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Have you guys heard about JP Aerospace? This is low budget independent space program. They figure they could make it to orbit by using specialized balloons. Sounds crazy? Well, at least they are putting their time and money where their mouth is.
This is their blog update:
www.jpaerospace.com/blog/
Their main site indicating past upper atmosphere missions:
www.jpaerospace.com/
This is their blog update:
www.jpaerospace.com/blog/
Their main site indicating past upper atmosphere missions:
www.jpaerospace.com/
posted by:
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St. Louis
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Re: JP Aerospace -- balloning to space
Tue, September 15, 2009 - 12:01 AMWas out at the Black Rock Desert a good decade ago and happened upon this team after one of their flights had a, well, learning-experience of a landing. Picked up a postage-stamp remnant of their rocket from the subsequent crash-site during a chat with JP himself. Thanks, Eric for puting them back on my curiosity radar! -
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Re: JP Aerospace -- balloning to space
Tue, September 15, 2009 - 8:30 AMThanks Tom for sharing that.
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Re: JP Aerospace -- balloning to space
Sat, October 3, 2009 - 6:44 PMI see and like the business model, but I don't see much REAL advantage in "rockoons" like JP's for getting into orbit. 98,000 feet is less than 20 miles. You still have at least 80 miles to go while supporting a payload and accelerating to orbital velocity. The fuel expenditure and mass ratio are going to be substantially the same as launching from the ground. Anyone who's got a better command of the physics and wants to correct me with quantitative details, please feel free. -
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Re: JP Aerospace -- balloning to space
Mon, October 5, 2009 - 11:33 AMactually, launching from altitude reduces the atmospheric drag.....a lot. So you will need less fuel than on the ground. And you can use most of your fuel for horizontal velocity which is a requirement for orbit. -
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Re: JP Aerospace -- balloning to space
Mon, October 5, 2009 - 11:54 AMAtmospheric pressure is closely related to atmospheric density.
The following is a wiki about atmospheric pressure:
en.wikipedia.org/wiki/Atmo...c_pressure
There's a graph showing atmospheric pressure related to altitude. It shows that at 52,000 ft the atmospheric pressure is a tenth of that at sea level, and that at 101,381 its one hundredth.
And here is a wiki on the equation for atmospheric drag:
en.wikipedia.org/wiki/Drag_equation
You can see that atmospheric drag is directly related to atmospheric density.
So launching at altitude reduces the drag tremendously thus the fuel required to get to orbit is much less. And for a rocket launched from the ground, most of the fuel is expended trying to overcome the atmospheric density along with gravity.
Its interesting to see a launch with an on board camera. When the first stage falls away, the seconds stage starts, and as it goes up high and higher the plum form the rocket gets a lot larger. That's a function of atmospheric density. -
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Re: JP Aerospace -- balloning to space
Mon, October 5, 2009 - 12:09 PMrocket plume example (SpaceX Falcon1 flight 5):
www.youtube.com/watch
Starting at around minute 3:08 in this video you see the plume from the first stage get bigger and bigger as the rocket travels through less and less dense atmosphere. Its a vivid demonstration on how the atmospheric pressure changes with altitude.
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