- earth monitoring
- solar monitoring
- potentially hazardous NEO monitoring
- basic science for the understanding of the sun and asteroid/comet composition
- high performance computer simulation and prediction of solar and NEO threats
- technology development and demonstration for the purposeful diversion of NEO threats
- harnessing of solar power
- utilization of extraterrestrial resources; and
- eventual migration of polluting industry off-earth.
Quite a number of these are best done using robotic tools, satellites for example, but some of them are what we could call "exploration" and can be done most effectively, in terms of time, with human missions – and time matters. Every day we don’t have a good understanding of NEO composition, for example, we’re in danger of incorrectly characterizing those threats.
When we start recognizing that external threats to the earth are real and require constant diligence to avoid, the argument for getting all the eggs out of the one basket starts to become less pie-in-the-sky and more sensible precaution.