Failure Analysis of Hyperion

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I'm not a mechanical engineer, but couldn't you have the case where the shear pin holes deform unequally (i.e. the nose cone is separating in a lopsided way).. then instead of breaking 3 shear pins, you have a force that's breaking one shear pin at a time? Thus requiring less overall force?

No scientific knowledge here, either. But if the pins break at different times, I think you increase the likelihood of the NC not coming out, rather than coming out too soon. Tendency would be for the coupler to cant in the tube and get hung up. That's why many people using anything less than three pins.
 
No scientific knowledge here, either. But if the pins break at different times, I think you increase the likelihood of the NC not coming out, rather than coming out too soon. Tendency would be for the coupler to cant in the tube and get hung up. That's why many people using anything less than three pins.
The effect should be that it takes less force to shear the pins with no jam, but also that yes you increase the risk of a jam. Quantifying the first part is relatively easy. Quantifying the second, not so much :) I'd rather not de-rail this thread so I'll just mention it, but there was a previous thread here discussing how loose pins might make it easier for the pins to shear even if all pins are loaded at the same time.
 
The visual distance to the horizon from an observer on the ground is about 3.2 miles. So in this case the count pixel method would estimate the distance to the horizon, which is already a known quantity. Fortunately with the strong and steady upper level winds the direction of the wind was pretty stable at about 320-330 degrees. Get the exact value and you know the line. Start at 3 miles and draw the line to 5 miles. In between is where your rocket is. (more or less).

We were all hammered and looking at photos on FB at the time, so I forget the exact process, but involved the angle of the lens (internally, the actual angle to the sensor), the total pixels of the shot, and the pixels of the parachute, compared to the known width of the chute.


If you are taking photos and know something is going to break hard to find, mark your location on the ground, pile rocks, draw a line, etc. Also don't over zoom. You want as many land marks as possible to reference. If possible look behind you and try to line up two points to keep a line. At one club launch I saw a rocket go into 6' tall beans. we had a shot of it going in, and the speaker tower was in the shot. pretty easy to line that up.

I've considered putting out 4' flags at every half mile spread across the field, or even just at treelines just to act as markers.... but its hard enough to setup, and it'd be of limited use.
 
Man, I wish I could get back out there and look. I live 75 minutes away, so it's no casual drive. And we don't return to Higgs until after crop season, usually Nov. or Dec.

I drove back up to Ash Grove (75 min from my house) to find a second stage (29mm and black) once after realizing it was at least a half mile farther East after viewing Google maps. Took about an hour and a half in the hot sun, but I found it!
 
I may be able to go look for this thing Saturday. Who would be up for getting together for a systematic approach (always asking permission from landowners, though!) ?
 
I've learned that it's always further than you think, no matter how much you try. I also fly RDF as well as EggFinder. They're small enough to tag onto the recovery harness, so what's a few grams gonna hurt? Unless you're trying for a F altitude record, then disregard that :rolleyes:

Best of luck finding this thing. It sounds like you learned a lesson in regards to "Go fever". I have had go fever many times, and I always consider the consequences. If I do succumb to Go Fever, I double check everything. I learned that one from a early main due to an aggressive drogue... Probably a good thing it went anyway since the nose cone quick link (which had the chute connected to said quick link) wasn't closed... I keep that one in my range box as a reminder.... It's no longer oval.
 
Guys let's focus on retrieval. A lot of people better than me have estimated where they think it should be. What do you think would be a good search plan? If the collective can get their neuron pairs to run together and come up with one, I'll try to make a Saturday of it. I am sans children this weekend, and it looks like a beautiful day to walk around over there. Get me a plan and I'll do the legwork.
 
Guys let's focus on retrieval. A lot of people better than me have estimated where they think it should be. What do you think would be a good search plan? If the collective can get their neuron pairs to run together and come up with one, I'll try to make a Saturday of it. I am sans children this weekend, and it looks like a beautiful day to walk around over there. Get me a plan and I'll do the legwork.

If you get a team, I have used this search and rescue app
https://sarapp.com/

Networks your searchers, keeps track by gps where you have collectively searched. Really excellent.
 
Guys let's focus on retrieval. A lot of people better than me have estimated where they think it should be. What do you think would be a good search plan? If the collective can get their neuron pairs to run together and come up with one, I'll try to make a Saturday of it. I am sans children this weekend, and it looks like a beautiful day to walk around over there. Get me a plan and I'll do the legwork.


https://www.google.com/maps/d/viewe...&ll=39.05094354877484,-75.83206774999996&z=13

This is the best estimate I have right now.



If you get a team, I have used this search and rescue app
https://sarapp.com/

Networks your searchers, keeps track by gps where you have collectively searched. Really excellent.

That's really neat. I have that on my phone now for when I search for rockets. :)
 
Do the event organizers have downrange spotters for this? It seems like it might be a worthwhile for a large event like this to have 2 or 3 people out along the path of the wind.

Tinker
 
In hindsight, I should have had a vehicle parked downrange with a spotter.
 
