Though the public may demand a further reduction in the risks and an increased commercial payoff from NASA, the agency and researchers hope public support for the agency's aeronautics and space programs will continue. Fueling those hopes and driving the search for the unknown is NASA's lofty, stated mission – to improve life here on Earth, extend life to space and find life beyond this planet.
Why explore the heavens?
"There is an element of human curiosity that has to be satisfied," says retired U.S. Air Force Gen. George Harrison, now research director of the Georgia Tech Research Institute (GTRI). "Why did Columbus set sail to the West? He wanted to prove his theory.... In 1957, the space program was initially formed to map the Earth.... Then we wanted to learn more about what was in space."
The human desire to explore is probably the strongest motivation behind support of the U.S. space program's future, says Associate Professor John Olds of the School of Aerospace Engineering.
"Humans are natural explorers. We always want to find out what lies around the next unexplored corner of the universe," Olds observes. "The findings often have a direct impact on some of the most important questions we ask ourselves, 'Where did we come from and where are we going?'
photo by Gary Meek
|
|
Professor Paul Steffes of the School of Electrical and Computer Engineering says NASA is providing knowledge that is of use and inspiration to Americans.
(300-dpi JPEG version - 815k)
|
|
In addition, the space program has produced a number of important and useful technology spinoffs as a result of the need to make things smaller, more energy efficient and more durable in harsh environments. Products from miniaturized microelectronics to Velcro trace their development to the space program."
Robert Loewy, chairman of the School of Aerospace Engineering, cites additional technologies that directly resulted from the hurdles NASA has faced in deploying missions. For example, aircraft and spacecraft design has yielded stronger composite materials, such as graphite, Teflon and Kevlar – materials now used in tennis rackets, automobile tires and military equipment. Harrison adds to the list the development of satellite communications, which now enable live television and intercontinental telephone service.
In addition to technology development, NASA research has delivered insights into solving Earth's environmental problems, Steffes says. For example, studies of the runaway greenhouse effects in the carbon-dioxide-dominant atmosphere of Venus are important to understanding global warming on Earth, he explains.
Also, research based in space provides the unique opportunity to study the effects of microgravity, or weightlessness, Neitzel notes. For example, on Earth, hot fluids rise. That motion is called natural convection, which is driven by the phenomenon of buoyancy. Buoyancy disappears in a weightless environment, and consequently, motions driven by buoyancy go away. Then other "masked" forces – those overshadowed by buoyancy on Earth – become more important, he explains.
One phenomenon of note is convection driven by surface tension, a force that can dominate when buoyancy is eliminated. Its dominance then makes it easier for researchers to study the force, which can affect material structures and properties, Neitzel says.
How should we get there?
With consensus that a continued presence in space is worthwhile, researchers at Georgia Tech have varying perspectives on whether humans or human-made machines should explore and conduct missions in space. The issue is particularly debated with regard to Mars.
courtesy of NASA
|
|
Many space researchers support human exploration of space. In December 1972, geologist and astronaut Harrison Schmitt, Apollo 17 Lunar Module pilot, posed next to the American flag during extravehicular activity of NASA's final lunar landing mission. The highest part of the flag appears to point toward Earth in the distant background.
|
|
"There has always been a group, particularly in the science community, that has argued that good space science can be done less expensively if you do it unmanned," Loewy says. "I personally believe that humans will never be content to live the space experience vicariously. There will always be a drive to have people be there and experience what can and must be done in space."
Loewy hastens to add that uninhabited aerial vehicles (UAVs) definitely have roles in space, notably in military and weather surveillance and long-term space data collection.
"Putting humans in space is best for completing tasks that require immediate decisions that depend on all kinds of information being looked at and integrated," Loewy says. "It's appropriate where the unanticipated is so prevalent – things like repairs and disassemblies of satellites."
Thom Davis, a senior research scientist at the Georgia Tech Research Institute (GTRI), agrees that humans are superior to machines for many space missions. Yet, the researchers also cite the advantages of UAVs. They can extend the capabilities of the space program, while lowering the costs and risks to humans. For example, the U.S. Air Force is experimenting with microsatellites that operate autonomously for a fraction of the cost of a shuttle or expendable booster launch. Microsatellites may make possible more complex uninhabited space missions, such as maintenance of other satellites or even perhaps in-orbit shuttle inspection or repair, says Davis, who supervised the successful experimental mission of the XSS-10 microsatellite in late January 2003 (see sidebar article titled "The Little Engine That Could").
courtesy of NASA
|
|
The schematic shows the Entomopter's unique wing structure, reciprocating chemical muscle and fuel storage cartridge.
