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#11
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SuperDraco's Also Key to Falcon 9 Reuse?
Jeff Findley wrote:
From what I understand, reusable launch vehicles are being treated a bit different than aircraft. The guys on ARocket know the gory details because they're actually fling small, reusable, VTVL liquid fueled vehicles for quite some time. SpaceX is definitely scaling things up, but I don't see anything they're trying that's completely unproven. Good point. I should go back through the ARocket archive and look into this a bit more, esp. to see what the Armadillo folks have to say about this. Dave |
#12
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SuperDraco's Also Key to Falcon 9 Reuse?
In article , nospam@
127.0.0.1 says... Jeff Findley wrote: From what I understand, reusable launch vehicles are being treated a bit different than aircraft. The guys on ARocket know the gory details because they're actually fling small, reusable, VTVL liquid fueled vehicles for quite some time. SpaceX is definitely scaling things up, but I don't see anything they're trying that's completely unproven. Good point. I should go back through the ARocket archive and look into this a bit more, esp. to see what the Armadillo folks have to say about this. Since I'm an aerospace engineer by degree, I tend to pay close attention to the technical side of things on ARocket. But the observation has been made on ARocket many times that it is more difficult and time consuming to get launch licenses than engineering types like me would think. As far as current state of the art is concerned, I'd think that Armadillo Aerospace has as much experience with liquid fueled rocket powered VTVL control algorithms as anyone else in the business. Jeff -- " Ares 1 is a prime example of the fact that NASA just can't get it up anymore... and when they can, it doesn't stay up long. " - tinker |
#13
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SuperDraco's Also Key to Falcon 9 Reuse?
Jeff Findley wrote:
As far as current state of the art is concerned, I'd think that Armadillo Aerospace has as much experience with liquid fueled rocket powered VTVL control algorithms as anyone else in the business. No doubt! The guys at SpaceX that think they can bring F9 stage one down in one piece ought to talk the Armadillo folks about active control of something with a long lever arm. Forget about cross-winds, just pretend you're bringing the whole thing down in a vacuum. That seems plenty hard right there. Oh and don't forget the weight in that arm tends to shift a bit to and fro... Dave |
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SuperDraco's Also Key to Falcon 9 Reuse?
David Spain was thinking very hard :
Jeff Findley wrote: As far as current state of the art is concerned, I'd think that Armadillo Aerospace has as much experience with liquid fueled rocket powered VTVL control algorithms as anyone else in the business. No doubt! The guys at SpaceX that think they can bring F9 stage one down in one piece ought to talk the Armadillo folks about active control of something with a long lever arm. Forget about cross-winds, just pretend you're bringing the whole thing down in a vacuum. That seems plenty hard right there. Oh and don't forget the weight in that arm tends to shift a bit to and fro... You seem to think that it is more difficult to control coming down than going up. /dps -- Who, me? |
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SuperDraco's Also Key to Falcon 9 Reuse?
Snidely writes:
David Spain was thinking very hard : Jeff Findley wrote: As far as current state of the art is concerned, I'd think that Armadillo Aerospace has as much experience with liquid fueled rocket powered VTVL control algorithms as anyone else in the business. No doubt! The guys at SpaceX that think they can bring F9 stage one down in one piece ought to talk the Armadillo folks about active control of something with a long lever arm. Forget about cross-winds, just pretend you're bringing the whole thing down in a vacuum. That seems plenty hard right there. Oh and don't forget the weight in that arm tends to shift a bit to and fro... You seem to think that it is more difficult to control coming down than going up. Powering through the atmosphere with nearly empty fuel tanks and no full second stage and payload on top (and the center of gravity resulting from that) *is* more difficult. A F9 first stage on its own with nearly empty fuel tanks will try very hard to fly with the bottom forward. Jochem -- "A designer knows he has arrived at perfection not when there is no longer anything to add, but when there is no longer anything to take away." - Antoine de Saint-Exupery |
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SuperDraco's Also Key to Falcon 9 Reuse?
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SuperDraco's Also Key to Falcon 9 Reuse?
Snidely wrote:
You seem to think that it is more difficult to control coming down than going up. I do. Dave |
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SuperDraco's Also Key to Falcon 9 Reuse?
David Spain wrote:
Snidely wrote: You seem to think that it is more difficult to control coming down than going up. I do. Dave Unless I can get rid of that bulky, aerodynamic column with loose mass that I can't thrust into stability and that works against me most at the worst time possible, a time when I need it to be most stable, when my airspeed is almost nil. Dave |
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SuperDraco's Also Key to Falcon 9 Reuse?
David Spain formulated on Thursday :
David Spain wrote: Snidely wrote: You seem to think that it is more difficult to control coming down than going up. I do. Unless I can get rid of that bulky, aerodynamic column with loose mass that I can't thrust into stability and that works against me most at the worst time possible, a time when I need it to be most stable, when my airspeed is almost nil. I don't know what SpaceX's response to this is, but I'd think that a small ring of thrusters at the upper end would provide sufficient control (with today's processors) and would have less impact on the payload-to-orbit than adding a set of SuperDraco's. I'm sure Elon's people have been keeping an eye on flight tests by Bezo's crew and Armadillo, plus all the DC-X reports (granted that DC-X was stubbier than an F9-1st). /dps -- Who, me? |
#20
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SuperDraco's Also Key to Falcon 9 Reuse?
Snidely wrote:
I don't know what SpaceX's response to this is, but I'd think that a small ring of thrusters at the upper end would provide sufficient control (with today's processors) and would have less impact on the payload-to-orbit than adding a set of SuperDraco's. Well that would help and yes I agree with what you say. I think you have a good idea there. I'm sure Elon's people have been keeping an eye on flight tests by Bezo's crew and Armadillo, plus all the DC-X reports (granted that DC-X was stubbier than an F9-1st). I'd be curious to know how stable Armadillo's tethered Stig runs were. That was one strange looking test rig. Anybody else ever try this? Dave |
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