To get both lines to appear together
on the chart, I just plotted the
relative change.
Second, even though the balloon
burst occurs in a near vacuum, the
parachute opens fully within two
seconds. The image strip in Figure
12 is a series of stills from a video
recorded at 98,000 feet. The images
show that indeed the parachute does
fully open within two seconds of the
balloon burst.
Let’s assume the near spacecraft
behaves as if it’s in free fall with no
significant drag for the first two
seconds after balloon burst. At the
point of burst, the near spacecraft is
ascending at a speed of 1,000 fpm,
or 17 fps. According to the equations
of motion for a mass under uniform
velocity and acceleration (d = vt +
½at2), the near spacecraft will fall,
17t + (1/2)(- 32)t2, or 17*2 + (1/2)*
(- 32)* 22, 34-64, or 30 feet from
burst altitude.
The equation for speed is v – at,
and this indicates the near spacecraft
is falling 17 – 32*2, 17-64, or 47 fps
by the time the parachute finally
opens. This is equal to a descent
speed of 32 mph. In high altitude
balloon bursts, the near spacecraft
NEAR SPACE
falls at a speed between 70 and 100
miles per hour. Therefore, it appears
a parachute doesn’t do much initially,
other than keep the near spacecraft
from flipping over and tangling.
Onwards and Upwards,
Your near space guide NV
USEFUL WEBSITES
Additional information about
parachutes can be found
at these websites.
www.aero.com
http://inventors.about.com
-/$%, ( 9 -/$%, '/3 6ARIABLE OUTPUT 6$# !MP "% 34 3%,,).' 34! 4)/. -/$%, &' -/$%, &' -/$%, ( 9 6ARIABLE SPEED TOOL n .O $IGITAL $ISPLAY $IGIT $ISPLAY -(: -/$%, 7,# 20- WITH ACCESSOR Y KIT IN A 4WO 6$# !MP VARIABLE OUTPUTS ).#, 5$% 3 02/"% 3 PLUS 6 ! lXED $IGITAL $ISPLAY HARD PLASTIC CARR Y CASE 6 $2
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