrival of Barack Obama in the White House in January of that year had brought a much cooler reception for Bush’s Vision for Space Exploration (VSE), whose umbrella architecture—the Constellation Program—sought to return American astronauts to the Moon by 2020 and press onward to Mars. In the fall of 2007, during his election campaign, Obama expressed his desire to delay Constellation by five years to divert $5 billion into education programs. And soon after entering office, he attacked Constellation as “over-budget, behind schedule and lacking in innovation”.
In May 2009, at Obama’s behest, former Lockheed Martin chairman Norman Augustine led a commission to ensure that NASA and the nation were on “a vigorous and sustainable path to achieving its boldest aspirations in space”. Augustine’s report, published the following October, revealed Constellation to be behind schedule, underfunded and grossly over-budget, rendering its goals unattainable under NASA’s established timeframe.
The commission did not recommend the program’s cancelation, but rather advised that “destinations should derive from goals” and considered the Moon, Mars and Near-Earth Objects (NEOs) as candidates for exploration. Augustine advocated a “flexible path” to locations in the inner Solar System, including lunar orbit, Lagrange Points, NEOs and Mars’ twin moons, Phobos and Deimos.
In February 2010, Obama took steps to radically reshape America’s human space exploration landscape and revealed plans to cancel Constellation with the 2011 budget. On 15 April, during a visit to KSC, he pledged to increase NASA’s funding by $6 billion over five years and design a new heavy-lift launch vehicle by 2015. But Obama rejected plans for a return of American boots to the lunar surface and instead posited a crewed voyage to an NEO by 2025 and a mission to Mars orbit in the mid-2030s.
At one memorable moment in his 15 April 2010 speech, Obama even turned to attendee Buzz Aldrin—the second man to set foot on the Moon—and casually dismissed a return to the lunar surface, remarking “We’ve been there; Buzz has been there”. The decision was met with praise and vilification in equal measure, but Obama intended work on Orion to continue, perhaps as a Crew Return Vehicle (CRV) for the International Space Station (ISS).
In June, Obama released his administration’s National Space Policy and in October 2010, despite protests from former NASA Administrator Mike Griffin, the NASA Authorization Act of 2010 was signed into law, requiring the development of a new heavy-lift launch vehicle and continued support for a crew-carrying spacecraft, capable of Beyond Low-Earth Orbit (BLEO) exploration, from 2016. By November 2010, NASA had selected 13 U.S. companies to submit proposals for the heavy-lift booster and with the passage of the 2011 budget allocation in April 2011 the Constellation Program breathed its last.
New NASA Administrator Charlie Bolden described Obama’s plan as a “clear path forward to continue America’s leadership in human spaceflight, exploration and scientific discovery” by lifting funding restrictions which “limited our flexibility to carry out our shared vision for the future”.
As part of this shared vision, Bolden referred to a new Multi-Purpose Crew Vehicle (MPCV), based upon the original Orion design, which was formally unveiled to the world on 24 May 2011. With the future responsibility for sending astronauts to and from the ISS now expected to be handed over to commercial partners, NASA could at last focus upon its deep-space exploration goals.
Construction of the first Orion spacecraft formally commenced on 9 September 2011 with its “first weld” at the Michoud Assembly Facility (MAF) in New Orleans, La., only seven weeks after Atlantis landed from the 135th and final mission of the Space Shuttle Program. The welding process utilized an innovative friction-stir process, which created a seamless, leak-proof bond of exceptionally higher quality than could be attained via conventional welding techniques. It marked the onset of the first “new” NASA spacecraft built to carry humans since the completion of shuttle Endeavour in early 1991.
Elsewhere, work on Orion’s parachute landing system resumed at the Army’s Yuma Proving Ground in Yuma, N.M., with a successful drop-test on 22 September by a C-130 Hercules aircraft from an altitude of 25,000 feet (7,600 meters). The test featured the deployment of a pair of drogue canopies at 19,000 feet (5,800 meters), followed by three pilot parachutes, which then released the three “mains”.
Touchdown of the Orion test article was achieved at a relative speed of 17 miles per hour (27.4 kilometers per hour). Another test in mid-December examined the parachute system’s ability to adapt to contingencies, including the failure of one of its three main canopies to properly deploy. This produced a slightly faster landing at 33 miles per hour (53 kilometers per hour).
