Orion Shuttle time gap

[Fred]

"Lightcraft" utilized a ground-based laser to detonate thin layers of propellant on the underside of the craft, propelling it upward. Unfortunately, a quick search online has only provided information about their progress from the year 2000 or before.

My personal favorite methodology for routine, inexpensive shuttle service is pretty well outlined at Alternative Accelerators. By utilizing a ground-based initial thrust system such as a maglev rail, an air breathing carrier craft to reach the uppermost useable atmosphere, and rockets for only the nearly frictionless last leg to space; efficiencies are maximized by using each propulsion system where it performs best. Moving the craft from zero to near mach can be done with resources on the ground so that the craft need not supply any of this propulsion, thereby leaving more room for propellant, crew, and cargo. An airbreathing stage utilizes atmospheric oxygen instead of onboard oxidizer to burn it's fuel, again leaving more room for propellant, crew, and cargo. Also, an airbreathing carrier could separate from the spacecraft proper at the edge of its operating envelope, removing the unnecessary wings and weight associated with it. The last stage to orbit would utilize the rockets where they work best and could easily be almost any shape deemed necessary for it's specific purpose and viable for reentry.

Spaceship One used a carrier from ground to 50,000 feet operating two regular jet engines before the ship itself detached and ignited its own hybrid rocket motor for ascent to over 100km. It's an approach that differs only slightly from the X-15 project years ago, and if I'm not mistaken - it's the design that won the X-prize.

For interplanetary and galactic travel, I think it would be best to put the pieces of a larger ship into orbit where they would be assembled before departure. The ship could simply remain in orbit for maintenance upon return, while the crew shuttled down to the planet surface for drinks and conjugal visits. The larger ship could make use of a different kind of engine, perhaps one that provided approx. 1G of acceleration over a long period of time to provide the crew with some simulated gravity.

Peace,
Mike

Interesting post. Using a laser to ignite propellant. How cool is that
Cheers
fred

 

[cjl]

"Lightcraft" utilized a ground-based laser to detonate thin layers of propellant on the underside of the craft, propelling it upward. Unfortunately, a quick search online has only provided information about their progress from the year 2000 or before.

My personal favorite methodology for routine, inexpensive shuttle service is pretty well outlined at Alternative Accelerators. By utilizing a ground-based initial thrust system such as a maglev rail, an air breathing carrier craft to reach the uppermost useable atmosphere, and rockets for only the nearly frictionless last leg to space; efficiencies are maximized by using each propulsion system where it performs best. Moving the craft from zero to near mach can be done with resources on the ground so that the craft need not supply any of this propulsion, thereby leaving more room for propellant, crew, and cargo. An airbreathing stage utilizes atmospheric oxygen instead of onboard oxidizer to burn it's fuel, again leaving more room for propellant, crew, and cargo. Also, an airbreathing carrier could separate from the spacecraft proper at the edge of its operating envelope, removing the unnecessary wings and weight associated with it. The last stage to orbit would utilize the rockets where they work best and could easily be almost any shape deemed necessary for it's specific purpose and viable for reentry.

Spaceship One used a carrier from ground to 50,000 feet operating two regular jet engines before the ship itself detached and ignited its own hybrid rocket motor for ascent to over 100km. It's an approach that differs only slightly from the X-15 project years ago, and if I'm not mistaken - it's the design that won the X-prize.

For interplanetary and galactic travel, I think it would be best to put the pieces of a larger ship into orbit where they would be assembled before departure. The ship could simply remain in orbit for maintenance upon return, while the crew shuttled down to the planet surface for drinks and conjugal visits. The larger ship could make use of a different kind of engine, perhaps one that provided approx. 1G of acceleration over a long period of time to provide the crew with some simulated gravity.

Peace,
Mike

While airlauching sounds all fine and good, the reality is that an airbreathing launcher adds almost no benefit and many costs to a rocket compared to a pure ground launch. See here for more.