With everyone else speculating about the root causes for failure let me answer the question decisively. It was because of the name "Hyperion". In the early 2000s, at RocLake in Alberta, Anthony Cesaroni launched one of the most beautiful rockets I've seen. It was also named Hyperion. His flight failed more spectacularly by coming down without deploying any chutes in spite of having redundant duplicate AltAcc altimeters, which were solely accelerometer based.
In his case the duplication of electronics is what killed his flight. Both of his altimeters failed exactly the same way. He was flying a Hypertek hybrid motor. Hybrids often pulse. The sampling rate of the AltAccs was nearly the same as the pulsation rate of the motors so apogee wasn't correctly calculated.
100% of the flights I've seen named Hyperion have had anomalies with deployment; therefore that's got to be the cause.

Seriously, Matt, you had a nice flight. I saw it and I've been over and over it in my mind wishing that I could remember what line it's on. Where we launch we frequently have rockets drift out of site, but we don't have trees and tall grass like here. I think someone will find it and you'll get it back, but in my mind the thing I dislike most is to lose a rocket. It just gnaws at you. It probably doesn't help to have this many people telling you what they think you did wrong. I would suggest you get some friends and just go look for it and get away from the forums for a while to avoid discouragement.

Steve Shannon
 
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Don't get discouraged enough to stop looking, this thing is big enough that in the right area, someone is going to see it. I wish I was close enough to go back out and help look myself. Did you put your name and cell on the chutes, parts etc? We're holding on to the notion that you WILL find it.
 
With everyone else speculating about the root causes for failure let me answer the question decisively. It was because of the name "Hyperion". In the early 2000s, at RocLake in Alberta, Anthony Cesaroni launched one of the most beautiful rockets I've seen. It was also named Hyperion. His flight failed more spectacularly by coming down without deploying any chutes in spite of having redundant duplicate AltAcc altimeters, which were solely accelerometer based.
In his case the duplication of electronics is what killed his flight. Both of his altimeters failed exactly the same way. He was flying a Hypertek hybrid motor. Hybrids often pulse. The sampling rate of the AltAccs was nearly the same as the pulsation rate of the motors so apogee wasn't correctly calculated.
100% of the flights I've seen named Hyperion have had anomalies with deployment; therefore that's got to be the cause.

Seriously, Matt, you had a nice flight. I saw it and I've been over and over it in my mind wishing that I could remember what line it's on. Where we launch we frequently have rockets drift out of site, but we don't have trees and tall grass like here. I think someone will find it and you'll get it back, but in my mind the thing I dislike most is to lose a rocket. It just gnaws at you. It probably doesn't help to have this many people telling you what they think you did wrong. I would suggest you get some friends and just go look for it and get away from the forums for a while to avoid discouragement.

Steve Shannon


I agree... it's been gnawing at me ever since I lost it.

I dreamed that night that we found it and I woke up so excited and then realized it was a dream. -_-
 
Sorry to hear about this flight , nothing like losing something too big to lose ...to make you feel like a Cap'n Dunce.

You touched on a problem you haven't solved before .. main deployment at apogee , if this has happened more than once -- you need to get ahead of it .. I have some tricks if you are interested .. although the best one was 'fly something DD at every launch ' helped keep me sharp and develop the other stategies . I don't want to be preachy , but that is what jumps out at me in reading your analysis .

The other thing is don't use 1S for rocketry or at least for nothing beyond a redundant altimeter like the Quark . After watching others scratch their head after a Raven 1S flight being intermittant -- intermittant means it worked on the bench and failed in the field ..1S is the common denominator in a few failures that seemed like a mystery.

Kenny
 
The 1S battery on the EggFinder without backup was not a good idea. A 2S battery could have saved the recovery. Due to the leisurely descent from 7k under main, one would have been able to jump in a vehicle and chase it to maintain a lock.
Agreed that 1S has no place in rocketry EXCEPT in those situations where the makers and the users confirm success with deployment devices. I get the jitters running a Raven on a 1S 180mah "thread cell" but it works and
is necessary with small high flying rockets. Just the same, I try not to let a rocket with this configuration sit on the pad for long periods of time in the ready mode. Kurt
 
Might also want to upgrade the Eggfinder antenna to an RP-SMA for the tx and rx. Might get up to 20k ft. range then, so you'd definitely be in range to track it. I also include an audible warbler so I can find rockets when in thick grass or trees. Those are a nice investment. Something like an Adept SB40 if you want to hear it 2+ football fields away. That would annoy residents enough to seek it out and call you to yell. :wink:
 
I can't help you find your rocket, but I hope you can get some help and walk it out until it is found. BTW, it is always windy in Kansas so practically everything is recovered multiple miles down-range. One adage we recognize is "It's always farther than you think." I would keep this in mind as others have suggested during your search.

For future reference ...

Pay attention to Jim Hendrickson. RDF trackers as backup to GPS are a necessity. I spent the weekend at Argonia watching several flyers fiddle with flaky GPS units of various makes. I am certain I would not trust my L3 attempt to GPS alone. All our regular, experienced GPS flyers use RDF trackers, especially on high-altitude flights.

