Space Gun

[maheshkhati]

In 1992, I submit mathematical detail idea of space gun to NASA & ISRO. They appreciated that thoughts but problem is atmosphere. If anything moves suddenly with orbital velocity then it disintegrate. Spaceship will collide with dense atmosphere. This problem can be solve if we move gun to the upper atmosphere.

I am putting this new idea for discussion.

here, short paper is attached. 

spacegun.pdf

[Buffy]

Have you read From the Earth to the Moon?

 

Are you seeing this as a solution for putting anything useful into orbit? Have you considered the G-forces that are encountered during acceleration in the barrel? 

 

While it's true you need less acceleration to overcome the Earth's gravity starting from high altitude, assuming your gun is stationary relative to some point on Earth, your payload still must be accelerated from 500 meters/sec to orbital velocity of 30,000 meters per second inside it the time it takes to reach the end of your barrel. You may find that nothing organic would survive and neither would most mechanical devices. 

 

The US Dept of Defense tried a gun launcher with Project HARP in the 1960s, but it was then only funded for re-entry experiments. The inventor behind it, Gerald Bull, had the same dream as you, but never succeeded in getting anywhere with it, largely due to the G-Force issues, and while he got funding from Saddam Hussein (who really just wanted a big gun to fire at Iranians), he was assassinated in Belgium in 1990, which has kept the conspiracy theorists going about how "they" wanted to suppress the idea that a gun is the best way to get into space.

 

 

It is astonishing to realize that until Galileo performed his experiments on the acceleration of gravity in the early seventeenth century, nobody questioned Aristotle's falling balls. Nobody said, Show Me! :phones:

Buffy 

[Vmedvil]

Use Teflon Thermal shielding, it is the same stuff that spaceship heat shields use to protect them from thermal damage during reentry. If you are have problems with the mass driver bullet breaking up make the bullet of Teflon, otherwise I don't see a problem with a orbital gun physically. You would be surprised the level of thermal resistance possible with Nonstick coatings along with a high tensile strength.

 

[maheshkhati]

You are true for human travel & delicate electronics, this gun is not useful due to high acceleration but for other pay load like cargo & sturdy satellite, this can be use.. For example, in page no 9 of 

paper http://www.maheshkhati.com/spacegun.pdf  

It is clear that electronics of satellite can be operative at the acceleration of 20000 g. (News of Times of India) This was the news of 2006. Now, technology is again improved, So,  this range will definitely more than previous.

-----------------------------------------------------------------------------------------------------------------------------

Teflon is really a magical substance. This can be use here for thermal shield. I think http://www.maheshkhati.com/spacegun.pdf , this gun is also possible by using such thermal shield. We can even use some shield which burn completely by air friction but protect inner satellite by sacrificing our self. 

[exchemist]

Use Teflon Thermal shielding, it is the same stuff that spaceship heat shields use to protect them from thermal damage during reentry. If you are have problems with the mass driver bullet breaking up make the bullet of Teflon, otherwise I don't see a problem with a orbital gun physically. You would be surprised the level of thermal resistance possible with Nonstick coatings along with a high tensile strength.

 

 

Are you sure about this? I can't find any reference to Teflon being used as a spacecraft heat shield. See here for example: https://cosmosmagazine.com/technology/how-do-heat-shields-spacecraft-work  Nothing about Teflon here, so far as I can see.

 

Do you have a reference showing Telfon is used in this application?

[Vmedvil]

Are you sure about this? I can't find any reference to Teflon being used as a spacecraft heat shield. See here for example: https://cosmosmagazine.com/technology/how-do-heat-shields-spacecraft-work  Nothing about Teflon here, so far as I can see.

 

Do you have a reference showing Telfon is used in this application?

 

Go a little deeper https://ntrs.nasa.gov/?R=19730051530 and http://abcnews.go.com/Technology/nasa-tests-crucial-heat-shield-technology-future-mars/story?id=37518000

Edited November 10, 2017 by Vmedvil

[exchemist]

Go a little deeper https://ntrs.nasa.gov/?R=19730051530 and http://abcnews.go.com/Technology/nasa-tests-crucial-heat-shield-technology-future-mars/story?id=37518000

Thanks. However I see the first is just a research paper, examining the future possibility of using Teflon, in conjunction with a reflector material, while the second is nothing to do with heat shields at all. 

 

So in fact it appears Teflon has not so far been used as a spacecraft heat shield, though it may have some future promise as part of a composite design.

[Vmedvil]

Thanks. However I see the first is just a research paper, examining the future possibility of using Teflon, in conjunction with a reflector material, while the second is nothing to do with heat shields at all. 

 

So in fact it appears Teflon has not so far been used as a spacecraft heat shield, though it may have some future promise as part of a composite design.

 

"A 9-foot diameter HIAD model made of Zylon and Teflon materials was tested using a vacuum pump, with engineers repeatedly checking it for potential damage, according to a NASA blog post. With that test successful, engineers now plan to create a larger HIAD that can be packed in a rocket and withstand extreme temperatures, such as those it may encounter when a spacecraft descends onto Mars."

[exchemist]

"A 9-foot diameter HIAD model made of Zylon and Teflon materials was tested using a vacuum pump, with engineers repeatedly checking it for potential damage, according to a NASA blog post. With that test successful, engineers now plan to create a larger HIAD that can be packed in a rocket and withstand extreme temperatures, such as those it may encounter when a spacecraft descends onto Mars."

HIAD is not a heat shield. 

 

It is a device for inducing atmospheric drag, thereby reducing the need for a heat shield. 

[Vmedvil]

HIAD is not a heat shield. 

 

It is a device for inducing atmospheric drag, thereby reducing the need for a heat shield. 

 

Yes, but the HIAD would be subject to extreme temperatures when it reduces the drag made of Zelfon and Teflon.

Edited November 11, 2017 by Vmedvil

[exchemist]

Yes, but the HIAD would be subject to extreme temperatures when it reduces the drag made of Zelfon and Teflon.

There is a lot more to a heat shield than simply ability to tolerate high temperatures. And this is not a heat shield. It's just a kind of air brake or parachute, for use at very high speeds in a very tenuous atmosphere. 

 

The other article is actually more helpful in that it suggests, if I am reading it right, that it may be possible to make a true heat shield of Teflon, backed by some form of reflector. Evidently Teflon on its own would not work. That would seem to be a new and very different approach from the ceramic tile or graphite heat shields used up to now.  

Edited November 11, 2017 by exchemist

[michaellee8]

Hey I think your idea can be combined with railgun https://en.m.wikipedia.org/wiki/Railgun