By A.J.S. Rayl
It’s one thing to think about studying Earth from above or sending robots and humans to the moon or Mars or conducting experiments in space. It’s something else to create the technology to actually do these things. The people who turn space exploration dreams into real NASA missions or projects are engineers and scientists.
Space science pioneer - James Van Allen, key contributor to 25 space missions.
Engineers draw the cutting edge in every capacity for NASA, from avionics to electronics, software to rocketry. Similarly, to explain the things and places it explores, NASA enlists scientists from a multitude of specialties within the fields of astronomy, biology, chemistry, geology, materials science and physics. As NASA has extended its presence on the final frontier, they have defined new fields and expanded knowledge and technology on almost every front. One in every 1,000 patents issued by United States Patent and Trade Organization has gone to scientists or engineers working on NASA projects and tens of thousands of scientific studies from the agency’s missions have been published in leading journals worldwide.
If your image of a NASA engineer or scientist is that of a white male in a crisp white shirt with black clip-on tie and pocket protector, think again. NASA has evolved and so has it workforce. Drawing on the talents of individuals from all nationalities and cultural backgrounds, NASA is looking to acquire the best of what humanity has to offer.
No one builds a rocket or makes a discovery in space alone. Hundreds, sometimes thousands of people may be involved in a single project. For a mission to succeed, NASA scientists and engineers must share certain qualities despite their inherent differences, “qualities like patience, dedication, optimism, faith in colleagues, a willingness to take informed risks, and the capacity to be a team player,” according to former Jet Propulsion Laboratory (JPL) Director Edward C. Stone, also the Voyager project scientist. Only together can scientists and engineers do the work of NASA and it has been that way from the start.
While engineering – building the rockets and spacecraft and getting them out to their destinations in working order – was clearly the driving force of NASA in the early years, science was always an integral part of the space program. Even Sputnik was the U.S.S.R.’s contribution to a cooperative global science project called International Geophysical Year 1957-’58, at least officially. Its beep-beep-beep startled the world and scored the U.S.S.R. an unprecedented achievement. But the United States response – Explorer 1 – flew higher and returned textbook-changing knowledge. It was engineering and science together that demonstrated American capabilities and put the U.S. on the space map. Thousands of inspiring stories involving extraordinary scientists and engineers have been lived and told in NASA’s first 50 years. Only a few are mentioned here.
Legendary leader - Alan Shepard, John Glenn, and James Webb (behind microphones) look on as President John F. Kennedy presents Dr. Robert Gilruth, director of the Manned Spacecraft Center, Houston, Texas, with the Medal for Distinguished Federal Civil Service. The ceremony took place on the White House Lawn.
When the United States announced in September 1955 that it would produce the first artificial satellite for the International Geophysical Year project, James Van Allen, head of the University of Iowa’s physics department, began building an instrument to measure radiation in the Earth’s upper atmosphere. Explorer 1 lifted off on Jan. 31, 1958, and his cosmic ray detector was onboard “by virtue of preparedness and good fortune,” as he often recalled. The data revealed a donut-shaped ring of charged particle radiation trapped by Earth’s magnetic field surrounding the planet. It was the first major discovery of the Space Age.
In demonstrating the possibilities for the world, Explorer I made space a race. It also laid the initial groundwork for NASA’s exploration of the moon and planets. “The event was symbolic of the mixing process between engineering and science, between the world and the research laboratory … it had mixed rocket technology with the universe, and reduced astronautics to practice at last,” then-JPL Director William Pickering reflected years later.
Van Allen and colleagues discovered a second ring of radiation on another flight in December 1958. The two rings became known internationally as the Van Allen Radiation Belts. Van Allen became the icon of a space scientist. He also went on to be one of the most influential people at NASA, sending instruments on more than 25 missions from the moon to Neptune, and serving as a member of the powerful Space Science Board that recommends how science projects should be chosen.
Pay It Forward
Software designer - Margaret Hamilton, lead Apollo flight software designer.
President John F. Kennedy’s moon proclamation in May 1961 set NASA on a bold and daring adventure. Leadership was critical. Aeronautical engineer and aviation pioneer Robert "Bob" Rowe Gilruth, the appointed director of the Manned Spacecraft Center from Mercury through Apollo, came to the agency from NACA’s Langley Aeronautical Laboratory, where he had already laid the groundwork for the country’s first launch of humans into space. “There were many heroes during the early days of the space program, but Bob Gilruth was the most respected of them all and particularly by those who knew what it took to reach the goals that were established,” noted former Johnson Space Center Director Christopher Kraft, Jr., a longtime associate and friend, on Gilruth’s passing in August 2000.
At NASA, Gilruth fostered a work environment that encouraged independent thinking, empowering the engineers and scientists to achieve the technological breakthroughs the agency needed to accomplish Kennedy’s goal. “Gilruth allowed the space program to happen,” said Kraft, who had first worked for Gilruth at NACA before being selected as one of the original members of the Space Task Group. “He shaped my mind by letting me do what I thought was the right thing to do and encouraging me to go further,” Kraft said. “He had confidence that I could do the job, then did whatever he could to promote my ideas and at the same time gave me the tools and the responsibility to get the job done -- and the authority to get it done. It meant we took the hits as well as the glory.”
For Kraft, it was quite a job: helping develop basic mission and flight control techniques, serving as deputy director of the Manned Spacecraft Center, flight director for the mission that sent America’s first astronaut, Alan Shepard, on his sub-orbital flight in the Freedom 7, as well as all the subsequent Mercury missions and some Gemini missions. Later, he was appointed director of Flight Operations and also oversaw the design and implementation of the Mission Control Center. “Gilruth instilled that approach in every aspect of the program. He never wanted to overshadow anyone and always, always gave credit where it was due.”
