Source.

Most of you are familiar with the laser spacecraft, but few have seen the theory actually work in practice.

I think the last part of the video, which demonstrates a combination helium lift and microwave-based propulsion system has the most merit, long-term.

What's with the '70s style?

Excellent video Mugs, thanks. Apart from the propulsion, I was interested to see the use of an 'airspike' to reduce high speed drag. The fact that no-one currently uses it, is one of my pet gripes!

I was surprised about the efficiency. I always thought beamed energy was hugely inefficient, but was a plus because it didn't have to be lifted.

I would be concerned with the safety of the beam, especially after seeing the precaution they used with the little demo, along with frying it.

I also see a lot to do with height, but not much with speed. I would imagine it's just a matter of tilting the emitter, but with a horizontal movement, I would think line of sight would become a large issue.

I guess I'm just not clear on the application of it.

Would an astronaut have to be spun wildly before takeoff like in the demo?

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Numbers are not case sensitive. (me)

One slight breeze and you'd be toast, based on what I saw.

CJSF

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Two years ago moved from my town
I was looking up past the city lights
But the city lights got in my way

See the constellation ride across the sky
No cigar, no lady on his arm
Just a guy made of dots and lines

-from "See The Constellation"
by They Might Be Giants

Yeah, this worried me too. Still does. But then I thought that we've gotten used to strapping ourselves on top of a great big bomb. So maybe, given time... *Shrugs*

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Explosions are volumetric, and expand spherically so only a little bit is directed at a passenger. That laser uses directed energy, which is rather directional.

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"What you think you thought you saw you did not see." Agent J, MiB - Manhatten Bureau

They don't appear to be doing any sort of tracking with the beam. A real system would certainly use active tracking, which really won't be that hard to implement.

The beam stop...the idea of them jeopardizing satellites seems unlikely, I wonder if it was more airplanes and FAA regulations that made it necessary. A real orbital launch facility would presumably have the tracking information needed to avoid frying sats. Also, a large number of beam stations focused on a single target would result in missed beams spreading out as they pass the target, would give greater tolerance against beam/tracking failures, and would allow simple incremental expansion for larger vehicles.

I'm really more interested in an orbital version, which would avoid the satellite/aircraft hazards, and more importantly, would be workable with beam powers too low to lift the craft against gravity.

There are no degrees of dead Ara.

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No-one else like the airspike idea? They should use it more!

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But there are degrees of almost dead. At a km distance, I'd be more comfortable with a plate of metal between me and a kiloton nuclear explosion than between me and a multi-MW laser shooting at me.

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"What you think you thought you saw you did not see." Agent J, MiB - Manhatten Bureau

Where did you get 'km distance' from Ara? I was talking about chemical launch rockets.

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Yeah, but Project Orion was pretty cool. I wish we could have a least tried that. No more lethal then all the nuclear testing humanity was doing at that time.

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Several comments have been fielded about stability, and even a gentle sideways breeze spelling the death knoll...

Not so.

In an Earth to orbit design, the craft itself wouldn't be spun, but it's likely that a gyro aboard the craft may be spun to provide stability.

The reflecting cone would be able to be vectored, which would provide maneuvering thrust to keep the craft in the general vicinity of where it's supposed to be.

Fine-tuning the aiming would consist of both optical imaging/recognition as well as several position determining pulses between the thrust pulse. These positioning pulses would nail down precisely where the craft will be the moment the thrust pulse arrives.

Naturally, some of this is a bit difficult to achieve in a 4" pilot(less) project.

Just picked it at random.

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"What you think you thought you saw you did not see." Agent J, MiB - Manhatten Bureau

Awesome video!! Thanks for posting!

OMG its a UFO!

Seriously though, that was the coolest thing I have seen in a while.

His model weighed ounces, a space vehicle would weigh many tonnes. Slight breeze becomes hardly a worry.

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