Ed Lu

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is an American physicist and a former NASA astronaut. He is a veteran of two Space Shuttle missions and an extended stay aboard the International Space Station.

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edluB612395 karma

Here is some food for thought. Sometime in the next decade, Sentinel will find an asteroid that is going to hit the Earth. And the people of Earth will take action and deflect that asteroid. For real.

edluB612244 karma

Apollo 13!
and of course Galaxy Quest.

edluB612197 karma

BTW, my crewmates and I on Shuttle mission STS-106 all watched Galaxy Quest in crew quarters just before our launch! "Never Give Up!"

edluB612188 karma

My first thought was literally "Holy Sh**!" It is beyond beautiful.

edluB612129 karma

Nice graphic. But we don't need to stop all of them, just the ones that are going to hit us! And the point is that it is going to take public support to do that, just like it takes public support to build the San Francisco Museum of Modern Art addition.

edluB61296 karma

Thanks! Public support for Sentinel is crucial. The public needs to know that they can make Sentinel happen. Yes, it is expensive - it will cost roughly as much as half of the new addition to the San Francisco Museum of Modern Art! http://www.sfmoma.org/our_expansion/expansion_project/expansion_project_faq#whenbegin But in this case we get to save the world!

edluB61291 karma

BTW, Scott Manley of Kerbel Space Program fame made that video!

edluB61280 karma

Once Sentinel gives us decades of warning, we have many options to deflect an asteroid. The key is realizing it only takes a very tiny change in the velocity of an asteroid to make it miss (as long as you apply that change many years before the impact). We could use a combination of kinetic impacts (simply running into the asteroid with a small spacecraft like we did with the Deep Impact Mission in 2005 on Comet Tempel 1) and Gravity Tractors to fine tune our deflection.

But again, this only works for asteroids we know about! So the first and most important step is Sentinel.

edluB61266 karma

If you spend enough time seeing the Earth from space, and looking out at craters on the Moon and on Earth, it becomes clear that we have to eventually solve this problem of asteroid impacts. We only recently have the technology to do something about it. The infrared detector technology for Sentinel, as well as asteroid deflection technology like kinetic impactors were not possible just 20 years ago. We have no excuse not to do this now!

edluB61257 karma

Perhaps it will be possible someday. Of course the real question is if it will be profitable or not! But again, you can't mine an asteroid you haven't found yet.....