In 1972, Gilruth retired and Kraft was asked to follow in his footsteps. He had already followed his approach. “I brought on the best people I could and let them do the job. I’m very proud of the people I chose,” summed up Kraft. “They made the program happen.”
Rock hound - Planetary geologist Gene Shoemaker.
At the start of the Apollo program, the onboard flight software needed to land on the moon didn’t exist. Computer science wasn’t in any college curriculum. NASA turned to mathematician Margaret Hamilton, of the Massachusetts Institute of Technology, to pioneer and direct the effort. With her colleagues, she developed the building blocks for modern “software engineering,” a term Hamilton coined. What later became the foundations for her Universal Systems Language (001AXES) and Development Before the Fact (DBTF) formal systems theory, allowed the team to create what she called ultra-reliable software for the moon trip. In addition to creating the concept of priority displays, where the software in an emergency could interrupt the astronauts so they could reconfigure in realtime, Hamilton established hard requirements on the engineering of all components and subsystems, insisted on debugging all component and testing everything before assembly, then simulated every conceivable situation at the systems level to identify potential problems before releasing the code.
“There was no second chance. We all knew that,” Hamilton said. “We took our work very seriously, but we were young, many of us in our 20s. Coming up with new ideas was an adventure. Dedication and commitment were a given. Mutual respect was across the board. Because software was a mystery, a black box, upper management gave us total freedom and trust. We had to find a way and we did. Looking back, we were the luckiest people in the world; there was no choice but to be pioneers; no time to be beginners.” Hamilton’s integrity and ability to balance fearlessness with attention to detail may have ensured Apollo 11’s success.
On July 20, 1969, three minutes before the Eagle landed, the ultra-reliable software overrode a manual command because of a faulty operations script. If the software had not functioned, the moon landing might not have happened. Instead, Neil Armstrong took that “giant leap” for all humankind. Remarkably, no “bug” occurred in the software during any crewed Apollo mission.
Fly Me to the Moon
First interplanetary spacecraft - Launched Aug. 27, 1962 NASA’s Mariner 2 spacecraft was the first robotic probe to pass near a planet. On Dec. 14, 1962 the spacecraft flew within 21,000 miles of Venus, sending back valuable new information about the solar wind, and our sister planet’s temperature and atmosphere.
Although the Space Race was mostly about beating the Russians and achieving the milestone of landing on the moon, there were forward-thinking scientists who saw the opportunity – and the future. Geologist-astronomer Eugene “Gene” Shoemaker, of the U.S. Geological Survey (U.S.G.S.) in Flagstaff, Ariz., anticipated years before Apollo how geologic studies would expand as humanity ventured out to other planets and set out to be the first geologist to walk on the moon. A diagnosis of Addison’s disease soon clipped his wings. Instead of taking that walk himself, Shoemaker prepared others and encouraged NASA to make geology a part of Apollo. As he shifted goals, he established the field of astrogeology, studying planets from telescopic and spacecraft imagery. He also organized the geologic tasks planned for the Ranger and Surveyor missions to the moon, and gave crash courses to the Apollo crews training for the mission he would forever long to fly.
In December 1972, Jack Schmitt, of the U.S.G.S. Astrogeology Center that Shoemaker created, became the first and so far only Ph.D. geologist to walk on the moon. While he was realizing Shoemaker’s dream during the Apollo 17 mission, Shoemaker was by Walter Cronkite’s side, giving geologic commentary for CBS News. The walk on the moon would be Shoemaker’s greatest unfulfilled dream. But his story doesn’t end there.
Known for loving life and knowledge even more, Shoemaker, who co-discovered comet Shoemaker-Levy 9 in 1993, became a revered legend in his own time and among planetary science’s first royalty. He was beloved for his “hearty body-quaking laugh that bounded its happy way across a room,” as his former student, friend and colleague Carolyn Porco described it. Then, in July 1997, his illustrious life came to a sudden, tragic end in a car accident in Australia. Though deeply saddened, an inspired and determined Porco, now leader of the Cassini Spacecraft Imaging Science Team, initiated Shoemaker’s final mission. On July 31, 1999, 30 years to the month after humans first set foot on the moon, the Lunar Prospector deposited a polycarbonate capsule containing some of Shoemaker’s ashes on the surface of the moon’s south polar region. “The fulfillment of one man’s dreams and the final episode of his inspirational life met on impact,” Porco announced later in a heartfelt tribute in Astronomy magazine (February 2000). To date, Shoemaker is the only human to have been “interred” on another celestial body.
Ready for the voyage - Technicians work on the Voyager 1 spacecraft prior to its launch to the outer planets in 1977.
When Pickering and his JPL team first set their sights on planetary exploration, nobody had ever built a spacecraft to another planet. NASA’s order was astronomically tall: design, build, fly, and operate robot spacecraft – the very first spacecraft – capable of surviving for a long time over great distances in space to reach Venus or Mars, find a way for it to study the planet with onboard scientific instruments, then get the data back to Earth.
In 1959, the NASA/JPL’s Chief of Mechanical Engineering John Small assigned John R. Casani to lead a team of young engineers that included Marc Comuntzis, Walter Downhower and James Burke to build a “planetary machine,” as Pickering first described it. “In the beginning, it was all about learning how to build systems that could be flown, operated successfully in space and be used for science,” recalled Casani, who arrived at JPL in 1956.
