It may still be almost three years into the future, but the maiden voyage of NASA’s gigantic Space Launch System (SLS) booster—destined to carry humans beyond low-Earth orbit for the first time in five decades—drew tantalizingly closer today (Tuesday, 2 February), with the formal announcement of 13 shoebox-sized CubeSats which will ride aboard the mission. Accompanying the first “full-up” Orion spacecraft on Exploration Mission (EM)-1 and its journey beyond the Moon, scheduled to fly no sooner than November 2018, will be a fleet of miniaturized payloads devoted to lunar science, heliophysics, asteroid exploration and solar-sail propulsion technology. Significantly, several secondary payload slots aboard EM-1 remain open for NASA’s Cube Quest Challenge, which is open to U.S.-based, non-government teams, and offers a $5.5 million prize “purse” for completing advanced missions beyond the Moon.
Today’s event was held on the Flight Robotics Laboratory Flat Floor at NASA’s Marshall Space Flight Center (MSFC) in Huntsville, Ala. Backdropped by a half-scale model of the solar-sail propulsion technology which will be employed by one of the 13 CubeSats—the Near-Earth Asteroid (NEA) Scout mission—the event was opened by Todd May, who was yesterday (Monday, 1 February) appointed as the new center director. Mr. May, who previously served as acting director since November 2015 and as deputy director since August 2015, is a 25-year NASA veteran and has been intimately involved in SLS since its conception. He managed the program for four years from August 2011, leading it from its origin as a replacement for the canceled Ares V through a series of key milestones, including engine tests and enabling it to reach Critical Design Review (CDR) level. This made SLS the first U.S.-built, human-capable rocket to have cleared all of the steps necessary to reach CDR in almost four decades.
Describing SLS as “the largest and most powerful rocket ever built”—even in its “barebones” Block I configuration, destined to be trialed on EM-1, it will stand around 321 feet (97.8 meters) tall, generating 8.4 million pounds (3.8 million kg) of combined propulsive yield at T-0 from its four RS-25 engines and a pair of five-segment Solid Rocket Boosters (SRBs)—Mr. May explained that the Orion spacecraft will undertake a “proving-ground mission”, as NASA prepares to deliver humans beyond low-Earth orbit for the first time since the return of the Apollo 17 crew, way back in December 1972. He noted that the “robust capability” of SLS allows for the inclusion of small technology experiments, before handing the floor over to NASA Deputy Administrator Dava Newman, for her address. Dr. Newman began by congratulating Mr. May as MSFC’s 13th director and stressing that the center remained at the core of the SLS testing program as the agency pressed ahead with the “many facets” of its ongoing journey to someday plant human bootprints on Mars.
She highlighted that CubeSats are “really showing us how to do exploration in a new way” and that, to her, they represented a “synergy of what we can do in science and technology”. As outlined in a previous AmericaSpace article, the idea of these shoebox-sized satellites originated in 1999, as a means to design, build, test and operate small, relatively inexpensive and lightweight spacecraft in low-Earth orbit. The first half-dozen CubeSats flew from the Plesetsk Cosmodrome, in the northern Russia, in June 2003, and over the following decade others rocketed to space from Baikonur in Kazakhstan, Omelek Island in the Marshall Islands, the Satish Dhawan Space Centre in India, the Uchinoura Space Centre in Japan, the Guiana Space Centre in Kourou, French Guiana, together with U.S. installations at Vandenberg Air Force Base, Calif., Cape Canaveral Air Force Station, Fla., Wallops Flight Facility in Wallops, Va., and Alaska’s Kodiak Launch Complex. They have ridden numerous boosters, including SpaceX’s Falcon 1 and Falcon 9, Japan’s H-II, Europe’s Vega, India’s Polar Satellite Launch Vehicle (PSLV), the U.S. Minotaur, Taurus and Delta II rockets and Russia’s Rokot, Kosmos and Dnepr workhorses.
