Author Topic: SNC Captive Carry test sees Dream Chaser take flight  (Read 79125 times)

Online Chris Bergin

http://www.nasaspaceflight.com/2012/05/snc-captive-carry-test-dream-chaser-take-flight/

Great work by Lee Jay to get photos and videos of this test (L2). Used some in the article.
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Offline Lars_J

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Re: SNC Captive Carry test sees Dream Chaser take flight
« Reply #1 on: 05/29/2012 09:18 pm »
Thanks for the article - but a Q: Was this a full size Dream Chaser or a sub-scale one?
(The article did not specify - or I missed it)

Offline Jason1701

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Re: SNC Captive Carry test sees Dream Chaser take flight
« Reply #2 on: 05/29/2012 09:20 pm »
Pictures looked totally full scale.

Chris, you might want to write that ETA means Engineering Test Article. ;)
« Last Edit: 05/29/2012 09:24 pm by Jason1701 »

Offline Downix

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Re: SNC Captive Carry test sees Dream Chaser take flight
« Reply #3 on: 05/29/2012 09:21 pm »
Thanks for the article - but a Q: Was this a full size Dream Chaser or a sub-scale one?
(The article did not specify - or I missed it)
Based on the images, if its sub-scale, the finished one could not be lifted by Atlas, so I'd call this full-size.
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Online Chris Bergin

Thanks for the article - but a Q: Was this a full size Dream Chaser or a sub-scale one?
(The article did not specify - or I missed it)

Full size, but without engines. I'll add that into the article! :)
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Offline jimvela

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Re: SNC Captive Carry test sees Dream Chaser take flight
« Reply #5 on: 05/29/2012 09:26 pm »
Wow!  I wish I'd have known, I'd have tried to arrange a chance to shoot pictures.

Is the date of the drop test @ Edwards known?

Online Chris Bergin

Wow!  I wish I'd have known, I'd have tried to arrange a chance to shoot pictures.

Is the date of the drop test @ Edwards known?

Not known yet, but SNC have offered Lee Jay a tour and interview tomorrow! So more articles to come! :)
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Offline neilh

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Re: SNC Captive Carry test sees Dream Chaser take flight
« Reply #7 on: 05/29/2012 09:35 pm »
Sweet! Looking forward to the drop test.
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Offline Lee Jay

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Re: SNC Captive Carry test sees Dream Chaser take flight
« Reply #8 on: 05/29/2012 09:40 pm »
Wow!  I wish I'd have known, I'd have tried to arrange a chance to shoot pictures.

Is the date of the drop test @ Edwards known?

Not known yet, but SNC have offered Lee Jay a tour and interview tomorrow! So more articles to come! :)

The day after tomorrow, actually.

Offline Dappa

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Re: SNC Captive Carry test sees Dream Chaser take flight
« Reply #9 on: 05/29/2012 09:49 pm »
Nice scoop! Good article, great pictures! (especially on L2)

But I'm wondering, the article says that a drop test from a plane is to be carried out under CCDev-2. If that's the case, why would SNC do a captive carry test with a helicopter?

Is it possible that a high altitude drop test from a (White Knight 2 like) airplane is not planned until later (CCDev-3?), and CCDev-2 is only going to see a drop test from the SkyCrane?

Offline JBF

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Re: SNC Captive Carry test sees Dream Chaser take flight
« Reply #10 on: 05/29/2012 09:53 pm »
What is the purpose behind a captive test? Unless it's just to make sure the hookups work before the drop test....
« Last Edit: 05/29/2012 10:09 pm by JBF »
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Offline simonbp

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Re: SNC Captive Carry test sees Dream Chaser take flight
« Reply #11 on: 05/29/2012 09:57 pm »
Partially, as well as verifying that the payload puts no crazy loads on the carrier aircraft and as a practice of procedures. If you look through the history of air-launched experimental aircraft (e.g. X-1, X-15, Enterprise, SS1), it's pretty common to have several captive carries before the first release.

Offline mr. mark

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Re: SNC Captive Carry test sees Dream Chaser take flight
« Reply #12 on: 05/29/2012 09:58 pm »
Not sure if this is just a full scale model or an actual spacecraft?

Offline Jorge

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Re: SNC Captive Carry test sees Dream Chaser take flight
« Reply #13 on: 05/29/2012 10:00 pm »
Not sure if this is just a full scale model or an actual spacecraft?

Full scale engineering test article.
JRF

Offline Jorge

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Re: SNC Captive Carry test sees Dream Chaser take flight
« Reply #14 on: 05/29/2012 10:01 pm »
What is the purpose behind a captive test? Unless it's just to bake sure the hookups work before the drop test....

Verify the dynamics of the config before the drop test.
JRF

Online Chris Bergin

There's a video of the lift (as opposed to the flight), via hobbyspace.com



The kid in the video is exactly what I'd sound like if I was there ;D
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Offline Rocket Science

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Re: SNC Captive Carry test sees Dream Chaser take flight
« Reply #16 on: 05/29/2012 10:15 pm »
Nice touch with the NASA meatball. ;)
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Offline mmeijeri

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Re: SNC Captive Carry test sees Dream Chaser take flight
« Reply #17 on: 05/29/2012 10:15 pm »
The kid in the video is exactly what I'd sound like if I was there ;D

A wocket ship, do you find that ... wisible .. Mr Shelby? ;)

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Offline Lee Jay

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Re: SNC Captive Carry test sees Dream Chaser take flight
« Reply #18 on: 05/29/2012 11:47 pm »
What is the purpose behind a captive test? Unless it's just to bake sure the hookups work before the drop test....

Verify the dynamics of the config before the drop test.

If the drop test is from White Knight II, isn't the attachment and therefore the dynamics very different than the dynamics in this case?

Offline simonbp

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Re: SNC Captive Carry test sees Dream Chaser take flight
« Reply #19 on: 05/29/2012 11:51 pm »
IIRC, the plan was to do low-altitude drops from the Sky Crane first, and then move on to higher altitude/speed drops from WK2.

Dropping from the Sky Crane is presumably lower cost, both from a rental and insurance point of view...
« Last Edit: 05/29/2012 11:52 pm by simonbp »

Offline Lee Jay

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Re: SNC Captive Carry test sees Dream Chaser take flight
« Reply #20 on: 05/29/2012 11:52 pm »
IIRC, the plan was to do low-altitude drops from the Sky Crane first, and then move on to higher altitude/speed drops from WK2.

That would explain it, but low-speed means DC is sub-stall at drop, and low-altitude means not a lot of time to recover before landing.

Offline Rocket Science

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Re: SNC Captive Carry test sees Dream Chaser take flight
« Reply #21 on: 05/29/2012 11:55 pm »
IIRC, the plan was to do low-altitude drops from the Sky Crane first, and then move on to higher altitude/speed drops from WK2.

Dropping from the Sky Crane is presumably lower cost, both from a rental and insurance point of view...
That’s what I said in the other thread Simon. Unmanned drop tests from Skycrane and manned drop tests from WK2. But Lee Jay can verify in person... ;)
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Offline Lee Jay

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Re: SNC Captive Carry test sees Dream Chaser take flight
« Reply #22 on: 05/29/2012 11:59 pm »
IIRC, the plan was to do low-altitude drops from the Sky Crane first, and then move on to higher altitude/speed drops from WK2.