Perhaps most significantly, the team deemed it necessary to have complete control of the spacecraft for flights to the planets, in all three axes – roll, yaw, and pitch – instead of it stabilizing it by spinning like Explorer. The three-axis stabilization design would allow for more precise pointing of the science instruments and antenna, as well as maximize solar power collection and thermal control. Flight trajectory would be “tweaked” by igniting an onboard rocket in a midcourse maneuver, with a small rocket available to compensate for minor guidance errors on launch. From their huddles, NASA’s first spacecraft emerged.
“The very first spacecraft to go to the moon was Ranger,” Casani noted. Although the early Rangers failed, the first two because of rocket issues, every loss bestowed the engineers with necessary lessons and by the end of the project in 1965 the mission had returned thousands of highly informative images in plenty of time for the piloted missions to come. Before that, however, Casani and his team moved on to advance the work with Mariner, the first spacecraft bound for Venus and Mars.
Mounting a planetary mission took a colossal effort on the part of an enormous number of people. First, the spacecraft had to be designed and configured. Having directed the design teams, Casani not only helped architect these robot explorers but knew more about the parts of what they were building than anyone, pioneering the role of the missions’ system engineer, the one responsible for the overall “blueprint.”
Mechanical engineers Marc Comuntizis and Walter Downhower, along with John H. Gerpheide, and Bill Layman, designed the octagonal shape and magnesium frame structure of the Rangers and the 9.5-foot-tall Mariner, determining where everything went. Meanwhile, electronic engineers Steve Szirmay and Ted Kopf advanced avionics technology as they worked on the electronics for operating the spacecraft and its subsystems, creating a system of digital circuits and switches so it could maintain balance and orientation in space. Another team of electronic engineers, including Tom Gavin, William “Bill” Shipley, Larry Wright and Tom Gindorf, developed the fundamentals of “armoring” a spacecraft so it could survive the harshness of space, pioneering long life design and enabling the vast majority of NASA’s robot emissaries to live longer and prosper.
Since interplanetary spacecraft travel such great distances, they had to make adjustments along the way. Electrical engineers Walt Brown, Wayne Kohl and Ed Greenberg developed the fundamentals of spacecraft command and data handling by putting together an electronic system to take in telemetry and commands from Earth, prepare data for transmission back, process information from all subsystems and payloads, carry out commanded maneuvers and manage the collection of solar power and charging of the batteries, among other things.
Given the route to Mars or Venus had never been charted, NASA’s engineers and rocket scientists also had to figure out how interplanetary spacecraft would move through space. “Up to then, rocket propulsion was a controlled explosion,” Casani explained. “What we needed for spacecraft were systems that could operate reliably for years in a much different environment.” JPL’s propulsion engineers Duane Dipprey and Dave Evans literally transformed basic rocket technology into low thrust-level, long duration, highly reliable restartable systems, ironing out material compatibility issues and other things that were just not part of the existing rocket technology.
Influential visionary - Long before he became world famous, Carl Sagan was one of NASA’s most influential contributing scientists and outspoken visionaries. “Everybody starts out as a scientist,” he once noted. “Every child has the scientist’s sense of wonder and awe.” Sagan inspired a generation of young people to become scientists.
The weight of fuel makes rocketing directly to another other planet besides the moon prohibitive; therefore, the engineers knew that planetary spacecraft would have to rely on a combination of solar cells and batteries for power in space. Terry Koerner and Joe Savino designed the first schemes for power generation, distribution and management, enabling the necessary automatic shift from solar power to batteries and back again even as the power source, the sunlight, changed as the attitude of the spacecraft changed or when it moved into shadowed areas.
Another challenge for planetary missions was getting right with celestial mechanics, so that a spacecraft would rendezvous with its target at the correct time and place. Based on fundamentals developed by electrical engineer and mathematician Clarence R. (John) Gates, engineers Charles Kohlhase, Norman R. Haynes, Vic Clarke, John Beckman, and William Melbourne defined planetary mission design and space navigation. Also, to get the spacecraft to its destination, it takes more than knowing where the planets are. “You have to consider everything, from the launch vehicle to scientific instruments and their objectives, how steady the spacecraft has to be to hold the cameras, what light levels are out there, how we would use gravity assist, and what requirements every element places on the others, everything,” Kohlhase pointed out.
Most planetary missions launch on one-way trips, so telecommunications and tracking were obviously mission critical. In 1958, Pickering brought in a former student, electrical engineer Eberhardt Rechtin to develop spacecraft telecommunications. Beyond grasping complex systems, Rechtin had a knack for coming up with ingenious solutions to technical problems. The earliest space missions featured their own tracking and data acquisition systems, but it made much more sense if ground facilities could perform the functions for all projects. Moreover, the single station approach in use in the early 1960s to track satellites couldn’t monitor the spacecraft all the time.
Rechtin proposed a network of receivers in select locations around the globe which comprised a Deep Space Instrumentation Facility. With his principal system designer, Walter Victor, and a small team of engineers, Rechtin established three stations approximately 120 degrees longitude apart so one would always be in view of any spacecraft. One was placed north of Barstow, Calif.; another near Woomera, Australia; the third near Johannesburg, South Africa. Since the ground receivers would need large apertures and be highly directional to pick up the extremely weak signals coming from distant locales in space, William Merrick and Robertson Stevens borrowed an antenna design from radio astronomers and fashioned a 85-foot-diameter parabolic dish for the ground, while Lee Randolf and system engineer Sam Zingales worked on the redesign of the receivers to go inside spacecraft. Thus the Deep Space Network was born.