(300-dpi JPEG version - 611k)
|
|
Meanwhile, other GTRI researchers are developing a type of UAV called an "Entomopter" to explore the inhospitable atmospheres of planets such as Mars. And aerospace engineering students led by Professor Dan Schrage designed a helicopter to explore the Martian atmosphere. Uninhabited missions will be vital before any human exploration of the Red Planet, researchers say. The flapping wing Entomopter – conceived by GTRI researcher Robert Michelson – is a patented mechanical insect intended to both fly and crawl. Working with NASA's Institute for Advanced Concepts and the Ohio Aerospace Institute, Michelson envisions a fleet of Entomopters landing and taking off, perhaps from a rover able to refuel and support them as it crawls across the Mars surface gathering scientific information.
Another way to explore our solar system and others is by remote sensing. Steffes, for example, uses radio telescopes and infrared spectroscopy – as well as data from radio sensors aboard uninhabited spacecraft – to study planetary atmospheres. He predicts an increase in space exploration by remote sensing in the next 20 years because of the cost savings and lesser risk involved.
"The cost of sending humans to Mars would require an investment of about $250 per taxpayer per year," Steffes says. "I'm not sure the American taxpayer would buy that, given that we have so many other needs. It's a question of how human presence could be extended to planetary environments without a physical human presence. The technology for this is making virtual presence more realizable."
courtesy of NASA
|
|
In July 2001, back-dropped against a blue and white Earth some 237 miles below, the Quest airlock was being installed onto the starboard side of the Unity Node 1 of the International Space Station.
|
|
Remote sensing is essential to the search for life beyond Earth, Steffes adds. "Except for Europa (a moon of Jupiter) and the fossil records of Mars, the most likely detection of life will be outside our solar system," he says. "And clearly, interstellar travel is hundreds of years away. We can find life, if it exists, with remote sensing technologies."
In the near term, NASA is planning numerous missions with humans aboard spacecraft. With questions raised about the safety of NASA's aging shuttle fleet, the pressure is on designers of replacement vehicles. The nearest-term solution is an orbital space plane that sits atop an expendable rocket, similar to that used for the Apollo missions. The plane would be ready between 2010 and 2012.
By 2015, NASA may have a second-generation reusable launch vehicle composed of a two-stage, rocket-powered vehicle. "It looks like two shuttles put together," explains Olds, who with his colleagues in the School of Aerospace Engineering and at the University of Florida is designing a third generation of this spacecraft. "No parts fall off. It's all reusable." Each vehicle could be used for 200 to 250 flights – 20 per year instead of a shuttle's five to six a year.
Georgia Tech file photo
|
|
"There is an element of human curiosity that has to be satisfied," says retired U.S. Air Force Gen. George Harrison, now research director of the Georgia Tech Research Institute (GTRI).
(300-dpi JPEG version - 456k)
|
|
The third-generation reusable launch vehicle is an "air-breathing space plane that looks like a supersonic airplane," Olds says. "It takes off horizontally from a runway. There may be a lot of them, which creates a space tourism potential." This vehicle, projected to be ready in 25 years, could be used for 1,000 flights – 75 to 100 a year. The cost of designing and testing the third-generation vehicle is $5 billion to $10 billion, Olds estimates. To manufacture it would cost another $2.5 billion.
Cost, rather than technological capability, may be the deciding factor on how NASA explores space – whether by UAV or some future space vehicle piloted by humans in the next 10 or 20 years, Olds adds. Though he doubts Congress or the American public will ultimately agree to foot the $25- to $30-billion bill for humans to explore Mars in this century, Olds acknowledges that the concept has strong support.
Only humans can provide the public with an emotional attachment to space research and the ability to deal with the unforeseen, Harrison says. He acknowledges the risks and costs, but urges perspective.
photo by Gary Meek
|
|
Aerospace Engineering Professor Narayanan Komerath wants to communicate to people that space holds a future with careers and business opportunities.
(300-dpi JPEG version - 708k)
|
|
"After 41 years in space, we have lost a relatively small number of people and spacecraft," Harrison notes. "The cost in human lives has made us more careful, but it has not stopped us. You have to consider the hazards inherent in other activities when you look at the cost of the space program. There's no comparison, for example, when you look at the space program versus the costs of the first 20 years of aviation."
What will the future hold?
Peering into a crystal ball and making predictions is not a comfortable activity for most researchers.
"Yogi Berra said, 'It's tough to make predictions, especially about the future,' " Loewy quips. "It seems that whenever you predict the short run, you overestimate, and for the long run, you underestimate."
