Author Topic: Upper Stratosphere "near-space" station for "space" tourism?  (Read 27703 times)

Offline ChrisWilson68

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Plasma thrusters are a subset of ion thrusters.

No they're not. Plasma is not ions, by definition.

Actually, plasma is ions, mixed in with electrons.  Turning a gas into a plasma is called "ionizing" it.

The Wikipedia entry for "Plasma propulsion engine" starts with "A plasma propulsion engine is a type of Ion thruster..."

Offline QuantumG

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Actually, plasma is ions, mixed in with electrons.  Turning a gas into a plasma is called "ionizing" it.

The Wikipedia entry for "Plasma propulsion engine" starts with "A plasma propulsion engine is a type of Ion thruster..."

Yah! Score one point for Chris.
Human spaceflight is basically just LARPing now.

Offline ChrisWilson68

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Seeing as you're disinterested in actually reading what was linked, can you please stop commenting on it like you have?

It seems more likely you're the one who is uninterested in actually reading what was linked, since what I've said is consistent with the article while what you said is not.

If you think I misrepresented anything in the article you linked to, please quote the specific part of the article and what I said that you claim is inconsistent with it.

Offline R7

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*Sigh*

Summary of QG's link:

- Shotput I test used Sergeant X248 Sergeant XM-33/ABL X248 powered suborbital rocket to send Echo prototype up to test how it inflates.
- Rocket burnout happened at 60miles (~320kft!), then payload separated and started to inflate.
- Residual air intentionally left inside folded mylar balloon expanded too quickly in near vacuum, damaging the balloon.
- Balloon pieces feel back down creating spectacular light show.
- The public was told uplifting news story which didn't mention the failure at all and gave false impression that the balloon fell into sea intact. You know, cold war and all, would have been embarrassing to admit failure while the Russians were seemingly(their censorship was at least as good ;)) getting everything right.


So yeah, technically big mylar balloons have been flown hypersonic through atmosphere ... while safely riding packed under rocket PLF.

edit: fixed the rocket description, those are the first and second stages of the sounding rocket.
« Last Edit: 06/19/2013 08:59 am by R7 »
AD·ASTRA·ASTRORVM·GRATIA

Offline QuantumG

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.. and five more flights. Including a completely successful deployment.

But hey.. way to reward the know-it-all who can't even read a chapter.
« Last Edit: 06/19/2013 08:41 am by QuantumG »
Human spaceflight is basically just LARPing now.

Offline R7

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.. and five more flights. Including a completely successful deployment.

Yes, when done at least 60 miles up  ;)

edit: from the article
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... the Shotput tests, whose ABL X248 carried the test balloons only to 200 to 250 miles above the surface ...
« Last Edit: 06/19/2013 09:26 am by R7 »
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Offline Vultur

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http://nextbigfuture.com/2011/10/floating-airship-could-radically-reduce.html

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Question: For the airship going to orbit, would the engines be chemical, ion, or some sort of hybrid?
The engines would be a hybrid, employing both ion thrusters and chemical propulsion. At certain points we will be using ion thrust, and at other points we will be using chemical. There is a tradeoff between efficiency and time to orbit, the more efficient you are, the longer it takes to achieve orbital velocity. Rockets are measured in terms of specific impulse, which provides an indication of the efficiency of the system, with higher being better. The specific impulse of our hybrid is about 1100, which compares to about 450 for chemical rockets and 30,000 for ion thrusters. So this hybrid can either be viewed as being the most efficient chemical rocket ever, or the least efficient ion rocket.

Question: So this rocket is half ion and half chemical?
Yes, it is almost always half and half. The final insertion is all chemical. The chemical rocket will use wax/nitrous oxide. That is what we are currently testing. With sufficient R&D, I am confident that we could get a hybrid engine up to 2,000 specific impulse. That would obviously have a beneficial effect on payload capacity, perhaps as much as a quarter increase in payload.

Hmm, well, that provides some hope. Although I'm still skeptical what the ion engines can actually contribute...

Offline Vultur

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I looked at the Echo link and I don't see anything stratospheric/mesospheric. There was one failed deployment at 60 miles, but the air's far thinner there than ~200k ft (~38 miles). What am I missing?

Online FutureSpaceTourist

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Recent Facebook updates suggest JPA are making progress with their next Ascender:

https://www.facebook.com/jpaerospace/posts/517502808298901:0

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Inside the tail of the new Ascender

https://www.facebook.com/jpaerospace/posts/520246294691219:0
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Putting away the port Ascender envelope at the end of the day.

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