List small or large improvments we can make to design, process, or operations, in reverse-chronological order.
Successes:
Test-flight timeline (even without test flight) made us do much less last-minute so IREC weeek was less stressful
Same goes for integration tests well before IREC
Failures:
Never weighed rocket
Showed up to Tuesday saftey checks without fully-assembled rocket
Mitigations & ideas:
Show up to saftey check fully assembled (sans energetics)
Weigh the rocket in the field
Assign a systems engineer
Failures:
Long tube makes assembly very hard
Tubes fill with dust when wind gusts
Weathercock off rail
Low-ish TWR
Long railguides levered and caught on rail
Winding improvements
Redesign and reprint filament holder end caps
Design a dowel/other holding system for the rollers
Mitigations & ideas:
Aim for higher TWR
Return to button rail guides
Shorter/more open tubes
Printed end caps for tubes
Make long tubes before lengths are figured out (work in parallel)
Successes:
Sleds not wired together
Crimping multiple conductors into one ferrule for bridging
Huge Big Red Bee battery
Batteries with protection circuits
T-shaped and tapered key, easy to insert and stops in the right place
Failures:
Glued nut stuck inside, could not remove avionics bay
FSR judge didn’t like the massive battery and thin sled parts
it did break during flight
Sleds were loose when not in a tube
Big Red Bees are way too unreliable for a COTS part, we’ve had 4 failures in total
BRB antenna smashed into nose cone bulkhead and could not transmit
Upper end cap broke
Mitigations & ideas:
Retain the sleds while outside a tube
Impact test avionics bay
Re-do FEA after all changes, new holes/slots mean new stress concentrations
Think about assembly forces, not just flight forces
Better nut retention on the mounting bars
Do smaller slots for wire pass or put them on the side of the sled (DO backplane sled, DON’T do COTS sled)
Reduce the number of threaded connections, labor-intensive to Loctite everything
Have spares for everything (backup Big Red Bees saved us)
Tripod for the antenna holder on the stands
Use rubber ducky (or other encased antenna) for everything sticking up
GSW tracks “time of last update” and “time of last change” for GPS packets to check lock
Successes:
Mounting electronics to side panels improved density and made assembly easier
JST connectors worked well
Good to buy batteries with protections
Failures:
Line cutter immediately got cut
Alternate: Early main due to pressure spike
Need to depanel payload in the field to plug things in
Not enough venting
Mitigations & ideas:
Put a switch on every battery
Stronger line for line cutter
Successes:
Drogue streamer is easier to integrate, easier to see on descent/recovery, less snatch force
Mini-Tamiya connectors worked and did not need to be zip tied. Very cheap and easy to use.
Failures:
Needed to reach down 5’ of tube
Main at apogee for TBD reasons
Single-bay might be more complicated than worth, but not totally clear since we had >1’ of payload
Booster coupler tube cut shock cord, load rating did not matter
Couldn’t de-integrate fully because integration testing didn’t have us threadlock the charge caps or
Mitigations & ideas:
Back to dual bay
Higher TWR for less weathercocking
Fully (dummy energetics) integration test! No exceptions
Protect potential cut points (wrap more kevlar/other protection)
Wrench flats on charge cups
Weigh the rocket
More radio training
Land navigation training
Require all recovery to be HAM licensed
Earpiece microphones
More radio training
Make sure one person has cell reception (Verizon seems reliable)
Timer to drink water
More testing overall
Avoid Cessaroni
Epoxying nuts into bolted connections
Successes
Airframe “smoothness” did not detract from flight performance and apogee - exceeded expected apogee
Heat shrink tubing was an overall success!
Revised fin support structure design performed well
Overall easier and faster integration due to additional separation point
Unless otherwise specified below, all other structural components performed well (bulkheads, fins, thrust plate, retainer, etc)
Failures
Nose cone weights & tip were not properly secured and became detached - most likely upon impact(?) - and damaged avionics sled
Shear pin holes became stripped due to repeated use, leading to issues with disintegration and shear pins falling out
Several epoxy failures. Some of the damage may have occurred due to suspected hard impact, but improper surface preparation & alternative epoxy (Proline 4500 vs “rocket epoxy” G5000) likely contributed
Uneven tube ODs, especially between CF and FG. Surprisingly little noticeable impact on flight performance, but aesthetically bad and problematic for simulations.
