Airship to Orbit, Airship video.

[spacefire]

no, MrMorris is an accountant of sorts, and if he's representative of that guild, I'd rather make do without.<br /><br />but you make a good point. I shall take 99 able engineers and one busty secretary. <div class="Discussion_UserSignature"> <p>http://asteroid-invasion.blogspot.com</p><p>http://www.solvengineer.com/asteroid-invasion.html </p><p> </p> </div>

 

[spacefire]

"Uh, some 17th century dude worked this out already. Can't remember was it Torricelli, Pascal or somebody else, but do remember a vivid image from some history book where a boat floated in the air, lifted by vacuum filled copper spheres. Too bad it didn't work then, doesn't work now and probably never will"<br /><br /><br />Francesco Lana's boat suspended under 4 metal spheres emptied of air is the first known sketch of an airship.<br /> <div class="Discussion_UserSignature"> <p>http://asteroid-invasion.blogspot.com</p><p>http://www.solvengineer.com/asteroid-invasion.html </p><p> </p> </div>

 

[grooble]

I want to build a flying pirate ship that instead of sails has a giant blimp type balloon lifting it, covered in a patchwork quilt to enhance the fantasy image of it.<br /><br />I'd fly around the earth giving stuff to kids.

 

[spacefire]

dob't forget to also build a ranch called Neverland <div class="Discussion_UserSignature"> <p>http://asteroid-invasion.blogspot.com</p><p>http://www.solvengineer.com/asteroid-invasion.html </p><p> </p> </div>

 

[jpowell]

Moving back to the real world a little, JP Aerospace is flying a development mission for the Dark Sky Station. It's a small balloon platform (under 12 feet wide and maybe smaller) that will unroll it's balloon during flight. The mission is called 'Away 28'.<br /><br />The large Dark Sky Stations will use this technology to replace balloons in flight. The next Dark Sky Station that we fly, (fall 2005) will be about 30 feet across and will also use this roller system. <br /><br />We have drawing and a pics at the web site:<br />www.jpaerospace.com<br />Look under the update log.<br /><br />John Powell<br />JP Aerospace, America's OTHER Space Program

 

[spacefire]

if crewed, you will have a re-entry module I assume? it would be good idea in case of an abort. <br />Such a big craft stands a higher chance of being hit by micro-meteorites or orbital debris than anything ever conceived, so you want to be able to separate the re-entry module and return to Earth if this happens.<br />at orbital altitudes, have you calculated how much bouyancy is produced by the 3rd stage airship?<br /><br />the orbit airship, will it look partially deflated when you launch it on the first flight? or are you going to assemble and inflate it at the dark-sky station?<br /> <br />what kind of payloads are you looking at taking to orbit with the intitial test vehicle?(1 mile long)<br /><br />why not a full triangle shape for the ATO? you would generate more lift dynamically that way?<br /><br />ok enough questions <img src="/images/icons/smile.gif" /> <div class="Discussion_UserSignature"> <p>http://asteroid-invasion.blogspot.com</p><p>http://www.solvengineer.com/asteroid-invasion.html </p><p> </p> </div>

 

[nacnud]

<font color="yellow">if crewed, you will have a re-entry module I assume? it would be good idea in case of an abort. <br /><br /><font color="white">More like a skydiving rig, there isn't the need to lose the velocity of an orbital abort.</font></font>

 

[spacefire]

how are you going to come back down if your airship is punctured? <div class="Discussion_UserSignature"> <p>http://asteroid-invasion.blogspot.com</p><p>http://www.solvengineer.com/asteroid-invasion.html </p><p> </p> </div>

 

[tap_sa]

fast?

 

[mrmorris]

<font color="yellow">"fast?"</font><br /><br />I would have said 'effortlessly'. Heck, that part is <b>simple</b>!

 

[spacefire]

exactly-in a fiery plume of gas. so you need a heatshield on the passenger compartment. <div class="Discussion_UserSignature"> <p>http://asteroid-invasion.blogspot.com</p><p>http://www.solvengineer.com/asteroid-invasion.html </p><p> </p> </div>

 

[cmedwards]

Hello again, JP.<br /><br />Speaking of Dark Sky Station, are they still selling those balsa wood DSS model kits? And has the oscillation problem that annoyed DSS 1 and destroyed DSS 2 been solved?<br /><br />I was once part of a group toying with designs for multi-cell high altitude balloons. We never got anywhere with it, but came up with a few testing techniques that might be useful. For example, rather than trying to employ balloons large enough to simulate a realistic center of pressure for your models, an oscillation problem might be better represented by turning the whole thing upside down and using bags partially filled with water instead of balloons. The greater inertia amplifies problems that might go unnoticed, and it's certainly easier to shake the model around. <br /><br />Hmm... Might get me one of those kits if they're still around.