As for the laser idea, it definitely sounds interesting. Do you have any idea what kind of exhaust velocities they were achieving?

 

[Peartree]

Ultimately, to build anything sizable in space is impracticable. How long and how many launches has it taken for ISS? How many launches would it take to build a spacecraft that included significant habitation and propulsion modules that could carry a human crew to the boundaries of the solar system? 100? 400? Yikes! Long-term space elevators are the way to go (although not without their problems - radiation is an obvious one). this has been labelled as fantasy for decades but now engineers and even NASA are realizing that it will soon be technically feasable given recent advancements in materials science. IEEE Spectrum (Electrical Engineering magazine) ran a feature story on this technolgy sometime last year. More information can be found in these links.

https://www.spectrum.ieee.org/print/1690

https://usgovinfo.about.com/library/weekly/aa041702a.htm

https://en.wikipedia.org/wiki/Space_elevator

 

[skippy-2]

I think actually mtmind you will find the Lightcraft uses no propellant of any kind. The ground based pulsed laser heats air behind the craft to force it upwards. The vehicle is 'laser powered' not 'laser ignited propellant powered'.

We are well overdue for a new spaceflight paradigm...

A lot of people will say that the DC-X or similar would have been a better option than the shuttle, including such luminaries as John Carmack.

https://en.wikipedia.org/wiki/McDonnell_Douglas_DC-X

https://www.armadilloaerospace.com/n.x/Armadillo/Home

Hindsight is always 20/20.

As others have said in this thread, space elevators will be the most cost effective way to get cargo into LEO. That technology however is a number of years away from bearing fruit. Until then, Progress capsules will continue to be a major part of ISS construction and supply.

All IMHO of course.

 

[eastvolt]

Forget rockets. I've got my money on the Space Elevator!

Definitely a promising technology especially when you consider phase 2 entails the use of capturing an asteroid and tethering it above earth in a geosynchronous orbit!

 

[cjl]

Of course, the problem with something like the DC-X is that it is physically impossible with any propellants we have right now...

That tends to put a damper on most plans...

 

[user 1400]

I had forgotten about the space elevator concept, I very much favor that as a mover of large quantities of material etc to orbit. I doubt they'll have one up by the end of the year, but but maybe while I can still go for a ride.

I think actually mtmind you will find the Lightcraft uses no propellant of any kind. The ground based pulsed laser heats air behind the craft to force it upwards. The vehicle is 'laser powered' not 'laser ignited propellant powered'.

I had thought that myself until I read Riding Laser Beams to Space at Space.com. In the article they state:

"The laser energy strikes a parabolic condensing reflector mounted on the bottom of the Lightcraft. This area is lined with a thin coat of propellant. Struck by laser pulses, the propellant detonates and thrusts the Lightcraft upward."​

This is the only source I've seen so far that mentions any propellant.

As far as the carrier craft for a tri-mode launch system is concerned, I would not prefer the plane-like version except for small, fast response launches. I'm thinking in terms of providing emergency supplies or crew to an orbital station or a larger craft already in orbit and unable to reenter the atmosphere for whatever reason. In a the tri-mode concept, the air breathing stage is simply that - an air breathing ramjet running on solid or liquid fuel, which has already been accelerated to operational velocity by the ground support system.

Near Ft. Stockton, TX there are plenty of nice plateaus. I can see a ten or twenty mile, large scale maglev rail aimed straight East at one of those plateaus and then curving upward more or less with the curve of the land to terminate aimed nearly vertical. A relatively large launch vehicle could be accelerated down that rail to be catapulted directly at the sky and would need no wings to provide lift. If there were an issue half-way down the track, the launch could be aborted by reversing the maglev rail and the ramp would give that extra insurance by utilizing gravity as a brake. When I referred to the first stage as a carrier craft, I merely meant that it would be reuseable and might have deployable wings and/or aerobrakes to return safely to a designated landing site.

