Balls 2013 - Personnal launch report - Jarvis

I'm going to start a new thread for the Balls report. Here's a quick summary with more data to be posted later (after I get a few things under control).

I had a chance to repeat the N5800/N1100 flight from LDRS where the sustainer didn't light. I really hadn't expected to be able to do it, but things just kind of lined up.

The weather here is not too good, but Friday was OK until up to about 2 PM. Then, the high winds kicked in. Knowing that the wind was coming, I planned to launch as early as I could Friday morning. As it turned out, I was first out of the box, and the wind was calm and the sky blue. Perfect conditions. The flight was fine. The staging delay seemed a bit long, but I won't know exactly until I download the Ravens. The rocket angled a bit to the west, but the gps indicates that it wasn't quite as much angle as it looked like from the ground. I had gps all of the way. The booster came down about 2 miles out to the northwest. Fortunately, someone turned in the coordinates or we would have been looking for a long time (it has a tracker, but the range is limited). It was laid out perfectly with no damage.

The sustainer came down 9 miles out, which isn't that bad all things considered. Apogee was about 6 miles out and then it drifted a few miles further. My wife and I had about a 1.5 mile walk to recover it. No damage to the sustainer either, other than some rock nicks.

I was able to download the gps data and the result was 118,600 AGL It's a bit below the simulation, but with the angle, not a bad match. I'll have quite a bit of gps data, so I should be able to calculate the flight angles through most all of the flight.

I also got a nice on-board video of the entire flight. I was hoping that the camera would work as planned, and it did. It will take a while to process this, but attached is a screen shot just a second or so before the apogee event.

Overall, I'm very happy with the flight. I've been trying it for a while, and it's nice to get one where everything worked. Like I said, it will take a while to get back home and get everything digested, but I'll post everything at some point.

Jim

Pretty Dang Cool!

Just..........WOW! Beyond impressive Jim!

Absolutely astonishing Jim! I mean really, really incredible. Shots like that are what keep me inspired.
Can't wait to see the video (and more pictures).

Alex

A great flight! I saw it go up just after I arrived at the flight line but no video.

Very nice, Jim - Congrats!

I'm happy to hear that things worked the second time around!

-Kevin

troj said:

Very nice, Jim - Congrats!

I'm happy to hear that things worked the second time around!

-Kevin

Click to expand...

Thanks Kevin (and everyone else)! That two-month delay to light the sustainer was a bit long.

Jim

Jim,

First of all congrats! I think hitting 100K is a rocket equivalent of climbing Everest!

Anytime you can get a pic with the curvature of the earth and then be able to say, "My rocket, that I designed, did that." is just plain cool in anyone's world.

How long have you been pursuing this dream?

Greg

I guess I'd have to claim 5 attempts in the 4x4 configuration (but it's not insanity if it finally works ... right?).

The first was an N4000/N1100 combination. It came apart at the end of the sustainer burn, after it had already started slowing down. Never figured out why.

The second (and the remainder) was the N5800/N1100 combination. This was the one with the altimeter firmware problem. It reached 100K, blew all of the charges at Mach 1.2 or something like that, and only the nosecone was recovered.

The third was a flight where the sustainer lit shortly after takeoff. Not good - a one-in-a-million short circuit. Learned a few important lessons on that flight, one of which is that no one except me is around when the rocket is armed. Period.

The fourth was LDRS, where the sustainer didn't light. Finally, the fifth time was a charm.

The 4x3 pathway was just as tortuous (I learned about "slinky" fiberglass tubing, the bad things that happen above Mach 2.5, problems that can occur when you have a bad simulation, and that even though it's rocket science, you still have to connect all of the quick links).

Let's not talk about climbing mountains though - nothing to do with rocketry whatsoever.

Jim

Jim, congrats on getting FCY to work as designed. It's been tremendously inspiring to watch you work all the kinks out over the years. I know the lessons learned are far beyond what can be typed in a single message, but I do have one specific question:

JimJarvis50 said:

the bad things that happen above Mach 2.5

Click to expand...

Can you expand on this one a little bit? Everyone that's been there finds out something new or different, and I love hearing about them all. Thanks!