Dropping from the Sky Crane is presumably lower cost, both from a rental and insurance point of view...
That’s what I said in the other thread Simon. Unmanned drop tests from Skycrane and manned drop tests from WK2. But Lee Jay can verify in person... ;)

I'm not going to Edwards! ;)
« Last Edit: 05/29/2012 11:59 pm by Lee Jay »

Offline Rocket Science

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Re: SNC Captive Carry test sees Dream Chaser take flight
« Reply #23 on: 05/30/2012 12:00 am »
IIRC, the plan was to do low-altitude drops from the Sky Crane first, and then move on to higher altitude/speed drops from WK2.

Dropping from the Sky Crane is presumably lower cost, both from a rental and insurance point of view...
That’s what I said in the other thread Simon. Unmanned drop tests from Skycrane and manned drop tests from WK2. But Lee Jay can verify in person... ;)

I'm not going to Edwards! ;)
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Offline Lee Jay

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Re: SNC Captive Carry test sees Dream Chaser take flight
« Reply #24 on: 05/30/2012 12:12 am »
When you speak with Mark?

Speak quietly so you don't wake me up.

Offline Rocket Science

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Re: SNC Captive Carry test sees Dream Chaser take flight
« Reply #25 on: 05/30/2012 12:16 am »
When you speak with Mark?

Speak quietly so you don't wake me up.
Ha! Is my enthusiasm showing again?  :)
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Offline Downix

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Re: SNC Captive Carry test sees Dream Chaser take flight
« Reply #26 on: 05/30/2012 12:22 am »
IIRC, the plan was to do low-altitude drops from the Sky Crane first, and then move on to higher altitude/speed drops from WK2.

That would explain it, but low-speed means DC is sub-stall at drop, and low-altitude means not a lot of time to recover before landing.
Which also means a safe landing from that situation bodes well for the design.
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Offline simonbp

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Re: SNC Captive Carry test sees Dream Chaser take flight
« Reply #27 on: 05/30/2012 01:21 am »
For reference, X-37 followed the same path, with the 85%-scale X-40 dropping from a helicopter and the full-scale X-37A dropped from WK1.

Offline gladiator1332

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Re: SNC Captive Carry test sees Dream Chaser take flight
« Reply #28 on: 05/30/2012 01:50 am »
Its been an exciting two weeks for commercial space!

Offline CitabriaFlyer

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Re: SNC Captive Carry test sees Dream Chaser take flight
« Reply #29 on: 05/30/2012 02:29 am »
Lee Jay,
Thanks for the forthcoming article.  See if you can get us some details on the spaceplane's anticipated performance.  Stall speed at typical weights, speed on final and touchdown, etc.  Also anticipated rollout.  Also will it fly a shuttle trajectory around a HAC and down to final.  Thanks again for all the details you can get.

Offline CitabriaFlyer

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Re: SNC Captive Carry test sees Dream Chaser take flight
« Reply #30 on: 05/30/2012 02:34 am »
Also see if you can get us some scoop on the avionics.  How far along are they?  Do they have a prime contractor for the avionics?  Honeywell?  Garmin? 

How will they fly it.  Will it have translational and rotational hand controllers like the shuttle?  Will the RHC be center stick like shuttle or sidestick?
 
Have they figured out what their abort modes will look like?
Do they have any idea about cross range?
How many missions do they think they can get out of an airframe?
Any details about the test flight program?
Ejection seats?

Offline Lee Jay

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Re: SNC Captive Carry test sees Dream Chaser take flight
« Reply #31 on: 05/30/2012 02:34 am »
From the "impressive progress" article on DC:

"Dream Chaser is targeting a landing speed of 191 knots..."

"In fact, it was noted the vehicle has around one thousand miles of theoretical cross range, ..."
« Last Edit: 05/30/2012 02:35 am by Lee Jay »

Offline FinalFrontier

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Re: SNC Captive Carry test sees Dream Chaser take flight
« Reply #32 on: 05/30/2012 03:58 am »
Well this is a surprise. With all the recent hubub over dragon its easy to forget about SNC.

I for one did not think this vehicle was this far along yet.


Great job on the article as usual Chris. Is this particular vehicle a mockup or an actual spacecraft (minus avionics thrusters ect)?
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Offline Jason1701

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Re: SNC Captive Carry test sees Dream Chaser take flight
« Reply #33 on: 05/30/2012 04:07 am »
Great job on the article as usual Chris. Is this particular vehicle a mockup or an actual spacecraft (minus avionics thrusters ect)?

Engineering Test Article. Much closer to mockup than spacecraft.

Offline pathfinder_01

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Re: SNC Captive Carry test sees Dream Chaser take flight
« Reply #34 on: 05/30/2012 04:12 am »
How many missions do they think they can get out of an airframe?


Only question I know the answer to. Unless they have changed their minds since I read an article a two years ago, they are aiming for 20 missions per spacecraft.

Offline Rocket Science

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Re: SNC Captive Carry test sees Dream Chaser take flight
« Reply #35 on: 05/30/2012 12:41 pm »
Seeing the pics of Dream Chaser airborne is my birthday present. Thanks for the gift… ;D
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Offline manboy

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Re: SNC Captive Carry test sees Dream Chaser take flight
« Reply #36 on: 05/30/2012 01:08 pm »
So was this a captive carry test of the HL-20 mock-up built back in 1990 by college students?
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Offline Lee Jay

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Re: SNC Captive Carry test sees Dream Chaser take flight
« Reply #37 on: 05/30/2012 01:25 pm »
So was this a captive carry test of the HL-20 mock-up built back in 1990 by college students?

No.  This is the ETA built by SNC.

Offline manboy

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Re: SNC Captive Carry test sees Dream Chaser take flight
« Reply #38 on: 05/30/2012 01:45 pm »
So was this a captive carry test of the HL-20 mock-up built back in 1990 by college students?

No.  This is the ETA built by SNC.
Do we have a confirmation on that?
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Offline psloss

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Re: SNC Captive Carry test sees Dream Chaser take flight
« Reply #39 on: 05/30/2012 01:56 pm »
So was this a captive carry test of the HL-20 mock-up built back in 1990 by college students?

No.  This is the ETA built by SNC.
Do we have a confirmation on that?
Yes; it's been noted in CCDev2 documentation and press releases like this one:
http://www.sncorp.com/press_more_info.php?id=476

Offline Lurker Steve

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Re: SNC Captive Carry test sees Dream Chaser take flight
« Reply #40 on: 05/30/2012 02:18 pm »
Great job on the article as usual Chris. Is this particular vehicle a mockup or an actual spacecraft (minus avionics thrusters ect)?

Engineering Test Article. Much closer to mockup than spacecraft.

I assume it must be a fully functional "glider" airframe.

The ETAs of the capsules were just instrumented shells of approxiametely the correct shape.

This vehicle needs controllable aero-surfaces (rudder / flaps / etc) along with the instrumentation. They can't just drop it and watch it imitate a rock.

