Search query: Solar sail spacecraft projects
Video title:  it could have a much lower mass. It could, also, in theory, go very, very fast. With a huge laser array putting out 50-70
gigawatts of power, a 100 kilogram ship -- about the size of Voyager 1 -- could travel at around
1.5% of the speed of light -- nearly 300 times Voyager’s top speed. But there are still challenges to solve, when
it comes to making spaceships powered by giant lasers. We /could/ send a smaller probe to Mars in
3 days, or a larger craft on a trip that would take about a month. But we’d need a giant, square laser array
that’s 10 kilometers long on each side -- which presents some obvious problems. Getting stuff to space is expensive, let alone
100 square kilometers’ worth of high-powered laser equipment. And even if we did get everything to the right
spot, it would be incredibly difficult to assemble. Building a laser sail for this super-fast
trip to Mars would also be tough. According to the researchers, it would have
to be only a micron thick -- that’s a thousandth of a millimeter. But to work properly, that whisper-thin laser
sail would have to weigh about as much as the spaceship itself! Meaning that it would have to be a huge, thin
sail, but strong enough to be stable while the ship is moving ridiculously fast. And … we also have no idea how to slow the
spacecraft down once it gets to wherever it’s going. So if we’re talking about sending ships
to Mars in 3 days, we’re probably getting ahead of ourselves a little bit here. Really, the first step to making this research
a reality is building a much smaller set of lasers. The team’s plan -- assuming NASA chooses
to move forward with their idea -- is to start with a laser array that’s only one meter
square. Then we’d just keep building bigger sets
of lasers, until we eventually figured out how to build one that’s 10 kilometers on
a side. Then, we could use that to launch what are
known as wafer sats. These miniature spacecraft would weigh no
more than a gram, but they’d have sensors, a power source, teeny-tiny thrusters, and
communications equipment. That giant set of lasers could accelerate
these wafer-sats to about 25% of the speed of light, sending them light-years away, where
they could tell us all about interstellar space and exoplanets. They might even be able to reach the nearby
star system Alpha Centauri only 15 years after