Experts in interstellar travel have picked future candidates to make the first extrasolar trek.

Their names: Caenorhabditis elegans and Tardigrades, otherwise known as water bears.

“These are real interstellar passengers” says Philip Lubin, head of the Starlight program at the University of California, Santa Barbara (UCSB).

“We are developing the capability to test whether terrestrial life, as we know it, can exist in interstellar space by preparing small life forms…C. elegans and radiation resistant Tardigrades…which are ideal candidates to be our first interstellar travelers,” Lubin explains.

Directed energy

Lubin spoke last month and updated his research findings supported by NASA’s Innovative Advanced Concepts (NIAC) program.

At the university, Lubin, his students and research colleagues have established the Starlight program, known as DEEP-IN (Directed Energy Propulsion for Interstellar Exploration) and DEIS (Directed Energy Interstellar Studies), the NASA-supported work to use large scale directed energy to propel small spacecraft to relativistic speeds to enable humanity’s first interstellar missions.

The bottom line for interstellar travel: “It will not be easy,” Lubin says. “There are many difficult technical issues. It will not be cheap. But it is possible.”

Laser focused

Humanity’s first interstellar missions will ride a beam of laser light. Indeed, the work of Breakthrough Initiatives in San Francisco – via its Breakthrough Starshot effort — is spurring a revolution in spacecraft miniaturization that can contribute to the development of “StarChips” that are centimeter- and gram-scale. Lubin is a project leadership member.

The Starchip wafer work is progressing, Lubin advises, and is “boldly going where no chip has gone before.”

In his “Directed Energy for Relativistic Flight” report to NIAC, Lubin cited collaboration with the lab of Joel Rothman in the Department of Molecular and Cellular Developmental Biology at UCSB Santa Barbara.

The upshot, Lubin noted, is that Caenorhabditis elegans, or C. elegans for short, a ubiquitous species of nematode found in soil samples world-wide, and the water-dwelling micro-animals called Tardigrades, are perfect candidates to be “our first interstellar travelers.”

Rothman told Inside Outer Space that much of the Caenorhabditis elegan literature calls them soil nematodes, but they are generally found in mulch piles with rotting fruits world-wide.”

Star trek traits

Lubin’s team explains that, before we ever have the technology to send humans to other stars, a plan is to send tiny animals that have been shown to tolerate extreme environments of cold, heat, the vacuum of space, extreme dehydration, high accelerations (tens of thousands of g’s), and high doses of radiation – and survive unscathed.

These minuscule creatures have already been propelled into space. They’ve travelled into low Earth orbit during the Space Shuttle program and have also flown on the International Space Station.

C. elegans and tardigrades have a number of traits that make them model passengers for long interstellar voyages, reports Lubin and his study group.

“Besides being microscopic, and thus conveniently fitting on our first interstellar wafer craft, they can be frozen and put into a state of anhydrobiosis, meaning they can be dehydrated and put into suspended animation. When they are re-hydrated, they wake up as good as new!”

UCSB’s Rothman advises via e-mail: “We can do one or the other (or both) but anyhydrobiosis doesn’t require freezing and vice-versa.”

Wake-up calls

Scientists in the UCSB Rothman Lab are studying the behavior of these tiny subjects to better understand their behavior and needs before sending them into space.

Scientists in the Lubin Lab, in the Starlight Program, are figuring out what kind of tiny chambers to design for them, where to place them on “wafersats,” and how to wake them up at various points in the journey and remotely observe their behavior.

Key questions to ponder: Will they survive? Could they take root on another planet with water? And then there’s the question – how did they get to Earth in the first place? Could they have come here from some other solar system?

Rich broth…seed source?

Rothman advises Inside Outer Space: “There is no reasonable doubt that worms and tardigrades arose on this planet from the earliest terrestrial organisms. The question really is how did life get to the Earth in the first place? Did it spontaneously arise in the rich broth of the early seas of the young planet or was it seeded from another distant source?”

Furthermore, Rothman notes that although it’s reasonable to wonder whether the simplest life forms (bacteria) might have come to Earth from another solar system, “it is virtually certain that all complex life forms, including animals arose on this planet during the long process of biological evolution that began about 4 billion years ago, shortly after the planet could even conceivably sustain life. That conclusion is based in part on the universality of the genetic code, metabolic pathways, and the structure of many universally proteins, as well the evolutionary relationships throughout the tree of life that can be inferred from the analysis of extant genomes.”

Interstellar mandate

In his NIAC-sponsored work, Lubin underscored the major challenges ahead for directed energy interstellar flight.

“Clearly there are many technical challenges. This is a long-term humanity changing program,” Lubin says. The biggest challenge is that NASA, the U.S. government does not plan 30-50 years ahead in space. Perhaps a public/private alliance is needed. Similarly, what may be required is a new division of NASA or new agency whose mandate is interstellar flight.

How do we maintain the drive towards this goal? Interstellar travel necessitates a dedicated program over a long period, and the U.S. should lead in this transformation, Lubin concludes.

For more information on Starlight – Directed Energy for Relativistic Interstellar Missions work, go to:

http://www.deepspace.ucsb.edu/projects/starlight