Centauri Dreams discusses a DNA-based self-replicating interstellar probe:
Think of a probe that gets around the payload mass problem by using molecular processes to create cameras and imaging systems not by mechanical nanotech but by inherently biological methods.
A Von Neumann self-replicating probe comes to mind, but we may not have to go to that level in our earliest iterations. The biggest challenge to our interstellar ambitions is propulsion, with the need to push a payload sufficient to conduct a science mission to speeds up to an appreciable percentage of lightspeed. The more we reduce payload size, the more feasible some missions become
This is similar to Robert L. Forward‘s starwisp concept (popularised by Charlie Stross in Accelerando).
I suspect that if and when we do get round to interstellar exploration it will involve sending small-mass packages that are capable of bootstrapping themselves to a broadcast/exploration mode using local materials on arrival in the target system.
It remains to be seen what kind of space-based molecular replicating systems become viable. Will we be able to create space-hardened bioware, or good ol’ fashioned machine phase fullerene nanotech?
[image from neurollero on flickr]
In an attempt to address the problem of a digital dark age engineers at Berkeley have developed a technique called Nanoscale Reversible Mass Transport for Archival Memory that is intended to combine high bit-density and deep-time survival:
We have developed a new mechanism for digital memory storage with the potential to store data with both long lifetime and high density. Our memory device consists of a crystalline iron nanoparticle enclosed in a multiwalled carbon nanotube. The nanotube can be reversibly moved through the nanotube by applying a low voltage, “writing” the device to a binary state represented by the position of the nanoparticle. The state of the device can then be subsequently read by a simple resistance measurement.
The abstract of the paper claims thermodynamic stability in excess of one billion years with data density of 1012 bits/in2.
[via Next Big Future][graph courtesy Zettl Research Group, Lawrence Berkeley National Laboratory and University of California at Berkeley]
Eric Drexler discusses “vaults” – tiny structures present in the cells of every plant and animal:
Like ribosomes, they’re atomically precise self-assembled structures made of protein and RNA, but they’re big and hollow, large enough to pack many ribosomes inside.
Looking forward, this information could help protein engineers develop methodologies for designing large self-assembling structures.
Vaults are unusual in many ways, but what I find most surprising about them is this:
To this day, no one knows what they do.
Mmm. A nanoscopic biological structure of unknown purpose and potential technological utility: I smell MacGuffin…
[image from Eric Drexler’s blog]
Space elevator prospects have improved with the development by Cambridge scientists of a method for creating longer, less brittle carbon nanotubes by combining multiple nanotube strands:
Currently, the Cambridge team can make about 1 gram of the new carbon material per day, which can stretch to 18 miles in length. Alan Windle, professor of materials science at Cambridge, says that industrial-level production would be required to manufacture NASA’s request for 144,000 miles of nanotube. Nevertheless, the web-like nanotube material is promising.
“The key thing is that the process essentially makes carbon into smoke, but because the smoke particles are long thin nanotubes, they entangle and hold hands,” Windle said. “We are actually making elastic smoke, which we can then wind up into a fiber.”
Also worth checking out some of the alternatives to traditional space elevators that aren’t so demanding of tensile strength, like Keith Lofstrom’s launch loop, an electromagnetically “inflated” orbital launch system. [thanks to Bruce Cohen (SpeakerToManagers)]
It’ll be fun to see which of these designs actually gets off the ground: just as long as they don’t get off the ground then return unexpectedly.
[from Physorg][image from neilbetter on flickr]
Scientists at John Hopkins University, Maryland have developed minute hands that can grasp tiny pieces of tissue when exposed to particular chemicals:
The researchers describe development of tiny metallic microgrippers shaped like a hand that work without electricity. The grippers are about 0.03 inches wide when open — smaller than the diameter of a grain of sand and made from a gold-coated nickel “palm” joined by six pointy metallic “fingers.”
The addition of certain chemicals triggers the hands to open or close. In laboratory studies, the scientists demonstrated that the grippers could grasp and release tiny pipes and glass beads and transport these objects to distant locations with the aid of a magnet, showcasing their potential for pick-and-place operations that are ubiquitous in manufacturing, they say.
The field is apparently called Micro-Chemo-Mechanical-Systems (MCMS) and along with Micro-Electro-Mechanical-Systems (MEMS) is set to have a major impact over the next several decades, particularly in the realm of health and medicine:
…the untethered grippers devised by Gracias’ team contain gold-plated nickel, allowing them to be steered by magnets outside the body. “With this method, we were able to remotely move the microgrippers a relatively long distance over tissue without getting stuck, he said. “Additionally, the microgrippers are triggered to close and extricate cells from tissue when exposed to certain biochemicals or biologically relevant temperatures.”
[from Physorg][image from the Physorg article][also check out the paper for more technical details]