Supersonic Vertical Assault

19 responses to “Supersonic Vertical Assault”

1. 

   jurvetson

   Aug 9, 2011 at 4:58 am

   Looking vertical…. we are go flight…..

   

   wiring up the igniter, avionics computer already armed
   
   the foothills of Old Razorback Mountain and the flight line are in the background.

   Climbing
   

   HCX flight computer readout
   

   But the rocket was at about a 25° angle from vertical, based on the "climbing" photos above. The computer is measuring the vertical component of speed from the baro sensor change over time. My son worked out a quick trig graph to convert the 1.32 vertical component of Mach (0 degrees from vertical on his graph) to the actual airspeed along the diagonal hypotenuse of flight (x is degrees from vertical and y is the actual Mach number):

   

   So we were going about Mach 1.44 along the diagonal, and those speed ratios also lead to a 15K ft. flight distance given the 13.7K vertical ft. distance traveled.

   Compensating for the speed of sound dropping at higher altitudes, she hit Mach 1.5 at 1,084 MPH.

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2. 

   jurvetson

   Aug 9, 2011 at 5:16 am

   Pad cam photos:
   

   And the iPhone photo Todd snapped from the top of Old Razorback when he heard the launch sound (the thin line goes up and off the top of the frame, tilting toward Todd):

   

   a Happy recovery… with a bounce mark from the aluminum boat-tail hitting the playa:
   
   Because of wind, I removed the drogue parachute altogether, and swapped in a downsized main chute. I knew the aluminum boat tail could take the impact, and the only damage from the fast 39 MPH landing was a ruptured plastic zip-tie that was holding the 9V battery in a metal brace.

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3. 

   Pieces of Eye

   Aug 9, 2011 at 6:50 am

   Video?

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4. 

   Astrocatou

   Aug 9, 2011 at 12:45 pm

   Almost as good as today’s APOD of the Jupiter probe. (9/8/11)
   Wonder what speed at true vertical would have been…

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5. 

   karl.simpson

   Aug 9, 2011 at 1:26 pm

   Awesome, well done (the rocket, the launch AND the photo :o).

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6. 

   Gubbins66

   Aug 9, 2011 at 3:10 pm

   Steve- If you didn’t get the msg already; thanks for showing my scouts your rocket and stuff. Watching a big bird like that is even better when you have touched the booster, motor and such. I’d love to see the time lapse they got from Razorback (Gubbins66@gmail.com)

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7. 

   jurvetson

   Aug 9, 2011 at 3:48 pm

   thanks y’all. More to come. I want to edit down the various video segments before posting. For something like the pad cam, it records several minutes of video for one second of action. =)

   For the scouts, I posted a getting started primer on rockets, part of a photoblog series on various rocketry topics. Also a rocket science summary on GeekDad. Oh, and a short TED video visual summary too. =)

   Dave: from the trig exercise above, we estimate it went 1,084 MPH, and had that been vertical, it would be pretty similar (more gravity to fight, but less air resistance too).

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8. 

   solerena

   Aug 9, 2011 at 4:47 pm

   Great pictures and wonderful collection of information for educating kids… wonder how many amateur rocket scientists out there… not many of them probably are photographers with your skill level… so we could vote for you to be #1 rocket man in the world:):)

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9. 

   Happy Tinfoil Cat

   Aug 9, 2011 at 4:51 pm

   Just reading those numbers give me chills

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10. 

    Astrocatou

    Aug 9, 2011 at 4:55 pm

    Itching to ask one more ? dumb question….
    Did it make a "boom"…?
    Only heard that once….it was hot.

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11. 

    Aris Jansons

    Aug 9, 2011 at 5:15 pm

    An interesting report. Thanks for sharing the results.

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12. 

    ! Polyhedra !

    Aug 9, 2011 at 5:58 pm

    Prodigious!

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13. 

    Rocketman8911

    Aug 9, 2011 at 10:16 pm

    Great Flight Steve. Thanks again for the L730. I am going to build the basically the same rocket again except using Fiber Glass tubing.

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14. 

    jurvetson

    Aug 9, 2011 at 11:10 pm

    I had the same experience and reaction….. I lost my V2 on the same L730 (left), and then I bounced back with a fiberglass enlargement (right)

    .

    Notice the clean thermoplastic burn on the L730 on the left… and it got that phat V2 moving. It will take a strong skinny rocket to survive that blast.

    I got some good photos of your launch. Just emailed them to ya. Here we are loading the jammed rail with a bit of creativity:
    

    And here is the supersonic shred overhead, with each frame 0.25 seconds apart:

    
    
    

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15. 

    jurvetson

    Aug 10, 2011 at 1:31 am

    My heart was beating too fast to tell…

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16. 

    Astrocatou

    Aug 10, 2011 at 1:36 am

    +1

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17. 

    jurvetson

    Aug 12, 2011 at 5:28 pm

    Oh, and I can’t wait to see the Saturn 1B fly at BALLS this year….

    6 P + 8 N motors… Almost 2K lbs! Heck, they use four K1100’s just for stage separation!

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18. 

    profsr_jones

    Aug 16, 2011 at 1:13 am

    Wow, nice still capture! As fast as that thing left the pad (from watching the video) even on continuous fire that’s nice timing!

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19. 

    jurvetson

    Aug 16, 2011 at 3:58 am

    Thanks… There is a lot to be gained by practice here… Looking for the igniter puff, avoiding the urge to pan, knowing the motor/weight ratio to estimate the acceleration for zoom choice.. And the dumb reflex from about 20,OOO rocket launch photos.

    Reply