Did you ever want to be a time traveler? To go back in time to see the dinosaurs? Or to visit the future to see how something turned out? Well, I am a time traveler. And in the next few minutes, I want to show you how time travel is useful in innovation（创新）. Now when I say I'm a time traveler, I don't mean I'm from the past or from the future, future, future.

  No, I'm from right now. But I've traveled thousands of years into the past by studying Latin（拉丁语） in ancient Greek. And in my work as a geologist（地质学家） and geophysicist, I went even farther back millions and billions of years. Today, I work（使工作） into the future as a space technologist, applying the lessons of yesterday and today to the problems of tomorrow. Many of the things we can't do in space yet are things we've been doing on Earth for a very long time. And sometimes to move forward, you have to look back.

  We don't currently refuel satellites（卫星）. What would it be like if every time you ran out of gas, you left your empty car piled（堆叠） up with the other ones by the side of the road and went out and bought a new car? Well, that's kind of how it is in space right now. But on Earth, we have a long history of refueling our vehicles, everything from grazing（放牧） our horses to refueling aircraft（飞机） in mid-flight. I had the opportunity to work on a satellite refueling project. And one of the many challenges in that field is deciding who will do which part of the distribution（分发）.

  When we fill up our cars, we take them to the gas station. But when we fill up a plane in the air, the gas station comes to the plane. Looking at these and other analogies（类似） helped me to consider different fuel distribution（分发） models for space. I looked back again on a recent family trip. I told myself as we were leaving that I would turn off work and focus on our vacation. We went to this beautiful town in southern France that's built up on ancient Roman（罗马的） ruins（废墟）.

  And there's a museum there with an exhibit（展览品） on metal recycling in the ancient world. When I saw that, I was jolted（摇晃） right out of vacation and right back to work, because another aspect（方面） of what I do is metal recycling for space. Humans have launched（发射） thousands of tons（吨） of metal into space over the years. And a lot of it's not being used anymore, like those old, empty satellites. Metal recycling could find（找到） itself at the fulcrum of industrial（工业的） activity in space, because it has literally（照字面地） been a linchpin of civilization（文明） for thousands of years. When we first started our work on metal recycling, we looked back at what our colleagues at NASA had learned from melting（（使）融化） metals on the International Space Station over the past 20 years.

  We have other colleagues who plan to drill holes in asteroids（[天] 小行星）, and they should learn what they can from experienced drillers. Now I know what you're thinking. It's not quite like the movie Armageddon, but you get the general idea. In real life, though, even oil drillers got good at it by looking back. When they wanted to figure（ 认为） out how to drill horizontal（地平的） wells（井） in the ground, they looked at old patents（专利权） for dental（ 牙齿的） drilling and used those as a jumping off point.