Mitigations
Better surface preparation for epoxy joints + consider using G5000 again
More attention given to making consistent tube ODs between CF and FG tubes
Keep a better inventory of tube and coupler stock…
Tensile testing epoxy joints
Removable/replaceable rail guides
Tighter nose tip protector
Successes
Integration of single bay system
Main parachute and streamer deployed successfully
Good separation and no shock cord getting cut
Integration was faster than last year, but more room for improvement
Gaff tape protected beacon antennas from separation and deployment forces
Failures
No recovery points
Beacons were not audible until within 20ft
Went from 2 TD-2s to 1 after a failure mode was discovered mid integration
Primary BP charge did not separate rocket
Potential RRC3 not detecting apogee, need to follow up on
Delayed post apogee due to RRC3 apogee detection
Mitigations
More heavily consider dual bay systems
Integrate sabot and shock cord ahead of time
Better manage beacon wiring to prevent snags
Make beacons more accessible
Measure BP charges ahead of time
Shorten detonation time between primary and secondary charges
Research effect of orientation and air speed on deployment tests
Successes
Screw Retention worked very well for retaining and working on sleds
Screw cones worked wonderfully for guiding arming key
Backplane antennas notches decreased assembly time
Backplane did function before flight
18650 holder was very robust and did not fail in flight despite structure failure (backplane was still on)
RRC3's detected boost and deployed nominally
Failures
Structural failure during extreme loads (Impact?) led to the destruction of the sleds and damaging of electronics <- most of the bay would need to be replaced
Battery fatigue/transportation voltage not accounted for leading to decrease run time
Potato not easily serviceable in final assembly (Potato ran out of space as it was full of junk data by following day)
Camera did not record flight due to seating of SD card
GPS packets not received after boost (Possibly related to avionics structural failure)
Mitigations
Make the structure of stiffer materials or change the end cap design
Additional spares and dedicated transportation procedures
Move Potato into avionic section and add usb C for easier linking
(skill issue) -> better pre spaceport procedures for ensuring proper seating
(skill issue) -> Better procedures for ground station/radio tower setup
Successes
Grim worked very well, detecting launch, powering cameras, and collecting flight data
Cameras proved incredibly valuable for validating reefing performance, as well as observing the state of OMEN after separation. Cameras should absolutely be present on both the 2025 payload and rocket.
Reefing system survived flight and worked almost flawlessly in its reefed position, operating within 5.5% of the expected open area.
In field integration time was down to <15 minutes after practice
All data and systems survived flight, landing at a higher than anticipated speed, and being rained on for an hour.
More of the sabot recovered than in previous years
Failures
Short igniter leads caused piranhas to be ripped free of them and parachute was not disreefed
Static line to the parachute bag broke on separation (Assumed by In-Flight Footage), causing the parachute bag to separate later than desired, from centrifugal/aero forces. This delay caused roughly 7.5s of free fall after separation.
Due to this free fall, shock forces were greatly increased, overloading the load cell and destroying the sensor.
Poor venting for the secondary RRC3 caused strange altitude readings (Assumed by data consideration and observation of payload layout)
Grim had some trouble running sensors at full speed (I think, someone who knows more should expand on this)
Reefed parachute had more drag than expected, causing a slower decent velocity than expected (-46ft/s)
Only one packet was received during flight (radiosonde on accent w/o data), and payload was located by another team on recovery (ie dumb luck). While it is unknown how much this is due to the ground ops vs transmission from the payload, more testing is absolutely necessary to ensure this never happens again.
Sabot was not fully recovered, we some litterbugs fr
Mitigations
More testing is needed for novel systems like the reefed parachute. Simple errors like the igniter leads being too short, or the extra drag the parachute made would have been discovered if a full test of the system was ever performed.
More FOS consideration is needed for things like the load cell and the static line. There were already concerns that there was a case that the load cell could break, and while that didn’t happen, this case shows that our estimates for the loads we expect don’t take into account every case.
More radio testing using ground hardware is essential.
Sabot hinges were blasted apart, the kevlar loops kept it together, thus should be used on future flights. Additional kevlar loops in other parts of the sabot could certainly allow for full recovery.
Use tensile tester to calibrate strain gauge systems
Successes
We had an accurate Openrocket model
Flight sims for multiple wind cases
23rd overall in Barrowman award accuracy (451 ft, 3.85%) off our actual apogee
First of its kind separation force calculation
Tracked masses accurately throughout the year, weighed rocket at Spaceport
Modular weight system for stability
Legitimate proof of rocket’s stability during flight using simulations
New, more in depth fin flutter calculations
Failures
Predicted apogee didn’t factor in different launch angles
Did not use tools that could have given us more points (CADWIND, RocketPy)
Poor OpenRocket version control
Overestimated weight gain from paint
Likely overestimated surface roughness after paint
Mitigations
Simulate flight for a wide range of launch angles
Communicate to Pad Ops what the angle is supposed to be
Recruit more people
Tie Openrocket version control to project management software
Use data from this year for a more accurate paint/epoxy estimate
Weigh and track epoxy use
Measure surface roughness of painted components
Alan Grilley (RIT Student) check with tech labs
Successes
We found both payload and rocket
Semi consistent radio between teams and pits, teams could communicate with each other consistently
Extendo pole and Jonathan's mini computer promising additions to field recovery
Universal HAM licenses
Well prepared team, no need to run out and buy camelbaks, hats, or other reco gear
Failures
Beacons weren’t audible until really close
Coordination of Rocket recovery team
Ensuring recovery hardware (extendo pole and mini computer) work BEFORE you carry them an hour into the desert.
