Difference between revisions of "AirFish"
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I let the balloon go nearly 90 degrees vertical up. I didn't know the length of the line. When I pulled it back in I weighed the line at 35.75 g. I figured that later I could weigh pieces of known lengths of the line to estimate the total length. | I let the balloon go nearly 90 degrees vertical up. I didn't know the length of the line. When I pulled it back in I weighed the line at 35.75 g. I figured that later I could weigh pieces of known lengths of the line to estimate the total length. | ||
− | + | == Lift of balloon == | |
# The volume of a sphere is 4/3 * pi * r^3, where r is the radius of the balloon. | # The volume of a sphere is 4/3 * pi * r^3, where r is the radius of the balloon. |
Revision as of 15:23, 26 July 2008
Contents
Basecamp
The project management is through AirFish Basecamp
weight of line to estimate length
I let the balloon go nearly 90 degrees vertical up. I didn't know the length of the line. When I pulled it back in I weighed the line at 35.75 g. I figured that later I could weigh pieces of known lengths of the line to estimate the total length.
Lift of balloon
- The volume of a sphere is 4/3 * pi * r^3, where r is the radius of the balloon.
- One cubic foot of helium will lift about 28.2 grams, so multiply the volume of the balloon by 28.2.
- Divide by 448 -- the number of grams in a pound -- to determine the number of pounds it can lift.
(4/3) * pi * (r^3) * 28.2 = lift in grams ((4/3) * pi * (r^3) * 28.2) / 448 = lift in pounds
Flip Video Camera
Aprox 150g total weight = 94g body + 50g batteries (2-AA)
helium supplies SF
Party Warehouse
28 Westlake Ave, Daly City, CA THE MAP IS INCORRECT. IT IS A FEW BLOCKS SOUTH IN THE WESTLAKE MALL. http://maps.google.com/maps?f=q&hl=en&geocode=&q=28+Westlake+Ave,+Daly+City,+CA&sll=37.0625,-95.677068&sspn=79.379181,85.429688&ie=UTF8&ll=37.6999,-122.464256&spn=0.010068,0.010428&z=16&iwloc=addr (650) 992-5570
rental $10 - 25 balloons rental $20 - 72 balloons disposable $30 - 50 balloons
We were pretty happy with this place. The prices were cheap.
Party City: Daly City
317 Gellert Blvd, Daly City, CA (650) 756-0215 -
disposable 30 balloon tank $30 disposable 50 balloon tank $35
payload computers
Phidgets
They sell a rather expensive pressure sensor ($50), but it looks like it might be easy to interface 1115 Pressure Sensor. It plugs into the analog input of the Phidget Interface kit (Phidgets: 1018, 1202 or 1203). It measures absolute pressure 20 to 250 kPa (2.9 to 36.3 psi). This means it's probably not much good above 35000 feet.
S60 control
Send an SMS with S60
This stuf looks trivial. This could be a very viable downlink. http://wiki.forum.nokia.com/index.php/How_to_send_SMS
import messaging messaging.sms_send('number', 'text')
pyspy
http://sourceforge.net/projects/pyspy http://www.symbian-freak.com/forum/viewtopic.php?t=15756
Pressure versus Altitude
See also Boyle's Law.
volume of helium at altitudes.