One thing I haven't seen discussed and which may be obvious to some but not to others: Did the rocket have small pressure equalization holes in each airframe section? Forgetting to provide those can cause the main compartment to be pressurized to the ground-level atmosphere which is trying to push things apart at altitude. This is a condition that can't be replicated during ground tests and cause pre-mature separation, especially when the forces of the drogue deployment occur.

Again, good luck.

--Lance.
 
Off of a suggestion from several forum members, I'll be moving to a RF beacon.
 
I can't help you find your rocket, but I hope you can get some help and walk it out until it is found. BTW, it is always windy in Kansas so practically everything is recovered multiple miles down-range. One adage we recognize is "It's always farther than you think." I would keep this in mind as others have suggested during your search.

For future reference ...

Pay attention to Jim Hendrickson. RDF trackers as backup to GPS are a necessity. I spent the weekend at Argonia watching several flyers fiddle with flaky GPS units of various makes. I am certain I would not trust my L3 attempt to GPS alone. All our regular, experienced GPS flyers use RDF trackers, especially on high-altitude flights.

One thing I haven't seen discussed and which may be obvious to some but not to others: Did the rocket have small pressure equalization holes in each airframe section? Forgetting to provide those can cause the main compartment to be pressurized to the ground-level atmosphere which is trying to push things apart at altitude. This is a condition that can't be replicated during ground tests and cause pre-mature separation, especially when the forces of the drogue deployment occur.

Again, good luck.

--Lance.

Thank you for the suggestion. And yes, I did have 2x3/16" holes in each section of the rocket.
 
Off of a suggestion from several forum members, I'll be moving to a RF beacon.

Matt,

I highly suggest running both. They both have pros and cons. The GPS when working can tell you exactly where it is. The last packet I got when I was standing at the launch site on my was at 37ft altitude and within 20' of where the rocket landed. When you get packets back GPS works well. Also, the downlink from the TRS was very useful for determining altitude and charge status on descent.

However, RDF is nice redundancy. If your receiver doesn't work, you can fix it and re-acquire signal. It's not dependent on a negotiated handshake and that's good because a "dumb" transmitter receiver setup is robust. It's very useful for tracking down in trees and tall brush.

If you can swing both, use both.
 
Do all RDF trackers require HAM licensing? Or are there some good ones in the 900 mHz range?

900Mhz doesn't have the range on the ground like 1.25 meters or 70cm has. In the air with a GPS tracker it's fine. The "falcon trackers" don't "require" a license but some will argue the semantics using them for rocket tracking.
Me? Even though I do both types of tracking, Ham and ISM, I don't care because rocket flying is out in the boondocks and not likely to "bother" users like "real" wildlife trackers. Others will pick a bone with that belief.
Kurt
 
https://rocstock.org/advanced/advanced-rocket-tracking-using-onboard-radio-transmitters/ is a good overview of the options and what's available in non-licensed and licensed. https://www.walstonretrieval.com/main.htm has a good rep for non-licensed RDF tracking.

Walston had a good reputation. I believe that Jim Walston's website is up, but the company is essentially defunct. I know a few folks who have ordered for him and not received product.

That said, I would look at the LL Electronics receivers and transmitters.
 
I don't know of ANY license free transmitters compliant with FCC Part15 below 900Mhz. Even some of the 900 mhz units are of dubious legality. But fortunately FCC enforcement of this is not anywhere near a priority.
 
I'm reading up on 900m MHz transmitters. Seems like they work great in the air with people getting 5-20 miles range depending on the receiver antenna. However, once on the ground, range is severely limited to hundreds of yards or less. I'm thinking it's probably not the best for our purposes.

I'm currently not breaking any altitude records, so I'm not in a rush at the moment to get into RF tracking. However, I think I'll add it to my plans in the future. So my tracking would be:

Eggfinder
BRB RF
SB40 beeper
 
Thank you for the suggestion. And yes, I did have 2x3/16" holes in each section of the rocket.

Two is generally a not a great idea, as it sets up possibilities for a Kármán vortex street. Think about what can happen in your car with two opposite windows open - it's not pleasant for your ears until you open the third. I don't have definitive wind tunnel data to show that it is an issue with rockets, but I have enough experience trying to avoid the effect in other applications to know that three holes spaced roughly evenly around the airframe would be better.

Note that I am not making the claim that this caused the issue.
 
2 ea 3/16" pressure relief holes is likely not enough. With a 7.5" diameter by 46" main parachute compartment the time constant is about 9 seconds. The altitude wasn't too high so the pressure delta was only about 3psi. With no venting the pressure pushing on the nose would be about 130 pounds. while#4-40 nylon screws shear at about 40 pounds or 120 pounds for 3. The vents helped but there was still a significant preloading on the shear pins at apogee.

I didn't run any pressure data through my filter.
 
In case nobody has said so yet, good on ya for opening up to some critical analysis. It can be hard to hear about your mistakes but I think you're getting a lot of really good advice here and you (hopefully) won't make the same ones twice. Learn from it and kick ass on the next one. Good luck!
 
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