Peace,
Mike

 

[skippy-2]

Of course, the problem with something like the DC-X is that it is physically impossible with any propellants we have right now...

That tends to put a damper on most plans...

Oh, details, details!

 

[skippy-2]

[snip]

I had thought that myself until I read Riding Laser Beams to Space at Space.com. In the article they state:

"The laser energy strikes a parabolic condensing reflector mounted on the bottom of the Lightcraft. This area is lined with a thin coat of propellant. Struck by laser pulses, the propellant detonates and thrusts the Lightcraft upward."​

This is the only source I've seen so far that mentions any propellant.[snip]

Good link Mike. I agree, that is the only article that mentions propellant in any way, shape, or form. My conclusion is that they have it wrong!

There is some good information here on lightsails and laser lightcraft:

https://www.vectorsite.net/tarokt_6.html#m4

especially the way the ship is designed to function below Mach 1, above Mach 1 and above Mach 11 (Mach 11!!).

Good thread guys!

 

[Robert Davidson]

New propulsion would be great if the time was available to develop it. And the way safty freaks cry when a nuke powered probe go's up could you imagine a large ship? And when the next president comes in office he or she will cut or outright cancel the whole deal. They were test firing nuke engines in the 60's so the technology is there. But we all know thet has been moth balled instead of improving it.
I love space exploration but I think people worry more about a $20 mil sports contract than hire more engineers. I could go on for hours on the subject but I will stop for now.

I now the feeling. Imagine if "The Astronaut Farmer" had been given a 120 million dollar budget from Hollywood. They might have actually have built a real rocket.

 

[Chilly]

Are any companies actually cutting metal on this?
Cheers
Fred

SpaceX has recently passed financial and design evaluation gates with NASA for the COTS program. Besides the Falcon launchers, they have a great capsule concept called Dragon which is their COTS focus.

XCOR has recently gotten some solid financing for their Xerus program, which will begin as a suborbital ship. They intend to go orbital at some point, and I believe they probably will be successful.

And of course, there's Virgin Galactic. Their eventual goal is suborbital point-to-point travel (which I really like for the long-term career prospects).

All these are at some stage of cutting metal. When you say no "U.S." manned launch, don't count out the private programs. The sad thing is they'll probably render NASA superfluous.

Keep your eyes out for a new X-Prize contest that's supposed to be announced Sep. 13th. It's supposed to be pretty audacious.

 

[Nerull]

The sad thing is they'll probably render NASA superfluous.

Unlikely, but if they let NASA concentrate on what only it can do well (research and exploration) that'll be a positive. NASA probobly isn't the best suited to run cargo back and forth, but private companies won't launch space probes or explore the solar system.

 

[Chilly]

Unlikely, but if they let NASA concentrate on what only it can do well (research and exploration) that'll be a positive. NASA probobly isn't the best suited to run cargo back and forth, but private companies won't launch space probes or explore the solar system.

That was kind of my point. NASA's proper role should be research and exploration. But building all-new launchers when truckloads of tax $$ have already been spent on Delta IV and Atlas V is just stoopid, IMO. I really wish we were using multiple launches and developing on-orbit propellant storage & transfer. That would eliminate the perceived need for another Saturn V-class vehicle (regardless of how much I'd like to see another one).

 

[Fred]

SpaceX has recently passed financial and design evaluation gates with NASA for the COTS program. Besides the Falcon launchers, they have a great capsule concept called Dragon which is their COTS focus.

XCOR has recently gotten some solid financing for their Xerus program, which will begin as a suborbital ship. They intend to go orbital at some point, and I believe they probably will be successful.

And of course, there's Virgin Galactic. Their eventual goal is suborbital point-to-point travel (which I really like for the long-term career prospects).

All these are at some stage of cutting metal. When you say no "U.S." manned launch, don't count out the private programs. The sad thing is they'll probably render NASA superfluous.

