Posted on 02/10/2022 2:53:38 PM PST by BenLurkin
NASA challenged engineers to design a mission to Mars that would deliver a payload of at least 1,000 kilograms in no more than 45 days, as well as longer trips deep into, and out of, the solar system. The short delivery time is motivated by a desire to ferry shipments and, someday, astronauts to Mars while minimizing their exposure to the damaging effects of galactic cosmic rays and solar storms.
McGill's concept, called laser-thermal propulsion, relies on an array of infrared lasers based on Earth, 10 meters in diameter, combining many invisible infrared beams, each with a wavelength of about one micron, for a powerful total of 100 megawatts—the electric power required for about 80,000 U.S. households. The payload, orbiting in an elliptical medium Earth orbit, would have a reflector that directs the laser beam coming from Earth into a heating chamber containing a hydrogen plasma. With its core then heated as high as 40,000 Kelvin (72,000 degrees Fahrenheit), hydrogen gas flowing around the core would reach 10,000 K (18,000 degrees Fahrenheit) and be expelled out a nozzle, creating thrust to propel the ship away from Earth over an interval of 58 minutes. (Side thrusters would keep the craft aligned with the laser's beam as Earth rotates.)
When the beaming stops, the payload zips away at a velocity of almost 17 kilometers per second relative to Earth—fast enough to go past the moon's orbital distance in a mere eight hours.
Laser-thermal propulsion had first been studied in the 1970s using 10.6 micron CO2 lasers, the most powerful at the time. Today's present-day fiber-optic lasers, at one micron, which can be combined in massively parallel, phased arrays with a large, effective diameter, means a focal length of power delivery over two orders of magnitude higher—50,000 km in Duplay's laser-thermal propulsion concept.
(Excerpt) Read more at phys.org ...
Of course cloudy days will render the laser useless
That much power just blasts the clouds out of the way.
The problem is not getting to Mars, the problem is how to get back...
How will you carry enough fuel to get back to Earth?
45 days to Mars. That is faster than my 68 Impala. How would they slow it down when they get there?
That much power just blasts the clouds out of the way.
—
uh-huh.
I don’t believe it for a second. I think it is small-minded cover story for a system designed to destroy incoming ICBMs, enemy bombers, etc.
That was the technique used by the Airborne Laser. An initial zap cut a hole through the clouds followed by the zap that destroyed enemy rockets.
The Moties already did this in The Mote in Gods Eye. Great book.
Frickin space lasers!
“the problem is how to get back...”
Notice that NASA only asked for ideas about how to send a payload TO Mars?
It’s a one way trip. If we ever send anyone there, we aren’t bringing them back.
Sounds like Biden's plan. Patterned after the Afghanistan and Ukraine abandonments.
Great book that should have been made into a film decades ago.
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