Tag: NAR

High Power Rocketry: L2 Certification Flight

improbableventures2 Comments

Officially level 2 certified!

rocket launching into the blue sky, with fire and smoke below
textbook flight

Fulfilling a 2020 goal

I really started getting into rocketry last fall, less than a year ago, and I had set some goals for 2020 when the year began. My goals included getting level 1 and level 2 certifications in high power rocketry (HPR) through the National Association of Rocketry (NAR).

I think 2020 threw some curveballs at just about everybody, myself included – but after a few false starts and delays, I was able to launch my first high power rocket in central Washington on a beautiful day in June, and as I wrote about previously, I got my L1 cert.

I deliberately chose and constructed a rocket that could be used for both L1 and L2 certification (i.e. it is capable of launching on a more powerful motor), and I built it to be dual deploy capable. I also had plenty of time to study for the written exam, which is required after the L1 certification but prior to the L2 flight. Timing is everything.

Because of this, I was able to do everything in a single day – L1 flight, L2 written exam (which I passed, of course), and L2 flight. I had more than six months to prepare for this day, so it’s not particularly impressive!

white rocket with orange and yellow parachutes lying on ground in green field
a safe landing

L1 vs. L2 flights

On the L1 flight – the maiden voyage – I didn’t want to take any unnecessary risks and decided to keep it as simple as possible, so I didn’t attempt using any electronics or dual deploy. The rocket separated through a simple motor ejection charge.

But for the L2 flight, I wanted to try the flight computer and dual deploy. I was a little nervous because while I checked and rechecked everything in advance, this was still the first actual attempt and there were a lot of firsts: first time using any flight computer or black powder charges, first time arming the electronics on the launch pad, first time using the ground station to communicate via radio with the rocket (using a laptop with the appropriate software and a connected Yagi antenna), etc.

Everything went smoothly, from the launch (see first photo above) to deployment of the drogue parachute at apogee and the main parachute closer to the ground. I recovered the rocket without any damage.

white rocket with text "improbable ventures" lying on ground in green field
mildly improbable

L2 flight data breakdown

What’s particularly cool is the flight computer not only fires multiple pyro charges (and therefore controls the rocket’s separation and deployment of two parachutes), but it also contains an altimeter and other sensors that record the rocket’s maximum height and its descent speed.

For my L2 flight, the rocket reached 3,506 ft, with a maximum speed of 599 ft/sec (Mach 0.5). In other words, the rocket’s max speed was about one-half the speed of sound.

The descent rate under the drogue parachute was 39 ft/sec, and under the main parachute it was 27 ft/sec. The HyperLOC 835 is a fairly lightweight cardboard rocket with a gross liftoff weight (that is, a weight including the motor, parachutes, and everything else inside) of only about 6 lbs, and this descent rate was more than sufficient for a safe landing.

All in all, this was a fantastic experience. A four hour drive each way made this a very long day, but it was absolutely worth making the trip. Inevitably, I also learned a tremendous amount – for example, how to set up a large rocket on the pad and launch rail, how to use the flight computer and ground station software, etc. I also learned what types of things that I could do better next time. Overall, I’m even more excited about future launches – trying out new techniques, flying on even more powerful motors, and capturing data with the flight computer to beat my own previous records!

High Power Rocketry: L1 Certification Flight

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Finally! According to the National Association of Rocketry, I now officially have my level 1 certification in high power rocketry.

rocket launching into the air with fire and smoke below
liftoff!

I finished building my first high power rocket, the HyperLOC 835, back in December, but getting certified requires a successful flight and recovery of the rocket. But clubs don’t often host launch events in the winter months, and those that do are still subject to weather conditions (e.g., snowstorms). It’s helpful to have a club host a launch because you need (a) access to a large suitable area of land, (b) a waiver from the FAA to launch up to a certain altitude, and (c) launch equipment, such as launch pads and rails and an electric ignition system.

Clubs often start hosting launch events in the spring, but in spring 2020, COVID-19 hit, and things were cancelled or postponed.

I was finally able to attend a launch in June in south central Washington, about a 4 hour drive from where I live in the Seattle area.

I ended up launching the HyperLOC 835 on an Aerotech I-140 motor. The rocket is capable of dual deploy using a flight computer, but for this L1 certification flight I wanted it to be as simple as possible, so I didn’t use electronics. The recovery system was a parachute that deployed when the rocket separated using the motor ejection charge.

white and red rocket on launch pad
maiden flight

The weather looked ominous: it was cloudy, and we felt a few raindrops hitting us periodically, but it seemed to be holding steady.

