BALLS Flights

[Steve Shannon]

Thank you to the hard working moderators!
I sensed that this discussion would take more than a few posts and asked for it to be forked into its own thread.

I think you make my point. For the flights you mentioned, it would probably have been possible to select a more appropriate lockout altitude, but because there was a lockout altitude, the sustainers were away from people when they lit. In those cases, the fact that the sustainers lit was less of a safety problem and more of a waiver problem (since there aren't many places, including Blackrock, where you can light a sustainer horizontally and stay within the waiver). Yes, use tilt too, but altitude is the first line of defense for safety.

A while back, I studied some flight data from FredT on his multi-staged flights. He sent data from quite a few flights, and I was impressed at how tightly he set his altitude criteria. As I recall, he had some cases where he had about a half second window. Based on his experience, I tightened up my criteria just a bit. It is entirely possible to do this - to set altitude criteria that ensures a reasonable flight (and that would prevent sustainers from lighting while arcing over).

Jim

That’s great information. I never would have expected such tight settings. And personally I think that extreme projects should have multiple methods to prevent off-vertical staging for both safety as well as waiver protection.

 

[FredA]

And personally I think that extreme projects should have multiple methods to prevent off-vertical staging for both safety as well as waiver protection.

If only we had multiple VALIDATED tools to use?

My understanding is currently there is only ONE unit in production and another one being developed.
And there seems to be a lot of pilot errors with the current production unit.

Not a good state.

 

[jderimig]

If only we had multiple VALIDATED tools to use?

My understanding is currently there is only ONE unit in production and another one being developed.
And there seems to be a lot of pilot errors with the current production unit.

Hi Fred,
It may be unfair to expect the maturity of these devices to be that far ahead of the vehicles they are flown in especially when you need the latter to validate the former.

It projects like yours that push the development of flight computer capability. But sample size is low. Both activities are research activities and anomalies will be revealed early in each. But at this year's Balls, electronics reliability was far ahead of vehicle reliability.

BTW there are 2 units in production. One was 4 for 4 in correct operation. 3 sustainer ignitions when they should have and one inhibit when it should have.

 

[Chris_H]

Hi Fred,
It may be unfair to expect the maturity of these devices to be that far ahead of the vehicles they are flown in especially when you need the latter to validate the former.

It projects like yours that push the development of flight computer capability. But sample size is low. Both activities are research activities and anomalies will be revealed early in each. But at this year's Balls, electronics reliability was far ahead of vehicle reliability.

BTW there are 2 units in production. One was 4 for 4 in correct operation. 3 sustainer ignitions when they should have and one inhibit when it should have.

One of these is the Marsa Gyro, correct? And the other is Kate?

 

[jderimig]

One of these is the Marsa Gyro, correct? And the other is Kate?

and AltusMetrum products.

 

[FredA]

It may be unfair to expect the maturity of these devices to be that far ahead of the vehicles they are flown in especially when you need the latter to validate the former.

Totally agree - but with events two years in a row, I can see TRA BOD requiring immature technology.
Just trying to make sure the cart doesn't get ahead of the horse.

Four for Four sounds like a nice start! Congrats!

 

[Steve Shannon]

Totally agree - but with events two years in a row, I can see TRA BOD requiring immature technology.
Just trying to make sure the cart doesn't get ahead of the horse.

Four for Four sounds like a nice start! Congrats!

Another perspective is that impulse levels and the attempted altitudes are increasing much faster than people’s ability to stage or recover rockets safely. Of the 12 class 3 projects flown at BALLS this year only two recovered safely. With that as a statistic should people be allowed to try and outdo their failed flights each year? Put another way, should people be required to show complete success at one altitude or impulse level before being allowed to fly to a higher altitude or impulse level? Which is the cart and which is the horse?

 

[mikec]

should people be required to show complete success at one altitude or impulse level before being allowed to fly to a higher altitude or impulse level?