Barometric Pressure vs. Altitude Table | |||||||||
Altitude Above Sea Level |
Temperature |
Barometer |
Atmospheric Pressure |
||||||
Feet |
Miles |
Meters |
F |
C |
In. Hg. Abs. |
mm Hg. Abs. |
PSI |
Kg / sq. cm |
kPa |
-5000 |
-1526 |
77 |
25 |
35.58 |
903.7 |
17.48 |
1.229 |
120.5 |
|
-4500 |
|
-1373 |
75 |
24 |
35.00 |
889.0 |
17.19 |
1.209 |
118.5 |
-4000 |
|
-1220 |
73 |
23 |
34.42 |
874.3 |
16.9 |
1.188 |
116.5 |
-3500 |
|
-1068 |
71 |
22 |
33.84 |
859.5 |
16.62 |
1.169 |
114.6 |
-3000 |
|
-915 |
70 |
21 |
33.27 |
845.1 |
16.34 |
1.149 |
112.7 |
-2500 |
|
-763 |
68 |
20 |
32.70 |
830.6 |
16.06 |
1.129 |
110.7 |
-2000 |
|
-610 |
66 |
19 |
32.14 |
816.4 |
15.78 |
1.109 |
108.8 |
-1500 |
|
-458 |
64 |
18 |
31.58 |
802.1 |
15.51 |
1.091 |
106.9 |
-1000 |
|
-305 |
63 |
17 |
31.02 |
787.9 |
15.23 |
1.071 |
105.0 |
-500 |
|
-153 |
61 |
16 |
30.47 |
773.9 |
14.96 |
1.052 |
103.1 |
0 |
|
0 |
59 |
15 |
29.92 |
760.0 |
14.696 |
1.0333 |
101.33 |
500 |
|
153 |
57 |
14 |
29.38 |
746.3 |
14.43 |
1.015 |
99.49 |
1000 |
|
305 |
55 |
13 |
28.86 |
733.0 |
14.16 |
0.996 |
97.63 |
1500 |
|
458 |
54 |
12 |
28.33 |
719.6 |
13.91 |
0.978 |
95.91 |
2000 |
|
610 |
52 |
11 |
27.82 |
706.6 |
13.66 |
0.960 |
94.19 |
2500 |
|
763 |
50 |
10 |
27.32 |
693.9 |
13.41 |
0.943 |
92.46 |
3000 |
|
915 |
48 |
9 |
26.82 |
681.2 |
13.17 |
0.926 |
90.81 |
3500 |
|
1068 |
47 |
8 |
26.33 |
668.8 |
12.93 |
0.909 |
89.15 |
4000 |
|
1220 |
45 |
7 |
25.84 |
656.3 |
12.69 |
0.892 |
87.49 |
4500 |
|
1373 |
43 |
6 |
25.37 |
644.4 |
12.46 |
0.876 |
85.91 |
5000 |
0.95 |
1526 |
41 |
5 |
24.90 |
632.5 |
12.23 |
0.86 |
84.33 |
6000 |
1.1 |
1831 |
38 |
3 |
23.99 |
609.3 |
11.78 |
0.828 |
81.22 |
7000 |
1.3 |
2136 |
34 |
1 |
23.10 |
586.7 |
11.34 |
0.797 |
78.19 |
8000 |
1.5 |
2441 |
31 |
-1 |
22.23 |
564.6 |
10.91 |
0.767 |
75.22 |
9000 |
1.7 |
2746 |
27 |
-3 |
21.39 |
543.3 |
10.5 |
0.738 |
72.40 |
10,000 |
1.9 |
3050 |
23 |
-5 |
20.58 |
522.7 |
10.1 |
0.71 |
69.64 |
15,000 |
2.8 |
4577 |
6 |
-14 |
16.89 |
429.0 |
8.29 |
0.583 |
57.16 |
20,000 |
3.8 |
6102 |
-12 |
-24 |
13.76 |
349.5 |
6.76 |
0.475 |
46.61 |
25,000 |
4.7 |
7628 |
-30 |
-34 |
11.12 |
282.4 |
5.46 |
0.384 |
37.65 |
30,000 |
5.7 |
9153 |
-48 |
-44 |
8.903 |
226.1 |
4.37 |
0.307 |
30.13 |
35,000 |
6.6 |
10,679 |
-66 |
-54 |
7.06 |
179.3 |
3.47 |
0.244 |
23.93 |
40,000 |
7.6 |
12,204 |
-70 |
-57 |
5.558 |
141.2 |
2.73 |
0.192 |
18.82 |
45,000 |
8.5 |
13,730 |
-70 |
-57 |
4.375 |
111.1 |
2.15 |
0.151 |
14.82 |
50,000 |
9.5 |
15,255 |
-70 |
-57 |
3.444 |
87.5 |
1.69 |
0.119 |
11.65 |
55,000 |
10.4 |
16,781 |
-70 |
-57 |
2.712 |
68.9 |
1.33 |
0.0935 |
9.17 |
60,000 |
11.4 |
18,306 |
-70 |
-57 |
2.135 |
54.2 |
1.05 |
0.0738 |
7.24 |
70,000 |
13.3 |
21,357 |
-67 |
-55 |
1.325 |
33.7 |
0.651 |
0.651 |
4.49 |
80,000 |
15.2 |
24,408 |
-62 |
-52 |
0.8273 |
21.0 |
0.406 |
0.406 |
2.80 |
90,000 |
17.1 |
27,459 |
-57 |
-59 |
0.520 |
13.2 |
0.255 |
0.255 |
1.76 |
100,000 |
18.9 |
30,510 |
-51 |
-46 |
0.329 |
8.36 |
0.162 |
0.162 |
1.12 |