10. Advanced Missions and Development Needs(From the Journal of the British Interplanetary Society 1997, 50, 93-102. Michael N. Mautner)
Advanced technologies can increase substantially the probability of success, and reduce the required swarm mass, which is a major economical barrier.
Preparation of biological payload: Genetically engineer microorganisms, including multicellular eukaryotes, that combine extremophile traits for survival in unpredictable, diverse environments, and that can efficiently metabolise extraterrestrial nutrients. It may be necessary to devise missions where the microbial payload can defrost and multiply/recycle periodically, say every 1E5 yr, for renewal against radation-induced genetic degradation.
Propulsion: Develop new methods to accelerate sub-milligram objects to 0.01 c. For example, antimatter - matter recombination has the potential to reach velocities close to c. Interestingly, the energy for a capsule of 1E-6 kg travelling at 0.01 c, ie., 4.5E6J, which can be provided by mass-to-energy conversion of 5E-11 kg of antiparticles. Launching smaller, microgram capsules at 0.01 c requires the production of 5E-14 kg of antiparticles, which brings even this exotic technology within the capabilities of current technology .
Navigation: Apply on-board intelligent robots for in-course navigation, and for identifying suitable accretion systems and habitable planets; for landing on these targets; and to control the initial incubation.
Accretion into comets and asteroids: Use self-replicating robots to multiply on those bodies and to turn them into biological hatcheries. Use comets and asteroids in this solar system to grow large panspermia biomasses for interstellar and galactic panspermia, and as growth and storage media in the target systems.
At the highest technological level, human interstellar travel can promote life. For example, Oort-belt cometary nuclei can be converted to habitats with resources to sustain each up to 1E13kg biomass (1E12 human population), and their large-aphelion orbit readily perturbed to leave the solar system. Human interstellar travel may require centuries of far-reaching developments, including the bioengineering of space-adapted, science-based "homo spasciense". Space adaptation may also need man/machine cyborgs and the risk of robot takeover, or strong measures to ensure that control stays vested in organic intelligent brains with self-interest in perpetuating their (and our) genetic heritage as DNA/protein life.
Such problems illustrate that human interstellar travel is tenuous. The longevity of intelligent civilisations is unknown, and the long-term ability of organic intelligent Life to propagate itself in space is unpredictable. It is therefore prudent to enact a panspermia program early using available techology, and advanced technologies can be incorporated as they develop.
Please note: numbers in square brackets refer to the references that you will find under "resources"