Increased confidence in the design led NASA to reveal on 8 November 2011 that Orion would perform an uncrewed Exploration Flight Test (EFT)-1 atop a United Launch Alliance (ULA) Delta IV Heavy rocket in early 2014. The EFT-1 mission would see Orion complete two Earth orbits, “to a high apogee”, followed by “a high-energy re-entry through Earth’s atmosphere” and “a water landing” in the Pacific Ocean, just off the California coast. Significantly, the high-apogee nature of EFT-1 would permit the gathering of pertinent data to build a vehicle capable of protecting astronauts during lunar-return re-entry velocities approaching 25,000 miles per hour (40,000 kilometers per hour).
In tandem with the decision to press on with Orion and fly EFT-1, the new heavy-lift booster received a name, the Space Launch System (SLS), on 14 September 2011. Unlike the Constellation Program, which would have featured one rocket (the Ares I) for Orion and another (the Ares V) for cargo, it was intended that the SLS would fill both roles.
Described as America’s most powerful launch vehicle since the Saturn V, it grew out of technologies from the unrealized Ares V, with a Core Stage powered by shuttle-era RS-25 engines and a pair of five-segment SRBs providing first-stage propulsion for the initial minutes of each flight. The J-2X engine would then feed an upper stage to deliver Orion out of low-Earth orbit and into deep space.
Testing of the J-2X—an evolved, modernized version of the engine used by the Saturn IB and Saturn V boosters in the Apollo Program—had entered high gear since June 2011 and in November completed a 500-second, full-flight-duration firing at NASA’s Stennis Space Center (SSC) in Bay St. Louis, Miss., on 9 November.
Two months later, the process to transfer NASA’s inventory of RS-25 shuttle main engines from KSC to Stennis for SLS modification got underway. In the meantime, J-2X powerpack testing continued—achieving a record-setting 1,150 seconds in one firing—and by March 2012 NASA successfully trialed a sub-scale motor for the five-segment SRB at the Marshall Space Flight Center (MSFC) in Huntsville, Ala.
The 20-second firing served to evaluate new materials for the lining of the booster’s nozzle, ahead of a planned Qualification Test (QM)-1 in the spring of 2013. With remarkable speed, SLS moved swiftly through a major technical review of its 212-foot-tall (64.6-meter), RS-25-fed Core Stage in June 2012.
This served as “the first major checkpoint” of the program, according to Tony Lavoie, manager of the SLS Stages Element at MSFC, and allowed it to move from the concept into the design stage. Completion of a combined System Requirements Review (SRR) and System Definition Review (SDR) in July 2012 established requirements for the entire vehicle, allowing the new booster to advance to its preliminary design phase.
Elsewhere, efforts to modify the Mobile Launcher (ML) for SLS got underway, through contracts awarded in early 2013, and the following summer the program sailed through its Preliminary Design Review (PDR). The latter finally allowed the new booster to advance into the hardware fabrication stage, ensuring that the Core Stage could integrate with the RS-25 engines, the five-segment SRBs, Orion and the KSC launch infrastructure.
Testing of the booster’s autonomous flight control system was trialed aboard an F/A-18 research aircraft in November 2013, to ascertain how well it responded to vehicle and environmental variations, including propellant sloshing and vibrational characteristics which might be encountered during the first two minutes of an SLS ascent. “By flying a high-performance F/A-18 jet in a similar manner to our rocket, we’re able to simulate SLS flight conditions and improve our software,” explained Tannen Van Zwieten, SLS flight controls working lead.
“First light” of the SLS flight software and avionics came in January 2014, followed by tests of a scaled model of the sound suppression water system, culminating in August at Key Decision Point (KDP)-C, which provided a development cost baseline for the rocket. This review produced a revised No Later Than (NLT) date of November 2018 for the maiden voyage of SLS, which would carry an uncrewed Orion spacecraft on Exploration Mission (EM)-1 into deep space.
Also that summer, the 178-foot-tall (54.2-meter) Vertical Assembly Center was officially opened at MAF in New Orleans, ready to begin the construction of the SLS Core Stage. And as the rocket’s design evolved, the J-2X was deleted from the upper stage, in favor of an Interim Cryogenic Propulsion Stage (ICPS) and eventually an Exploration Upper Stage (EUS), based upon the RL-10 engine.
As these plans crystallized, Orion stepped ever closer to its maiden launch on EFT-1, which had by now slipped into the fall of 2014. Parachute tests in Yuma, Ariz., continued through 2012, helping to evaluate the influence of the disturbed air-flow in the spacecraft’s wake and the effects of improper canopy deployment and water-impact testing was conducted in the Hydro Impact Basin at the Langley Research Center in Hampton, Va. But from a visible public relations perspective, the major event of the EFT-1 campaign came on 2 July 2012 when the actual Orion spacecraft arrived at KSC for the installation of its heat shield and other subsystems.
