Discovery first flew in 1984, the third orbiter to join the fleet. It was named for one of the ships commanded by Captain James Cook. Space shuttle Discovery is the most-flown orbiter; today will be its thirty-ninth and final launch. By the end of this mission, it will have flown a total of 365 days in space, making it the most well traveled spacecraft in history. Discovery was the first orbiter to carry a Russian cosmonaut and the first to visit the Russian space station Mir. On that flight, in 1995, Eileen Collins became the first woman to pilot an American spacecraft. Discovery flew twelve of the thirty-eight missions to assemble the International Space Station, and it was responsible for deploying the Hubble Space Telescope in 1990. This was perhaps the most far reaching accomplishment of the shuttle program, as Hubble has been called the most important telescope in history and one of the most significant scientific instruments ever invented. It has allowed astronomers to determine the age of the universe, postulate how galaxies form, and confirm the existence of dark energy, among many other discoveries. Astronomers and astrophysicists, when they are asked about the significance of Hubble, will simply say that it has rewritten the astronomy books. In the retirement process, Discovery will be the “vehicle of record,” being kept as intact as possible for future study.Discovery was the return-to-flight orbiter after the loss of Challenger and then again after the loss of Columbia. To me, this gives it a certain feeling of bravery and hope. ‘Don’t worry,’ Discovery seemed to tell us by gamely rolling her snow-white self out to the launchpad. 'Don’t worry, we can still dream of space. We can still leave the earth.’ And then she did.
To understand this new frontier, I will have to try to master one of the most difficult and counterintuitive theories ever recorded in the annals of science: quantum physics. Listen to those who have spent their lives immersed in this world and you will have a sense of the challenge we face. After making his groundbreaking discoveries in quantum physics, Werner Heisenberg recalled, "I repeated to myself again and again the question: Can nature possibly be so absurd as it seemed to us in these atomic experiments?" Einstein declared after one discovery, "If it is correct it signifies the end of science." Schrödinger was so shocked by the implications of what he'd cooked up that he admitted, "I do not like it and I am sorry I had anything to do with it." Nevertheless, quantum physics is now one of the most powerful and well-tested pieces of science on the books. Nothing has come close to pushing it off its pedestal as one of the great scientific achievements of the last century. So there is nothing to do but to dive headfirst into this uncertain world. Feynman has some good advice for me as I embark on my quest: "I am going to tell you what nature behaves like. If you will simply admit that maybe she does behave like this, you will find her a delightful, entrancing thing. Do not keep saying to yourself, if you can possibly avoid it, 'But how can it be like that?' because you will get 'down the drain,' into a blind alley from which nobody has yet escaped. Nobody knows how it can be like that.