I kick the week off with a short exchange with technology writer Paul Gilster author of Centauri Dreams: Imagining and Planning Interstellar Exploration on the subject of spaceflight.

MT In an ideal world manned and unmanned spaceflight shouldn’t be at odds with one another. But it appears that funding wise they are. Do you see this dichotomy changing in the near future?

PG Yes, absolutely, and for long-term reasons. But let’s talk first about the short-term, where this remains a problem. I know plenty of people working on space projects who are deeply frustrated with today’s situation. If we could have put half the money we’ve put into the Space Shuttle and International Space Station into robotic exploration instead, we’d have Cassini-style orbiters around most of the planets by now. The beauty of Cassini is that it’s a multi-year mission with profound possibilities because its instrument package is so rich. We’re finding out new things every day because of Cassini, but it’s also considered to be the last of the big-ticket robotic missions. And that reflects current spending priorities, which I wish could be reversed.

However, that said, let me add that there is a tremendous future for humans in space, and I am deeply committed to this ideal. Long-term, the human vs. robot distinction (as in Neil Armstrong vs. Mars rovers) simply disappears. This is because advances in robotics that may happen in the relatively near future will bring us robotic spacecraft that are more and more human in their capabilities and personalities. And as we continue to go down this road, the idea of sending a robot to Alpha Centauri won’t seem like such a slap in the face to humans.

Think of Greg Bear’s wonderful novel Queen of Angels, where you have a robot probe called aXis that, as the mission progresses, acquires a definite personality and sense of self. I would argue that as our technology makes this possible, we’ll stop seeing such a yawning gulf between we the tool creators and the tools we create. We’ll start with robotics when we go to the stars, but we’ll gradually follow that up with a choice of technologies, ranging from things forseeable today, such as world ships on 1000-year journeys, or missions using forms of suspended animation, or fast vehicles that can take advantage of Einsteinian time dilation. We may find even better ways through wormholes or Alcubierre-style ‘warp drives’ that can make the human experience in space even more likely, and when we do, I’m sure we’ll be
traveling with machines as partners in that exploration.

MTWhat recent developments in spaceflight have captured your interest the most?

PG Recent events that stand out for me are the aforementioned Cassini and Mars rover missions (and those rovers are just outstanding, outliving all our predictions), and also the New Horizons Pluto mission, now on its way to a 2015 encounter. We’re living in an era of tight budgets and it’s remarkable to me that the New Horizons team was able to get that mission off. What’s coming up if we can ever figure out a funding channel are the terrestrial planet-hunter missions. People have been upset that the Terrestrial Planet Finder as developed largely via JPL has lost its funding, but I think this is a golden opportunity to re-think the basic technologies. In particular, Webster Cash at the University of Colorado, is working on a fast, cheap planet-finder mission that could bring us much if not all of the TPF data before 2020, with a serious upgrade to the methods used and the promise of better still down the road.

Space missions to discover exoplanets are fascinating things, but even now we’re working with amazing technologies like the Spitzer Space Telescope with its infrared eye on the universe, the Hubble telescope as updated with its Advanced Camera for Surveys, and other instruments that are providing a rare look at nearby space. But consider this: organizations like transitsearch.org are working not with huge observatories but, instead, well-equipped amateur observers using CCD devices and good telescopes to search for planetary transits around other stars. Can you believe that? Amateur astronomers catching the tiny shift in light caused by a transiting exoplanet and feeding their results into the mainstream astronomical science track. It’s extraordinary.

MT Should the Drake equation be rethought in light of what we now know about extrasolar planets?

PG No, I think Drake identified key variables quite well. The trick is to figure out what values to assign those variables, and on that score we have much to learn. Our current knowledge of exoplanets is based on an extremely unrepresentative sample. It’s just the nature of the methods used; so far we’ve relied primarily on radial velocity measurements, actually observing the minute changes in a star’s motion caused by the pull of one or more planets. Radial velocity is terrific, given that we are learning how to fine-tune these methods to unheard of precision, but the most obvious detections are huge gas giant planets close to their stars. These are what we found first and I think we’re going to realize this is not the usual solar system configuration.

Other methods are helping to demonstrate that. We use gravitational microlensing, where the mass of a star between us and our target actually acts as a ‘lens’ to warp and magnify the light of the more distant object. Intriguingly, if a star with a planet acts as the lens, astronomers can detect the bump in their data as first the star and then the planet create the lensing effect. Several planets have been identified that way; they’re interesting, of course, but also a long way from here in the direction of the galaxy’s center. Also, we’re just beginning to get results from planetary transits, where the planet crosses between us and its parent star, and these may be capable of bagging Earth-size and even Mars-size worlds around small stars like nearby M-class red dwarfs.

But so far we have little idea of the range of solar system types out there, and because of that, we can’t get too picky about what Frank Drake chose as his parameters, or make any real decisions about some of the Drake Equation’s prominent variables, like how many stars have
habitable worlds. So I think we’ll have to leave the Equation alone for now until we learn more.

Related

Centauri Dreams Paul’s blog (link)
Brain Parade Manned vs. Unmanned Spaceflight

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