“Standard” CubeSats measure 10 x 10 x 10 cm (3.9 x 3.9 x 3.9 inches) and are described as “1U” (or “one-unit”), but are scalable and for EM-1 several of the miniaturized payloads will fly in their largest configuration, the “6U”, each of which measures 60 x 10 x 10 cm (23.6 x 3.9 x 3.9 inches) and weighs less than 18 pounds (7.9 kg). Although 13 CubeSats will fly aboard EM-1—mounted on the interior rim of the Orion Stage Adapter for their journey uphill—only seven have been specifically identified to date. The remainder will include three satellites provided by NASA’s International Partners, for which discussions are ongoing, and another three which will be determined in 2017 through the Cube Quest Challenge, sponsored by NASA’s Space Technology Mission Directorate.
Initiated two years ago, and forming part of NASA’s Centennial Challenges Program, the Cube Quest Challenge offers the space agency’s largest-ever prize purse of $5.5 million to teams which can design, build and develop flight-qualified CubeSats for operations near and beyond the Moon during the EM-1 mission. As well as contributing to NASA’s goals and engaging the public, the challenge also provides a tool for open innovation and the prize purse is divided into four qualifying Ground Tournaments—the second stage of which closes on Friday, 5 February—worth $500,000, followed by the $3 million “Lunar Derby” to place a CubeSat into a stable lunar orbit and demonstrate durability and communications and a $1.5 million “Deep Space Derby” to achieve “innovative solutions” to communications challenges further afield at distances greater than 2.5 million miles (4 million km), about ten times as far as the Moon from the Earth.
The first Ground Tournament, which concluded last August, saw five teams—Team Miles of Tampa, Fla., MIT KitCube of Cambridge, Mass., Cislunar Explorers of Ithaca, N.Y., Novel Engineering of Cocoa Beach, Fla., and Ragnarok Industries of Wilmington, Del.—chosen by a NASA/industry/academia judging panel from a total of 13 candidates. With Ground Tournament-2 due to close on Friday, the third and fourth tournaments are currently scheduled for August 2016 and February 2017, with the winners “downselected” in March 2017 to three finalists which will be granted CubeSat spots aboard the SLS for EM-1.
Although the identity of these six small satellites, provided through the Cube Quest Challenge and from the International Partners, will be determined at a later date, more is known about the seven NASA-sponsored CubeSats. EM-1 will transport an unpiloted Orion—equipped with a European-built Service Module (SM)—into Lunar Distant Retrograde Orbit, which will send it further from Earth than any human-capable vehicle has ever traveled. Following an initial boost out of low-Earth orbit by the SLS, the spacecraft will separate from the stack, exposing the Orion Stage Adapter and setting the stage for the deployment of the CubeSats. According to Bill Hill, deputy associate administrator for Exploration Systems Development at NASA Headquarters in Washington, D.C., the stage adapter provides a “nice, easy interface”, allowing for a smooth separation of the satellites in the wake of Orion’s departure. He noted that CubeSats had previously been deployed in low-Earth orbit (and from the International Space Station) on several occasions, but this would be the first time they had been turned loose in cislunar space.
Due to the proximity of the EM-1 mission to our closest celestial neighbor, it is unsurprising that four of the seven identified satellites will be devoted to aspects of lunar science. Two payloads were selected in 2015 through NASA’s Next Space Technologies for Exploration Partnerships (NextSTEP) Broad Agency Announcement. Lockheed Martin will provide Skyfire, which seeks to perform spectroscopic and thermographic observations of the Moon for surface characterization, remote-sensing and landing site selection, whilst Morehead State University of Morehead, Ken., is constructing Lunar IceCube to search for water deposits from a low orbit of just 62 miles (100 km). The latter will utilize an innovative electric ion engine, powered by a solid iodine propellant, which will allow it to achieve lunar capture and enter its desired orbit within about three months of launch.
