Gravity's Just a Habit: Difference between revisions

Revision as of 11:00, 8 February 2024

Gravity's Just a Habit ("GJaH") is my first two-stage high-power rocket. The initial build took place between May and July 2021, and I had it finished by November for its first flight.

GJaH is a Wildman Shapeshifter Jr. with the optional booster kit. I built a Shapeshifter Jr. for my level 1 certification in 2013, and my initial idea was to just build a booster for it, but then I decided I was sentimental enough about that rocket to just build a whole new one. The booster fins are reversed from the normal orientation (with the curved edge facing backwards) just because I liked the way it looked.

The sustainer uses the same electronics (Altus Metrum TeleMega), sled and bulkheads as Kestrel but it has its own coupler. The sustainer also carries a Mobius Maxi video camera. The interstage currently uses an EasyTimer and a BigRedBee RDF tracker. The booster is recovered by motor ejection and uses a Jolly Logic Chute Release.

GJaH's first (and so far, only) flight in November 2021 resulted in a safe recovery, but the sustainer motor did not fire. The rocket was not stable enough while flying on the booster, and was well outside its tilt limit when it would have staged. I've made two changes since then: I've added about 10 ounces of nose weight, and I have selected an I-470 booster motor instead of the original I285 to increase velocity off the pad.

A second flight is planned for February 10 2024, with the I-470 booster staging to an H-100 in the sustainer. Predicted altitude is 5700 feet AGL.

The rocket's name is a lyric from the song "Upside Down and Inside Out" by OK Go.

GJaH and my original L1 Shapeshifter Jr.
Internal fillets in the booster.
External view of interstage (before I found that this type of igniter would not work).
One side of the interstage sled showing the EasyTimer and switches.
The other side of the interstage sled showing the BigRedBee RDF tracker.
Schematic showing wiring of the interstage.
GJaH on the launch pad in Elsberry, MO, November 2021.

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 The sustainer uses the same electronics ([https://altusmetrum.org/TeleMega/ Altus Metrum TeleMega]), sled and bulkheads as [[Kestrel]] but it has its own coupler. The sustainer also carries a [https://mobiusactioncam.com Mobius Maxi] video camera. The interstage currently uses an [https://altusmetrum.org/EasyTimer/ EasyTimer] and a [https://shop.bigredbee.com/pages/rf-transmitters BigRedBee RDF tracker]. The booster is recovered by motor ejection and uses a [https://jollylogic.com/products/chuterelease/ Jolly Logic Chute Release].
-GJaH's first (and so far, only) flight in November 2021 resulted in a safe recovery, but the sustainer motor did not fire. The rocket was not stable enough while flying on the booster, and was well outside its tilt limit when it would have staged. I've made two changes since then: I've added about 10 ounces of nose weight, and I have selected an I-470 booster motor instead of the original I285 to increase velocity off the pad. Unfortunately, I have not yet had another opportunity to fly the rocket and try these changes.
+GJaH's first (and so far, only) flight in November 2021 resulted in a safe recovery, but the sustainer motor did not fire. The rocket was not stable enough while flying on the booster, and was well outside its tilt limit when it would have staged. I've made two changes since then: I've added about 10 ounces of nose weight, and I have selected an I-470 booster motor instead of the original I285 to increase velocity off the pad.
+A second flight is planned for February 10 2024, with the I-470 booster staging to an H-100 in the sustainer. Predicted altitude is 5700 feet AGL.
 The rocket's name is a lyric from the song [https://www.youtube.com/watch?v=LWGJA9i18Co "Upside Down and Inside Out"] by [https://okgo.net/ OK Go].