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  • Venice is just a few centimetres above sea level, about as far from space as you can

  • get. But in 1609, Galileo Galilei brought this city a bit closer to the stars when he

  • gave one of the very first demonstrations of his telescope.

  • A few months after that, he discovered Jupiter's moons, Io, Ganymede, Callisto and Europa.

  • Four centuries later, another telescope is making history here, as scientists gather

  • to discuss the latest results from Hubble.

  • Hubble was launched in 1990. And that's of course when its history of scientific discoveries

  • starts.

  • But Hubble's history isn't just about science and technology. Like Galileo's story, it's

  • also one of politics, money... and extremely smart people doing very difficult things.

  • I became the first project scientist for the observatory in 1972. Probably in the most

  • difficult decisions were the simplifications that we had to make. For example, originally

  • the design was for a 3-metre aperture observatory. But in order to save money, we had to reduce

  • it to its final size of 2.4 metres.

  • While the Hubble team hacked away at the technical problems and struggled to stay on budget,

  • a political storm was brewing in Washington DC. Politicians were alarmed by the rising

  • costs, and told NASA to find an international partner.

  • It was a huge boost to the support of the programme in our own Congress because there

  • was a sense that there would also be collaboration and support from outside and in particular

  • from Europe.

  • Hubble survived the politics, only to be derailed by optics. Spherical aberration - a flaw in

  • the main mirror - meant that the telescope couldn't focus properly. Where Hubble's images

  • should have been razor-sharp, astronomers instead struggled to make out the fine details

  • of their observations.

  • I look back on the days when we diagnosed the spherical aberration as simultaneously

  • the most exhilarating and depressing days of my scientific career.

  • Because, for the better part of two weeks, we were puzzled as to why this telescope wasn't

  • performing and it became a scientific problem that scientists had to solve.

  • But in a great irony in the process of solving it and finding out what was wrong we also

  • unearthed this enormous, monumental disaster.

  • Though nobody had predicted a problem with the mirror, Hubble was designed with the unexpected

  • in mind. It's the only space telescope ever launched that was meant to be serviced in

  • space. This meant astronauts were able to return to Hubble to fix the problem. They've

  • been back another four times to carry out repairs and install upgrades.

  • As an astronaut the Hubble Space Telescope mission is kind of the holy grail of being

  • able to go up and do something that is widely regarded as extremely important.

  • When we send a crew and when I go up to the Hubble Space Telescope, with the teams that

  • I've led, there's always been rule number one: rule number one is don't break the telescope.

  • You know, we're in big bulky space suits and after all it's a delicate scientific instrument.

  • So when the first images come down, you know, it's beautiful.

  • To see some star that is in the act of exploding, or a beautiful galaxy interacting with another

  • galaxy.

  • And the science is very deep and meaningful. But to those of us who have been up there

  • working on the telescope, it means that we didn't break rule number one. That the telescope

  • really works. And there's a tremendous amount of satisfaction in that.

  • I think the crowning achievement of all of our missions has been on this mission in 2009

  • where we did brain surgery on the STIS instrument and on the Advanced Camera for Surveys. Removing

  • tiny screws and pulling circuit boards. This was technically the hardest but I think also

  • the most rewarding.

  • Risky, difficult and exciting in space, these Hubble repair missions are nail-bitingly tense

  • for the team here on Earth too.

  • It was nerve-wracking, I've never experienced anything like that. We were there as a team,

  • waiting for John Grunsfeld to open up the camera and to repair it, and everything rested

  • on a successful repair.

  • And it was just wonderful when we did the aliveness test and saw that the repair had

  • been successful. And then we did the functional test, which was done a few hours afterwards,

  • when we got the first set of data coming and it looked... it was better than it had been

  • before because of the updated electronics. So it was extremely satisfying and exhilarating.

  • And so from planning, to launch, to repair, Hubble's history has been a rollercoaster

  • of highs and lows.

  • With the telescope recently serviced, Hubble has more years in it still. And scientists

  • are already preparing what comes next.

  • The James Webb Telescope is aimed to go beyond what Hubble does by looking at things that

  • are further away, or fainter, or redder than Hubble can see, so that we can look further

  • back towards the beginning of time: we can see inside dust clouds where stars are being

  • born today; we can study planetary systems as they're being made and as they change with

  • time.

  • Scientifically we learned that Hubble is wonderful, but not quite wonderful enough. There's stuff

  • just beyond what the Hubble can see that we really want to be able to pursue.

  • The first galaxies. The first stars. The formation of stars. The evolution of planetary systems

  • and the hunt for exoplanets' atmospheres. These are some of the things we can look forward

  • to seeing in the years to come.

Venice is just a few centimetres above sea level, about as far from space as you can

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B1 中級 美國腔

哈勃的勝利記憶 (Hubble's Triumph Remembered)

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    稲葉白兎 發佈於 2021 年 01 月 14 日
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