We love to take sci fi adventures through space, but the reality of how we’ll someday
explore worlds beyond our solar system will be much different than the cryogenically-induced
slumbers astronauts take in the movies.
This is how the spacecrafts of the future will probably look.
Instead of a team of astronauts, it’s cargo will include tiny sensors, a camera, and a
plutonium battery.
Instead of rocket fuel, it will be propelled by a 4-meter-wide sail that will catch concentrated
laser beams so powerful they haven’t been invented yet.
This most interesting megaproject of the future, a real Hail Mary, is called Breakthrough Starshot.
It’s mission?
To give us our first view of a planet outside the Solar System.
Last year researchers announced the discovery of Proxima b, a potentially Earth-like planet
orbiting the red dwarf star Proxima Centauri, part of a triple-star system that’s closest
to our own Sun.
It’s our next-door-neighbor!
This gave interstellar explorers searching for extraterrestrial life their first truly
appealing target, one that could — theoretically — be reached in our lifetimes.
The project is backed by a $100 million investment from Russian billionaire Yuri Milner:
“This is something that people have been dreaming and thinking about for thousands
of years.
The first one to propose that type of project was Johannes Kepler in 1610 and there were
many smart people after him.
So we’re sort of standing on the shoulders of giants.
But only in the last fifteen years it became practically possible to talk about this project.
And we know that this is just the beginning.
We know it will take a long time, probably a generation, to actually launch a spacecraft
that can travel interstellar.
But we do know that the time is to start now given that technology is available and it’s
mostly an engineering challenge and not a scientific challenge.”
Milner’s $100 million is just a down payment to spur development of the tech needed to
launch the mission within 20 years.
The project’s total cost will be in the ten billion dollar range.
Here’s how it will work.
A chip about one-centimeter wide will carry circuitry, thrusters, a camera, spectrometer,
plutonium battery, and a laser beam to send data back to Earth.
It will be surrounded by a sail.
An array of lasers back on Earth will beam it up to a speed of roughly 20% the speed
of light.
At that speed, it will take the craft just three-and-a-half days to reach the edge of
the solar system.
Five months later it will reach the treacherous Oort cloud — trillions of icy objects surrounding
the Solar System that will take seven-and-a-half years to pass through.
If it emerges intact it will then journey for another 13 years before encountering the
Proxima Centauri system.
But it won’t stay long.
Traveling so fast, with no way to slow down, it will scream through the star system in
just two hours, giving it a brief window of opportunity to capture data, which will take
four years to transmit back to Earth.
Sounds simple right?
Until you think about all the hurdles.
All this technology — from the lasers to the craft itself — doesn’t exist yet.
The good news is that initial research on sail-based laser propulsion looks promising.
The bad news is that the lasers needed to propel the sail are 1 million times more powerful
than what’s currently available.
The lasers will hit the craft with g-forces tens of thousands of times stronger than anything
we feel on earth.
Artillery shells can take this level of force for less than a second.
Starshot will need to withstand it for minutes.
Any object — even a speck of space dust — could easily destroy the probe, or if
it somehow survives a collision, send it careening off course.
The interstellar medium is the vast unknown.
The first and only manmade object to reach interstellar space is the Voyager 1 probe,
launched in 1977.
It took the iconic pale blue dot image of planet Earth in 1990 and crossed the heliosphere
in 2012 and is still active.
Breakthrough Starshot will launch exploratory probes as soon as a prototype propulsion system
is complete.
While Voyager took incredible photos of the Solar System, no camera has ever taken a photo
while traveling at one-fifth the speed of light.
No manmade object has ever even travelled the fast period.
Perhaps the biggest challenge will be transmitting any photos and data it does collect back to
Earth.
Fitting a power source on an already crowded centimeter-wide chip capable of shooting a
laser back home to us doesn’t seem possible.
That’s why it’s best to think about this project in the broader context of space exploration.
Even if it fails, simply attempting to solve the seemingly impossible always has residual
benefits, just like the space race and moon missions did.
There are other efforts underway to reach Proxima b up close, including sending a larger,
nuclear-fusion-powered spacecraft.
But that mission wouldn’t launch for a century.
Another hope for taking a peek at Proxima b lies with several giant telescopes coming
online in the next decade, including the James Webb, scheduled to launch late next year.
But as Voyager demonstrated time and again, there’s nothing like going to a new place.
Thanks for watching.
This story was based on an article by Gabriel Popkin in the journal Nature.
Many of you agreed that we need to invest in Africa’s Clean Energy Future.
Some of you pointed to Morocco and other North African nations as evidence that progress
on this front is well underway.
Until next time, for TDC, I’m Bryce Plank.