Online Chris Bergin

NASA.gov's got their own (short) article on this now:
http://www.nasa.gov/exploration/commercial/crew/snc_captivecarry.html#
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Offline catdlr

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Re: SNC Captive Carry test sees Dream Chaser take flight
« Reply #42 on: 05/31/2012 12:38 am »
and...NASA has released a video on YouTube:

Published on May 30, 2012 by NASAKennedy
Sierra Nevada Corporation (SNC) Space System's Dream Chaser design passed one of its most complex tests to date with a successful captive-carry test conducted near the Rocky Mountain Metropolitan Airport in Jefferson County, Colo., on May 29.

The captive-carry test marks the completion of another milestone for the Dream Chaser Space System as part of the Commercial Crew Development Round 2 (CCDev2) agreement with NASA's Commercial Crew Program (CCP).



« Last Edit: 05/31/2012 12:39 am by catdlr »
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Offline Rocket Science

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Re: SNC Captive Carry test sees Dream Chaser take flight
« Reply #43 on: 05/31/2012 12:47 am »
It states “flight vehicle” in the NASA press release and if you look closely in the video you can see control surfaces…

Edit: typo
« Last Edit: 05/31/2012 01:51 am by Rocket Science »
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Offline Lee Jay

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Re: SNC Captive Carry test sees Dream Chaser take flight
« Reply #44 on: 05/31/2012 01:38 am »
It states “flight vehicle” in the NAASA press release and if you look closely in the video you can see control surfaces…

Here's a tight crop from one of my shots.

Offline Go4TLI

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Re: SNC Captive Carry test sees Dream Chaser take flight
« Reply #45 on: 05/31/2012 02:04 am »
Great job on the article as usual Chris. Is this particular vehicle a mockup or an actual spacecraft (minus avionics thrusters ect)?

Engineering Test Article. Much closer to mockup than spacecraft.

Just the opposite. An Engineering Test Article is typically a high-fidelity step toward the operational item.  In a vehicle's case it is typically a pathfinder meant to be structurally similar to the intended production vehicle with similar mass properties and aerodynamics.

Systems can and will very depending on the scope, nature and reason for the tests.

Offline Go4TLI

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Re: SNC Captive Carry test sees Dream Chaser take flight
« Reply #46 on: 05/31/2012 02:08 am »
NASA.gov's got their own (short) article on this now:
http://www.nasa.gov/exploration/commercial/crew/snc_captivecarry.html#

More than NASAWatch has. For all the talk that website does it is now only a cheerleading site for SpaceX and the current administration. I note there was no mention of the CST-100 drop test or the SNC test yet.

Offline QuantumG

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Re: SNC Captive Carry test sees Dream Chaser take flight
« Reply #47 on: 05/31/2012 02:12 am »
More than NASAWatch has. For all the talk that website does it is now only a cheerleading site for SpaceX and the current administration. I note there was no mention of the CST-100 drop test or the SNC test yet.

If you can figure out how to spin this story to "see how much NASA sucks?" then it will be welcomed there. That's their role.

Human spaceflight is basically just LARPing now.

Offline FinalFrontier

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Re: SNC Captive Carry test sees Dream Chaser take flight
« Reply #48 on: 05/31/2012 02:14 am »
More than NASAWatch has. For all the talk that website does it is now only a cheerleading site for SpaceX and the current administration. I note there was no mention of the CST-100 drop test or the SNC test yet.

If you can figure out how to spin this story to "see how much NASA sucks?" then it will be welcomed there. That's their role.



I almost fell out of my chair laughing seeing NASA watch mentioned here again. That place is literally the "media matters" equivalent for spaceflight. Its been nearly two years since I saw them crop up in discussion here, thanks for that was a good laugh :)
« Last Edit: 05/31/2012 02:14 am by FinalFrontier »
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Offline docmordrid

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Re: SNC Captive Carry test sees Dream Chaser take flight
« Reply #49 on: 05/31/2012 02:17 am »
More than NASAWatch has. For all the talk that website does it is now only a cheerleading site for SpaceX and the current administration. I note there was no mention of the CST-100 drop test or the SNC test yet.

If you can figure out how to spin this story to "see how much NASA sucks?" then it will be welcomed there. That's their role.



I almost fell out of my chair laughing seeing NASA watch mentioned here again. That place is literally the "media matters" equivalent for spaceflight. Its been nearly two years since I saw them crop up in discussion here, thanks for that was a good laugh :)

Me too. Someone owes me a keyboard because this one has iced tea all over it ;)
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Offline Lars_J

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Re: SNC Captive Carry test sees Dream Chaser take flight
« Reply #50 on: 05/31/2012 03:06 am »
More than NASAWatch has. For all the talk that website does it is now only a cheerleading site for SpaceX and the current administration. I note there was no mention of the CST-100 drop test or the SNC test yet.

If you can figure out how to spin this story to "see how much NASA sucks?" then it will be welcomed there. That's their role.

And it is a useful role - although I know Keith's anti-CxP and anti-SLS opinions are not very popular amongst many here. But I would welcome more sites with different "agendas" to keep the spotlight on NASA.

-------

Back on topic - Very nice to see more progress from SnC with Dream Chaser. I'm looking forward to actual drop tests.

I do wonder about the tiny vertical tail - it is so small that it *looks* like it would hardly give any aerodynamic benefit.

Offline vt_hokie

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Re: SNC Captive Carry test sees Dream Chaser take flight
« Reply #51 on: 05/31/2012 03:18 am »


I do wonder about the tiny vertical tail - it is so small that it *looks* like it would hardly give any aerodynamic benefit.

I keep wondering about the lack of a body flap, both for pitch control and for shielding the docking ring during re-entry.

Offline Lars_J

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Re: SNC Captive Carry test sees Dream Chaser take flight
« Reply #52 on: 05/31/2012 03:24 am »
Good point - without such a flap the docking ring/tube will have to telescope in and out.

Offline Patchouli

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Re: SNC Captive Carry test sees Dream Chaser take flight
« Reply #53 on: 05/31/2012 03:50 am »

Just the opposite. An Engineering Test Article is typically a high-fidelity step toward the operational item.  In a vehicle's case it is typically a pathfinder meant to be structurally similar to the intended production vehicle with similar mass properties and aerodynamics.

Systems can and will very depending on the scope, nature and reason for the tests.

That would make it similar to the shuttle Enterprise.

Offline Jorge

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Re: SNC Captive Carry test sees Dream Chaser take flight
« Reply #54 on: 05/31/2012 03:54 am »

Just the opposite. An Engineering Test Article is typically a high-fidelity step toward the operational item.  In a vehicle's case it is typically a pathfinder meant to be structurally similar to the intended production vehicle with similar mass properties and aerodynamics.

Systems can and will very depending on the scope, nature and reason for the tests.

That would make it similar to the shuttle Enterprise.

Right. Or Challenger, back in her STA-099 days.
JRF

Offline Go4TLI

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Re: SNC Captive Carry test sees Dream Chaser take flight
« Reply #55 on: 05/31/2012 03:54 am »

Just the opposite. An Engineering Test Article is typically a high-fidelity step toward the operational item.  In a vehicle's case it is typically a pathfinder meant to be structurally similar to the intended production vehicle with similar mass properties and aerodynamics.