What is "slinky" fiberglass tubing? Shallow-angle filament winding?

daveyfire said:

Jim, congrats on getting FCY to work as designed. It's been tremendously inspiring to watch you work all the kinks out over the years. I know the lessons learned are far beyond what can be typed in a single message, but I do have one specific question:

Can you expand on this one a little bit? Everyone that's been there finds out something new or different, and I love hearing about them all. Thanks!

Click to expand...

Well, I don't really have anything quantitative in mind at Mach 2.5, except that that's the point where it seems like if there is a weak point in the rocket, it will be exposed (shallow angle filament-wound "slinky" tubing will go before that). Consequently, I try to stay below that value on my flights (although the current one reached Mach 2.7, but at a higher altitude). David, you might remember a flight I had maybe four years ago where the sustainer did a particularly violent shread at Mach 2.7 (the one with the X-shaped smoke plumes). That was a strong rocket, although a high L/D ratio. It's the flight that made me go from 5 to 7 wrap tubes for 3" rockets.

Jim

OK, I've downloaded the Raven's and a screen shot and a file are attached. A few things I notice...

The signal to light the sustainer came at 18.4 seconds, about a second later than for the LDRS flight. The signal was generated at V=850 ft/s, but the motor didn't light until 730 ft/s, nearly 3 seconds later. The motor only took about 1 second to come up to pressure in the 2011 flight. So, the added 3 seconds is why the delay was so long. Doing this again, I would raise the trigger velocity.

Even though the motor lit at 730 ft/s, the velocity topped out at 2990 ft/s, or about Mach 2.7. I don't like going that fast (see previous post).

Looks like inertial deploy with this particular Raven would have worked fine. The timers did the apogee event slightly before actual apogee (which was the plan).

That funny oscillation showed up again (where the sustainer drops back through Mach 1). In the movie, the rocket spin reverses at that point.

This time, the separation charge separated the parts. You can see the spike in the axial acceleration data just after burnout.

Adrian, what have I missed?

Jim



View attachment Balls 2013 FCY 1215.FIPa

Awesome job, Jim. I have been following along with this project for a while now. Glad it worked out for you. You are an inspiration to many.

Jason
(waiting for the video)

Awesome! Inspirational! Pushing new boundaries! It is people like Jim Jarvis that advance this hobby through their amazing achievements.

Jim superb flight and long-term project! It inspires me to go back and rresurrect a couple projects in limbo that I have bigger plans for. /Tim

Simply Amazing Jim. Truly inspiring as many have said before me. I am waiting to see the flight video.

Good on ya

Chris

JimJarvis50 said:

Well, I don't really have anything quantitative in mind at Mach 2.5, except that that's the point where it seems like if there is a weak point in the rocket, it will be exposed (shallow angle filament-wound "slinky" tubing will go before that). Consequently, I try to stay below that value on my flights (although the current one reached Mach 2.7, but at a higher altitude). David, you might remember a flight I had maybe four years ago where the sustainer did a particularly violent shread at Mach 2.7 (the one with the X-shaped smoke plumes). That was a strong rocket, although a high L/D ratio. It's the flight that made me go from 5 to 7 wrap tubes for 3" rockets.

Click to expand...

I do remember that one. High Mach numbers are terrifyingly fun Thanks for the notes. FWFG is great for day-to-day but your method of convolute winding is far superior from a strength and weight perspective for this kind of flying. What's next?!

Wow. Congrats. Jim.

Is this a solo attempt altitude record?

How about pics of the rocket and specs?

Congrats on the spectacular flight, Jim!!! Fantastic effort rewarded with astounding results; well done!:clap: Very happy I was able to witness the flight!

I do have a photo of the project on the rail; though I missed the liftoff due to the...uh...brief countdown! Will post once I download.

Great Job!!!

-Eric-

JimJarvis50 said:

OK, I've downloaded the Raven's and a screen shot and a file are attached. A few things I notice...

The signal to light the sustainer came at 18.4 seconds, about a second later than for the LDRS flight. The signal was generated at V=850 ft/s, but the motor didn't light until 730 ft/s, nearly 3 seconds later. The motor only took about 1 second to come up to pressure in the 2011 flight. So, the added 3 seconds is why the delay was so long. Doing this again, I would raise the trigger velocity.

Even though the motor lit at 730 ft/s, the velocity topped out at 2990 ft/s, or about Mach 2.7. I don't like going that fast (see previous post).