Other CubeSats include Arizona State University’s Lunar Polar Hydrogen Mapper (LunaH-Map), destined to search for water-ice deposits within the permanently shadowed regions of the Moon’s south pole. It will pass just 3 miles (5 km) from the surface at its closest point, which is necessary in order for its twin neutron spectrometers—both of which have large effective fields of view—to better spatially isolate any locations of enriched water-ice. Lastly, Lunar Flashlight will employ an 860-square-foot (80-square-meter) solar sail to reach the Moon, whereupon it will focus an infrared spectrometer onto its core mission goal of investigating the size and composition of water-ice deposits within the south pole. The spacecraft, which will use its solar sail as a “mirror” to reflect up to 50 kilowatts of sunlight onto the shadowed regions, producing a “spot” of illumination about 1,300 feet (400 meters) in diameter, and allowing for the mapping of these water-ice concentrations at scales of below 1.2 miles (2 km).
The three remaining NASA-funded payloads include BioSentinel, which will expose the budding yeast Saccharomyces cerevisiae to deep-space radiation for up to 18 months, thereby adding to our existing knowledge database about the potential human health risks of long-term immersion of living organisms in galactic cosmic rays and solar radiation. Notably, BioSentinel is NASA’s first mission since Apollo 17 in December 1972—which saw astronauts Gene Cernan, Ron Evans and Jack Schmitt voyage to the Moon and back—to send living organisms beyond low-Earth orbit. The particular strain of yeast selected was chosen due to its well-studied nature and its similarity to the Double-Strand Break (DSB) repair mechanisms present in human cells. The BioSentinel payloads includes a radiation dosimeter, equipped with a three-color spectrometer.
Rounding out the EM-1 group of CubeSats are CuSP, which will provide a “space weather station” for heliophysics research and better forecasting of solar events, and the Near-Earth Asteroid Scout (NEA Scout). The latter is tasked with developing the capability to close gaps in our knowledge of near-Earth asteroids, particularly in the size range below about 330 feet (100 meters). Due to challenges with detecting, observing and imaging these small-sized bodies over long periods, their nature remains largely unknown, with schools of thought postulating that they may represent fragments of larger objects or “rubble-piles”. According to Jitendra Joshi, technology integration lead for the Advanced Exploration Systems Division at NASA Headquarters, the results would “Reduce our uncertainty in enabling a human mission” to an asteroid, as outlined in President Barack Obama’s plan to rendezvous with and capture an NEA in cislunar space by 2025.
As well as offering important insights for the Asteroid Redirect Mission (ARM), it is hoped that NEA Scout will allow better characterization of objects greater than about 66 feet (20 meters) in diameter, in order to better guard against close encounters and impacts with Earth. The CubeSat seeks to rendezvous with a small asteroid, approaching within 6 miles (10 km), and will direct a high-resolution camera onto the surface to glean insights into its rotation rate and orbit, its physical properties, its mass and density and other morphological features. It is expected that NEA Scout will image around 85 percent of the surface.
Shortly after deployment from the Orion Stage Adapter, NEA Scout would deploy an 890-square-foot (83-square-meter) solar sail, readying it for a mission which could last for up to 30 months. The solar sail, built in-house at MSFC, is fabricated from aluminized Kapton and is maneuverable to provide attitude changes in lunar orbit. In pride of place in the Flight Robotics Laboratory Flat Floor for today’s event was a half-size mockup of the sail. According to Leslie McNutt, project manager for NEA Scout at MSFC, the flat floor allows for airbearing technology to be brought to bear on testing the solar sail.
Noting that EM-1 represents a “great endeavor we’re about to get on: the Journey to Mars”, Mr. Hill’s sentiments were echoed by Michael Seablom, chief technologist for the Science Mission Directorate (SMD) at NASA Headquarters, who praised the “miniaturization of instruments” which enabled the development of new scientific platforms. He pointed to the fact that many CubeSats are built not solely at large institutions, but also at universities which have not previously done business within NASA, and expressed his admiration for a “young and diverse set of new researchers”.
In less than three years’ time, EM-1 will transport these 13 CubeSats to a peak distance of about 275,000 miles (442,570 km) beyond Earth. The mood on the Flight Robotics Laboratory Flat Floor today was one of excitement and anticipation for a new era, which—if realized—could promise an opportunity for our species to finally break out of low-Earth orbit and explore the Solar System with humans once again. And that mood was summed up best by Dr. Dava Newman herself.
“We’re not just talking about it,” she told her rapt audience. “We’re doing it.”
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