The Class 3 committee has the ability to review any aspect of a particular design they want, as do the RSOs at BALLS. If you want to put a lot more rules and regulations in place, it should be on the basis of real solutions, not risk aversion and CYA, and those rules should be openly discussed and clearly defined in advance. I am not an advocate of requiring any specific technology, but if there is required technology, it should be certified by an unbiased group of experts, just like certified motors are, on the basis of real-world tests.

For me, the scariest moments at BALLS this year were from big single-stage rockets coming in ballistic with no tracking from altitude, not from any of the staged flights. By this time a single-stage apogee deployment should be pretty established technology.

BALLS is intended for extreme projects that aren't guaranteed to succeed. Overregulating it will kill that end of the hobby.

 

[mpitfield]

This is not likely going to be a popular position, but why not consider staging to be an ad on certification?

Staging has its own unique set of challenges that someone should demonstrate some competency in, before they move up in class. I would also be in favour of imposing time and min number of stressful flights required before moving up the certification process.

An example would be that if you are an L1 then you to stage you world need your "S1" endorsement. You would end up with an L1S1, and so on.

For an L3S3, the criteria for a pass should be strict in all aspects, from safety, recovery, to obtaining your fight plan goals. This strict adherence would hopefully result in only the best of the best moving up the ladder.

 

[Steve Shannon]

Mikec: C3RC only currently looks at waiver matters. They do not review for safety or probability of safe recovery. We (BoD) will be reviewing what we need to do to improve the odds of safe recovery. I agree that Black Rock is a great venue for more extreme projects, but we cannot continue to keep having high percentages of rockets coming in ballistic.
Risk aversion is not inappropriate.

I absolutely agree about single stage flights, but I would suggest that the safe recovery of sustainers for staged flights should be reasonably certain also. We need to figure out the recovery part.

 

[FredA]

Steve & co.
I poke at this thread so that perhaps TRA will consider a move from their current "hands off, capitalism will get it right" approach to taking a proactive approach to flight control.

TRA funded development and testing, similar to motor testing, could and should help improve safety.

The individuals trying their best to get this right are commendable.
A cooperative, well-thought-out venture on a organizational level would spread comprehension and accelerate solutions.
Food for thought.............

 

[mikec]

This is not likely going to be a popular position, but why not consider staging to be an ad on certification?

IMHO, this doesn't solve the issues at BALLS and is unneeded at other venues. I'm sure everyone who flew a staged flight at BALLS had lots of less extreme staged flights that were completely successful previously and would have easily qualified for any additional certification.

 

[mikec]

we cannot continue to keep having high percentages of rockets coming in ballistic.

What is an acceptable number? If it's zero, we all might as well quit flying, because perfection is not achievable.

Also, define "ballistic". My project wasn't under chute, but came down in pieces at less than 100 fps -- is that "ballistic"?

 

[jderimig]

It seems at Balls as more people attempt flights with more power and speed they have never done before we are entering a new era of stress > strength simple failures.

In many of these failures the electronics bay does not survive the initiating catastrophic event. Not surprising because much of that construction is the same as their L2 rocket.

Perhaps hardened electronics bays would be an area of research for these types of flights?

 

[Cameron Anderson]

Steve & co.
I poke at this thread so that perhaps TRA will consider a move from their current "hands off, capitalism will get it right" approach to taking a proactive approach to flight control.

TRA funded development and testing, similar to motor testing, could and should help improve safety.

The individuals trying their best to get this right are commendable.
A cooperative, well-thought-out venture on a organizational level would spread comprehension and accelerate solutions.
Food for thought.............

100% concur. TRA has a duty to establish safety policy norms. Everything from material strength, epoxy selection, parachute Cd, even rail button placement, can and should have safe baseline norms tested, determined, and enforced. This is a science and so far, there hasn't been enough science.

 

[Steve Shannon]

What is an acceptable number? If it's zero, we all might as well quit flying, because perfection is not achievable.

