"Exploration" means expanding the realm of human experiences. We have explored our own planet Earth mostly by physically traveling to new places. Space exploration, by contrast, is carried out mainly by machines, which can carry human awareness far away from our home planet. The vast majority of space can be explored passively, by telescopes. Probes can give us a more close-up view of objects within our solar system, and we can even place robotic landers on planetary surfaces, giving us the ability to interact, even in a limited fashion, with these new environments.
The degree to which machines can project human consciousness depends largely on the links between the probes' sensors and our own senses -- the more high-fidelity, virtual-reality feedback we can incorporate into our probes, the more we can feel that we are actually "exploring" a new environment. I will discuss the projection of human consciousness into space by different kinds of machines and will also consider the constraints imposed by the speed of light on our ability to interact with remote environments.
Human consciousness can also be carried into space inside human bodies, of course, allowing us to experience new environments in ways fundamentally different than what can be transmitted by remote probes. Human presence brings a dimension to exploration that goes beyond scientific investigation. Part of this lecture will be devoted to trying to share some of the human dimension of space flight, which I have been fortunate enough to experience as an astronaut who has flown five times on the Space Shuttle.
Many people have expressed a desire to explore space for themselves, and no matter how good our virtual-reality capabilities become, it is hard to imagine recreating the experience of weightlessness on the surface of the Earth. I will talk about what developments are necessary to allow large numbers of people to travel safely and economically into space.