Systems can and will very depending on the scope, nature and reason for the tests.

That would make it similar to the shuttle Enterprise.

Yes.

Offline Go4TLI

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Re: SNC Captive Carry test sees Dream Chaser take flight
« Reply #56 on: 05/31/2012 04:10 am »


I do wonder about the tiny vertical tail - it is so small that it *looks* like it would hardly give any aerodynamic benefit.

I keep wondering about the lack of a body flap, both for pitch control and for shielding the docking ring during re-entry.

I'm not an aerodynamics expert by any means but a body flap generally just controls the static margin, which is a function of stability based on the mass distribution. 

If the expected mass distributions fall within the vehicle control envelope, then a body flap wouldn't necessarily be required.  There are other options for dealing with the docking ring and the first step is modeling what the expected environments will be in order to inform the engineering solutions. 
« Last Edit: 05/31/2012 04:13 am by Go4TLI »

Offline Rocket Science

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Re: SNC Captive Carry test sees Dream Chaser take flight
« Reply #57 on: 05/31/2012 12:03 pm »
If you look carefully at the back of DC you can see 4 rectangles that are the control surfaces responsible for pitch and roll very similar as was used on the X-24A.

http://www.dfrc.nasa.gov/gallery/photo/X-24/HTML/E-23377.html

http://www.vskylabs.com/vsl-techreports/martin-marietta-x-24a-reports/x-24-approach-flare-and-landing
« Last Edit: 05/31/2012 12:04 pm by Rocket Science »
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Offline adrianwyard

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Re: SNC Captive Carry test sees Dream Chaser take flight
« Reply #58 on: 05/31/2012 04:53 pm »
I believe the central vertical fin moves as a single unit. If so, that should give you quite a bit of control especially when hard over. IIRC a key function of this control surface is for yaw control in cross winds during landing, i.e. pointing straight down the runway. Can anybody confirm? As others have pointed out there are six other control surfaces in addition to this which act in sum to give the traditional rudder/aileron/elevator functions.

Talking of crosswinds, X-24 was occasionally blown sideways during landing as it presented a big surface area to the side. The Dream Chaser will presumably face a similar challenge. Elsewhere people have wondered if steering is achieved by differential braking of the main landing gear. My guess is this technique would give you more ability to overcome this sort of crosswind problem, at least it would be better than small steerable nose wheels.

As for body flaps, as others have noted these lie flush to the body and do not extend beyond the rear of the fuselage. I'm not sure why this is the case. If they were further back extending out (a la X-33) that would give a larger control moment, and would provide protection for the engine bells.

There is a Q&A thread, perhaps this belongs there.

http://forum.nasaspaceflight.com/index.php?topic=9921.new;topicseen#new

Offline Rocket Science

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Re: SNC Captive Carry test sees Dream Chaser take flight
« Reply #59 on: 05/31/2012 05:11 pm »
I believe the central vertical fin moves as a single unit. If so, that should give you quite a bit of control especially when hard over. IIRC a key function of this control surface is for yaw control in cross winds during landing, i.e. pointing straight down the runway. Can anybody confirm? As others have pointed out there are six other control surfaces in addition to this which act in sum to give the traditional rudder/aileron/elevator functions.

Talking of crosswinds, X-24 was occasionally blown sideways during landing as it presented a big surface area to the side. The Dream Chaser will presumably face a similar challenge. Elsewhere people have wondered if steering is achieved by differential braking of the main landing gear. My guess is this technique would give you more ability to overcome this sort of crosswind problem, at least it would be better than small steerable nose wheels.

As for body flaps, as others have noted these lie flush to the body and do not extend beyond the rear of the fuselage. I'm not sure why this is the case. If they were further back extending out (a la X-33) that would give a larger control moment, and would provide protection for the engine bells.

There is a Q&A thread, perhaps this belongs there.

http://forum.nasaspaceflight.com/index.php?topic=9921.new;topicseen#new
All info shows central vertical stabilizer as fixed. As far as cross wind, it will have to face similar cross wind constraints on landing as Shuttle. What that number is in Knots for DC I can't say...
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Re: SNC Captive Carry test sees Dream Chaser take flight
« Reply #60 on: 05/31/2012 05:12 pm »
Elsewhere people have wondered if steering is achieved by differential braking of the main landing gear. My guess is this technique would give you more ability to overcome this sort of crosswind problem, at least it would be better than small steerable nose wheels.

Actually, the Shuttle had both differential braking and steerable nosewheels, and after 'issues' (a blowout) they started using the latter more. More here.

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Offline adrianwyard

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Re: SNC Captive Carry test sees Dream Chaser take flight
« Reply #61 on: 05/31/2012 05:16 pm »
The HL-20 certainly had an all-moving vertical fin - at least it did in the documents I'm reading... If Dream Chaser forgoes this, it would be one of the more significant aerodynamic changes.

As a much lighter vehicle, my guess is cross wind constraints will be different to Shuttle. The total sideways surface area is less than The orbiter of course, but from the side those tip fins look like weather vanes. I think the gating factor is density, and Carbon composite DC will be less dense. Anyway, with enough wheel steering and yaw control I'm sure it can be managed.
« Last Edit: 05/31/2012 05:23 pm by adrianwyard »

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Re: SNC Captive Carry test sees Dream Chaser take flight
« Reply #62 on: 05/31/2012 08:03 pm »

Offline psloss

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Offline Rocket Science

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Re: SNC Captive Carry test sees Dream Chaser take flight
« Reply #64 on: 05/31/2012 09:33 pm »
The HL-20 certainly had an all-moving vertical fin - at least it did in the documents I'm reading... If Dream Chaser forgoes this, it would be one of the more significant aerodynamic changes.

As a much lighter vehicle, my guess is cross wind constraints will be different to Shuttle. The total sideways surface area is less than The orbiter of course, but from the side those tip fins look like weather vanes. I think the gating factor is density, and Carbon composite DC will be less dense. Anyway, with enough wheel steering and yaw control I'm sure it can be managed.
Adrian,

Could you please provide me a link to the document that indicates the HL-20 had a moveable central vertical control surface? Even if it did there is no guarantee it will be so in DC. That being said of course it will “weather vane” into the wind. This is what you have to deal will with cross wind limits with a lifting body-shuttle type of spacecraft when landing. Conditions will have to be correct for launch and landings as well as alternates and or abort sites or it will be a NO GO for launch as was with the Shuttles.

~Robert
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Offline adrianwyard

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Re: SNC Captive Carry test sees Dream Chaser take flight
« Reply #65 on: 06/01/2012 01:35 am »
Hi Robert, here are a few references to the moving rudder, all historical HL-20 stuff:

http://dscb.larc.nasa.gov/DCBStaff/ebj/Papers/aiaa-91-2955-HL20simtools.pdf page 7,
http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19920021931_1992021931.pdf page 3,
http://dscb.larc.nasa.gov/DCBStaff/ebj/Papers/TM-107580.pdf page 5.