Keep your eyes out for a new X-Prize contest that's supposed to be announced Sep. 13th. It's supposed to be pretty audacious.

Have any of them actually built a rocket that will boost something into orbit or carry cargo to the ISS?
Cheers
fred

 

[DaveCombs]

That was kind of my point. NASA's proper role should be research and exploration. But building all-new launchers when truckloads of tax $$ have already been spent on Delta IV and Atlas V is just stoopid, IMO. I really wish we were using multiple launches and developing on-orbit propellant storage & transfer. That would eliminate the perceived need for another Saturn V-class vehicle (regardless of how much I'd like to see another one).

What I guess I'm stuck on is the fact that yes, Ares will be online in a few years, and we can resume the long-term exploration goal then. But will the ISS be completely assembled by the time the STS is retired? I think that's the hang-up; are we sending up ISS bits using the shuttle because we also have to send up the manpower to do the assembly? And if so, does that exclude Delta etc. because they're not the right vehicle for spam-in-a-can?

(Plea of ignorance; I haven't read up that much on the whole timeline thing, so some of these questions may be moot. Wah.)

 

[TimW]

I'll put money on the US NOT returning to the moon. At least not with the current plans

With China already stating they will go to the moon, I'll bet we will.

 

[cjl]

Have any of them actually built a rocket that will boost something into orbit or carry cargo to the ISS?
Cheers
fred

Nope - all suborbital right now (if even off the ground). Of course, there is an absolutely HUGE energy difference between suborbital and orbital flight. To get something to 300km (LEO altitude) takes (within about 2%) 3 MJ/kg of energy. To get something to orbit, you need to lift it to altitude (same as before, 3MJ/kg), but you also then need to accelerate it to around 8km/s, which adds another 30MJ/kg, for a total of 33MJ/kg, or 11 times the amount of energy needed simply to lift something to orbital altitude. In addition, most of the current entries are not reaching 300km, but instead 100-130km, which drops the energy requirement to 1-1.3 MJ/kg, or 1/30 of the energy required for orbit.

 

[Fred]

Nope - all suborbital right now (if even off the ground). Of course, there is an absolutely HUGE energy difference between suborbital and orbital flight. To get something to 300km (LEO altitude) takes (within about 2%) 3 MJ/kg of energy. To get something to orbit, you need to lift it to altitude (same as before, 3MJ/kg), but you also then need to accelerate it to around 8km/s, which adds another 30MJ/kg, for a total of 33MJ/kg, or 11 times the amount of energy needed simply to lift something to orbital altitude. In addition, most of the current entries are not reaching 300km, but instead 100-130km, which drops the energy requirement to 1-1.3 MJ/kg, or 1/30 of the energy required for orbit.

And therein lies the rub
Cheers
fred

 

[henry8minus1]

Have any of them actually built a rocket that will boost something into orbit or carry cargo to the ISS?
Cheers
fred

Both SpaceX and Rocketplane Kistler are scheduled to launch demo missions of their respective COTS vehicles near the end of 2008.

https://www.spacex.com/

https://www.rocketplanekistler.com/

SpaceX has built and launched two Falcon 1 rockets. The first one failed just after it launched and the second did reach space, although its payload was not placed correctly into orbit.

To my knowledge Rocketplane Kistler has not launched anything yet, although they do have a strategic partnership with Orbital Sciences who has launched many satellites into orbit.

 

[Fred]

Both SpaceX and Rocketplane Kistler are scheduled to launch demo missions of their respective COTS vehicles near the end of 2008.

https://www.spacex.com/

https://www.rocketplanekistler.com/

SpaceX has built and launched two Falcon 1 rockets. The first one failed just after it launched and the second did reach space, although its payload was not placed correctly into orbit.

To my knowledge Rocketplane Kistler has not launched anything yet, although they do have a strategic partnership with Orbital Sciences who has launched many satellites into orbit.

Should be interesting
Cheers
fred