Also, define "ballistic". My project wasn't under chute, but came down in pieces at less than 100 fps -- is that "ballistic"?

It’ll never be zero, but less than 10% successful isn’t acceptable.

No, coming down spontaneously rekitted isn’t ballistic, but neither is it successful. What would you do to fix that? Based on your results this year would you come back next year trying to fly twice as much impulse? That’s what a few have done, as if the problem was not enough Newton-seconds.

I applaud those who retry nearly the same rocket over and over, learning and tweaking, until they are confident in their ability to recover successfully. That’s a central (very admirable) theme in Jim Jarvis’s attempts. His advances are incremental and controlled, not an effort to get lucky.
But sometimes luck does have something to do with it. I’m not trying to bash those who are trying to fly high; I just want all of us to realize that a higher success rate would be better for all of us. At some point the BLM might decide that round holes in the playa with metal, nylon, and electronics discarded at the bottom are unacceptable. Then where will we be?

 

[mikec]

No, coming down spontaneously rekitted isn’t ballistic, but neither is it successful. What would you do to fix that? Based on your results this year would you come back next year trying to fly twice as much impulse?

"Spontaneously rekitted" isn't accurate but we're not talking about my specific flight. And no, I wouldn't double the impulse. In fact, my flight was a downscale of an earlier failed group project.

Rules requiring previous experience of some sort are much more reasonable IMHO than more arbitrary one-size-fits-all rules about rocket construction, what electronics are used, etc, which devolve in many cases to the particular biases of the rulemakers and not actual flight experience. As long as the experience rules provide an on ramp to get started. Black Rock is difficult enough to get to, and so far beyond what one can fly at other sites, that it's hard to build up to it incrementally.

 

[mpitfield]

I don't see this as a single solution magic button problem. In other words, improvements will be come on many fronts and incrementally.

Based on my experience, if all of the improvements, recommendations, best practices, etc. are up to the individuals involved, then that is only going to move this so far. Not that I am a fan of more rules and requirements, but we are in a digital and very hyperbolic time, and it will only take one incident, real or perceived, to get out of hand and have an negative effect on the hobby as a whole. So whether it is up to the people running the launch or Tripoli, something needs to tighten up. That is assuming we want to be proactive.

I work with University students and I tell them all the time that they need to expand their view to include the hobby. There is more a stake here than someone's failed flight.

IMHO, this doesn't solve the issues at BALLS and is unneeded at other venues. I'm sure everyone who flew a staged flight at BALLS had lots of less extreme staged flights that were completely successful previously and would have easily qualified for any additional certification.

 

[Steve Shannon]

"Spontaneously rekitted" isn't accurate but we're not talking about my specific flight. And no, I wouldn't double the impulse. In fact, my flight was a downscale of an earlier failed group project.

Rules requiring previous experience of some sort are much more reasonable IMHO than more arbitrary one-size-fits-all rules about rocket construction, what electronics are used, etc, which devolve in many cases to the particular biases of the rulemakers and not actual flight experience. As long as the experience rules provide an on ramp to get started. Black Rock is difficult enough to get to, and so far beyond what one can fly at other sites, that it's hard to build up to it incrementally.

I think we’re more in agreement than disagreement. I’m glad to hear you wouldn’t come back next year trying with twice the impulse. Unfortunately what we’re seeing in some few instances is that a person or team has a failure one year and thinks they need to redeem their reputation by trying something bigger. That’s what has me concerned.
If I had a deployment failure, I would come back the next year with a similar rocket and the same motor and try to nail the deployment. And I agree with you that only experience can bring about that result, learning what doesn’t work and learning what does. I would only change those things that didn’t work.
If successful I might make an incremental change to fly a little bigger motor, using what worked.
Certainly building up incrementally to Black Rock is possible. To think anything else may be go fever. Yes, it’s awesome, but there’s no rule saying you have to fly bigger than you ever have.

 

[Steve Shannon]

I don't see this as a single solution magic button problem. In other words, improvements will be come on many fronts and incrementally.