Interestingly, in the pictures of the flight test article it looks to me as though the rudder might not be one piece...

Offline Rocket Science

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Re: SNC Captive Carry test sees Dream Chaser take flight
« Reply #66 on: 06/01/2012 02:11 am »
Hi Robert, here are a few references to the moving rudder, all historical HL-20 stuff:

http://dscb.larc.nasa.gov/DCBStaff/ebj/Papers/aiaa-91-2955-HL20simtools.pdf page 7,
http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19920021931_1992021931.pdf page 3,
http://dscb.larc.nasa.gov/DCBStaff/ebj/Papers/TM-107580.pdf page 5.

Interestingly, in the pictures of the flight test article it looks to me as though the rudder might not be one piece...
Thanks Adrian,

I guess you caught that one correctly, well done! ;) It’s been 20 years since I had contact with HL-20 at Langley. Looks like 30 degree +/- deflection. Give me a chance to go through it further. It could even be a split speed brake…

~Robert

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Offline adrianwyard

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Re: SNC Captive Carry test sees Dream Chaser take flight
« Reply #67 on: 06/01/2012 02:46 am »
Not to spoil your reading fun, but they did test some Shuttle-like split-rudder speed brake configurations, and did not recommend implementing for HL-20.

Offline Rocket Science

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Re: SNC Captive Carry test sees Dream Chaser take flight
« Reply #68 on: 06/01/2012 05:02 pm »
Not to spoil your reading fun, but they did test some Shuttle-like split-rudder speed brake configurations, and did not recommend implementing for HL-20.

Hi Adrian,

Thanks again for the links. I might have had one or two of those on my old dead computer drive. I noted the reduction of the interconnect to the rudder to improve cross wind performance and the use of the 4 body flaps as speed brakes like the X-24A. The two vehicles seem to share many of the same flight development characteristics…

~Robert
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Offline simonbp

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Re: SNC Captive Carry test sees Dream Chaser take flight
« Reply #69 on: 06/01/2012 08:01 pm »
If you look carefully at the back of DC you can see 4 rectangles that are the control surfaces responsible for pitch and roll very similar as was used on the X-24A.

http://www.dfrc.nasa.gov/gallery/photo/X-24/HTML/E-23377.html

http://www.vskylabs.com/vsl-techreports/martin-marietta-x-24a-reports/x-24-approach-flare-and-landing

Nice catch! (And a plug that you can see the control surfaces much better in Lee Jay's photos on L2.)

Correct me if I'm wrong, but when they finally drop, will this be the first large American lifting body to do a runway landing since X-24B? X-38 only landed on the lakebed under a parachute.

Offline Rocket Science

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Re: SNC Captive Carry test sees Dream Chaser take flight
« Reply #70 on: 06/01/2012 08:15 pm »
If you look carefully at the back of DC you can see 4 rectangles that are the control surfaces responsible for pitch and roll very similar as was used on the X-24A.

http://www.dfrc.nasa.gov/gallery/photo/X-24/HTML/E-23377.html

http://www.vskylabs.com/vsl-techreports/martin-marietta-x-24a-reports/x-24-approach-flare-and-landing

Nice catch! (And a plug that you can see the control surfaces much better in Lee Jay's photos on L2.)

Correct me if I'm wrong, but when they finally drop, will this be the first large American lifting body to do a runway landing since X-24B? X-38 only landed on the lakebed under a parachute.
You are correct Simon! :) 38 years ago first concrete landing at Edwards!! :o
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Re: SNC Captive Carry test sees Dream Chaser take flight
« Reply #71 on: 06/01/2012 09:50 pm »
Correct me if I'm wrong, but when they finally drop, will this be the first large American lifting body to do a runway landing since X-24B? X-38 only landed on the lakebed under a parachute.

You are correct Simon! 38 years ago first concrete landing at Edwards!!

The Shuttle doesn't count as a lifting body? Are the wings too large? :)

Noel
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Offline Rocket Science

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Re: SNC Captive Carry test sees Dream Chaser take flight
« Reply #72 on: 06/01/2012 10:10 pm »
Correct me if I'm wrong, but when they finally drop, will this be the first large American lifting body to do a runway landing since X-24B? X-38 only landed on the lakebed under a parachute.

You are correct Simon! 38 years ago first concrete landing at Edwards!!

The Shuttle doesn't count as a lifting body? Are the wings too large? :)

Noel

Hey Noel,

Yes, it does have lifting body properties… But, Simon’s a purist. Don’t get him started on Biconics… ;)

~Robert
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Offline simonbp

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Re: SNC Captive Carry test sees Dream Chaser take flight
« Reply #73 on: 06/02/2012 05:52 am »
This is what a real lifting-body shuttle looks like... ;)

Offline Jorge

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Re: SNC Captive Carry test sees Dream Chaser take flight
« Reply #74 on: 06/02/2012 06:29 am »
Correct me if I'm wrong, but when they finally drop, will this be the first large American lifting body to do a runway landing since X-24B? X-38 only landed on the lakebed under a parachute.

You are correct Simon! 38 years ago first concrete landing at Edwards!!

The Shuttle doesn't count as a lifting body? Are the wings too large? :)

No and Yes. :)
JRF

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Re: SNC Captive Carry test sees Dream Chaser take flight
« Reply #75 on: 06/02/2012 11:53 am »
This is what a real lifting-body shuttle looks like... ;)
Love the StarClipper Simon… :) Another might have been… (sigh)….
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Re: SNC Captive Carry test sees Dream Chaser take flight
« Reply #76 on: 06/02/2012 12:31 pm »
The Shuttle doesn't count as a lifting body? Are the wings too large? :)

No and Yes. :)

They remind me of the wings on a penguin - insufficient to hold it aloft. I can't think what class to put it in other than 'lifting body' (and in fact, maybe not even in that, since some lifting bodies actually did generate enough lift to keep them aloft).

Noel
« Last Edit: 06/02/2012 12:32 pm by jnc »
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Offline Lee Jay

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Re: SNC Captive Carry test sees Dream Chaser take flight
« Reply #77 on: 06/02/2012 02:25 pm »
If you look carefully at the back of DC you can see 4 rectangles that are the control surfaces responsible for pitch and roll very similar as was used on the X-24A.

I don't see where the split is in my pictures from the SNC laboratory.

Offline adrianwyard

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Re: SNC Captive Carry test sees Dream Chaser take flight
« Reply #78 on: 06/02/2012 02:47 pm »
I think Robert was referring to the body flaps on the upper and lower surfaces of the rear fuselage.

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Re: SNC Captive Carry test sees Dream Chaser take flight
« Reply #79 on: 06/02/2012 02:57 pm »
Not to chase our own tails with arguments over definitions but...

The X-37B did a runway landing at Edwards, so by the logic so in this thread so far, either its wings are too large for it to count as a lifting-body, and/or 11,000 lb doesn't count as 'heavy.'