International co-operation had long been courted and on 16 January 2013 NASA contracted with the European Space Agency (ESA) to build the European Service Module (ESM) for Orion’s second mission, EM-1. This came as little surprise to most observers, since ESA had for at least two years before the announcement expressed interest in using its Automated Transfer Vehicle (ATV) technology as part of the Orion architecture.
Also that January, the process of attaching—by means of no less than 3,000 bolts—the titanium “skeleton” of Orion’s heat shield onto its carbon-fiber skin got underway at Lockheed Martin’s Waterton facility in Denver, Colo. And MSFC engineers began manufacturing two forward and two aft rings for welding onto barrel panels to form the adapter to join the EFT-1 vehicle to the Delta IV Heavy.
Orion’s landing system progressed through ever more complex and hairy descent scenarios, including one February 2013 test which saw the spacecraft land safely on just two of its three main parachutes and another in April which deployed the canopies at a peak velocity of 250 miles per hour (400 kilometers per hour).
Further tests in early 2014 evaluated the performance of systems for deploying Orion’s forward bay cover, which must be jettisoned for the parachutes to be released. By thus guarding against irregular events, NASA engineers verified that the parachutes, upon which astronauts will soon depend for their lives, are reliable in the event of contingencies.
Meanwhile, in KSC’s Operations and Checkout Building, the EFT-1 airframe underwent static loads testing in June 2013, in which it was subjected to 110 percent of the pressures and loads it can typically expect during ascent. These loads ranged from 14,000 pounds (6,350 kg) to as high as 240,000 pounds (108,860 kg) and saw Orion pressurized to simulate the effects of near-vacuum.
“Power-up” of the EFT-1 Orion’s main computer for the first time took place in October 2013. A few weeks later, the separation of the SM fairing panels was successfully trialed and on 4 December the heat shield arrived at KSC aboard NASA’s Super Guppy aircraft.
After the shield’s titanium skeleton had been fabricated at Lockheed Martin’s Waterton facility, it was shipped to Textron Defense Systems, near Boston, Mass., in March 2013, for installation of a fiberglass-phenolic honeycomb structure, whose 320,000 “cells” were filled with the Avcoat ablator. The entire heat shield was then X-rayed and sanded to match NASA’s stringent design specifications.
Heading towards EFT-1, in April 2014 Orion completed a 26-hour integrated systems test and over the summer months the heat shield was installed and the CM was stacked atop its SM. But delays incurred during ULA’s busy flight manifest pushed the mission further to the right, slipping from September to December 2014. At length, in the second week of November, the spacecraft—atop the Delta IV Heavy—rolled out to Space Launch Complex (SLC)-37B at Cape Canaveral Air Force Station, Fla.
The mission got underway at 7:05 a.m. EST on 5 December and ULA’s trusty Delta IV Heavy lifted the Orion spacecraft smoothly into low-Earth orbit. Just under two hours later, a near-five-minute “burn” by the rocket’s Delta Cryogenic Second Stage (DCSS) pushed Orion to a peak apogee of 3,609 miles (5,808 kilometers), some 15 times higher than the altitude of the International Space Station (ISS). It was the furthest a human-capable space vehicle had traveled since Apollo 17.
The view from this high-radiation neighborhood, as captured by Orion’s on-board cameras, was nothing short of spectacular. Re-entry velocities of more than 20,000 miles per hour (32,000 kilometers per hour) and peak temperatures on its heat shield of 2,200 degrees Celsius (4,000 degrees Fahrenheit) closely mirrored the kind of conditions that EM-1 would experience during its return from lunar distance.
And four hours and 25 minutes after launch, having traveled over 60,000 miles (96,600 kilometers), the spacecraft completed a parachute-assisted splashdown in the waters of the Pacific Ocean, some 600 miles (935 kilometers) off the coast of Baja California. EFT-1 had triumphantly demonstrated Orion’s capabilities as a spacecraft capable of exploration beyond low-Earth orbit.
But a long path of almost a decade lay ahead before Orion would fly again. And before that next flight, hopefully on Monday morning, the program would gain a new name. And not just any name. For what program name could be more fitting for the successor to Apollo than the name of the ancient Greek sun-god’s sister, the goddess of wisdom and of the Moon itself, Artemis?Missions » SLS » Missions » SLS » Artemis »