stealth6
insert witty tagline here
Well that didn't go quite as planned.
So, I've been keeping quiet about a project I've been working on for a long time. And that is to set a new F-impulse altitude record. I've had this in the works since last summer. My reasons for keeping quiet are many, but one of them was Steve Boetto's own project to do the same. I had been watching his thread, and my own projections/sims were showing quite a bit more altitude that he was going for (and ultimately achieved). I didn't want to rain on his parade, as his own project and results were impressive. He ultimately grabbed the TRA record at 5407', which is very cool.
So. I got the bug to try this last spring, and started by blowing through all kinds of designs/ideas/sims and such. As time went on, I kept refining it over and over until my sims started to show some pretty impressive possibilities. Then I started building. I kept refining, and refining, eeking out a few more feet of (simmed) altitude here and there. By the late fall I was essentially ready to fly. But then came trying to be at a suitable club launch to make the attempt, and I kept missing my chance. All the while, I continued to refine, tweak, sim, ground test, flight test, etc. and I kept gaining a few more (simmed) feet along the way. I was using both RockSim and RASAero, and once the rocket was built I was able to get super accurate sim files, at least in terms of measurements and such. Eventually I was getting reasonably consistent sims from the two programs, enough so that I was pretty confident in them.
My motor(s) of choice were a CTI F30-W (longburn) which gave the best results on the sims, but I was a bit leary of the offset core, and a CTI F51-CL which came pretty close. The worst sim, all things considered was 6999' and the best on was over 7300' - at the launch site altitude I was going for. These were all good enough to easily set a new record for both Tripoli (my first choice) and NAR (which I decided to submit for as well).
So today was flight day.
Annnnnnnnnnnnnnnd.......as mentioned above, it did not go as well as planned. Had PERFECT weather and conditions, so that was good. Prep and assembly (which were very tricky) went fine. My custom built launch tower went up no problem. Ignition was fine, and the flight up looked excellent. I used a sparkle streamer, and was able to get visual lock at apogee (with binoculars), and follow it all the way to the ground.
Or so I thought. Once I went to retrieve it, my radio tracking was acting odd. It seemed the closer I got to where I "saw" it land, the weaker my beacon got, and in fact lost it altogether. After some time walking around, I headed back towards the flight line. Halfway back the radio signal returned and I started tracking. It didn't make sense as it kept pointing me in the direction of the launch pads and/or the flight line. Hmmmm.....did someone pick up the rocket? Was someone else using their own tracker and happened to match my frequency? And then it hit me......I bet the streamer actually detached from the rocket and THAT is what I "saw" landing. Sure enough, I tracked via radio only and found the rocket in minutes pretty close to the launch pads....with no streamer attached.
So I brought it back to the van, and attempted to download the flight report. When I got the real bad news ....... the altimeter glitched and did not record the flight. Well, it did record, but it said that I flew to a maximum altitude of 43 feet. Not good.
So. No record for me this time. It sure looked like it could have flown to 7000' but I'll never know. Will have to make another attempt, which likely won't happen till midsummer at best, more likely late fall. In the meantime, I'll tweak and refine more and more I'm sure. And if I fly at higher launch ground level (like Hartsel Colorado), I may be able to shoot for as much as 8000'.
Oh well. Still was a good day on the launch field.....saw a few TRF folk including Aksrockets, Kenstarr, 75Grandville, Aerostadt. Plenty of great flights, and perfect weather. There are worse ways to spend the day.
I'll post bits about the rocket itself in another post.
ssix
So, I've been keeping quiet about a project I've been working on for a long time. And that is to set a new F-impulse altitude record. I've had this in the works since last summer. My reasons for keeping quiet are many, but one of them was Steve Boetto's own project to do the same. I had been watching his thread, and my own projections/sims were showing quite a bit more altitude that he was going for (and ultimately achieved). I didn't want to rain on his parade, as his own project and results were impressive. He ultimately grabbed the TRA record at 5407', which is very cool.
So. I got the bug to try this last spring, and started by blowing through all kinds of designs/ideas/sims and such. As time went on, I kept refining it over and over until my sims started to show some pretty impressive possibilities. Then I started building. I kept refining, and refining, eeking out a few more feet of (simmed) altitude here and there. By the late fall I was essentially ready to fly. But then came trying to be at a suitable club launch to make the attempt, and I kept missing my chance. All the while, I continued to refine, tweak, sim, ground test, flight test, etc. and I kept gaining a few more (simmed) feet along the way. I was using both RockSim and RASAero, and once the rocket was built I was able to get super accurate sim files, at least in terms of measurements and such. Eventually I was getting reasonably consistent sims from the two programs, enough so that I was pretty confident in them.
My motor(s) of choice were a CTI F30-W (longburn) which gave the best results on the sims, but I was a bit leary of the offset core, and a CTI F51-CL which came pretty close. The worst sim, all things considered was 6999' and the best on was over 7300' - at the launch site altitude I was going for. These were all good enough to easily set a new record for both Tripoli (my first choice) and NAR (which I decided to submit for as well).
So today was flight day.
Annnnnnnnnnnnnnnd.......as mentioned above, it did not go as well as planned. Had PERFECT weather and conditions, so that was good. Prep and assembly (which were very tricky) went fine. My custom built launch tower went up no problem. Ignition was fine, and the flight up looked excellent. I used a sparkle streamer, and was able to get visual lock at apogee (with binoculars), and follow it all the way to the ground.
Or so I thought. Once I went to retrieve it, my radio tracking was acting odd. It seemed the closer I got to where I "saw" it land, the weaker my beacon got, and in fact lost it altogether. After some time walking around, I headed back towards the flight line. Halfway back the radio signal returned and I started tracking. It didn't make sense as it kept pointing me in the direction of the launch pads and/or the flight line. Hmmmm.....did someone pick up the rocket? Was someone else using their own tracker and happened to match my frequency? And then it hit me......I bet the streamer actually detached from the rocket and THAT is what I "saw" landing. Sure enough, I tracked via radio only and found the rocket in minutes pretty close to the launch pads....with no streamer attached.
So I brought it back to the van, and attempted to download the flight report. When I got the real bad news ....... the altimeter glitched and did not record the flight. Well, it did record, but it said that I flew to a maximum altitude of 43 feet. Not good.
So. No record for me this time. It sure looked like it could have flown to 7000' but I'll never know. Will have to make another attempt, which likely won't happen till midsummer at best, more likely late fall. In the meantime, I'll tweak and refine more and more I'm sure. And if I fly at higher launch ground level (like Hartsel Colorado), I may be able to shoot for as much as 8000'.
Oh well. Still was a good day on the launch field.....saw a few TRF folk including Aksrockets, Kenstarr, 75Grandville, Aerostadt. Plenty of great flights, and perfect weather. There are worse ways to spend the day.
I'll post bits about the rocket itself in another post.
ssix