The rocket launched, the parachute deployed, and it landed without a scratch in the tall grasses. The only tricky part was locating it. But since I was able to see the general area where it landed, it wasn’t too difficult to find.

yellow parachute in a sea of green tall grasses
a sea of tall grasses

Luckily the bright yellow parachute was pretty easy to spot from a distance, even though the rocket had sunk into a sea of tall grasses.

white rocket with text "improbable ventures" lying in tall grasses
a venture most improbable

Overall, it was a textbook launch and went as smoothly as could be expected! I’d estimate the rocket went about 1,700 ft in altitude, but as mentioned above, I didn’t use electronics for this flight so I can’t say for sure.

Immediately after this, I took the level 2 written exam, which is required prior to the level 2 certification flight, and I passed that (not difficult considering I’d had six months to study). It started raining more heavily, though, and we weren’t sure if we would need to call it a day and head out. But we waited another 30 minutes for the rain to stop, and then the skies cleared up and the sun came out. Perfect timing for my L2 certification flight, which I’ll summarize in my next post!

L3: a story of hubris

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At the beginning of 2020, before we collectively realized that COVID-19 would completely upend everything we know and love and that this year would be written off as a total disaster, I had set a couple of goals in a naive attempt to start the year off right.

picture of me looking wistfully into the sky, with large pine trees in background
overconfidence at its finest

Society might be crumbling, but looking back on the first quarter of 2020, I seem to have held up my end pretty well. My goals were to build my first high power rocket and electronics bay, and to transform my backyard shed into a workshop, primary for rockets and related projects. And I set an ambitious schedule of getting certified at not only L1 and L2 (realistically, this would already be fairly challenging) but also L3, the highest rocketry certification and something significantly more daunting, even for a seasoned pro (aka, not me). How has my progress stacked up so far, as of early April?

Well, I did build my first high power rocket, the HyperLOC 835, and I completed the e-bay. After I got my hands on some black powder, I conducted some ground testing. The rocket and e-bay can be used for both L1 and L2 certification, once society returns to some degree of normalcy and launch events are held again. I’ve studied for the written exam which is also required for L2. I have no doubt that I’ll get the L1/L2 certifications in the coming months. Piece of cake.

Plus, the workshop is nearly finished and I’d modestly deem that a spectacular success (although all of the electrical work was a joint effort with my friend Darrin, and by joint effort, I mean any success was entirely due to his expertise and generosity). The workshop bodes well for all future rocket construction, too.

But L3 certification is another story.

I started looking more closely at the NAR criteria for L3 certification. Objectively, and superficially, the criteria are similar to L1 and L2: build and successfully fly (including recovery) a rocket with a motor in a certain class (for L3, the motor must be classified as an M, N, or O). In addition, the L3 cert requires:

  • you must already be L2 certified;
  • you must have a member of the NAR L3 certification committee (“L3CC”) as your official advisor;
  • you must submit an L3 rocket design to the advisor for approval before beginning;
  • you must very thoroughly and comprehensively document every construction step along the way.

The rocket itself must also be built to certain specifications. For example:

  • each parachute event must be initiated by redundant control systems;
  • the rocket must have a safe rate of descent (20 ft/ sec is desirable);
  • you must be able to externally disarm all pyrotechnic devices on board the rocket, and so on.

However, what I didn’t realize – foolishly, in retrospect – was that it might not be a great idea to dive into the L3 rocket immediately after getting certified as an L2. Aside from the fact that the L3CC advisor might simply require additional experience before allowing you to proceed with an L3 project, more experience is clearly helpful. Rockets can be built in a large variety of sizes, and from a large number of different materials, from cardboard to fiberglass to aluminum, and more. They can be single-stage or multi-stage. They can involve different components and electronics. And there’s a lot to be said for a broad range of experience, including failures (which are plentiful, and which present excellent learning opportunities).

Let me be clear. I still fully intend to get the L3 certification as soon as possible. I’ve heard many people, whether they already have the certification or just intend to get it at some point in the future, talk about deliberately waiting years and emphasize that there’s no rush. This certification is a goal of mine, and I want to get it sooner rather than later. But at the same time, I fully appreciate the need for additional experience, something for which there is just no substitute. So I will build more and fly more, fail more and succeed more – so that when it comes time to embark on the L3 journey, I will be unquestionably ready.

I suppose it might be more accurate to say not that I was overconfident (perhaps), but rather than I was merely under-informed when initially setting the goal. I’ll go with that.