杏吧原创

Steve Squyres, lead scientist for NASA鈥檚 Mars rovers Spirit and Opportunity, will become an 鈥渁quanaut鈥� to help pave the way for a future human mission to an asteroid

Next week you will be travelling underwater off the coast of Florida as part of NASA鈥檚 undersea exploration mission. Why?
In 2025 NASA wants to send humans to explore asteroids a kilometre in size or smaller. These are effectively microgravity environments. Nobody knows how to do field geology in microgravity 鈥� the best way to simulate it is underwater.

This is quite a change from your usual job, managing NASA鈥檚 Mars rovers.
I have been saying publicly for years that I am a big supporter of human space flight. This is the chance for me to stop talking about it and actually do something towards it.

How big is the underwater laboratory you will be working in?
It鈥檚 about the size of a school bus, and it sits on the seabed at a depth of 19 metres. There will be six of us there 鈥� four NASA crew members and two folks from the National Undersea Research Center.

Have you spent much time underwater before?
I did some research diving in Antarctica back in the 1980s. We were interested in understanding what the sediments deposited in lakes on Mars might look like; Martian lakes would probably be covered with ice too.

What will a typical day be like in the underwater laboratory?
It鈥檚 going to be very intense. We have a very full mission timeline. Two crew members will go outdoors performing extravehicular activities 鈥� there鈥檚 one EVA in the morning and one in the afternoon, three hours apiece. We are not using scuba equipment, but instead have helmets to provide air and continuous voice communication.

We鈥檒l be simulating the process of doing basic field geology tasks on the surface of an asteroid, like deploying instruments and collecting samples. We will be trying lots of ways to do it, using ropes and small one-person subs to move crew members around.

What are the benefits of sending humans to an asteroid, rather than just robots?
In Antarctica, we had a remotely operated vehicle exploring the lake bottom. We could look around and answer first-order questions with it, but I found I didn鈥檛 really understand things until I got suited up and went down in that environment myself, where I could touch the surface and interact with it.

The human-robot argument is a silly argument to have. The key is to find the right mix of both. I think humans are going to be much more effective geological explorers than a robotic system would be, but robots are less expensive, and you want to find the right balance.

Are you hoping to be on board NASA鈥檚 asteroid mission in 2025?
I鈥檓 55 years old. I鈥檓 10 years older than anybody on the NEEMO crew. I think this is going to be the closest to an asteroid I鈥檓 ever going to get. I鈥檒l be watching the asteroid mission on TV from my rocking chair.