There's been a lot of talk about starships over the last week or so.
You know: exploring strange new worlds, seeking out new life, and all that.
And all thanks to a new engine that's stumping scientists.
Back in 2015, Hank took a trip into the SciShow Space Debunker, where we explored the rumor that NASA had created an EM drive, or an electromagnetic drive.
It's a propulsion system that doesn't need any propellant, and in theory, the technology could get you to Mars in only 70 days.
这是一个不需要任何推进物的推进系统 。从理论上讲，该系统可以在短短70年间让人类登录火星 。
Problem is, it also seems to violate the laws of physics.
Back then, other labs had created EM drives and reported that they generated a tiny amount of thrust, but nothing had been peer-reviewed.
And there was no official report that NASA had made their own EM drive.
But a year and a half later, it's official: NASA has actually created an EM drive.
And it seems to work.
The peer-reviewed paper, which was published last week in the AIAA Journal of Propulsion and Power, comes from researchers at Eagleworks, a lab at NASA's Johnson Space Center.
这篇经过同行评审的论文于上周发表在美国航空航天学会的《推进与动力杂志》上 。这篇文章是鹰工厂实验室的研究人员所作 。该实验室隶属于美国宇航局约翰逊航天中心 。
Instead of the usual rocket fuel, the EM drive works by bouncing microwaves back and forth in a cone-shaped chamber.
The waves start in the narrow end of the cone, and eventually generate thrust toward the wider end to move the spacecraft.
Which is really cool!
Except, according to Isaac Newton, it should also be impossible.
Newton's Third Law of Motion says that every action has an equal and opposite reaction -- so when the microwaves hit the chamber, the chamber should push back, and the spacecraft shouldn't go anywhere.
Right now, no one is actually sure why the EM drive works, but the researchers think it could have something to do with the pilot-wave theory of quantum mechanics.
According to the traditional, mainstream model of quantum mechanics, particles don't have a definite location until you observe them.
But according to pilot-wave theory, particles always have a definite location.
It might sound simple, but it has a lot of weird implications -- like that vacuums, which are supposed to be empty, must be filled with some kind of quantum field.
There isn't much support for the theory, but if it is true, it would mean the microwaves in the EM drive could sort of bounce against the vacuum.
The force between the waves and the chamber wouldn't cancel out, so Newton's Third Law wouldn't be violated.
If that sounds vague and complicated — well, it is.
Even the NASA researchers aren't sure how it really works, and pilot-wave theory is just one idea.
They have done tests to make sure nothing is interfering with the drive, though – like running it in a vacuum to make sure air molecules weren't getting in the way.
研究人员已经进行过测试，旨在确保驱动器不会受到干扰 。测试的方法比如：在真空环境中运行驱动器，确保空气分子不会阻碍驱动器运转 。
So, no one really knows what's going on, but it looks like the technology is legit.
It still has a long way to go before it could possibly be useful, though.
Right now, the drive produces about 1.2 millinewtons per kilowatt of thrust.
Compare that to the Hall thruster, which accelerates ions to move spacecraft through deep space and is a serious contender for Mars missions.
It generates about 60 millinewtons per kilowatt.
So even though the EM drive is lighter and might be easier to manage, we'll need a much more efficient version before we can use it to zoom around the galaxy.
Meanwhile, Elon Musk continues to make us all wonder if there's anything SpaceX can't do.
In September, the company announced big plans to colonize Mars -- but while they're working on that, they'll also be trying to deliver satellite internet to the entire world.
Last week, SpaceX filed an application with the United States Federal Communications Commission to launch 4,425 satellites into Earth's orbit for a global internet service.
And if you think that seems like a lot of satellites, you are right.
Right now, there are only around 7500 satellites in orbit, meaning SpaceX hopes to increase that number by 50% all by themselves.
This puts SpaceX on a growing list of companies, like Facebook and OneWeb, that are trying to bring the internet to everyone on Earth -- including the billions of people who don't have access to the internet right now.
太空探索技术公司的期望与许多公司不谋而合，比如脸书和一网公司 。这些公司都在努力将网络服务提供给地球上的每个人——包括很多连互联网都没机会接触的人 。
With traditional internet, the signal travels along wires from your phone or cable provider to your modem.
Satellite internet, on the other hand, sends the signals between a dish on your roof, a satellite in orbit, and a larger dish at a ground station.
Satellite internet doesn't require any cable or phone networks, so it's great for rural communities, but it also takes a while for the signals to bounce back and forth.
Other companies are already providing satellite internet to some of the world, but SpaceX's network will be faster and more accessible.
For one thing, their satellites will have much lower orbits -- around 1100 to 1325 kilometers, which will cut lag times down to 25 to 35 milliseconds since the signals don't have to travel as far.
For comparison, the company HughesNet has satellites orbiting around 35,400 kilometers up with lag times of 600 milliseconds or more.
The planned SpaceX network will be at least 17 times faster.
SpaceX also promises download speeds up to 1 gigabit per second, which is 100 times faster than other networks, which offer around 10 megabits per second.
If their application is approved, SpaceX will still have to build the satellites and ground stations, but satellites could potentially start launching as soon as 2019.
如果太空探索技术公司的申请得到审批，它还要先建造卫星和地面卫星接收站 。不过，卫星可能2019年就能发射了 。
Which means that pretty soon, a lot more people could have access to the internet — all thanks to a little rocket science.
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