Definitions aside, some real questions: my guess is X-37B experience is relevant to DC, especially surrounding autoland. Do people feel it is too dissimilar aerodynamically for this to be the case? Also, as a DoD (previously NASA) project, would SNC have access to lessons learned on the project?
« Last Edit: 06/02/2012 03:02 pm by adrianwyard »

Offline Lee Jay

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Re: SNC Captive Carry test sees Dream Chaser take flight
« Reply #80 on: 06/02/2012 03:03 pm »
I think Robert was referring to the body flaps on the upper and lower surfaces of the rear fuselage.

I see some rectangles there, but they don't look like control surfaces to me.  Perhaps they were locked down or not installed yet on the vehicle I saw.  There's still some time before the ALT tests so that's a possibility.

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Re: SNC Captive Carry test sees Dream Chaser take flight
« Reply #81 on: 06/02/2012 03:11 pm »
Also, as a DoD (previously NASA) project, would SNC have access to lessons learned on the project?

Complicated question. Some information from government work is off-limits - if it's classified (and then firms with clearances could get it), or if it's proprietary to a contractor. Most other written stuff is public, but of course not everything gets written down in formal form. And then of course there are FOIA requests... That's a brief gloss on a very complicated subject...

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Offline Jim

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Re: SNC Captive Carry test sees Dream Chaser take flight
« Reply #82 on: 06/02/2012 03:27 pm »
Also, as a DoD (previously NASA) project, would SNC have access to lessons learned on the project?

It depends on what the gov't contracted for.  If it was for sensor delivery and operations, then probably no, since the methodology to get the sensor there would be company propriety.

Offline yg1968

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Re: SNC Captive Carry test sees Dream Chaser take flight
« Reply #83 on: 06/02/2012 03:33 pm »
Not to chase our own tails with arguments over definitions but...

The X-37B did a runway landing at Edwards, so by the logic so in this thread so far, either its wings are too large for it to count as a lifting-body, and/or 11,000 lb doesn't count as 'heavy.'

Definitions aside, some real questions: my guess is X-37B experience is relevant to DC, especially surrounding autoland. Do people feel it is too dissimilar aerodynamically for this to be the case? Also, as a DoD (previously NASA) project, would SNC have access to lessons learned on the project?

Boeing is an important contractor for DC. So I am guessing that there must be some information that is shared from the X-37 within Boeing.

Offline clongton

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Re: SNC Captive Carry test sees Dream Chaser take flight
« Reply #84 on: 06/02/2012 03:52 pm »
NASA.gov's got their own (short) article on this now:
http://www.nasa.gov/exploration/commercial/crew/snc_captivecarry.html#

Somebody at NASA needs to seriously become familiar with the program before they put out official press releases about the vehicle.
Quote
Just like the space shuttle before it, SNC's Dream Chaser will go through extensive testing to prove its wings will work
....and is the only spacecraft under CCDev2 that incorporates wings
This is embarassing. They didn't even know it's a lifting body or that lifting bodies don't have wings.

I expect this kind of lack of knowledge from our politicians, but not in an official NASA press release. ......Seriously :(
Chuck - DIRECT co-founder
I started my career on the Saturn-V F-1A engine

Offline simonbp

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Re: SNC Captive Carry test sees Dream Chaser take flight
« Reply #85 on: 06/02/2012 04:02 pm »
To be clear, Shuttle and X-37 are not lifting bodies because their fuselages do not produce lift, and the only lifting surfaces are dedicated wings. The fact that the wings are small is irrelevant; they are still the only lift-producing surfaces. There's a reason why Dale Reed's history of the program is called "Wingless Flight".

Dream Chaser, on the other hand, is absolutely a lifting body. While the outboard fins provide a very small amount of lift, the vast majority is produced solely by the shape of the fuselage. The advantages of this are twofold. For a given mass and coefficient of lift, the internal volume of the vehicle can be much larger (allowing DC's internal abort rockets). In addition, the more rounded shape has much better hypersonic aerodynamics, increasing cross-range and decreasing the need for fragile sharp leading edges.

Dragon, incidentally, is also a lifting body during hypersonic flight, just one with a very poor L/D when slower than hypersonic, as was/is Apollo and CST. The Blue Origin vehicle is a lifting body with probably good L/D to high subsonic.

Offline Jorge

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Re: SNC Captive Carry test sees Dream Chaser take flight
« Reply #86 on: 06/02/2012 07:22 pm »
The Shuttle doesn't count as a lifting body? Are the wings too large? :)

No and Yes. :)

They remind me of the wings on a penguin - insufficient to hold it aloft. I can't think what class to put it in other than 'lifting body' (and in fact, maybe not even in that, since some lifting bodies actually did generate enough lift to keep them aloft).

simonbp got the definition correct. What matters is where the majority of the lift comes from, not the total amount of lift. If a majority of the lift comes from the body, it's a lifting body. If from the wings, it's not. Simple as that.

And *no* aircraft generates sufficient lift *without* *propulsion* to "hold itself aloft." They just have better glide ratios than the shuttle. Typically 20:1 for an airliner, compared to 4:1 for the shuttle.
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Offline jnc

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Re: SNC Captive Carry test sees Dream Chaser take flight
« Reply #87 on: 06/02/2012 07:31 pm »
And *no* aircraft generates sufficient lift *without* *propulsion* to "hold itself aloft." They just have better glide ratios than the shuttle. Typically 20:1 for an airliner, compared to 4:1 for the shuttle.

Yeah, I thought about that after I made the post - since the Shuttle is unpowered (in the descent phase), of course it's going to come down.

I wonder how the glide ratio for the Shuttle compares to that of the X-15, since the X-15 experience with unpowered landings was a big driver in making the Shuttle unpowered .. {quick Google} .. also 4:1. (And also the F-104...)

Noel

PS: Now that I think about it, I think the point I was trying to make is that in general, one never saw the Shuttle do anything that increased its altitude while in the unpowered phase (well, maybe in the hypersonic phase it did, I don't know all the fine details of how they did that - I just remember the banked turns). That's more what I meant by "hold itself aloft".

I assume that the Shuttle could generate enough lift (were it going fast enough) to pull up, and trade speed for altitude to gain altitude (in the unpowered mode), but I don't think they ever did so? That's more what I was thinking of when I compared it unfavourably to some of the experimental lifting bodies - 'never gained altitude'.
« Last Edit: 06/02/2012 07:47 pm by jnc »
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Offline adrianwyard

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Re: SNC Captive Carry test sees Dream Chaser take flight
« Reply #88 on: 06/04/2012 05:43 am »
I think Robert was referring to the body flaps on the upper and lower surfaces of the rear fuselage.

I see some rectangles there, but they don't look like control surfaces to me.  Perhaps they were locked down or not installed yet on the vehicle I saw.  There's still some time before the ALT tests so that's a possibility.

You can see them moving in the scale model at 01:56 in the following video: http://www.youtube.com/watch?v=xw_47CNIYNs#t=01m56s

As you say, perhaps they were not active on the very first test...

Offline adrianwyard

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Re: SNC Captive Carry test sees Dream Chaser take flight
« Reply #89 on: 06/04/2012 06:11 am »
Re: X-37 and lifting bodies.

It certainly looks like the X-37's wings provide the majority of the lift even if the body area is large by comparison, so this would make it not a lifting body. However, I've always been intrigued by the shaping of the fuselage at the rear, and assumed this was connected to lift somehow. (So far I've found nothing to back that up.)