 

[nacnud]

I've a question about the larger dark sky station to come.<br /><br />Away 28 plans to use a roller method of increasing the volume of the balloon to cope with the expansion of the gas (helium?) as the craft rises. I presume that this is for a variety of reasons, but is it planned for the larger dark sky stations to use a similar system but extended horizontally so a long tube is unrolled?<br />

 

[jpowell]

The roller system is designed specificly with the larger stations in mind. On the larger station the arms are segmented quite a bit. The result is the rollers won't be all that long. The roller and lifting gas balloon will be inclosed inside an outer envelope so from the outside the shape always stays the same.<br /><br />JP<br />www.jpaerospace.com

 

[lunatio_gordin]

wow. i think you've been mistaken for UFO's in the past.

 

[cmedwards]

"The roller and lifting gas balloon will be inclosed inside an outer envelope so from the outside the shape always stays the same. "<br /><br />Hmm. <br /><br />If I tried that with mere polyethylene, it would be an abrasion problem waiting to happen. <br /><br />It might still work though. It's wonderful how the slightest tension in the right direction will preserve folds in a balloon's fabric, and there's nothing to say you can't start off with the right folds. <br /><br />Good luck, JP.

 

[jpowell]

I've just added a new pic of the big airship and a drawing showing the whole ATO family of vehicles together.<br /><br />A week ago we also added pics from the tether test flight of the roll deployed balloon vehicle. Look under the "Update Log" section at the JPA web site.<br /><br />JP<br />www.jpaerospace.com

 

[barrykirk]

I've still got a big question about the airship that started this thread off. No matter how low it's density is. The gravitational acceleration is still the same. 9.8m/sec^2.<br /><br />You need lift force to overcome that acceleration. That lift force comes from buoyancy. OK, I'll buy that.<br /><br />Now they say that they will use an ion engine to gradually spiral out to orbit.<br /><br />Well, the moment that you start adding a horizontal velocity component you get drag. Now they are claiming to be so high in the atmosphere that the drag component will be negligible. That is where I have my problem with the system.<br /><br />The huge volume that allows enough buoyancy to get lift also comes with a huge surface area. If the air is thick enough to support the weight, won't it create drag? Enough drag to prevent you from getting to orbital velocity?<br /><br />I know that surface surface area to volume ratio goes down the bigger the object gets. But, we are talking about a huge surface area and a large velocity which both increase drag. And the counter to that drag is an ion engine that produces very low thrust.

 

[josh_simonson]

Seems to me that after a while the airship becomes a 'heavier than air' vehicle, using the thrust of the ion engine and an aerodynamic lifting body in the same way that an airplane is able to climb despite being heavier than air and having less thrust than mass.<br /><br />Could be that the thermal stress and friction of air molecules hitting the surface at 9km/s require that it be made of 'unobtanium' though.

 

[barrykirk]

But, if you had an antimatter spiked ion engine, I think you'd have enough thrust to get to orbit with one of those..... LOL

 

[nexium]

Can we compromise with; it is not presently practical above 140,000 feet? I don't think pressure gradient is essentuial to boyancy, but one gram of boyancy for a 100 ton ship gives almost zero accelleration and it would be over shadowed by 10 atoms per cubic meter of air resistance, light pressure, Earth's magnetic field, solar wind, Earth's gravity gradient, and punctured by micro meteories, which are dust size "asteroids" that orbit Earth or sun or the galaxy. Neil

 

[barrykirk]

Not that much O2 to burn that H2 that high up in the atmosphere. What is the density of air and H2 required to support combustion?

 

[nexium]

I don't think there is an exact pressure where combustion of an air-hydrogen mixture becomes impossible, but I will guess the fire hazzard is reduced by 1000 = negligible at 35,000 feet compared to the sea level fire hazzard for typical balloon designs. The lifting power of hydrogen is not double that of helium, more like 20% better. Methane or hot air are about half as good as helium in typical balloons. Neil

 

[jpowell]

I don't think most people are aware of the state of balloon technology. Several flights over 170,000 feet have taken place and it looks like someone will fly a balloon over 200,000 feet in the next few years, (I hope it's me, but the competition is stiff).<br /><br />JP<br />www.jpaerospace.com

 

[rocketman5000]

what are the air currents like at 200,000ft? would this thing be able to stay relatively stationary?