Looks like inertial deploy with this particular Raven would have worked fine. The timers did the apogee event slightly before actual apogee (which was the plan).

That funny oscillation showed up again (where the sustainer drops back through Mach 1). In the movie, the rocket spin reverses at that point.

This time, the separation charge separated the parts. You can see the spike in the axial acceleration data just after burnout.

Adrian, what have I missed?

Jim

Click to expand...

Awesome flight, Jim. I love seeing this data. Congratulations.

The baro-based apogee detection would have worked too, as it turns out. The atmospheric pressure at the top was 0.005 atmospheres, damn near vacuum. On the way down, before the chute came out, your rocket was dropping at about 500 feet/second.

At apogee, I don't see evidence of the same kind of slow tumble that the Aeropac team's rocket had.

You can see that the 4th channel, which blew the separation charge, got a little conductivity with the continuity voltage during the 2nd stage burn. It's probably some soot from the sustainer motor.

I wonder what the 2nd little acceleration impulse after the separation was. It happened about a half second later, and it was more of a gentle push.

The lateral oscillations at Mach 1 during the first coast-down are still mysterious. No apparent harm done, though. They don't show up during the 2nd coast, possibly because the air is so much less dense, and/or it's more stable after the sustainer burned its fuel.

Now you just need to put an N5800 on top, and go for 200,000 feet!

-Adrian

ECayemberg said:

Congrats on the spectacular flight, Jim!!! Fantastic effort rewarded with astounding results; well done!:clap: Very happy I was able to witness the flight!

I do have a photo of the project on the rail; though I missed the liftoff due to the...uh...brief countdown! Will post once I download.

Great Job!!!

-Eric-

Click to expand...

Did something odd happen on the countdown? I recall we had to wait for a train, but I thought everything was normal otherwise??

Jim

Adrian A said:

Awesome flight, Jim. I love seeing this data. Congratulations.

The baro-based apogee detection would have worked too, as it turns out. The atmospheric pressure at the top was 0.005 atmospheres, damn near vacuum. On the way down, before the chute came out, your rocket was dropping at about 500 feet/second.

At apogee, I don't see evidence of the same kind of slow tumble that the Aeropac team's rocket had.

You can see that the 4th channel, which blew the separation charge, got a little conductivity with the continuity voltage during the 2nd stage burn. It's probably some soot from the sustainer motor.

I wonder what the 2nd little acceleration impulse after the separation was. It happened about a half second later, and it was more of a gentle push.

The lateral oscillations at Mach 1 during the first coast-down are still mysterious. No apparent harm done, though. They don't show up during the 2nd coast, possibly because the air is so much less dense, and/or it's more stable after the sustainer burned its fuel.

Now you just need to put an N5800 on top, and go for 200,000 feet!

-Adrian

Click to expand...

I'll post the other Raven file too. It shows a little higher baro altitude. Can you determine if a delay would be required for the baro deploy?

The movie shows that the rocket was just doing a slow turn near apogee, but was not tumbling. I think it had turned sideways, but was still going up.

I don't know what that second push would be. This time, the staging coupler had BP residue in it, which means the parts were still together when the separation charge fired.

You know, it's just too bad that the sustainer can only fit a 6 grain motor and not a 6XL one. Otherwise, that N5800 in the sustainer is the first thing I woud do. Really! ....

Thanks for looking through the file. The Raven sure gives you a lot to look at!

Jim

JimJarvis50 said:

Did something odd happen on the countdown? I recall we had to wait for a train, but I thought everything was normal otherwise??

Jim

Click to expand...

Yes sir; there was no audible countdown....shortly after Waysie read the flight stats, your pretty bird simply leapt into the air without warning. I was prepping my camera and waiting for a countdown when she took to the skies. Unfortunately I missed any photos of the flight for that reason. We were at my tower (2500' out) at the time. Regardless; an astonishly awesome flight!!!!

-Eric-

ECayemberg said:

Yes sir; there was no audible countdown....shortly after Waysie read the flight stats, your pretty bird simply leapt into the air without warning. I was prepping my camera and waiting for a countdown when she took to the skies. Unfortunately I missed any photos of the flight for that reason. We were at my tower (2500' out) at the time. Regardless; an astonishly awesome flight!!!!

-Eric-

Click to expand...

