In October 2004 SpaceShipOne roared into space (twice) - the first privately funded spacecraft ever to reach suborbit, nearly 70 miles above Earth. A year later, "Stanley," a Volkswagen Touareg modified by Stanford University students, rumbled across some 130 miles of desert without a human driver, navigating the rough terrain guided by computer programs and sensors.
Chalk up two new technological accomplishments for the 21st century. In both cases, the designers were motivated to be the first to do something - and to win a cash prize. The Ansari X PRIZE for spaceflight paid out $10 million from a private foundation. The DARPA Grand Challenge for robotic vehicles awarded $2 million, put up by the federal Defense Advanced Research Projects Agency.
Using "grand challenges" to stimulate scientific progress isn't new. In 1714 the British government offered the equivalent of about $12 million to answer a vexing question: How could His Majesty's ships calculate their longitude - how far they were east or west of home - to avoid shipwrecks and other disasters? Great scientists of the day attacked the problem, but it was solved by John Harrison, a self-taught watchmaker.
In 1900 mathematician David Hilbert proposed 23 math problems he hoped would be solved in the 20th century (16 of them were). A problem "should not be too difficult lest it mock at our efforts," he said in presenting his challenges. "It should be to us a guidepost on the mazy paths to hidden truths...."
Now the early 21st century is seeing a raft of new grand challenges. The aim: Change the world - one prize at a time.
The cluster of challenges may be the result of both bad and good news facing science today, says Gilbert Omenn, president of the American Association for the Advancement of Science (AAAS) in Washington, D.C. On the downside, budget deficits have put federal science funding in jeopardy. Scientists are "quite anxious" about their projects, he says. Private "grand challenges" offer fresh resources and encouragement.
At the same time, breakthroughs like the sequencing of the human genome, announced in 2003, have brought exuberance, showing that complex scientific problems are solvable.
"Prizes change the public perception about an issue," says Peter Diamandis, founder and chairman of the X Prize Foundation in Santa Monica, Calif. People begin to believe that a problem is solvable. "The more prize money, the more the issue is seen as important by the public."
Last June, the Bill & Melinda Gates Foundation put an exclamation point after "grand challenge" when it announced one of the richest in history. The Grand Challenges for Global Health pledged $436.6 million (including $31.6 million from British and Canadian sources) toward solving some of the world's worst health problems. Preliminary funds have been granted to 43 groups attacking 14 challenges. They include: developing vaccines to prevent malaria, tuberculosis, and HIV that don't require refrigeration, needles, or multiple doses; finding new ways to stop the spread of insect-borne diseases; and developing more nutritious crops to feed the hungry.
"It's marvelous," Dr. Omenn says. The challenges are attacking problems "that have been neglected, probably to our shame, for lack of confidence that there was anything that could be done."
The AAAS has made "Grand Challenges, Great Opportunities" the theme of its annual meeting in St. Louis next month. And last July, a special issue of Science magazine asked, "What don't we know?" identifying 125 questions that puzzle researchers (though offering no prizes). Among them: "What is the biological basis of consciousness?" "What is the universe made of?"
"Science is shaped by ignorance," said 2004 Nobel physics laureate David Gross in an essay in that issue. "Great questions themselves evolve, of course, because their answers spawn new and better questions in turn."
Meanwhile, prize-based Grand Challenges continue to spring up:
• The Clay Mathematics Institute in Cambridge, Mass., is offering seven $1 million prizes for the solutions to seven classic problems in mathematics. The institute, founded in 1998, issued its challenge in May 2000. So far, no prizes have been awarded.
• Inspired by the X PRIZE's success, NASA has created its Centennial Challenges Program, funding a number of $250,000 challenges aimed at speeding space exploration. They include finding a way to extract oxygen from moon rocks and making advanced explorer robots.
• The Methuselah Mouse Prize will award more than $3 million to the first researcher who can extend the lifespan of a certain species of mouse from about three years to five years. "It's analogous to the sword in the stone. Whoever pulls it out gets the money," says David Gobel, cofounder of the Methuselah Foundation, which sponsors the prize, first offered in 2003.
But a successful grand challenge involves more than money, Omenn says. It needs to be clearly stated, socially worthy, and difficult but not impossible to achieve. It's misleading to assume "if you put a big enough amount of money on a stump every problem is solvable," he says.
Now that the first X PRIZE has been won, the X Prize Foundation is moving on to create new challenges, Mr. Diamandis says. The foundation expects to offer a prize, with NASA, for the first private orbital spaceflight. It also wants to offer a prize to uncover new energy sources for cars.
"Our mission is to cause radical breakthroughs for the benefit of humanity and to use prizes as our primary method," he says.
The government's DARPA robotic vehicle challenge was spurred by the X PRIZE concept. In the first DARPA challenge in 2004, none of the vehicles came close to completing the course. In 2005, four vehicles finished.
"The rate of success in just one year shows how powerful these challenges can be," says Ian Murphy, an X Prize Foundation spokesman.