Pulling the parts of a planetary mission together took serious management, structure and discipline. At JPL, Jack James and Harris “Bud” Schurmeier literally wrote NASA’s first Project Management Manual. “Jack James invented project management as practiced at JPL and set the foundation for all the projects that followed the first two Mariner missions and Bud Schurmeier came in and really refined what James put in place,” said Casani, who later followed in their footsteps. Known around the lab as an “organizing genius,” James established an overall mission structure that included milestones, rigorous status monitoring and change control, a system wherein “freezes” were set on every part and the spacecraft itself, as well as weekly project meetings, setting the tone for effective communication.
“A key thing was putting together the project team, selecting the people, then respecting their knowledge and their capability, communicating with them and making sure they had respect for you as the guy making the decisions,” said Schurmeier, whose leadership skills were recognized by Pickering early on when he assigned the young aeronautical engineer the task of developing the lab’s systems division and, later, management of Ranger. Importantly, the discipline started at the top with project mangers assuming full responsibility. “The buck always stopped,” he said, “with me.”
Historic X-ray - Image of the “Chandra Deep Field South” the deepest X-ray exposure ever achieved. The Chandra X-ray Observatory ultra-deep survey project was led by Nobel Laureate (Physics) Riccardo Giacconi.
On Dec. 14, 1962, Mariner 2 flew by Venus and into history books. It was the world’s first successful mission to another planet and the country’s first major space exploration achievement. It also returned the first data on the planet’s atmosphere and mass to the team’s scientists, which included a young astronomer named Carl Sagan. Less than three years later, on July 14, 1965, with James and Casani at the helm, as manager and system engineer, respectively, Mariner 4 – the NASA/JPL team’s “second generation spacecraft” -- flew by Mars and returned the first close-up photographs of another planet ever taken.
Following a string of successes, the planetary science community set its sites on the outer solar system and a celestial event that only occurs once every 176 years. In this rare event, the planets align, presenting a configuration that would allow spacecraft to travel efficiently from one to another. A Grand Tour was proposed to send four specially designed spacecraft to all four outer planets in only 12 years. Congress, however, cancelled it. “We just couldn’t let this opportunity slip by,” remembered Bruce C. Murray, then-JPL director, now professor emeritus of geology at Caltech. “As former NASA Administrator Tom Paine used to say: ‘The last time this alignment happened was when Thomas Jefferson was president. And he blew it.’ We weren’t going to.”
“We came up with a scaled-down version based on Mariner technology that we initially called Mariner Jupiter Saturn ‘77, or MJS77, and later renamed it Voyager,” said Schurmeier, the mission’s first project manager. “The most striking thing about Voyager was the timing – and not just the alignment of the planets. By that point, we had worked enough on these missions and we knew how to build the spacecraft, how to navigate, and the scientists knew how to make the right instruments. If it had been a few years later, politics wouldn’t have permitted it because of the space shuttle, any earlier and we wouldn’t have been ready.”
“Voyager was a third generation spacecraft with a specific design objective of going beyond Saturn and that was a big step up from Mariner,” added Casani, who took over project management from Schurmeier in 1975. “We had never built anything with that kind of longevity before.” To meet the challenge, they radiation-hardened all components, adopted a design policy that no single part failure could cause loss of mission, then implemented it with complete block redundancy of engineering systems, and enabled autonomous onboard fault detection and recovery.
Voyager 1 and Voyager 2 launched separately in the summer of 1977 and sailed off to the outer planets. Between 1979 and 1989 they flew by Jupiter and Saturn, then went on to Uranus and Neptune. For the scientists, it was an embarrassing challenge of riches. “As a scientist, you have most to learn when you see things you had not expected to see and with Voyager there was just a flood of discoveries at every encounter,” pointed out Ed Stone, who has served as project scientist from the beginning, even during his directorship of JPL from 1991 to 2001.
The discoveries were there for the taking. When Voyager 2 passed by Io, the innermost of the four Galilean moons of Jupiter, astronomer Linda Morabito (Kelly), cognizant engineer for the mission’s optical navigation imaging processing system, noticed something protruding from the limb. “I had the sense I was seeing something that no one else had seen before,” she recalled. One by one, she convinced colleagues the protrusion was worth closer examination. It wound up being the first active volcano discovered on another planet and one the likes of which no scientist had ever seen. “It was the greatest experience any scientist could ever hope for,” she said.
All told, the Voyager mission visited almost 60 different worlds, presenting the solar system in its beauty, complexity and diversity to everyone on Earth with picture “postcards” that took the world’s collective breath away and more science than any planetary mission ever collected. “It was an extraordinary, epochal voyage of discovery that will be remembered in much the same way as we remember Captain Cook’s explorations of the then-hidden parts of the world,” summed up Murray. “It revolutionized our perceptions of the solar system.” It would also revolutionize our perception of Earth.
Carl Sagan, a member of the Voyager imaging team and by then one of the most prolific and renowned scientists contributing to NASA missions, politicked for a decade, with Casani backing him, to ensure that when the spacecraft left our planetary neighborhood for the outer solar system in the early 1990s, they would turn around for one last set of planetary portraits. It was the Voyagers’ final photographic assignment. Although Earth appeared as but a dot, those images remain some of the most profound ever taken by NASA spacecraft. “Look again at that dot,” Sagan urged in his best-selling book Pale Blue Dot (Random House, 1994). “On it everyone you love, everyone you know, everyone you ever heard of, every human being who ever was, lived out their lives.”
In just 15 fast years, the engineers and scientists at NASA/JPL had gone from the Earth’s upper atmosphere to beyond Neptune, advancing robotic spacecraft technology with uncanny speed to pioneer the world’s first interplanetary spacecraft and blaze the first trails into our solar system. “Voyager culminated our era of learning,” said Casani.
