...
Goals
Team:
1. Fly to 80,000 ft
2. Recover to reflyable condition
3. Collect data: Nose cone heating throughout flight, load data from parachutes, visual data of parachutes, altitude, acceleration, vibration (NC and lower electronics)... (Lower electronics?) Recovery:
Add desired landing velocity, landing radius, other expectations
Structures:
All structures survive flight, nothing breaks, materials survive temperature changes
Avionics:
Measure altitude & acceleration and actuate necessary flight events
Payload:
Collect data on nose cone heating throughout flight
Propulsion:
Fly to 80,000 ft, motor performs nominally (no CATO, thrust curve within 5%)
Flight Data Files
Weather
Parameters | Nominal Value |
Launch Tower Ht. |
|
Launch Site Altitude | 1406m |
Landing Site Altitude |
|
Temperature | 68-95 |
Baro Pressure | 29.68 Hg |
Latitude | 32.9904 |
Longitude | 106.9750 |
Time | Windspeed |
7AM | NNW Wind:3.728 mph
|
4PM | N Wind:6.836 mph |
CAD
Video
Simulator Files:
12-17-2017
I've spent a few hours digging through RASAero, Open Rocket, BurnSim, the Mass Budget, and hitting all of the above with healthy doses of common sense. Andrew gave me a few good ideas on where to start sanity checking our numbers. I know these values still sound on the high side, but I'm inclined to believe them pending flaws inthesimfiles. I would be very happy to hit 80% of these values though, knowing how these kinds of flights go.
In case anyone was curious,therocksimfilethepreviousrasaeronumberswerebasedoffofstillwas usinganoffaxispistonand was almost 2 feet longer than the current design. This has led to some stability problems with the current design. At Burnout we hit a stability margin of 1.11. As this happens at Mach 3.35 I think we should increase the fin size to compensate.
These files are now correct to the design, as I understand it.
Motor file: 70kNs Rev 6
Composite Fin Can, OD of fin collar 6.25 in, 1/4 thick fins. .75 in edge chamfer .05 in rounding on edges.
Surface Finish: Rough Camouflage Pain
Rocket Length 11 feet 8 inches
GLOW is 158 lbs according to Mass Budget
Aft Closure include Boat Tail to 5.6 in aft diameter
Here are the relevant quantities.
GLOW: 158 lbs, +/- 14 lbs
Burnout Altitude: 12,200 ft AGL
Burnout Velocity 3,700 ft/s (Mach 3.35)
Maximum Altitude: 125,600 ft +/- 23,100 ft (from mass deltas)
These values came from some hand runsofRasAero
The next set of values came from OpenRocket on a dataset of 500 runs through Cassandra (Thanks Josh!). The raw values are quite different than the Open Rocket values, but with a healthy fudge factor (screwing with finishes and fin thicknesses) to get supersonic cd's to matchthoseofRasAero, the numbers were similar.Secondsemesterwe should improve Cassandra's aerodynamics. Anyways, Cassandra gives the following
GLOW = 158 lbs
Apogee 131,529 +/- 6,443 ft
Median Apogee = 133,142 (An average flight is pretty close to the average of the flights, which is good)
3-Sigma Altitude = 138,870 ft
Landing Zone = 4.3 miles east of base camp +/- 1.4 miles
...