How about this boys and girls. Mars in 72 hours (not sure how you slow down) and our nearest star in a few hours!

 

https://www.nasa.gov/ames/ocs/summerseries/2018/phil-lubin

 

"Experimental cosmologist Philip Lubin recently presented interstellar space travel scenarios at the Optical Society’s Laser Congress in Boston, informed by his direction of the NASA Starlight and Breakthrough Starshot programs.

Lubin, a professor of physics at the University of California, Santa Barbara, believes that by tapping into photonics-driven propulsion, researchers are well on their way to making laser-light-powered spacecraft that can deliver humans to Mars within one month."

Essentially you launch your vehicle and direct a high powered laser at it. No fuel onboard required, so constant acceleration.

Obviously the intensity of the beam diminishes but extreme velocities are still feasible.

https://www.photonics.com/Articles/UC_Santa_Barbaras_Lubin_Describes_Interstellar/a64359

Edited June 9, 20214 yr by martin-w

A quick video for those in a hurry.

Multiple lasers to create a phased array and suddenly you have a powerful propulsion technology.

 

 

This is actually fairly old tech though, at least as a theory.

I remember reading about various types of LightSail when I was a kid. Right up there with Bussard ramjets. (Larry Nivens Known Space books, especially)

22 minutes ago, martin-w said:

How about this boys and girls. Mars in 72 hours (not sure how you slow down) and our nearest star in a few hours!

I'm assuming you meant nearest star in a few years! 😺

Ok, so you aim a laser on Earth to “push” the craft to Mars. How does the craft come back? 🤔

1 hour ago, Mike A said:

Ok, so you aim a laser on Earth to “push” the craft to Mars. How does the craft come back? 🤔

If I had to guess, I would say some sort of slingshots around a few planets?

Or maybe, if it acts like a real sail..... Could it tack into the "wind"? 

2 hours ago, HiFlyer said:

I'm assuming you meant nearest star in a few years! 😺

 

Oops... 

2 hours ago, Mike A said:

Ok, so you aim a laser on Earth to “push” the craft to Mars. How does the craft come back? 🤔

I imagine that you would send a similar laser to Mars via conventional methods and install it in advance

A few more numbers here.

The guy certainly thinks big.  The numbers in the article seem to more or less match those in the paper cited above, which assumes a 70GW laser array.  For comparison the power of the Space Shuttle's engines and SRB's at liftoff is 12GW.   This focussed into a beam that's only 900m across at the edge of the solar system. 

To avoid atmospheric losses, DESTAR 4 is on an orbital platform.  Besides interstellar propulsion, it can be used to vaporize incoming meteorites as part of a space defence system.  I suppose care has to be taken not to point that beam anywhere near the Earth - though there will be those who will find this capability useful.

As described, the system is strictly one-way.  For return trips, according to the paper, "In cases of short distance travel, such as a manned mission to Mars for instance, two DE-STAR systems are employed, one orbiting the Earth and one stationed at the destination. "

15 minutes ago, DAH4062 said:

I imagine that you would send a similar laser to Mars via conventional methods and install it in advance

So this craft wouldn’t be for the “Neil Armstrong” of Mars, but Joe Commuter after a colony has already been established.

1 hour ago, HiFlyer said:

If I had to guess, I would say some sort of slingshots around a few planets?

Or maybe, if it acts like a real sail..... Could it tack into the "wind"?

I was assuming the craft would have been delivering people to the surface of Mars. If not, & it’s just a fly by mission, then your guess makes sense.

18 minutes ago, Mike A said:

So this craft wouldn’t be for the “Neil Armstrong” of Mars, but Joe Commuter after a colony has already been established.

Perhaps, but it could also be set up autonomously/remotely. After all, a helicopter has been flown on Mars long before any human got even close.

1 hour ago, HiFlyer said:

If I had to guess, I would say some sort of slingshots around a few planets?

 

Think it was on The Angry Astronaut channel. There is a way to do that. Or if manned you could use farts.

Okay I've got this...

 

You generate an inertial mass dampening field around your spaceship. Then you just shine a torch out of the back window. Duracell power and a Cree  LED gets you to Mars. Then you just run to the front window and shine it out to slow down.

1 hour ago, DAH4062 said:

I imagine that you would send a similar laser to Mars via conventional methods and install it in advance

I would do this too but the challenge is both Mars and Earth are not stationary, if they were stationary this would be very easy, point at target and accelerate, then target decelerates on  the other end. But since Earth and Mars are moving you would need to track a course perfectly to intercept the other end then decelerate, but if you missed the target you are now space junk

1 hour ago, Mike A said:

I was assuming the craft would have been delivering people to the surface of Mars. If not, & it’s just a fly by mission, then your guess makes sense.

Or the sail just drops off a package and continues on its merry way while the package (including possible passengers?) does some hairy aerobraking stuff....