Today, the Voyagers sail on, more than 30 years after launching. No other spacecraft have gone so far. In 2005, Voyager 1, the most distant human-made object in space, crossed the termination shock, the last major threshold in the solar system. Voyager 2 followed in 2007. “They’re in the heliosheath on the final lap of their race to the edge of interstellar space,” Stone said, projecting that Voyager 1 could cross the boundary in 2014, with Voyager 2 following two to three years later. The power systems should run to 2020 and scientists everywhere are anxiously hoping for that first glimpse of interstellar space. “It’s an incredible feeling,” Schurmeier smiled.
Across the universe
A great place to work - Little did Lebanese native Dr. Charles Elachi realize when he first read a science magazine about the Jet Propulsion Laboratory that he would eventually become JPL’s leader.
NASA’s spacecraft have sent numerous telescopes and observatories aloft above the Earth’s atmosphere, helping scientists open windows on the universe. In 1960, NASA began supporting physicist-astronomer Ricardo Giacconi in a search for celestial X-ray sources. After launching an experiment on an Aerobee rocket in 1962, he led the implementation of the UHURU and High Energy Astronomy Observatory 2, renamed Einstein after its 1978 launch, the first fully imaging X-ray telescope put into space. In his research, Giacconi discovered the X-ray background and first X-ray stars and thus became known as the “father of X-ray astronomy.” He also detected anomalous objects emitting X-rays many orders of magnitude greater than the sun that turned out to be neutron stars and black holes, observations that revealed extremely violent events happen all the time throughout the universe.
Giacconi, along with Harvey Tananbaum of the Harvard-Smithsonian Center for Astrophysics, first submitted a proposal to NASA in 1976 to initiate the design of a large, space-based X-ray telescope. The project survived delays and setbacks for more than 20 years in large part because of Martin Weisskopf, of Marshall Space Flight Center, the project scientist who persevered and guided the telescope to launch in 1999. Since then, the Chandra X-ray Observatory has been the agency’s flagship mission for X-ray astronomy. In 2002, Giacconi, who serves as the lead scientist on the ultra-deep survey, known as Chandra Deep Field South, was named co-recipient of the Nobel Prize in physics for his pioneering contributions to astrophysics that led to the discovery of cosmic X-ray sources.
New Hope from Columbia
Super computer team - Gravitational Astrophysics Laboratory Team. From left to right: Michael Koppitz, Jim van Meter, Joan Centrella and John Baker. Not pictured: Dae-Il “Dale” Choi.
As the biotechnology industry began to burgeon, NASA re-enlisted C.D. “Andy” Anderson, who had retired after a 20-year career, to form a kind of skunk works team at Johnson Space Center. The objective: to create a device to keep cells and tissue in experiments aboard the space shuttles alive and healthy from launch to landing. He brought in engineers Ray Schwarz and David Wolf and medical technician Tinh Trinh, a Vietnamese immigrant, to design the hardware. Their efforts were stalling until one day in May 1986 when, Anderson recalled, he walked into the lab to watch Trinh pull the trigger on a speed drill. On the end was a fluid-filled cylinder with little flakes. “It started spinning and the particles inside went into this beautiful orbital path,” Anderson recalled. At that point they needed a scientist to help figure out how to make it work. Anderson tapped biologist Thomas J. Goodwin.
In creating a new form of media or “soup” as the nutritional environment inside, Goodwin transformed the rotating wall vessel, aka NASA bioreactor, into a life-support system for the cells. He then went on to advance the technology, initiating its use in ground laboratories, overseeing and designing numerous bioreactor flight experiments and spearheading more than a dozen NASA patents. Intriguingly, the team found the cells inside the bioreactor in space grew in three dimensions, much like they would naturally inside the body. Perhaps the most impressive demonstration to date came when renowned prostate cancer researcher Leland W.K. Chung, of Emory University, Atlanta, Ga., and Goodwin grew the largest tumor tissue ever grown in space in an experiment to mimic the metastasis of human prostate cancer to bone on STS-107, Columbia’s last flight. While the data were lost with the crew and orbiter, videotape of the experiment that astronaut Michael Anderson downlinked to Goodwin before the tragedy gave them something to use.
Chung took the unfinished observation and with his team recreated the three-dimensional growth conditions in a NASA bioreactor using techniques Goodwin pioneered. “Remarkably, we found that when prostate cancer cells were placed in close proximity with either prostate or bone cells in microgravity, they underwent non-random genetic and behavioral changes that profoundly enhanced the ability of cancer cells to grow and survive in bone,” said Chung. Although unfinished, the experiment onboard Columbia “has resulted in clues in how to target cancer cells for future development of novel therapeutics,” he added. Beyond dramatically demonstrating the potential of biomedical research in space laboratories, the experiment has allowed a new hope to arise from Columbia’s final mission.
An American Dream
Joan Centrella’s team crunched Einstein’s theory of general relativity equations on the Columbia supercomputer to create a three-dimensional simulation of merging black holes (above). This was the largest astrophysical calculation ever performed on a NASA supercomputer. The simulation provides the foundation to explore the universe in an entirely new way, through the detection of gravitational waves.
When Sputnik launched, a young boy named Charles Elachi was listening to all the excitement on the radio in Rayak, Lebanon. He had always been fascinated with space and during the summer, when it was warm, he would sleep outside and watch the stars and wonder. “Something about the beauty of the sky and the stars impacted me and got me into science,” he said. Not long after that, he read a science magazine the American Embassy distributed. “I remember very clearly reading about America’s first satellite launch, Explorer I, by a place called J-P-L. I remember that page very clearly, because I thought, ‘Gee, that would a great place to work.’”