Offline Kojak


PS: Now that I think about it, I think the point I was trying to make is that in general, one never saw the Shuttle do anything that increased its altitude while in the unpowered phase (well, maybe in the hypersonic phase it did, I don't know all the fine details of how they did that - I just remember the banked turns). That's more what I meant by "hold itself aloft".

I assume that the Shuttle could generate enough lift (were it going fast enough) to pull up, and trade speed for altitude to gain altitude (in the unpowered mode), but I don't think they ever did so? That's more what I was thinking of when I compared it unfavourably to some of the experimental lifting bodies - 'never gained altitude'.


Generally speaking, if you are gliding unpowered you shouldn't have the need to increase altitude. You should be gliding at the best glide speed to make the most distance. If you are flying faster than that (which would give you a chance of trading airspeed for altitude), you are making less distance. If you are making less distance it either means that you are making a mistake (i.e. you will not make the runway) or you don't need extra distance (you'll make the runway like that), but in this case you won't need to gain extra altitude wich could eventually make you go long, you just need to kill airspeed.


Offline Rocket Science

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Re: SNC Captive Carry test sees Dream Chaser take flight
« Reply #91 on: 06/10/2012 01:03 am »
Lifting Body Air and Spacecraft Q & A

With all the interest generated by Dream Chaser and its direct ancestor the HL-20 and all the other lifting body vehicles, the thread linked below is to discuss, inform and exchange general questions, ideas and answers as to what exactly a Lifting Body is. This is to keep the Dream Chaser threads clean and without clutter and OT topics as things get busier now. :)

http://forum.nasaspaceflight.com/index.php?topic=29126.msg914401;topicseen#new
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Offline Prober

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Re: SNC Captive Carry test sees Dream Chaser take flight
« Reply #92 on: 06/12/2012 02:28 pm »
The passing truck gave the DC a good feel for size.

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Offline Prober

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Re: SNC Captive Carry test sees Dream Chaser take flight
« Reply #93 on: 06/12/2012 02:45 pm »
Not to chase our own tails with arguments over definitions but...

The X-37B did a runway landing at Edwards, so by the logic so in this thread so far, either its wings are too large for it to count as a lifting-body, and/or 11,000 lb doesn't count as 'heavy.'

Definitions aside, some real questions: my guess is X-37B experience is relevant to DC, especially surrounding autoland. Do people feel it is too dissimilar aerodynamically for this to be the case? Also, as a DoD (previously NASA) project, would SNC have access to lessons learned on the project?

you forgot about the DARPA years.   My "guess" is Boeing control of most of it.
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Offline Prober

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Re: SNC Captive Carry test sees Dream Chaser take flight
« Reply #94 on: 06/12/2012 02:53 pm »
I think Robert was referring to the body flaps on the upper and lower surfaces of the rear fuselage.

I see some rectangles there, but they don't look like control surfaces to me.  Perhaps they were locked down or not installed yet on the vehicle I saw.  There's still some time before the ALT tests so that's a possibility.

You can see them moving in the scale model at 01:56 in the following video:As you say, perhaps they were not active on the very first test...

that scale model is the perfect size.  3D printing anyone ?

or let's make some molds up and we can have in the stores for Xmas :-P
« Last Edit: 06/12/2012 02:55 pm by Prober »
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Offline Rocket Science

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Re: SNC Captive Carry test sees Dream Chaser take flight
« Reply #95 on: 06/18/2012 11:12 pm »
Re: X-37 and lifting bodies.

It certainly looks like the X-37's wings provide the majority of the lift even if the body area is large by comparison, so this would make it not a lifting body. However, I've always been intrigued by the shaping of the fuselage at the rear, and assumed this was connected to lift somehow. (So far I've found nothing to back that up.)
Hey Adrian,

I came across this a while back...

http://quest.arc.nasa.gov/aero/events/regimes/space.html

(It will make simon crazy... lol)

~Robert
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Offline Danderman

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Re: SNC Captive Carry test sees Dream Chaser take flight
« Reply #96 on: 06/19/2012 07:28 pm »
Along a similar vein:

WhiteKnight 3 plus what upper stage could provide a decent suborbital test for Dream Chaser?


Offline yg1968

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Re: SNC Captive Carry test sees Dream Chaser take flight
« Reply #97 on: 06/19/2012 07:43 pm »
What's WhiteKnight 3?

Offline Lurker Steve

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Re: SNC Captive Carry test sees Dream Chaser take flight
« Reply #98 on: 06/19/2012 07:51 pm »
Along a similar vein:

WhiteKnight 3 plus what upper stage could provide a decent suborbital test for Dream Chaser?



I assume it could fire it's hybrid engines after it's released from the White Knight 2, and pretend it's a SS2.

Offline Danderman

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Re: SNC Captive Carry test sees Dream Chaser take flight
« Reply #99 on: 06/19/2012 09:05 pm »
Along a similar vein:

WhiteKnight 3 plus what upper stage could provide a decent suborbital test for Dream Chaser?



I assume it could fire it's hybrid engines after it's released from the White Knight 2, and pretend it's a SS2.


WhiteKnight 3 is the Stratolauncher carry aircraft.

I suspect that WK3 could carry Dream Chaser plus a significant upper stage to provide for a short intercontinental flight.

Offline adrianwyard

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Re: SNC Captive Carry test sees Dream Chaser take flight
« Reply #100 on: 06/26/2012 05:17 pm »
That's an interesting idea. I'd feel more confident in the future of commercial projects like Dream Chaser if there were multiple revenue options beyond a small number of trips to the ISS for NASA. I've previously suggested powered sub-orbital hops from WK2 - offered at a premium over SS2 tickets since DC is a 'real' spacecraft. But taking passengers - or just deep-pocket joyriders - transcontinental to a real destination at high-speed is a service that has an obvious appeal over SS2. This would put Concorde and proposed supersonic bizjets to shame. High-value cargo too, perhaps.

I'd like to ask if there's anything like an appropriate upper stage that could be cheap enough to make this workable - and how large it would need to be - but since I can already feel the shockwave from Jim's approaching 'unfounded speculation' hammer, I will stop here.
« Last Edit: 06/26/2012 05:25 pm by adrianwyard »

Offline vt_hokie

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Re: SNC Captive Carry test sees Dream Chaser take flight
« Reply #101 on: 06/26/2012 05:42 pm »
That's an interesting idea. I'd feel more confident in the future of commercial projects like Dream Chaser if there were multiple revenue options beyond a small number of trips to the ISS for NASA.

I'd almost rather we stop the half-hearted efforts that have us spinning our wheels while going nowhere, and divert funding from SLS/Orion to very achievable projects like this one.  I was initially a supporter of SLS, but the timetables are just too drawn out and the flight rates too low...and meanwhile, vehicles like DreamChaser have been so close to reality so many times, and just need a little funding to push them over that hurdle.

