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Posted: Fri Dec 09, 2011 3:42 pm
by MrCrowley
That's awesome. Do they have a GPS controlled descent or has drift been calculated beforehand?

Posted: Sat Dec 10, 2011 3:53 am
by D_Hall
I know they have guidance on the way up and linear displacement was something like 10' at 20,000' altitude. On the way down I don't believe it was guided in any way but the chute wouldn't have been allowed to open fully until low altitude thereby minimizing drift.

Posted: Sat Dec 10, 2011 11:31 am
by saefroch
Any ideas as to what those red lines across the view are? Do you know if that rocket all fuel or if there was a test payload?

Very impressive.

Posted: Sun Dec 11, 2011 5:38 pm
by D_Hall
Said rocket certainly wasn't all fuel. If nothing else it had all the electronics, hydraulics, etc. associated with the flight control system (notice that there was no launch rail!). There were also cameras, GPS receivers, and such. So when you ask about "test payload"... Well, what do you define as a "test payload?"

As for the red lines... Almost certainly melted paint or similar running down from the nose cone.

Posted: Mon Dec 12, 2011 5:21 pm
by saefroch
Ah, didn't think of all that. I'm interested to know how much one could haul into space with a rocket like that. It sounds like some of the equipment on/in it wasn't actually required for operation, but most of it was, no? Do we have any numbers?

Posted: Mon Dec 12, 2011 5:25 pm
by MrCrowley
I'd be interested in how much more it takes to get a rocket like that to the middle of the thermosphere. Is it just a matter of a bigger rocket (more fuel?) or does the rocket need to be travelling faster (different design, fuel, etc,.) to get in to orbit?

Posted: Mon Dec 12, 2011 7:58 pm
by Insomniac
To get into orbit, it has to be travelling a LOT faster. So far, to my knowledge this has only ever been achieved with multi-stage rockets, where excess weight can be shed as the fuel is used up allowing the last stages to reach extremely high velocity. There's never been a successful single-stage-to-orbit rocket.

Posted: Mon Dec 12, 2011 8:42 pm
by evanmcorleytv
That was an awesome launch! Where are you located? And where do you work? This is the field that I hope to go into!

Posted: Mon Dec 12, 2011 9:31 pm
by D_Hall
MrCrowley wrote:I'd be interested in how much more it takes to get a rocket like that to the middle of the thermosphere. Is it just a matter of a bigger rocket (more fuel?) or does the rocket need to be travelling faster (different design, fuel, etc,.) to get in to orbit?
JUST getting to the thermosphere wouldn't be that difficult. The rocket shown could be scaled up with very little difficulty. Make it maybe 2X the diameter, slap 4 motors on the back (each identical to the one that's currently there), and double it's length. Take off would be slower, but I suspect you could reach the thermosphere that way; especially if you went with a boosted dart design.

Orbit, however, is a whole nuther ball o' wax. The velocity requirements are (as Insomniac says), much, much greater.

Single stage to orbit CAN be done, however. The technology to do it is 40 years old(*). It's just not practical as it's cheaper and more effective to use staged rockets.


(*) If flown with basically no payload, the 1st stage of the Atlas rocket is capable of SSTO.

Posted: Mon Dec 12, 2011 9:36 pm
by Gun Freak
Fascinating :)

Posted: Mon Dec 12, 2011 9:41 pm
by mobile chernobyl
D_Hall wrote:...

Single stage to orbit CAN be done, however. The technology to do it is 40 years old(*). It's just not practical as it's cheaper and more effective to use staged rockets.


(*) If flown with basically no payload, the 1st stage of the Atlas rocket is capable of SSTO.
Our school (and many others) have bought space upon Atlas rockets to send little cube satellites into space. Not sure which model in the series it was though.

At $15K a seat (about 20cm cubed sitting space...)... getting there ain't cheap!

Posted: Mon Dec 12, 2011 9:47 pm
by Insomniac
@D_Hall,

Ok, so SSTO is achievable. But do you know if it has been done? Since it's impractical for any real payload delivery purposes, do you know if anyone has successfully achieved SSTO or whether it is simply a theoretical ability?

Posted: Mon Dec 12, 2011 10:07 pm
by D_Hall
Insomniac wrote:@D_Hall,

Ok, so SSTO is achievable. But do you know if it has been done? Since it's impractical for any real payload delivery purposes, do you know if anyone has successfully achieved SSTO or whether it is simply a theoretical ability?
To my knowledge it has never been done. You'd have to find somebody who was willing to dump $10M or so just to say that they had done it. I mean, a Falcon 1 could do the same mission (albeit with stages) for a lot less money.