Not in three months, that would be faster than light travel. Now, if you could travel extremely quickly, close to speed of light, you could achieve a three months subjective travel time, if there were astronauts on board. But we are nowhere near that. And the first probes would surely be robotic meaning that the subjective travel time is not important.
It might though be possible to achieve a velocity of a tenth of the speed of light in a robotic craft. That's a commonly stated goal. You could then get to Alpha Centauri 43 years.
There are ideas for faster travel too. This recent suggestion could use laser propulsion to propel a one gram spaceship to the nearest stars at 25% of the speed of light, so in less than 20 years, if it worked.
Lasers Could Send A Wafer-Thin Spaceship To A Star
More here
There are many other ideas. They include
- Oberth effect. Dive close to the sun first. Accelerate using solar sails when closest to the sun, in a spaceeship designed to withstand very high temperatures. Accelerating so deep in the gravity well means you get much more "bang for the buck" due to the Olberth effect. And you also get much more solar power to power your sails. You could even use the same method to decelerate at the destination
- Use laser power
- Use smart bot tiny (grams to milligrams scale) spacecraft that are propelled by laser light from Earth - but they then are self guided towards the retreating spacecraft. That makes it much more effiicient beyond a certain point as it becomes impossible to focus a laser so accurately. They can just hit the spacecraft for momentum transfer.
- Send lots of small robotic spacecraft at high speeds. Though many will be destroyed, enough survive to get through to the destination.
At the destination star system, then once there they could spread out thin film mirrors, or if you manage to send many there, they could deploy in swarms making a phased array to communicate back to Earth.
They could do a flyby. If so, in and then out. Or a "fry by" where they go so close to the destination sun they slow down through friction with its atmosphere, a bit like aerobraking. Also can use solar sails and the strong light from a sun in such a fryby to brake.
If you go to a system with multiple stars like Alpha Centauri, you could use a fryby of one of the stars to then target another - and then may be able to slow down enough to go into a capture orbit around the second sun.
A larger craft could also slow down by using lasers from Earth - a large mirror which it releases and the light from Earth is reflected back from that larger mirror which goes ahead of it, to slow down the following spacecraft.
There are lots of ideas out there, but the technology isn't here quite yet and hard to tell which of them will be the best contender.
However having seen the pace of technology in my own lifetime, e.g. mobile phones, what's more with live video communication too - which when I was young in the 1960s and 1970s, was a dream of far future science fiction, then I think it's not impossible that we get small interstellar robotic spacecraft with a journey time of less than 100 years some time this century, maybe even lightweight robotic craft able to get there in decades.
But we certainly don't have that technology yet. Just lots of ideas about how to do it. Speculating about interstellar spacecraft now is a bit like speculating about mobile phone technology in the 1970s. You could guess the functionality - what it could do, but it is another matter altogether to sort out the engineering. And some things you can't predict such as the invention of fractal antennas which so shrunk the mobile phone antenna that it doesn't even need an external antenna any more, just an internal antenna inside the case. Nobody could have predicted that, without first thinking of the innovative idea that made it possible.
See also
About the Author
