Flight Log - 2011-12-04 - Rich DeAngelis's Sprint

The Sprint: This Astron Sprint is from the original '70s kit. It uses streamer recovery, but I changed it out for a small 8" parachute. It is designed for high-performance altitude flights, and generally requires longer-burning ejection delays for maximum height. The engine must be tape-friction-fit as this model does not have a metal motor clip. Instead it has the boattail end designed to reduce drag. This rocket was later given my "Iris" modification, which extends the body tube about 5 inches above the streamer/parachute bay, and allows for a payload with an Altimeter One to measure altitudes.

After this payload section was tragically lost when the screw-eye/balsa joint failed, I built a newer, lighter and smaller payload section. It is now 3-1/8" vs. 4-1/2", and weighs 9.8 grams.  I certianly hope now I can get that extra 12 inches of altitude out of this bird and finally crack that elusive 1200 foot mark!

Originally, I replaced the flimsy crepe paper streamer with plastic one, but the plastic seems to stick to body tube because of static electricity, so I replaced it again with a small 8" parachute. With this parachute it descends at about 9 mph, soft enough for a safe grass landing. The rather small size should prevent this from drifting too much - a real problem considering the height it can attain. (The Iris altimeter payload is named after the Greek god of the rainbow. She is a messenger of the gods, linking the gods with humanity.) This rocket has flown higher than the NY Times Building in NY, the John Hancock Tower, and the Aon Center in Chicago.

 

Flight Date: 2011-12-04
Rocket Name: Sprint
Kit Name: Estes - Sprint {Kit} (1249) [1970-1983]
Flyer's Name: Rich DeAngelis
Motors: A8-3
Launch Site: Penn Manor School Lancaster PA
Actual Altitude: 165 Feet

I had hoped to try for a record altitude on a C6-7, but it was way too windy. On this first flight of the day, I sent the old Sprint on a mission to see how the winds aloft were, since it was pretty breezy today. It was also carrying an Altimeter 2 to collect flight data to guage performance on this smaller A motor. The lauch went off as well as can be expected. I had hoped for at least 100 feet, and was suprised to reach 165 feet. The A8 burned for about 1/2 second, peaking the acceleration at 5.4 Gs and averaging 2.8 Gs on the powered flight.

The Sprint remained upright and reached a speed of 58 mph despite the winds. It then coasted for 2.8 seconds to 165 feet then descended 7 feet before ejection 0.6 seconds later. The small 8" chute deployed well and it then floated down at 11 mph to land 12.8 seconds later near the launch area. Success!

StageMotor(s)
1Estes A8-3

 

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