Self-Replicating von Neumann Probe (http://www.nada.kth.se/~asa/Hx/seed)
A self-replicating von Neumann Probe is a probe design for long-term exploration and perhaps, colonization on asteriods, and other systems that have a possibility to support life forms. It incorporates laser-driven solar sail technology for launch, navigation, and breaking. Sensors in the probe survey the system's general terrain. Once an asteroid has passed the probe's tests (in terms of capability to support life forms or just possibility for further explorations), the probe would plant a javellin-like seed onto the surface which releases its housed self-replicating nano- or micro-robots. These robots would start colonizing the asteriod's terrain piece by piece, transmitting a photovoltaic coverage of its explorations. Once the replication process is suggested to be complete, the system would build an antenna to ask for further directions regarding the developments of the asteroid.
I feel as if this self-replication method of exploration definitely helps in lessening time and effort on our behalf. It is almost like mechanical assembly-line for space explorations, having research grow exponentially. This massive growth rate may produce problems in terms of control, as other students have often brought up in class, i.e. Mickey Mouse losing control over his magic. If one machine was defected, growth would continue and cause complications. An advanced method of control must be developed for this project. Furthermore, calculations and judgements must be made carefully. For example, what is going to be the suggested completion quantity for replication and colonization? If an extra set of robots are completed, are they going to climb over each other, and destroy each other? What about traffic regulations? The robots cannot just travel randomly. The paths must be carefully designed and constructed for each robot. However, I think the interactions with the self-replicating system is a good idea. Rather than allowing the system of robots judge the terrain and act on its mechanical outputs, it is better to consult human judgement.
Terraformation of Mars and Venus via Self-Replication Systems (http://www.rfreitas.com/Astro/TerraformSRS1983.htm)
A self-replicating system is designed for terraforming, i.e. transforming the terrain of a planet to make it suitable for human habitats. This system involves employing a seed unit near the planet's surface. The seed unit would perform self-replication until there is a big company of machines that would mechanically manipulate the environment. The biggest challenge in terraforming is created artificial air. Massive amounts of oxygen are required. Nitrogen should be accounted for as well. The suggested scenario is using the self-replicating mechanics to create a factory, covering the entire surface of the planet, and start mass-producing oxygen, requiring approximately 24 years. An alternative is taking the oxygen out of the frozen water, which amounts to 3x1018 kg. The necessary water required to create oxygen is 6.8x1017, approximately 23% of the total frozen water. However, there are issues concerning the deposit of H2.
I think this is an interesting concept, but considerations have not been taken for ultra-violet ray protection (i.e. artificial ozone layer), the extremely cold weather of Mars and the extremely warm weather of Venus, usable water, and food source. It is possible create a human colony within a dome of oxygen, nitrogen, warm weather, and fruits and berries in Mars, but to completely transform Mars into another Earth requires immense efforts and money. There are many factors that come into play. We may need hundreds of years to perfect this environment because unique engineering problems are going to be coming up left and right due to our lack of knowledge in Venus and Mars. For the perfection of these planets, it may even take human lives. How are we to know if we can actually live and be compatible with the conditions of this artifical Earth? There may be lots of health complications. It may be easier, instead, to just create an underground city for population expansion, considering that it is a part of Earth that is less developed than its upper level.