Elachi received a bachelor's degree in physics from the University of Grenoble, France, and the Diplome Ingenieur in engineering from the Polytechnic Institute, Grenoble, in 1968, where he graduated first in his class. He then headed west to the California Institute of Technology, where he earned his master's degree in electrical sciences in 1969 and pursued his interests in electromagnetism and radar. In 1970, he landed a summer job at that place he had read about years before, just a few miles from school. After earning his doctorate from Caltech the next year, he accepted a full-time job at JPL to work on an imaging radar instrument to go to Venus. His American dream had come true -- and it was only beginning.
Elachi took the lead in developing the radar and was soon put in charge of JPL’s radar-mapping group. With the Venus mission stalled, he flew the imaging radar instrument on Seasat in 1978, then on the space shuttle in 1981 and again in 1984. The data returned was stunning, revealing a subsurface network of ancient drainage channels beneath the sands of the Sahara, among other things. His perseverance and enthusiasm not only earned Elachi promotion to director for space and Earth science programs at JPL, it turned spaceborne imaging radar from a small research area into a major field in which NASA is now a world leader. On May 4, 1989, the imaging radar finally headed for Venus onboard Magellan, with Elachi serving as co-investigator. It successfully mapped 98 percent of the planet’s surface producing a better whole planet topographic map than was then available for Earth.
Over the years, he wrote more than 230 publications on everything from space and planetary exploration, to Earth observation from space, remote sensing, electromagnetic theory, and integrated optics, and was awarded several patents. On Jan. 31, 2001, almost 31 years after he too
Rendering the Ripples of Spacetime
High flying robots - The Mars Exploration Rovers Spirit and Opportunity pose with the flight spare of the Sojourner rover from the 1997 Pathfinder mission.
Scientists have long known that massive objects in motion in space produce gravitational waves, the ripples in the fabric of spacetime that Einstein predicted in his general theory of relativity. They also know that when black holes collide they produce an abundance of waves that roll on altering spacetime sometimes for years depending on the masses involved. “These mergers are by far the most powerful events occurring in the universe, with each one generating more energy than all of the stars in the universe combined,” pointed out Joan Centrella, who leads the Gravitational Astrophysics Laboratory at Goddard. According to Einstein, such a black hole merger causes all of space to jiggle like a bowl of Jell-O, a mind-numbing concept and extremely difficult thing to model in computers.
Einstein’s theory employs a type of mathematics called tensor calculus that needs to be expressed in a language computers can understand and work with. That translation greatly expands the equations, requiring thousands of lines of computer coding. The complexity of the equations, coupled with the large numbers that represented the extraordinarily strong gravitational field near the black holes, caused even the most sophisticated supercomputers to crash. Then in April 2006, after months of work, the Goddard team, led by Centrella, including John Baker, Jim van Meter, Michael Koppitz and Dae-II “Dale” Choi, reached the breakthrough needed. The 3-D black hole merger simulations, as performed on the Columbia supercomputer at Ames, show two black holes orbiting each other seven times, then merging in a kind of psychedelic explosion. To date, they are the largest astrophysical calculations ever performed on a NASA supercomputer.
Bouncing onto Mars
Climate change researcher -James E. Hansen, director of the Goddard Institute for Space Studies.
In the early 1990s, NASA gave JPL’s planetary mission engineers a daunting assignment: build a spacecraft and rover, land them on Mars and do it for under $280 million. With many of the Lab’s engineers still working on the Galileo Jupiter mission or readying the Cassini Saturn mission, Project Manager Tony Spear turned to JPL’s younger generation, appointing Brian Muirhead as spaceflight systems engineer, Richard Cook as flight operations manager, Jennifer Harris as flight director, and Rob Manning as flight system chief engineer responsible for the design, development and testing of all aspects of the spacecraft to be called Pathfinder.
On the dime they had, the Pathfinder team was challenged with many things, but perhaps most importantly they had to find a new way of getting down to the surface since rocketing in with a controlled landing was cost prohibitive. Manning, who also served as the lead system engineer for the entry, descent and landing phase and his team of engineers started throwing out ideas. Over the course of many months they designed, developed, and tested a rather novel entry, descent and landing system. At the core, what would protect the spacecraft and cushion its “controlled crash landing” on the surface, as Manning called it, was a kind of bouquet of airbags. It seemed a wacky idea but on July 4, 1997, Mars Pathfinder, with rover Sojourner safely ensconced inside, demonstrated the landing system for the world.
Pathfinder hit the atmosphere at around 17,000 miles per hour and began the “six minutes of terror” to the Martian surface. First, the 36-foot-diameter parachute deployed to slow the spacecraft’s descent through the thin Martian atmosphere, then the heat shield separated, the lander separated, bridle was deployed and the landing radar switched on. Just eight seconds from landing, the airbags inflated, small retro rockets fired, and the bridle was cut. Pathfinder hit the ground and bounced to a stop within 13 miles of the center of the targeted ellipse in Ares Vallis. Some 100 million "hits" jammed the mission's Web sites that Independence Day, more than for any previous event "broadcast" on the Internet.
During the ensuing days, Sojourner emerged to explore its Martian site and captured the hearts of people around the world. Although the toaster-oven sized ‘bot named after American civil rights crusader Sojourner Truth had to stay in sight and radiolink of the lander, renamed the Carl Sagan Memorial Station, JPL’s ever-ebullient project scientist Matt Golombek and his colleagues reveled in the bounty of data collected from the atmosphere overhead and especially the rocks on the surface they named Barnacle Bill, Yogi and Scooby Doo. It was real honest-to-goodness ground-truthing on Mars, even if Sojourner redefined the word "crawl" as it moved 1.9 feet per minute, traveling a max of nearly 10 feet a day.
