The above question may already be a nonsequitor since automated space probes permeate the Solar System. The Moon and Mars are covered with mankind’s mechanical surrogates extensively with many more on the horizon despite NASA’s budgetary woes.
While lip service and political demagoguery concerning NASA’s budget and the manned space program rule the day and despite monetary cut-backs, the automated probe programs seem to have survived to a certain degree. And the public at large like the unmanned probe programs, it is the population in NASA districts in southern states who gripe about manned program budget short-falls. Tax-payer supported jobs there are popular in spite of the explosive cognitive dissonance.
In that vein, professor of electrical engineering at Penn State John D. Mathews spoke of SETI’s failure of finding ETIs and posits that exploring space will mean more machines, not Man:
“The basic premise is that human space exploration must be highly efficient, cost effective, and autonomous as placing humans beyond low Earth orbit is fraught with political economic, and technical difficulties,” John D. Mathews, professor of electrical engineering, reported in the current issue of the Journal of the British Interplanetary Society.
If aliens are out there, they have the same problems we do, they need to conserve resources, are limited by the laws of physics and they may not even be eager to meet us, according to Mathews.
He suggests that “only by developing and deploying self-replicating robotic spacecraft — and the incumbent communications systems — can the human race efficiently explore even the asteroid belt, let alone the vast reaches of the Kuiper Belt, Oort Cloud, and beyond.”
Mathews assumes that any extraterrestrial would need to follow a similar path to the stars, sending robots rather than living beings, which would explain why SETI has not succeeded to date.
“If they are like us, they too have a dysfunctional government and all the other problems plaguing us,” said Mathews. “They won’t want to spend a lot to communicate with us.”
It is extremely difficult to broadcast into the galaxy and requires vast resources. Radio signals need to emanate in every direction to fill the sky, and the energy requirement to broadcast throughout space is quite high.
“Current infrared lasers can communicate across our solar system,” said Mathews. “The problem in terms of SETI is they are highly directed beams.”
Point-to-point communications using infrared signaling requires less power, but the signals are extremely directional. If extra-terrestrial beings are using laser-generated infrared signaling, we would never notice their signals because they are so tightly targeted to their destinations.
Mathews suggests that if human exploration is not possible, robots could go where many people do not want to go and do what many do not want to do, not only on Earth, but also in space.
To minimize the cost, he suggests that the initial robots be manufactured on the moon to take advantage of the resources and the one-sixth gravity. He notes that we have the technology to create these exobots now, except for a compact power source. To create a network of autonomous robots capable of passing information to each other and back to earth, the vehicles must be able to identify their exact location and determine the time. With these two bits of knowledge, they should be able to determine where all the other robots near them are and target them with an infrared laser beam carrying data.
“The expensive part of launching anything is escaping the surface of Earth and its gravity well,” said Mathews. “It would also be easier to target the space debris in near Earth orbit and in geosynchronous orbit and even recycle it.”
Initially, the exobots would serve two purposes: clear existing debris and monitor the more than 1,200 near-Earth asteroids that are particularly hazardous in that they closely approach Earth during their orbits.
“As a first step, we really should launch robot vehicles to learn something about these asteroids and to place beacons on them for identification and tracking,” said Mathews.
Ultimately, the network of exobots — self-replicating, autonomous and capable of learning — will spread through the solar system and into the galaxy, using the resources they find there to continue their mission. Communicating with infrared lasers is communicating at the speed of light, which is the fastest we can hope to achieve.
“Our assumption in the search for extraterrestrial intelligence is that ET wants to be found,” said Mathews. “But who has energy resources to spend trying to wave their metaphorical hand across the galaxy?”
He said it is more likely that one of our exobots will intercept a signal from one of theirs if we are to make first contact.
I find this sad in a way, I do think mankind does have a place in exploring the Universe in person, beit in World Ships, suspended animation or by physics yet undefined in an engineering sense.
But if strong AI is the major way the Technological Singularity will occur, this could very well be the scenario by which humans will explore the Galaxy.
Paul Gilster of Centauri Dreams continues the discussion of the below light-speed seeding of Intelligence in the Galaxy from the paper that Robert Freitas wrote in the 1980s and the prospect that such an intelligence ( or future “human” descended intelligence ) could seed the Galaxy over a period of 1,000,000 years:
It was back in the 1980s when Robert Freitas came up with a self-reproducing probe concept based on the British Interplanetary Society’s Project Daedalus, but extending it in completely new directions. Like Daedalus, Freitas’ REPRO probe would be fusion-based and would mine the atmosphere of Jupiter to acquire the necessary helium-3. Unlike Daedalus, REPRO would devote half its payload to what Freitas called its SEED package, which would use resources in a target solar system to produce a new REPRO probe every 500 years. Probes like this could spread through the galaxy over the course of a million years without further human intervention.
