Click on the photo above to load a video of this flight (1.1 meg MPG file, 6 seconds of video)	Quick summary: Flight duration:  Thrust duration: Altitude at apogee:  Fuel Weight:  Nozzle throat:  Launch weight: Total Impulse:	6.14 seconds 0.5 seconds 41 meters 120.7 grams KN/sucrose 5/16 inch 4.25kg 131 N-sec

Details:  Spreadsheet output:
 

LumberCalc	Version 1d			Data for Flight 12-30-01B	Flying 4x4, flight 7
Measured:				Calculated:
Distance *	Feet	Meters		Rise/Run at apogee:	0.6556	< ratio of height on pole at apogee / distance to pole
A. Camera to measuring pole	7.5	2.285888		Rise/Run at burnout:	0.111107	< height on pole at burnout / distance to pole
B. Camera to launcher	217.6	66.32124
C. Camera to touchdown	197.1	60.07315		Height at apogee:	41.43208	< distance to apogee * rise/run ratio at apogee
D. Launcher to touchdown	32.5	9.905517		Height at burnout:	7.368732	< distance to burnout * rise/run ratio at burnout
E. Rise on pole at burnout	0.8333	0.253977		Rise height after burnout:	34.06335	< height at apogee - height at burnout
F. Rise on pole at apogee	4.917	1.498628
* Letters A-F refer to drawing on Sheet 2				Rise time, burnout to apogee:	2.636608	< calculated from rise height, deceleration by gravity
				Time, launch to apogee	3.136608	< boost time + rise time
Time	Seconds			Fall time, apogee to ground	2.907839	< calculated from height at apogee & gravity
Thrust duration	0.5	<Note		Total Flight time (calculated)	6.044447	< calculated boost + rise + fall time)
Descent from apogee	3.3			%Error between flight times:	0.015562	< comparing measured vs. calculated times
Total flight time (measured)	6.14
				Velocity at burnout (m/sec)	25.83876	< calculated from rise height, deceleration by gravity
Weight	Kilograms			Acceleration, actual (m/s^2)	51.67753	< velocity at burnout / thrust duration
Fuel charge	0.1207			Acceleration, felt (m/s^2)	61.47753	< actual acceleration + gravity
Total launch weight	4.2527			Thrust (Newtons)	261.4455	< felt acceleration * total weight
				Total Impulse (N-Sec)	130.7227	< thrust * thrust duration
				Isp (N-Sec/kg)	1083.038	< total impulse / mass of fuel charge
Jimmy Yawn				Seconds	110.5141	< Isp / gravity
jyawn@sfcc.net
12/30/01				Height (of doubtful accuracy)	53.361	< calculated from measured fall time
>Note: Thrust duration is not certain, audio and video data is ambiguous leading to figures ranging from 0.34 seconds
up to 0.7 seconds. Thus a mid-range value of 0.5 seconds has been used here.

Click here to download a copy of this spreadsheet, Excel format

Events:
0.6 seconds, Ignition switch clicks
2.4 seconds, Thrust begins
3.0 seconds, burnout
8.8 seconds, vehicle hits ground

Note that the launcher is 217 feet from the camera, causing a delay of about 0.2 second between the visual event and its sound.  Thus the ignitor delay is about 2/10 second less than the .wav file would suggest.  This ignitor delay is particularly long, probably because the grain was coated with 4 dips in nitrocellulose lacquer and not primed in any way.  The first ignitor (copper bridge wire with 1/2 gram black powder wrapped in masking tape) fired but did not ignite the grain.  The engine was re-armed by dropping a few large grains black powder (about 1/2 gram) into the core, and pressing them at the head-end with a second ignitor like the first.

JY
12/30/01