The original leader of the team that built the highly acclaimed little rover, engineer Donna Shirley, was instrumental in the 1980s and 1990s in the development of automation, robotics and mobile surface vehicles at JPL. Before Pathfinder launched, in August 1994, NASA created a Mars Exploration Program Office at the center and she was appointed project manager. But in the early, development days, she worked with an inspired team of engineers to create prototypes that led to Sojourner and would evolve into the Mars Exploration Rovers, Spirit and Opportunity.
A primary goal was to design in as much stability as possible so the rover could traverse Martian terrains. While working in his garage at night, engineer and robotic team member Donald B. Bickler came up with the rather unique design -- a rocker-bogie system that does not use springs and features six-wheels for greater stability giving the rover the ability to overcome obstacles three times larger than those crossable by four-wheeled vehicles. Sojourner took the first baby roves on that rocker bogie system on Mars and proved its worth to the world. Pathfinder defied the odds and lived up to its name in the process.
Protecting the Mothership: Earth Sciences
Proud principal investigator - Dr. Steve Squyres, of Cornell University, principal investigator for the Mars Exploration Rover’s science instruments, uses a rover model to illustrate a point during a science briefing for the media at the Kennedy Space Center.
For all NASA’s explorations, Earth is still the only planet we know of that harbors life and the only one that offers us a natural habitat. While the cosmos has beckoned many, some scientists chose to stay closer to home. Using various NASA and environmental satellites, like Landsat, Seasat, TOPEX/Poseidon, and building on the legacy of the first weather satellites TIROS and NIMBUS, NASA’s first Earth scientists began developing methods in the early 1970s of observing planetary changes on Earth, from the weather to measuring oceans and continents for the presence of dangerous pollutants to detecting holes in the ozone layer that shields the sun’s hazardous ultraviolet rays.
In 1976, Goddard Institute for Space Studies (GISS) scientist James E. Hansen and four colleagues studied human-made trace gases other than carbon dioxide and chlorofluorocarbons that might have an important greenhouse effect. They found methane and nitrous oxide were likely to be important, although measurements of how these gases might be changing were not then available. Two years later, he resigned a lead scientist berth on a mission to Venus to devote fulltime to studies of Earth. “It seemed to me then it was more interesting and important to study a planet that would be changing before our eyes and the one which housed civilization,” he said. Since then, Hansen has become one of the world’s leading climatologists, as well as the longtime director of Goddard’s Institute for Space Studies.
Trained in physics and astronomy in James Van Allen’s space science program at the University of Iowa, Hansen first testified on climate change before Congressional committees in the 1980s and raised the initial awareness of global warming. One of the most significant findings of Hansen’s years of research is that the Earth is now experiencing climate change due to a greenhouse effect caused by human-made trace gases emitted from fossil fuels. Although his research has stirred controversy in the past on both sides of the political fence, the scientific community and leaders around the world now agree with his assessment, that global warming and climate change are here and we need to address the issue by reducing greenhouse gas emissions and our reliance on foreign oil, among other things.
According to the GISS 2007 Temperature Analysis, last year tied for the second warmest year, behind 2005, in the period since instruments have been used. The analysis found no easing of the steep global warming trend of the past 30 years. While there is still much unknown about global warming – exactly how much carbon dioxide the planet can handle, for example – the concern, as Hansen views it, is that Earth’s capacity is nearing a “tipping point” past which the atmospheric and climate systems will take over. The goal now is to avoid that “tipping point,” although we may be perilously close to it already. The problem is we don’t know exactly where it is.
In January 2008, a comprehensive, first-of-its-kind study conducted by an international team led by Eric Rignot of JPL and the University of California Irvine, revealed that ice loss in Antarctica increased by 75 percent in the last decade due to a speed-up in the flow of its glaciers. “Our new results emphasize the vital importance of continuing to monitor Antarctica using a variety of remote sensing techniques to determine how this trend will continue,” said Rignot.
Earth scientists now regularly tap NASA satellites to monitor events, such as Hurricane Katrina and the massive Indian Ocean earthquake that caused a devastating tsunami in December 2004, as well as other natural phenomena. NASA plans to continue to advance the frontiers of scientific discovery about Earth, its climate and its future with new remote-sensing instruments in orbit and projects to research the intricate workings of the mothership.
The First Overland Expedition of Mars<
Jumping for joy - Richard Cook, Mars Exploration Rover (MER) deputy project manager and Wayne Lee, MER chief engineer for the rovers' descent and landing systems, jump for joy when the word reached the Jet Propulsion Laboratory that Spirit had successfully landed on the Red Planet on Jan. 3, 2004. Sitting at the control desk is Rob Manning, entry, descent and landing operations manager.
Despite the huge success of Pathfinder and Sojourner, Mars was still taking out two of every three spacecraft dispatched its way. That was the status when Steven W. Squyres, of Cornell University, a former student of Carl Sagan’s, got the call that NASA was giving him the go-ahead for his Mars Exploration Rovers. He had spent more than a decade writing proposals. Now he was going to Mars, the principal investigator for the rovers’ science payloads, and the project team had less than four years to get two robots designed, built, and buttoned-up for launch. They would be using the Pathfinder entry, descent and landing system, but the Mars Exploration Rovers, the approximate size of a golfcart, were significantly bigger and heavier and there was much to be done.