Nevertheless, researchers like to imagine humanity's future in space. From supersonic transport to space travel to extraterrestrial life, the greatest achievements may lie ahead.
courtesy of NASA
|
|
The Goldstone Deep Space Communications Complex, located in the Mojave Desert in California, is one of three complexes which comprise NASA's Deep Space Network (DSN). The DSN provides radio communications for all of NASA's interplanetary spacecraft and is also utilized for radio astronomy and radar observations of the solar system and the universe.
(300-dpi JPEG version - 653k)
|
|
In 20 years, Loewy predicts humans will have devised a supersonic transport that will fly more quietly and efficiently than the current Concorde aircraft so that people will be able to fly to distant places more rapidly, he continues. "We'll also have much more routine access to space, and we'll be operating a space station where quite of bit of research will take place.
"I don't know whether we'll have a colony on the moon," Loewy adds. "Maybe that's one of the things that gets underestimated.... Maybe we will go to Mars, but definitely we'll have UAVs on Mars traversing its surface and exploring its atmosphere."
Loewy doesn't think humans will find extraterrestrial intelligence. But Steffes leaves that door open. From 1996 to 2000, Steffes and former Georgia Tech Assistant Professor David DeBoer contributed to a Search for Extraterrestrial Intelligence (SETI) Institute project by collecting data with a pair of 30-meter antennas at Woodbury, Ga. Woodbury was part of an antenna network to detect signals of life from space.
courtesy of NASA
|
|
Space Shuttle Atlantis takes flight on its STS-27 mission on December 2, 1988. The STS-27 was the third classified mission dedicated to the Department of Defense.
|
|
The SETI Institute, based in Mountain View, Calif., continues the search today. Researchers are hopeful as a new initiative, headed by DeBoer, gets under way at the institute. The Allen Telescope Array, composed of 350 satellite dishes covering 10,000 square meters, is expected to become operational in 2006. It will have an incredibly sensitive capacity to detect radio signals from deep space.
As for humans extending their permanent presence beyond Earth, researchers vary in their opinions on how and when, but not if, it will happen. Aerospace Engineering Professor Narayanan Komerath and his students envision a lively space-based economy where most trading and transactions occur between entities away from Earth.
"We want to communicate to people that space holds a future with careers and business opportunities," he says. "It's not just for test pilots, astronauts, government employees and even tourists."
If NASA invests in the infrastructure, Komerath believes a space-based economy might exist in 20 years. But in addition to huge infrastructure costs, two other obstacles may delay the development of this economy – the perception that space is too difficult for average people to utilize and doubts that progress can occur so quickly. Positive public information campaigns could counter these obstacles, Komerath adds.
courtesy of NASA
|
|
Twin Mars Exploration Rovers launched in June 2003 seek to determine the history of climate and water at two sites on Mars where conditions may have once been favorable to life.
|
|
Meanwhile, Olds notes that the third-generation reusable launch vehicle he is designing will create a potential for space tourism and transportation. Yet those markets may not develop quickly because of the costs. A space ride ticket could cost up to $1 million, far exceeding the $20,000 price tag that some "everyday, normal people" might pay, he adds. Instead of space tourism, the most likely markets for the space plane are small-cargo transport (e.g., microsatellites) or materials processing in space.
"Space tourism is interesting," Olds concedes. "But other possibilities may be more likely."
For example, the space plane might transport solar energy panels from huge collection satellites in space. Such cargo missions might justify the cost because it's always daylight in space, making the supply unlimited, Olds says. The question of this mission's economic feasibility is raised when satellite maintenance and repair issues are considered, he adds.
Contemplating the future of humans in space produces excitement and hope in researchers, just as it has powered NASA's dreams for decades.
"This is what aerospace engineering is about," Komerath says. "You dream something and then figure out what might stop you from it – and how to get around that."
For more information, contact Robert Loewy, School of Aerospace Engineering, Georgia Tech, Atlanta, GA 30332-0150. (Telephone: 404-894-3002) (E-mail: robert.loewy@ae.gatech.edu); George Harrison, GTRI, Atlanta, GA 30332-0801. (Telephone: 404-894-7136) (E-mail: george.harrison@gtri.gatech.edu); Paul Steffes, School of Electrical and Computer Engineering, Georgia Tech, Atlanta, GA 30332-0250. (Telephone: 404-894-3128) (E-mail: paul.steffes@ece.gatech.edu); or Paul Neitzel, School of Mechanical Engineering, Georgia Tech, Atlanta, GA 30332-0405. (Telephone: 404-894-3242) (E-mail: paul.neitzel@me.gatech.edu).
Back to the Top
Contents
Research Horizons
GT Research News
GTRI
Georgia Tech
Send questions and comments regarding these pages to
webadmin@edi.gatech.edu
Last updated: August 11, 2003
