Jeffrey A. Hoffman, a former astronaut who is now a lecturer at MIT, described the experience of space flight to an MIT audience at last week's annual Massachusetts Space Grant Consortium lecture.
"The physical freedom of weightlessness is an utter delight ... it has psychological, emotional and maybe even spiritual dimensions. Unfortunately, we don't really possess the language to adequately express this because we don't have the shared experience," Hoffman said.
He said that being attached to the end of the shuttle's robot arm at the top of the Hubble space telescope was "one of the most spectacular and emotional moments that I experienced in space, floating between heaven and earth. I could let go and become a free-floating satellite. It was quite an extraordinary feeling, especially when I turned my back to the shuttle ... I really had the feeling of being lost in space."
Hoffman became an astronaut in 1978 and flew on five space shuttle missions between 1985 to 1996. Prior to joining NASA, he was a project scientist at MIT's Center for Space Research working in the field of X-ray astronomy. He returned to MIT last fall as a senior lecturer in the Department of Aeronautics and Astronautics. "Twenty-first Century Space Exploration with Humans and Robots" was the subject of his May 1 talk.
Hoffman participated as a spacewalker in the first Hubble servicing mission in 1993, one of the most ambitious missions ever launched by NASA.
"Having been both an astronomer and an astronaut, for me one of the most satisfying aspects of working on Hubble was being able to unite the world of space astronomy, which generally prefers automated spacecraft, with the world of human spaceflight," said Hoffman. "Our telescopes are the metaphorical vessels which carry our minds to the stars, and Hubble is the flagship of the fleet because it has taken us deep into space and back in time to the youth of the universe."
"Modern technology has really made it possible to use tools to project human presence," he said about the Sojourner Pathfinder rover that explored Mars' surface in 1997. "Even when we get to Mars, human beings will still have reached only a fraction of the domain which is already accessible today to our robotic probes, just as our robots have only reached a fraction of the domain explored by our telescopes. Most space exploration has been, and always will be, done by machines: telescopes, satellites, probes and robots," he said.
"But where people have gone, we've done things that machines could not do," said Hoffman. "If exploration is ultimately the expansion of human consciousness, then we need to do everything we can do to enable our minds and our spirits to follow our robots where our physical bodies can't go. We need to use robotic presence to extend our sensory experience, because our consciousness of the world is ultimately tied to our sensory experience of the world."
"The parallel challenges of future space exploration are going to be to push the outer boundaries of robotic exploration into realms previously explored only by telescopes, and at the same time, push the boundaries of human presence into realms previously explored only by robots," said Hoffman.
A version of this article appeared in MIT Tech Talk on May 8, 2002.