To meet the brutal launch deadline, the Mars Exploration Rover team would have to overcome extraordinary obstacles, from shredding parachutes to exploding airbags and blowing pyros. “There was a lot of skepticism and a lot of fear,” said Squyres. As they lived it, this particular group of engineers and scientists developed a camaraderie that got them through the worst of times on the long and winding road to Kennedy Space Center. “I give a lot of the credit, especially for the camaraderie between science and engineering, to Pete Theisinger, our first project manager,” Squyres acknowledged. “He set the tone. On day one, he brought everyone together and said: ‘Look, if all we do is land these things safely, we’ve done nothing.’ He instilled in everyone that the only real objective was to take the Pathfinder technology and use it to do science and everyone embraced that.” Truth told, they also embraced the tireless enthusiasm and “workability” of Squyres, not to mention the capabilities of their rovers.
Just three days before the launch window opened, Spirit got the green light and took off in beautiful blue skies June 10, 2003. Three weeks later, Opportunity experienced an equally “picture perfect” launch, but the misfortunes were far from over. En route, they were both zapped by the largest solar storm ever recorded. As Spirit closed in, the engineers realized the Martian atmosphere was nowhere near as dense as models had indicated and a large dust storm had suddenly whipped up. Manning, the MER entry, descent, and landing operations manager, Chief Engineer Wayne Lee and colleagues reconsidered, did the math and sent up new parameters for the Spirit’s entry, descent and landing system.
When the TV cameras weren’t on, the strains of Bobby McFerrin singing “don’t worry, be happy” wafted through mission control attempting to lighten the psychological load. Amidst the tension and anxiety, the eyes of NASA officials and more than 300 members of the global media that had descended on JPL Jan. 3, 2004, the rover team and everyone else watching could only wait as Spirit sped into the Martian atmosphere. With the one-way signal transit time between Earth and Mars nearly 14 minutes, it was on its own.
Once again, however, the landing system worked like clockwork and Spirit slowed from 12,000 miles per hour to zero with seeming ease. It signaled when it hit the ground. Then it bounced, presumably much like Pathfinder, only for a lot longer, 28 times actually, then rolled to a stop, upright in the heart of Gusev Crater.
Standing 5 feet tall, stereo panoramic camera “eyes” at the top of their masts, Spirit and Opportunity were created to emulate human field geologists. When the first images came streaming in, Cornell’s Jim Bell, Pancam’s lead scientist, almost couldn’t believe it. “I’m in a state of shock and awe,” he told reporters. In those moments, every extra minute, every drop of angst-ridden sweat was worth it. As the rover stood and snapped pictures all around its location, it looked around the alien surroundings much like a human tourist would. The images were so crisp, so clean, it seemed almost as if you could step out onto the Martian surface.
Within 72 hours of Spirit’s arrival, NASA tallied more than one billion “hits” on its Web sites, obliterating the record set by Pathfinder/Sojourner in 1997. But as Opportunity was closing in on Mars, Spirit’s computer got stuck in an endless reboot loop at its first rock target and for a while Squyres wondered if it would all be over – 16 years of his own life and years of effort from more than 4,000 other people. Just hours before Opportunity hit the Martian atmosphere, however, software engineers Tracy Neilson and Glenn Reeves managed to diagnose and “treat” Spirit for a flash memory problem. Then, Opportunity grabbed the spotlight. “We just scored the world’s first 300-million-mile interplanetary hole-in-one!” exclaimed Squyres at the post landing press conference. When it couldn’t get any better, it did. In the first image Opportunity returned: “Bang! Bedrock. Right in front of us,” Squyres confirmed. The rover had all but met its mission objective and it hadn’t even stood up.
With rover chief engineer Jake Matijevic and his drivers at the controls, Squyres and deputy principal scientist Ray Arvidson, of Washington University St. Louis, directed Spirit and Opportunity around Gusev Crater and Meridiani Planum. The Mars Exploration Rovers delivered their prime directive within the 90-day primary mission, with Opportunity sending home evidence of an ancient salty sea and Spirit returning evidence of water underground, bolstering the theory that Mars was once much wetter and perhaps hospitable to life.
Since then, Spirit and Opportunity have shown their robot right stuff time and again. As the solar-powered robot field geologists roved across these strangely familiar topographies, they have written new chapters in Martian geology and established rover records, the first to climb hills on another planet, find and study meteorites, capture images of the notorious Martian dust devils, drive miles across the Martian surface, and participate in collaborative experiments with orbiters overhead. Their ability “to move through a scene then keep on moving,” as Squyres often put it, underscores the capability in this new era planetary exploration.
Intriguingly, Spirit and Opportunity are also helping pioneer the robot-human relationships that will be a part of future explorations. During the last four-plus years, the rovers have endeared themselves by demonstrating an uncanny resilience. Spirit has had to drive backwards to its destinations dragging its broken right front wheel for more than two years now, but last year serendipitously uncovered one of the mission’s biggest finds because of that handicap. And when a monster Martian dust dervish whirled around and “sat” on top of Opportunity in July 2007, the rover could only hunker down while its team waited helpless on Earth. Words and prayers of support poured in to NASA via email, snail mail and phone calls and Arvidson was even approached during a trip to rural China and anxiously grilled about the “little rovers in the dust storm on Mars.” Neither rover was designed to withstand a Martian dust storm. Somehow both survived. As emissaries of the human race, NASA's Spirit and Opportunity have become the first "real" R2D2s on the landscape of planetary exploration. "They have gone beyond everyone’s wildest imagination,” said Squyres. "Yes, they are just robots, but we care deeply for them."
As of February 2008, the Mars Exploration Rovers were roving still. The team’s greatest hope is that they rove until they drop. If the twins can carry on, they will "greet” their descendant, the Mars Science Laboratory, slated to arrive in 2010. That rover is bigger, stronger, and faster. But Spirit and Opportunity will always hold a special place in space history as the valiant pioneers that took humanity on its first overland expedition of Mars.