Sure, I want to see us go back to the moon and beyond, but not if it means being unable to even do much in LEO for the next 10+ years while we wait for SLS/Orion to come online (and even then, not even being able to do much more than Apollo 8-style missions).
« Last Edit: 06/26/2012 05:46 pm by vt_hokie »

Offline Jim

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Re: SNC Captive Carry test sees Dream Chaser take flight
« Reply #102 on: 06/26/2012 05:52 pm »
transcontinental to a real destination at high-speed


No business case for that.
« Last Edit: 06/26/2012 05:53 pm by Jim »

Offline Jim

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Re: SNC Captive Carry test sees Dream Chaser take flight
« Reply #103 on: 06/26/2012 05:54 pm »
I've previously suggested powered sub-orbital hops from WK2 - offered at a premium over SS2 tickets since DC is a 'real' spacecraft.

Not really, the flight profile would be the same for either spacecraft.

Offline adrianwyard

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Re: SNC Captive Carry test sees Dream Chaser take flight
« Reply #104 on: 06/26/2012 05:55 pm »
transcontinental to a real destination at high-speed


No business case for that.

Unfounded speculation  :)

Offline Robotbeat

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Re: SNC Captive Carry test sees Dream Chaser take flight
« Reply #105 on: 06/26/2012 05:58 pm »
transcontinental to a real destination at high-speed


No business case for that.

Unfounded speculation  :)
No, it's not. Even some suborbital tourism evangelists don't think there's a business case for suborbital transcontinental transport. At this point and the foreseeable future, it will cost far too much (quite comparable to an orbital trip, because the velocity requirements are similar), plus will have crazy regulatory/treaty issues (same flight profile as an ICBM?).

In the very long term, MAYBE. But it will mean orbital trips must be very, very cheap.
« Last Edit: 06/26/2012 05:59 pm by Robotbeat »
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Offline Lurker Steve

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Re: SNC Captive Carry test sees Dream Chaser take flight
« Reply #106 on: 06/26/2012 06:07 pm »
I've previously suggested powered sub-orbital hops from WK2 - offered at a premium over SS2 tickets since DC is a 'real' spacecraft.

Not really, the flight profile would be the same for either spacecraft.

What's the proposed duration of a sub-orbital flight ? Any more takers for an
Orbital flight that does 2-3 full orbits before landing fairly close to the launch site ?

Offline adrianwyard

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Re: SNC Captive Carry test sees Dream Chaser take flight
« Reply #107 on: 06/26/2012 06:19 pm »
Re "no business case"

Well if we want to follow this general idea forward and get to real-world operational and regulatory details, then I could well believe the business becomes iffy. Predicting the future in detail is hard.

I thought you were saying that there's no case for high-speed travel per se. I personally paid the big bucks to travel on Concorde, and definitely felt as though I got my money's worth.

As you say, the first hurdle is the oft-quoted assessment that you need near-orbital velocity to get any useful (marketable) distance. If that's derived unambiguously from the physics, then that would a good reason to move on.

Another problem is disposal of the upper stage. I'm picturing Wile-E-Coyote duct-taping a sixpack of RocketMotorTwo's together to form an upper stage, which then falls back demolishing his house...
« Last Edit: 06/26/2012 06:22 pm by adrianwyard »

Offline Jorge

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Re: SNC Captive Carry test sees Dream Chaser take flight
« Reply #108 on: 06/26/2012 06:34 pm »
Re "no business case"

Well if we want to follow this general idea forward and get to real-world operational and regulatory details, then I could well believe the business becomes iffy. Predicting the future in detail is hard.

I thought you were saying that there's no case for high-speed travel per se. I personally paid the big bucks to travel on Concorde, and definitely felt as though I got my money's worth.

As you say, the first hurdle is the oft-quoted assessment that you need near-orbital velocity to get any useful (marketable) distance. If that's derived unambiguously from the physics, then that would a good reason to move on.

It is. Orbital velocity is around 25.8 kfps; a transatlantic flight requires about 18.4 kfps (see, for example, the STS-135 3-engine-out TAL boundary, below). SS2/WK2 will be in the 3-4 kfps range.
JRF

Offline adrianwyard

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Re: SNC Captive Carry test sees Dream Chaser take flight
« Reply #109 on: 06/26/2012 06:38 pm »
I've previously suggested powered sub-orbital hops from WK2 - offered at a premium over SS2 tickets since DC is a 'real' spacecraft.

Not really, the flight profile would be the same for either spacecraft.

What's the proposed duration of a sub-orbital flight ? Any more takers for an
Orbital flight that does 2-3 full orbits before landing fairly close to the launch site ?

Actually, DC powered flight would be much more limited than SS2 as it has about half the performance. (DC: 2x 15K lbf, SS2: 1x 60K lbf, both craft are ~10 t).

I would hope SNC could sell these seats at a premium because it is a 'real' orbital spacecraft that has probably been to the ISS. I'll admit not everyone will see the value in this feature, and suggested this not as a top tier business justification for DC, but as an example of how I think these companies need to operate. i.e. someone should notice that they have a craft that did sub-orbital hops as part of the test program, and then wonder if people would pay to ride it. The idea can then be shot down for any number of reasons...
« Last Edit: 06/26/2012 07:22 pm by adrianwyard »

Offline adrianwyard

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Re: SNC Captive Carry test sees Dream Chaser take flight
« Reply #110 on: 06/26/2012 06:44 pm »
Re "no business case"

Well if we want to follow this general idea forward and get to real-world operational and regulatory details, then I could well believe the business becomes iffy. Predicting the future in detail is hard.

I thought you were saying that there's no case for high-speed travel per se. I personally paid the big bucks to travel on Concorde, and definitely felt as though I got my money's worth.

As you say, the first hurdle is the oft-quoted assessment that you need near-orbital velocity to get any useful (marketable) distance. If that's derived unambiguously from the physics, then that would a good reason to move on.

It is. Orbital velocity is around 25.8 kfps; a transatlantic flight requires about 18.4 kfps (see, for example, the STS-135 3-engine-out TAL boundary, below). SS2/WK2 will be in the 3-4 kfps range.

Thanks Jorge, this is what's great about NSF. Now you mention it I was always struck by the brief time that TAL was preferred before ATO, and this does seem likely generalizable to all rocket trajectories.

If the US were cheap enough you could try and sell trips that went several hundred miles, but disposing of the US is now a big problem. Sounds like we've hit a pretty hard wall...

Offline Rocket Science

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Re: SNC Captive Carry test sees Dream Chaser take flight
« Reply #111 on: 06/26/2012 06:45 pm »
From Captive Carry test to sub-orbital tourism… Sooooooo OT… ;D
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Offline Jim

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Re: SNC Captive Carry test sees Dream Chaser take flight
« Reply #112 on: 06/26/2012 07:03 pm »
. I personally paid the big bucks to travel on Concorde, and definitely felt as though I got my money's worth.


Joyride and not a business decision

Offline adrianwyard

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Re: SNC Captive Carry test sees Dream Chaser take flight
« Reply #113 on: 06/26/2012 07:21 pm »
. I personally paid the big bucks to travel on Concorde, and definitely felt as though I got my money's worth.


Joyride and not a business decision

My purchase involved a business decision.

And yes, we are definitely OT.


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