Based on my experience, if all of the improvements, recommendations, best practices, etc. are up to the individuals involved, then that is only going to move this so far. Not that I am a fan of more rules and requirements, but we are in a digital and very hyperbolic time, and it will only take one incident, real or perceived, to get out of hand and have an negative effect on the hobby as a whole. So whether it is up to the people running the launch or Tripoli, something needs to tighten up. That is assuming we want to be proactive.

I work with University students and I tell them all the time that they need to expand their view to include the hobby. There is more a stake here than someone's failed flight.

Thank you! That’s exactly right. There’s room for improvement on several fronts. And thanks for your excellent work with university students. They’re our future.

 

[Kip_Daugirdas]

But sometimes luck does have something to do with it. I’m not trying to bash those who are trying to fly high; I just want all of us to realize that a higher success rate would be better for all of us.

First off, luck has nothing to do with it. My successes have come from my failures, perseverance, hard work, and committing vast amounts of my time. No one truly understands this until they actually do it themselves. You become your project. And quite frankly, it’s easy to pick out those who are putting their best design forward versus those who are just hacking something together and hoping for the best.

The day before Balls this year I got the question of “Do you think 6g in a surgical tube is enough to deploy at 100k?” This was from a TAP member.

My response in my head was “Wow, a bit late for this one!” There is nothing wrong with the question but there is with its timing. Just asking that question the day before the range is set to open puts their whole project in doubt - what else did they skimp on? I think identifying projects and individuals like this is quite easy.

But then there are less obvious issues. My flight this year was a complete mess. I didn’t catch the multiple failure modes and neither did the board nor the RSOs. But we learned about appropriate altitude lockouts, firmware, supplier support, etc. from the failure. And hopefully the findings will become available to all members.

We can eliminate some failures by working together to make the right decisions when it comes to flight computer settings, ejection charges, etc. But projects will still fail - and some years way worse than others. This should be okay - it’s Balls. High altitude two-stagers and high performance avionics are still in their infancy. But I’m confident that success rates will start to improve in both arenas - particularly for those who keep trying year after year.

This brings me to what we can do now:

If you want to gauge experience or evaluate a project, the time to do this is sooner than 2 weeks before Balls. Nothing is more annoying than turning in Class 2/3 paperwork in April and not hearing a peep until the week before Balls. And that is the current status quo from both the board and the Class 3 committee.

I recommend the following:

1.) If you want a minimum experience level for certain projects. Set one but make it clear to members what it is - call it Cert Level 4 or whatever. Tell them you have to be more than L3 or even a TAP.

2.) Establish a revolving committee of folks with actual high-altitude flight experience to provide feedback on projects MONTHS prior to launches so there’s time for discussions and incorporating improvements. I don’t see a need to review everything and micro-manage. Focus on big safety issues:

- Avionics and programming (especially staging)
- Deployment methods
- Recovery sizing.

3.) Best Practices. Even if flyers are just aware of best practices they will likely incorporate them. There are a lot of best practices for high-altitude that exist today. Lets make such a document. It can even be as simple as a list of links on how-to topics:

- Stress ground testing the deployment system. Suggest proven methods for deployment: Cannon, t-charges, CO2. And allow for new methods as long as there is proof of testing.

- Avionics settings for staging: Altitude lockout up-to 75% of staging altitude, tilt < XXdeg, rocket must still be ascending. You can make a chart: max altitude, dispersion, tilt that applies to nearly all projects as a starting point.

- Provide an actual number for max descent rates like 30 ft/s. No more bringing it in on a drogue at 100ft/s.

- Outline a process for evaluating the stability of a high Mach number rockets. Know your actual burnout CG. Measure it with an empty case, liner and nozzle installed - do not just simulate it.

...........................
I think we can come up with a process that doesn’t make flying at Balls a bureaucratic mess but still improves the likelihood of success and therefore safety too.

Lastly, I wouldn’t be writing this if I didn’t want to be part of the solution.

