The plan for deployment is to blow the nose cone off at apogee and have it descend under its own drogue and the main body tube come down separate under its own drogue. The nose cone had both main and apogee chutes installed in it, while the lower body only had a single, oversized chute for this test. Both apogee chutes were wrapped in Nomex to prevent black powder burns, then a single band of 3/4" elastic was used to hold the 2 chutes together. The latex band would pop off from the force of the nose cone separation and each chute would be free to bring its respective rocket section down to earth.
Here's a shot of the rocket Reed calls "Freedom" just before launch.
Freedom moves up the rail on a small KNSU motor.
Here's where things get interesting. I was using my mini telemetry system and the uplink commands as the sole means of recovery for this test. I had aimed the rocket a little south (left), and had expected a little weather cocking in the same direction. But the rocket few an almost straight flight and we all pretty much lost sight of the rocket because of the tree we were under. I needed the shade just to see my PC screen in the summer sun. Then the rocket reached apogee right in the sun... I had to ask Joel to let me know when the rocket reached apogee so I could fire the apogee charge at the correct moment. As it turns out, after reviewing the data logged on the PC we did hit apogee deploy at the correct moment. The rocket separated properly, but neither chute opened fully and both rocket sections came in fast, chutes trailing behind them. When I saw what was happening, I fired the main chute charge. Without the drogue opening, there was little chance the main would even deploy, but I gave it a shot. It was such a quick flight, from so low, I doubt by the time I hit the deploy main button the rocket was even in the air...
So everything worked just as planned, but both drogue chutes failed to open. When we recovered the two sections, both had the chutes fully deployed and nothing was tangled. Reed managed to get a few frames of each rocket section in his video as they neared ground level.
Here are two frames in one image of the nose cone section.
Here are four frames in one image of the lower body section. You can see the launch rail in the foreground, it's a bit of an illusion as the lower body came down several hundred yards from the tower. That's smoke from the launch that makes the picture foggy.
Click Here for a video Joel shot of the launch.
Click Here for Reed's video of the launch.
Click Here for a video and Reed's commentary of the aftermath of the flight.
After looking at the videos frame by frame, looking at the recovery components on the ground and looking at the
data logged on the PC from the telemetry system. The only explanation I have is that the Nomex cloth protecting
the chutes prevented them from "catching air" and opening. It's possible the Nomex slid up the shroud
lines and reefed the chutes, the video data would seem to support that since you can't see the Nomex cloth in the
pictures. Whether the Nomex reefed the chutes, or simply broke the air and prevented the chutes from opening (or
both), it seems pretty certain the Nomex was the problem. I think it's likely had the chutes had more time to open,
they would have at some point. But several hundred feet just wasn't enough in this case.
Damage was limited to a broken body tube and nose cone. The electronics not only survived, but the MTS was still transmitting data once on the ground. It seems my electronics have withstood an unintended shock test with flying colors! When the nose cone broke, it also broke off the antenna mount on the radio. It looks like it's just the solder joint so that's an easy fix. The nose cone broke right where I would have expected it to break. The thin area at the line between the aluminum and the all composite part of the nose. This area simply bonds the nose to the aluminum, in a flight all the load is internal on the lip of the aluminum. So I think the nose cone will be an easy fix too. Although I may add a few more layers of glass in that area for added insurance.
So the question that begs asking; "What needs to be changed?" Not using the Nomex cloth, or limiting it to small pieces. Sewing the Nomex to the shock cord to prevent it from reefing the chutes. Or I could just sacrifice the Nomex and not attach it at all. Perhaps I should go with Nomex recover bags, but that would require a different method of pulling the lower body tube chute out. I'll give it more thought before I decide on what changes to make...