Posted on 02/24/2016 8:12:54 AM PST by Freeport
It sounds like science fiction, but it's eminently possible, researchers say: Robotic spacecraft could get to Mars after a journey of just three days.
The key to making this happen is photon propulsion, which would use a powerful laser to accelerate spacecraft to relativistic speeds, said Philip Lubin, a physics professor at the University of California, Santa Barbara.
"There are recent advances which take this from science fiction to science reality," Lubin said at the 2015 NASA Innovative Advanced Concepts (NIAC) fall symposium last October. "There's no known reason why we cannot do this."
Lubin and his team were awarded one of 15 Phase 1 NIAC grants last year, which gave them about $100,000 to perform initial studies of their project, known as Directed Energy Propulsion for Interstellar Exploration (DEEP-IN).
The list of 2015 Phase 1 NIAC awardees also includes a squidlike rover that could study the oceans of icy moons such as the Jovian satellite Europa, ball-like robots that could explore shadowed craters on Earth's moon and even a proposal to mine asteroids with the help of concentrated sunlight. The hope is that one or more of these technologies will have a huge impact on space science and exploration down the road.
(Excerpt) Read more at space.com ...
“...The gravitational pull of the planet alone might be enough to capture...”
Nope. The velocity involved is a measurable percentage of the speed of light.
Chemical engines + aero braking are not getting you enough deltaV reduction without the object burning up in, bouncing off of, or being crushed like a bug on a windshield by the atmosphere.
The sudden stop might be an issue.
LOL that’s right. Bugs on windshields know all about sudden stops.
What, no URANUS jokes yet? You guys are slippin”!
I would assume the braking force would have to be roughly equal to the accelerating force, and that it would have to be applied at an optimal time to maximize the approach velocity without endangering the orbit.
But the math probably isn't all that complicated. And assuming there is a "go" engine capable of near-light speeds, there is also a "stop" engine with the same capability. The same engines that propel a commercial airliner are responsible for part of its braking upon landing. It's all a question of what direction their thrust is pointing.
Don't make too big of a deal about it.
She called me last night and she didn't even dump her husband.
Will. Never. Happen.
“I always love these “We can get there in X days things. Yes, and the object can wave at Mars as it goes flying by since there’s no equivalent system in Mars orbit, or the object of your choice orbit, TO SLOW IT DOWN! :-)”
Another issue. How do you GET BACK?
While you're planning the actual mission, send another one of the laser doohickeys on ahead. This also solves the problem of the return trip.
OF course, to do so, we would need to build a laser array at least 70 square miles. . . for the emitters. Power supply additional.
Minor, unimportant engineering issues. . . (grin)
Then fly for another two weeks or so and use Jupiter to slow down
;)
F = M a might be one.
ML/NJ
Sounds fun, just make sure the exhaust isn’t in the direction of the earth when it takes off.
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