Oh, that's too bad. I was at the flight line, so I guess I was hearing the countdown through the PA only and not the radio (I pushed the button, so I'm pretty sure there was one).

Jim

Jim, thanks for the FIP post and letting us live vicariously. Very inspirational.

Adrian A said:

I wonder what the 2nd little acceleration impulse after the separation was. It happened about a half second later, and it was more of a gentle push.
-Adrian

Click to expand...

I'm wondering if there might be a Mach wave interaction between the booster and sustainer. The same little acceleration is in the LDRS 2013 FCY 1215 FIP, so it is repeatable.

I have a little more data to share. One pic below is the gps trace for the two flights this summer (74K at LDRS and 118K at Balls). The second pic is a graph of the tiltometer data. It includes all three flights (including the FCY at LDRS where the sustainer didn't light). In addition to the tiltometer data, the graph includes the actual flight path angle calculated from the gps data. The data for the Balls flight is in black.

Comparing the tiltometer data to the actual flight path reveals that the tiltometer initially reads high under the initial acceleration, and then the readings go below the actual angle under deceleration. So, it's a bit difficult to use the tiltometer to control sustainer ignition based on the angle that exists at staging (because that angle is being underpredicted). However, the tiltometer will obviously catch a flight where the angle is significantly off, or where the initial angle is high (i.e., at the end of the booster motor burn).

The actual data for the Balls flight, based on gps, indicates that the angle at staging was about 9 degrees. Not bad, but I wouldn't want it to be too much higher.

By the way, the apogee picture I posted earlier clearly shows pyramide lake, but beyond that, in the same direction, is Lake Tahoe (with Reno in between).

Jim

JimJarvis50 said:

You know, it's just too bad that the sustainer can only fit a 6 grain motor and not a 6XL one. Otherwise, that N5800 in the sustainer is the first thing I woud do. Really! ....

Click to expand...

Time to start making a new booster?

I wonder how much more you'd have to worry about aeroheating. It could go past Mach 4 if at all optimized, but at the same time the air density would be far lower than on single-stage attempts.

I just realized: I've read your articles on tube-rolling, but never found out where you source your nosecones or how you make them if scratch-built. I don't remember even seeing them at LDRS (though that could have been me just not noticing). Could you enlighten us?

CarVac said:

Time to start making a new booster?

I wonder how much more you'd have to worry about aeroheating. It could go past Mach 4 if at all optimized, but at the same time the air density would be far lower than on single-stage attempts.

I just realized: I've read your articles on tube-rolling, but never found out where you source your nosecones or how you make them if scratch-built. I don't remember even seeing them at LDRS (though that could have been me just not noticing). Could you enlighten us?

Click to expand...

Well, it would be the sustainer I would have to make (a new booster would make it a 3-stage :y.

Speaking of boosters, I used the same booster for the two LDRS flights and the Balls flight. I'd have to say it was the worst rolled tube I've ever made. It had some air pockets in the wrap that I literally had to cut open and then glue down. Then, when I decided to step up from N4000's to N5800's, I added a five-wrap, 8" long tube over the top of the tube at the interstage location. Ugly, yes. Then, I decided that approach just moved the weak point further down, so I added five wraps over the top of the remainder of the upper airframe, up against that 8" section of tube. Don't try that at home. In spite of this weird airframe, this booster has flown perhaps a dozen N motors and would have to easily be the most successful rocket I've ever made. Go figure.

My nosecone approach isn't very exciting. Both the 3" and 4" are Performance rocketry cones (for whatever reason, making nosecones just doesn't have much appeal to me). The 3" is just a conical fiberglass cone, which I use because it's a little easier to "extend" the base of the cone to match the diameter of the thicker wall tubing that I make. The 4" is a filament-wound VK with the metal tip (which is firmly glued into place). Both cones are painted with many layers of the Cotronics 4525 to provide some heat resistance, and both cones are coated on the inside with perhaps a 1/4" thick layer of epoxy-milled glass.

Not much rocket science here, but that's what they are.

Jim

JimJarvis50 said:

Well, it would be the sustainer I would have to make (a new booster would make it a 3-stage :y.

Click to expand...

Ahahahah yes. I meant sustainer.

But for that matter, a 3-stage rocket with 98mm minimum diameter sustainers could be pulled off using a clustered booster....though that would surely be difficult to get regulatory approval for. Dispersion and all that.