JimJarvis50
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OK, here's my launch report from LDRS 32.
I had two flights. The first was my FourCarbYen two-stager. It's a 4x4 carbon fiber rocket, which I was flying on a CTI N-5800 to CTI N-1100 combination. It simulated to about 127K using RasAero (a modified approach for two-stage flights). Unfortunately, or perhaps fortunately, the tiltometer on board shut down the sustainer ignition. The device detected an angle of 16 degrees. I picked a maximum angle criteria of 15 degrees, so once that angle was exceeded, the flight was essentially over. More on the tiltometer later. With the sustainer not lighting, the sustainer drifted up to around 25K and all parts were recovered. Here is an on-board movie from the flight (with Stu as part of the recovery team):
https://tinyurl.com/kkts2kh
My second flight was my TooCarbYen two stager. It's a 4x3 carbon fiber rocket, which flew on a CTI
N-2500 to Gorilla M-745 combination. It simulated to 76K using RasAero. The flight went fine (with the tiltometer criteria increased to 25 degrees), and the gps-based altitude came out to 73,633 feet. The rocket had no significant damage, and I plan to submit for a Tripoli N-staged record for this flight. A pic of the liftoff (from Troj) is attached.
Here are some additional details, mainly from the electronics. Starting with the tiltometer, I've attached a picture showing the tiltometer angle readings for both flights. I have also included lines for both flights where the angles are calculated from the gps data. A comparison shows that the tiltometer tends to first read a bit high of the actual angle and then a bit low. However, it correctly shows that the angle for the FCY flight was greater than that for the TCY flight. For the FCY flight, the actual angle at the staging point was about 12 degrees, and I estimate that this rocket would have ended up at least 10 miles out had the sustainer lit (somewhere near the Black Rock I believe). So, it was a bit of a marginal flight. Since the instrument appears to read about 5 degrees high early in the flight, it looks like the correct criteria setting for my flights is either 15 or 20 degrees. Unfortunately, the device has been discontinued due to the non-availability of parts. That's too bad, because it is a useful device for tilt detection, and also for launch safety.
Also attached is the Raven graph of the TCY flight. From the data, it's clear that this isn't a particularly extreme flight. The rocket reached Mach 1.4 on the sustainer, slowed to Mach 0.66 for sustainer ignition, and reached a maximum speed of Mach 2.1. The sustainer lit at T=18 seconds after 12 seconds of coast, and the M-745 motor took 2.5 seconds to come up to pressure. The rocket was at an actual angle of about 7.5 degrees when the sustainer lit.
A google earth rendition of the flight is attached. One thing it shows is the eastward movement of the rocket when the rocket encountered the jet stream. Maximum winds were around 40 knots I believe at around 35K, but the movement was just enough to take the rocket to Old Razorback Mountain, about 3.5 miles from the launch point.
Recovery was fun. My wife and I were joined by Tony Alcocer and someone else (who's name has slipped my mind). Tony knew how to get over the tracks and to the general area where the rocket was. I knew from the gps that the rocket was about 600 feet above the playa, but we couldn't tell which side of the mountain it was on. Tony finally spotted the rocket on a cliff and started heading up the mountain on his cycle. After giving the situation a little thought, I grabbed as much water as I could carry and headed up after him. An attached pic shows where we were when Tony got to the rocket - WooHoo!. Tony was real glad that I brought along some water, and I was real glad he brought along my rocket. Tony's my hero - again.
Well, that's my launch report. As always, there are way too many folks to thank for making these launches possible, so if you loaned me equipment, or gave me technical advice, or helped me load or track the rocket, or searched for me, or rehydrated me, or took pics, or whatever, please know that I truly appreciate your help.
Jim
I had two flights. The first was my FourCarbYen two-stager. It's a 4x4 carbon fiber rocket, which I was flying on a CTI N-5800 to CTI N-1100 combination. It simulated to about 127K using RasAero (a modified approach for two-stage flights). Unfortunately, or perhaps fortunately, the tiltometer on board shut down the sustainer ignition. The device detected an angle of 16 degrees. I picked a maximum angle criteria of 15 degrees, so once that angle was exceeded, the flight was essentially over. More on the tiltometer later. With the sustainer not lighting, the sustainer drifted up to around 25K and all parts were recovered. Here is an on-board movie from the flight (with Stu as part of the recovery team):
https://tinyurl.com/kkts2kh
My second flight was my TooCarbYen two stager. It's a 4x3 carbon fiber rocket, which flew on a CTI
N-2500 to Gorilla M-745 combination. It simulated to 76K using RasAero. The flight went fine (with the tiltometer criteria increased to 25 degrees), and the gps-based altitude came out to 73,633 feet. The rocket had no significant damage, and I plan to submit for a Tripoli N-staged record for this flight. A pic of the liftoff (from Troj) is attached.
Here are some additional details, mainly from the electronics. Starting with the tiltometer, I've attached a picture showing the tiltometer angle readings for both flights. I have also included lines for both flights where the angles are calculated from the gps data. A comparison shows that the tiltometer tends to first read a bit high of the actual angle and then a bit low. However, it correctly shows that the angle for the FCY flight was greater than that for the TCY flight. For the FCY flight, the actual angle at the staging point was about 12 degrees, and I estimate that this rocket would have ended up at least 10 miles out had the sustainer lit (somewhere near the Black Rock I believe). So, it was a bit of a marginal flight. Since the instrument appears to read about 5 degrees high early in the flight, it looks like the correct criteria setting for my flights is either 15 or 20 degrees. Unfortunately, the device has been discontinued due to the non-availability of parts. That's too bad, because it is a useful device for tilt detection, and also for launch safety.
Also attached is the Raven graph of the TCY flight. From the data, it's clear that this isn't a particularly extreme flight. The rocket reached Mach 1.4 on the sustainer, slowed to Mach 0.66 for sustainer ignition, and reached a maximum speed of Mach 2.1. The sustainer lit at T=18 seconds after 12 seconds of coast, and the M-745 motor took 2.5 seconds to come up to pressure. The rocket was at an actual angle of about 7.5 degrees when the sustainer lit.
A google earth rendition of the flight is attached. One thing it shows is the eastward movement of the rocket when the rocket encountered the jet stream. Maximum winds were around 40 knots I believe at around 35K, but the movement was just enough to take the rocket to Old Razorback Mountain, about 3.5 miles from the launch point.
Recovery was fun. My wife and I were joined by Tony Alcocer and someone else (who's name has slipped my mind). Tony knew how to get over the tracks and to the general area where the rocket was. I knew from the gps that the rocket was about 600 feet above the playa, but we couldn't tell which side of the mountain it was on. Tony finally spotted the rocket on a cliff and started heading up the mountain on his cycle. After giving the situation a little thought, I grabbed as much water as I could carry and headed up after him. An attached pic shows where we were when Tony got to the rocket - WooHoo!. Tony was real glad that I brought along some water, and I was real glad he brought along my rocket. Tony's my hero - again.
Well, that's my launch report. As always, there are way too many folks to thank for making these launches possible, so if you loaned me equipment, or gave me technical advice, or helped me load or track the rocket, or searched for me, or rehydrated me, or took pics, or whatever, please know that I truly appreciate your help.
Jim
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