Mitigations
Ensure beacons are in RF transparent sections
Minimize chance of beacon wires getting tangled
Separate team lead and MCC backpack roles on recovery teams
Ensure recovery gear functions before leaving pits
Successes
Second trip to the pad went great. Everything went smoothly. All electronics were armed. Igniter went well, Jaden did it pretty much without help, FoR just watched.
Mylar blanket did a good job at keeping the temp of the rocket down.
Failures
First trip to the pad did not go well. We were sent to pad A but they overbooked it so then had to go to D. We also were late because people were walking in front of cars (Poor Rob was yelling at them not to). By the time we got to our rail most teams were already vertical. FSR was nice but spoke quietly so it was hard to hear him and that added to stress. As well as other FSR did not think we needed to oil rail and was confused by the fact we were using motor oil. Overall things were rushed and this pad team was new so they required a bit of guidance which was not conducive to the time restraints.
Igniter needed a lot of assistance from FoR.
Could not hear the Grim Reefer beeps - fairly certain it was not armed but had to leave it because of time constraint.
ESRA told us 85 deg +/- 1 so we did 85 which is different then what they originally said.
Not a horrible thing but we did walk pretty slow with the rocket.
Member that is assigned 10 ft away from the rocket is not the most effective use of a body. Especially when they are new.
We had trouble getting in contact with the ground station to see if we were getting packets.
Radio sonde did get hot in rocket
Mitigations
More practice: walking with the rocket, arming electronics, igniter wire and going over procedures. I think that would have made us more comfortable under high pressure situations on attempt 1.
Clear list of procedures, I think these could have been better organized - the material was there but hard to navigate to on pad with a bunch of loose papers. Practice would have helped with this.
Deciding pad team and lead BEFORE the week starts. (Mary) was pad lead but that wasn't decided until a day and a half before launch, or at least I was not told and I am CERTAIN of that. I also had a decent amount of other responsibilities to payload so it was tough to manage both of these and would have pivoted/delegated my payload responsibilities before the week if I knew I was pad lead. I would not say it is impossible to be heavily involved in pad and another team BUT I would have run the payload team differently knowing I had other responsibilities. So the moral of the story; just communicate.
Member that is assigned to stay 10 ft away: This person should be more than just a cameraman. Needs to help with getting things out of the bag when people need it. They need to be anticipating next steps and having supplies ready. They need to be a HAM to radio back to the ground station for packets. Should have the tape measure antenna. Preferably someone who is knowledgeable with APRS, GPS and radio things.
ESRA thing
Person needs to anticipate needs and know procedures
Longer dowel for ignitor wire - we were told ours was short.
“Dowel came with motor” -Donovan, info from Sam FoR
To help keep temp down damp towels work well (We did that for KONG)
Overall; it helps to have an assertive lead and more than 1 person who is familiar with the process at IREC.
Staple procedures
RIT Launch Bookbinders
Successes
Big pole with weather station was great
Failures
Big pole antenna was unplugged?
Big pole cable was not the correct ohmage
Backplane receiving antenna was not connected
Mitigations
Checklists
RP-SMA ban
Successes
Nobody got COVID
Towel holders stayed on the wall
Food was good
We left the place clean and got a positive review
Failures
Tetherball is dangerous
Overbought on food
Mitigations
Practice tetherball
Plan to eat out more nights
Successes
Passed FSR on first try, the reviewers were impressed by some of our design choices
Many people were interested in the ground station and avionics
Failures
ESRA decided that we should all do our best sardine impressions so everything was crowded
Mitigations
Figure out booth shifts early
We did a bunch of thermal analysis for our PETG boattail and put NONE of it in the report??????
BYU uses dual bay
Neither team Donovan looked at was concerned with rod speed
Vacuum bag for tubes
Tried in previous years
Paint booth autoclave
BYU patented zero degree wind
CFD the crap out of everything, ravenCFD
BYU bolt force calculator?