- Kip

 

[manixFan]

I think the real issue is few of us are engineers, scientists, physicists, etc., yet we are doing real rocket science. Many projects are done by just one or two people who try and cover all the bases as much as possible. But It's hard for one person to be good at the many disciplines required for a large BALLS style project. In that respect I think a review committee is important and can help provide expert guidance for someone who may be pushing the limits of their knowledge or experience. At an iterative rate of once per year, it takes a long time for one person to get there. Having an expert review committee as a standard part of the design process should be considered.

In another thread a couple of folks mentioned they had no desire to share their failure modes or design issues and thus be open to public scrutiny. I think that's the wrong way to look at it. As Tripoli members I think we have an obligation to try and make the hobby safer and more successful for everyone involved. That means sharing what works and does not work. A mistake we make and don't share is an opportunity squandered to personally improve the hobby. There are so few big projects every year that each should help inform the others as to how to best proceed.

I can personally think of at least two times I should have been stronger in my objection to a design parameter of a big project. I regret not doing so and if my input would have made a positive difference, I suspect the flyer would as well. Personally I welcome any help that helps me achieve a successful flight. I've learned the hard way the cost of ignoring good advice. To me, the biggest value Tripoli can offer is guidance and tools to successfully fly rockets, regardless of size or complexity.


Tony

 

[cwbullet]

Another perspective is that impulse levels and the attempted altitudes are increasing much faster than people’s ability to stage or recover rockets safely. Of the 12 class 3 projects flown at BALLS this year only two recovered safely. With that as a statistic should people be allowed to try and outdo their failed flights each year? Put another way, should people be required to show complete success at one altitude or impulse level before being allowed to fly to a higher altitude or impulse level? Which is the cart and which is the horse?

Wow, 2 out of 12. What is the normal success rate?

 

[Steve Shannon]

Kip and Tony,
Thanks for two very good posts.

 

[Steve Shannon]

Wow, 2 out of 12. What is the normal success rate?

I don’t know, but it’s something people are looking at.

 

[cwbullet]

I don’t know, but it’s something people are looking at.

I think it is always a good thing to look at safety. In Army Medicine, we are always striving to be a High Reliable Organization that strives to not oversimplify and focus on processes to ensure anyone can bring up a safety concern. I often wonder if we need to focus on the preflight prep more and ask more questions of fliers.

 

[Steve Shannon]

Relative to the question a TAP asked Kip about whether that was enough BP, a person flying a Class 3 flight should be able to answer any such question and if necessary produce calculations as proof.

 

[Cameron Anderson]

I don’t know, but it’s something people are looking at.

What about all of the non-class 3 failures? I saw one group go 0 for 6 flying identical min diameter rockets using L1000 motors. Most shredded but some came in ballistic. The number of "shovel recovery" flights was staggering. Two core-sampled within 300 feet of my truck.

 

[mikec]

Relative to the question a TAP asked Kip about whether that was enough BP, a person flying a Class 3 flight should be able to answer any such question and if necessary produce calculations as proof.

Not at extremely high altitude they can't. AFAIK, BP efficiency in near vacuum is difficult if not impossible to quantify, though various containment techniques have proved to be workable.

 

[cwbullet]

Relative to the question a TAP asked Kip about whether that was enough BP, a person flying a Class 3 flight should be able to answer any such question and if necessary produce calculations as proof.

I usually ask if they ground tested but at the altitudes that they are flying that is irrelevant.

What about all of the non-class 3 failures? I saw one group go 0 for 6 flying identical min diameter rockets using L1000 motors. Most shredded but some came in ballistic. The number of "shovel recovery" flights was staggering. Two core-sampled within 300 feet of my truck.

That number of shovel and core samples is always alarming especially that close to the crowd (interpretation so if I am wrong, correct me). Did any one thing about a safety standdown to look at procedures? We do this in the military when something preventable goes wrong and we feel that it might be due to an error in setup or procedures.