LOGAN — A top NASA scientist predicts that within a few decades, the space agency may be ready to launch its most ambitious probe — to another star.
Charles Elachi, senior research scientist at the Jet Propulsion Laboratory, Pasadena, Calif., said experts already are working on systems needed for interstellar exploration. He spoke with the Deseret News Tuesday during the annual Conference on Small Satellites at Utah State University.
Elachi was the keynote speaker at the meeting, sponsored by the university and the American Institute of Aeronautics and Astronautics. This year he received the institute's Dryden Lectureship in Research in recognition of his pioneering work on imaging radars.
Asked whether NASA is studying really far-out projects, like a probe to another star, he replied, "Basically, people are looking at it. . . . You need to miniaturize things, No. 1." The smaller a probe is, the less energy is required to move it.
A second concern is to develop a new "sail" that would provide the propulsion for a probe, he said. A ground-based system could fire an intense laser beam at the sail, accelerating the craft to great speeds.
A small investment has been made into researching such exotic propulsion, while much greater resources are poured into miniaturization, he said. That's because miniaturization has many immediate applications.
Before NASA visits a star, a similar craft might investigate the closer region outside our solar system, around 200 to 1,000 astronomical units away, he said. One astronomical unit, or AU, is the distance from the sun to Earth, or 93 million miles.
That "would really put you in interstellar space," he said.
A probe to go there may be ready "in the next decade or two," he said. It would let us know what interstellar space is like.
When can we send a minute probe zipping to another star?
That depends on how soon NASA can develop a much-faster propulsion system. At today's speeds, such a voyage would take 40,000 years to reach the closest star, in the Alpha Centauri system, which is about 26 trillion miles away.
"Probably another 25 or 30 years" are needed to develop a probe that could arrive after cruising only a century. Our close descendants would like to know about conditions around another star, he believes.
Would scientists need to identify a planet around that star before launch? "No, I think just the star itself" would be interesting.
Planets may show up as the probe approaches, so the device would need artificial intelligence to decide where to go to study them.
During his talk, Elachi noted that an experimental new electric propulsion system, called an ion engine, is blasting through space. It recently set a record of 2,000 hours of continuous use.
Among projects Elachi discussed are:
A tiny 2.2-pound probe, to be launched in a joint U.S.-Japanese project, that would roll around on an asteroid, gathering data and taking photographs.
A squadron of small satellites that would fly in precise formation, measuring fluctuations in gravity waves.
Pairs of spacecraft that would orbit Mars and Earth, mapping the planets' gravity fields to discover their interior structure.
A set of six small communications satellites in orbit around Mars, used to relay data from landers or humans exploring the red planet.
"I have no doubt that over the next decade you will have a network of this nature," he said. But Elachi indicated the fleet is also on the back burner. "Some people are not ready for it."
He agreed with a comment from the audience that space exploration is risky and that the public should be prepared for some failures. That doesn't mean abandonment of NASA's "faster, better, cheaper" policy for spacecraft development, he said. It just means less corner-cutting and more emphasis on "better."