iPhone 5
ƒ/2.4
4.13 mm
1/1,205
50
Our rocket was huge, but the winds took her far, far afield. Luckily we had a RF beacon on board, and even more helpful was a Navy pilot who’s keen eyes and tracking skills brought us so very close. More below.
8 responses to “Rocket Recovery”
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We found you!
Erik caught these recovery shots for us
And the body has a new zipper! I just fixed a double zipper from last time (repair photos).
I think I need to use a much longer kevlar shock cord. -
Not yet… Meanwhile, here are the flight stats from the onboard computers:
0 to 632 MPH in 3.46 seconds pulling 10 G’s. Apogee at 7,757 ft., a new record for this 60 lb. airframe. Looking at the HCX data logs, you can see positive speed in green (MPH), altitude in blue (miles), and g-shocks in red:
Zooming in on the launch to parachute moment, you can see the massive red shock event is the inflation of the parachute, quite late relative to apogee (you can see the blue parabola, as it is picking up speed heading down) and that is the reason the parachute cord ripped through the airframe again:
The white triangle up top shows that the computer triggered the pyro charge at 19 seconds (the perfect time approaching apogee), and the shock of the heavy nose cone yanking at the end of its cord is the little red spike at 20.5 seconds. And then there is a sickening delay of 9 seconds as the rocket is picking up speed coming back down ballistic. I remember saying "oh no" to the crowd at that point as I could tell it was late… Then the massive shock at 30 seconds as the parachute inflates and puts the air brake on the airframe, But the chute is pulling up and the rocket is nose down, with the parachute cord running out of the front of the airframe. The kevlar cord is like razor wire to the airframe, yanking it through a violent 180 and flipping it around. In the video, you can see shredded fiberglass flying everywhere.
To solve this problem, I could fly two parachutes, like I used to, perhaps with a very long shock cord between nose and body.
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