The technology doesn't belong to NASA. It belongs to a Japanese team. However since US is paper-tiger and a PR success you say it's a NASA technology. It was theorized by a US engineer but was first realized by Japanese engineers in 2002.
Laser propels plane : Nature News
ahem.
**cough, cough**
it was not only theorized by a usa engineer :
Yabe's team is revisiting an idea first proposed 30 years ago. In 1972, US engineer Arthur Kantrowitz pointed out that a laser beam focused onto some substance - the 'fuel' - on an aircraft's surface could produce a jet of gas that would push it forward, just like a normal jet engine.
but some americans also experimented :
Then, in 1997, researchers at the US Air Force Research Laboratory in California used a high-power infrared laser to propel a saucer-sized aluminium craft for a few seconds. Laser pulses converted air in an inlet chamber into a high-pressure plasma. The thrust thus created lifted the lightcraft hundreds of feet into the air.
This project was a NASA collaboration to investigate the possibility of using laser propulsion as a low-cost method for launching small satellites.
When a spacecraft is launched, the thrust comes from burning a chemical, such as rocket fuel. This fuel weighs down the spacecraft. It is an inefficient system when compared to using light or other electromagnetic radiation to accelerate objects.
“Electromagnetic acceleration is only limited by the speed of light while chemical systems are limited to the energy of chemical processes,” Lubin wrote in a report describing the technology.
However, electromagnetic acceleration requires complicated and expensive equipment that is not easy to scale up to the size required for space travel. Despite not having any mass, photons have both energy and momentum, and when they reflect off an object, that momentum is transferred into a little push. With a large, reflective sail, it is possible to generate enough momentum to gradually accelerate a spacecraft, researchers said.
While the researchers have not yet tried out their system, their calculations show that photonic propulsion could get a 100-kg robotic craft to Mars in just three days.
The system is not designed to send humans across interstellar distances. Instead, Lubin proposes wafer-thin spacecraft that can get close to the speed of light.
Some folks missed that last line ^^^ , it seems!
The energy of photons is minuscule by full spaceship standards. Yes, the theory behind this
proposal is sound but the amount of energy required to give sufficient push to a spacecraft
transporting humans and everything needed for their survival including a solar & cosmic radia-
tions shield would amount to a laser ... as big as the moon or about by present capacities.
Then for reasons known to high school students, that laser cannot be on the spaceship itself.
the op and tay's last line reminded me of a vid i had seen a few years ago... a usa study group ( supported by nasa, i think ) had experimented outdoors for spacecraft propulsion through laser... they called their engineering model as 'lightcraft'... you can watch a copy of that vid here
[1]... in the experiment, a infrared laser is on the ground and it shoots into the rounding-cone-shaped backside of the engineering model, sending it up into the sky... the propulsion happens because the laser acts upon the air molecules under the ring that tops the cone... in space, there can be some ablative material/gas that is emitted regularly under the ring.
that gave me a idea that combined two things i had read about - 'solar sail'
[2] and 'nuclear pulse propulsion'
[3][4] :
'solar sail' involves getting the sun's light or a star's light ( the photons essentially ) to bounce off a thin metallic sail which is connected to a space-craft... the photon bouncing will propel the space-craft opposite to the direction of the sun/star.
'nuclear pulse propulsion' involves having a big space-ship ( with human crew/passengers ) that has a heavy metal dish ( of copper, most literature says ) at the end connected to the ship by a shock-absorbers assembly... low-power nuclear bombs stored at the back of the ship main body are somehow released behind the dish ( most likely using a crane system ) and are exploded at some distance from the dish... each bomb explosion will push at very high speeds towards the dish a propellent stored within the bomb assembly... the striking of the propellent with the dish will propel the ship forward... successive explosions will accelerate the ship to very high speeds. faster than a chemical-propulsive ship.
i thought then why can't the 'lightcraft' assembly include have the laser assembly ( multiple beams ) sitting at the backside of the human-crewed space-ship connected to the ship by some gantry towers... the bottom of the main ship body can have the curving-cone structure as in the experiment and some ablative material regularly released from the upper ring structure of the cone... or indeed instead of ablative material there could be explosive material like fission-capable uranium in form of gas or gel, taking inspiration from the experiments in icf ( inertial confinement fusion ), most notably by the usa government organization called
nif ( national ignition facility )
[5]... the lasers acting on the ablative material ( and turning it into plasma?? ) or on the nuclear material ( causing it to explode in a nuclear reaction ) will create the thrust to propel the ship... so why can't laser propel the space-ship it is connected to??
i must mention a experimental and radical form of propulsion technology for space-ships and atmospheric crafts - the 'emdrive'
[6][7][8], first proposed by a british engineer in year 2000 and then prototyped, but which was pooh-poohed throughout by western engineers/scientists until china conducted a experiment some years ago... the radical part is that the drive/engine uses no propellent and works by bouncing microwaves within a closed, hollow, conical metal container.
what we need is a non-traditional way of thinking... a clearing away of the drawing boards... de-learning most of what has been taught in schools and colleges.
edit : also, i don't believe too much in the recent western structure of "peer review" of experiments and discoveries... too many of these "peers" have their thinking clouded by conventional and fixed thinking.
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@Levina @Zibago @django @Hamartia Antidote
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[1]
Laser beam powered propulsion spacecraft (Lightcraft) - YouTube
[2]
Solar sail - Wikipedia, the free encyclopedia
[3]
Project Orion
[4]
Nuclear pulse propulsion - Wikipedia, the free encyclopedia
[5]
National Ignition Facility - Wikipedia, the free encyclopedia
[6]
Nasa confirms 'impossible' fuel-free thrusters DO work | Daily Mail Online
[7]
Evaluating NASA’s Futuristic EM Drive | NASASpaceFlight.com
[8]
Emdrive - Home ( website of the original inventor )
why are we so hell bent on reaching moon and mars, could not we just use those aforementioned things like laser or solar light to fix energy crisis on Earth------green energy-----laser for jet engines,cars,ships,cooking-------------------