A Vision of Technological Propagation
I leave to wiser heads than mine the question of whether self-reproducing technologies like these will ever be feasible, or when. My thought is that I wouldn’t want to rule out the possibility for cultures significantly more advanced than ours, but the question is a lively one, as is the issue of whether artificial intelligence will ever take us to a ‘Singularity,’ beyond which robotic generations move in ways we cannot fathom. John Mathews discusses self-reproducing probes, as we saw yesterday, as natural extensions of our early planetary explorer craft, eventually being modified to carry out inspections of the vast array of objects in the Kuiper Belt and Oort Cloud.
Image: The Kuiper Belt and much larger Oort Cloud offer billions of targets for self-reproducing space probes, if we can figure out how to build them. Credit: Donald Yeoman/NASA/JPL.
Here is Mathews’ vision, operating under a System-of-Systems paradigm in which the many separate systems needed to make a self-reproducing probe (he calls them Explorer roBots, or EBs) are examined separately, and conceding that all of them must be functional for the EB to emerge (the approach thus includes not only the technological questions but also the ethical and economic issues involved in the production of such probes). Witness the probes in operation:
Once the 1st generation proto-EBs arrive in, say, the asteroid belt, they would evolve and manufacture the 2nd generation per the outline above. The 2nd generation proto-EBs would be launched outward toward appropriate asteroids and the Kuiper/Oort objects as determined by observations of the parent proto-EB and, as communication delays are relatively small, human/ET operators. A few generations of the proto-EBs would likely suffice to evolve and produce EBs capable of traversing interstellar distances either in a single “leap” or, more likely, by jumping from Oort Cloud to Oort Cloud. Again, it is clear that early generation proto-EBs would trail a communications network.
The data network — what Mathews calls the Explorer Network, or ENET — has clear SETI implications if you buy the idea that self-reproducing probes are not only possible (someday) but also likely to be how intelligent cultures explore the galaxy. Here the assumption is that extraterrestrials are likely, as we have been thus far, to be limited to speeds far below the speed of light, and in fact Mathews works with 0.01c as a baseline. If EBs are an economical and efficient way to exploring huge volumes of space, then the possibility of picking up the transmissions linking them into a network cannot be ruled out. Mathews envisages them building a library of their activities and knowledge gained that will eventually propagate back to the parent species.
A Celestial Network’s Detectability
Here we can give a nod to the existing work on extending Internet protocols into space, the intent being to connect remote space probes to each other, making the download of mission data far more efficient. Rather than pointing an enormous dish at each spacecraft in turn, we point at a spacecraft serving as the communications hub, downloading information from, say, landers and atmospheric explorers and orbiters in turn. Perhaps this early interplanetary networking is a precursor to the kind of networks that might one day communicate the findings of interstellar probes. Mathews notes the MESSENGER mission to Mercury, which has used a near-infrared laser ranging system to link the vehicle with the NASA Goddard Astronomical Observatory at a distance of 24 million kilometers (0.16 AU) as an example of what is feasible today.
Tomorrow’s ENET would be, in the author’s view, a tight-beam communications network. In SETI terms, such networks would be not beacons but highly directed communications, greatly compromising but not eliminating our ability to detect them. Self-reproducing probes propagating from star to star — conceivably with many stops along the way — would in his estimation use mm-wave or far-IR lasers, communicating through highly efficient and highly directive beams. From the paper:
The solar system and local galaxy is relatively unobscured at these wavelengths and so these signaling lasers would readily enable communications links spanning up to a few hundred AUs each. It is also clear that successive generations of EBs would establish a communications network forming multiple paths to each other and to “home” thus serving to update all generations on time scales small compared with physical transit times. These various generations of EBs would identify the locations of “nearby” EBs, establish links with them, and thus complete the communications net in all directions.
Working the math, Mathews finds that current technologies for laser communications yield reasonable photon counts out to the near edge of the Oort Cloud, given optimistic assumptions about receiver noise levels. It is enough, in any case, to indicate that future technologies will allow networked probes to communicate from one probe to another over time, eventually returning data to the source civilization. An extraterrestrial Explorer Network like this one thus becomes a SETI target, though not one whose wavelengths have received much SETI attention.
SETI as it is set up now does not concentrate its observations or detections on possible physical artifacts, just radio transmissions at certain frequencies.
Personally I think advanced civilizations (cultures?) would be evolved more than the mere “biological”, but would be cybernetic in nature and thus would be beyond “god-like” in nature and would’ve figured out a way past the light-speed barrier.
That would put the possiblity of old fashion radio transmission on the back burner, other than the construction of radio “beacons” as proposed by the Benford Brothers.