June 1, 2024

This is the first in a series of project logs for “Ascension” – a high power rocket I’m building for my Level 3 certification.

What the hell does that mean, you might ask? Good question. Any good technical project starts with a set of definitions. Some of you may already know what I’m getting at here (and feel free to skip down if you do), but to get the rest of y’all up to speed:

First off, what is a high power rocket, anyway? Remember those Estes model rocket kits from your childhood? (If you don’t, I’m sorry, but Google that one.) Well, a high power rocket is not really all that different. Except instead of taking a $5 black powder motor the size of your thumb in a cute paper rocket a couple hundred feet up, these are much closer to throwing a $500 chunk of space shuttle booster fuel in an all-composite airframe up to a rather concerning Mach number and into airline flight levels. If everything goes right. (Often not a given.)

It’s pretty safe to say that with greater power comes greater risk in this case. The fact high-power rocketry is allowed to exist as a hobby at all in the United States relies almost entirely on the hobby’s self-regulation through two major organizations: NAR (the National Association of Rocketry) and TRA (Tripoli Rocketry Association). Almost all rocketry clubs in the U.S. are sections of one or both of these national organizations. They have some differences, but the most that matters right now is that NAR leans closer to traditional model rockets, while TRA is more friendly to high-power and experimental rocketry.

TRA and NAR may be all fun and games at face value, but above all, they are insurance brokers. For the price of a TRA or NAR membership, a local section’s members can rest assured their rocketry activities are carried out with a healthy safety net should something go wrong. The members’ side of the bargain is that in turn, they must follow the TRA or NAR safety codes – documents of not entirely legal weight that define a set of safe operating procedures for rocketry. These include safety distances, standard procedure, and most importantly, the certification system.

High power rocketry certification, at least between TRA and NAR, is broken down into three levels:

• Non-certified: Limited to up to G-class (160 Ns) certified rocket motors, no more than 80N average thrust, no sparky effects allowed
• Level 1: Up to J-class (1,280 Ns) motors, no thrust restriction, no sparky restriction
• Level 2: Up to L-class (5,120 Ns) motors
  TRA ONLY: Permits development, test, and use of homemade “experimental” motors
• Level 3: Up to O-class (40,960 Ns) motors

The jump in available impulse per classification level (note: rocket motors are classified by impulse, i.e. thrust * time, in a set of lettered classes each equal to double the total impulse of the previous) is rather large, as you can tell. As such, the work needed to obtain a certification increases with each level.

The core of an “HPR cert” is the same – you have to successfully prove you can build, fly, and recover a rocket of that impulse class safely. For this purpose, TRA or NAR allows you a single flight using a motor of that class to serve as a test of your skill. The flight is monitored by a club officer or other representative, and you are only given your certification if the rocket completes its flight successfully and safely. Once certified, you are free to buy, use, and fly motors of your certification level at any TRA or NAR launch (certifications are reciprocal).

There is, however, more to it. Level 2 certifications (as well as minors attempting a Level 1) must also pass a written test on the respective organization’s safety code. Level 3 certifications, due to the massive jump in permitted impulse, must instead be thoroughly documented projects overseen by two members of the NAR Level 3 Certification Committee or Tripoli Technical Advisory Panel – often highly experienced, life-long rocketeers. The L3CC or TAP members must sign off and grant their approval during multiple steps of a Level 3 certification project, including the initial design, final build, assembly of the motor, and on the day-of-launch. Level 3 builds must also demonstrate use of redundant, active flight computers controlling the rocket’s recovery system, and can easily reach tens of thousands of feet.

Once an “L3”, a rocketeer essentially has permission to fly almost any motor at any club’s launch, given it fits within the relevant physical restrictions of the site. However, it is important to note that neither the certification system or the safety codes have direct legal standing. At most, they incorporate existing regulation, but are not themselves regulatory documents. NAR and TRA ask vendors of rocket motors to check for certifications before selling high-power motors, but few do, and they are not legally bound to.

Technically, rocketry is largely governed* by FAR 101 Subpart C, a set of FAA regulations that breaks rockets into Class 1, 2, or 3. Class 1 rockets use less than 125 grams of propellant, and as such are deemed harmless enough that the FAA allows them to be freely launched without further scrutiny. This roughly includes anything less than an L1-class rocket (often just “L1 rocket”), but a few H motors slip the gap between L1 and <125 grams. You could technically fly these on your own and be entirely legally clear in the right places.

* There are some technicalities here, including legal adoption of NFPA 1127 and the California State Fire Marshal’s additional rules.

Class 2 rockets envelop essentially everything TRA and NAR consider “high power” – everything not Class 1 up to the peak of “O” impulse, 40,960 Ns. Launch of Class 2 rockets requires obtaining a flight waiver for a general area from the FAA, permitting launch up to a given pre-determined safe altitude for a certain area and period of time. For the most part, any amount of Class 2 rockets could be launched under a given waiver, given they do not exceed the ceiling. Again, you could get a waiver from the FAA entirely on your own, but you would not be insured and would have to deal with quite the headache. This alone is why a vast majority of high-power flyers choose TRA and NAR.

Class 3 rockets – anything between the bottom of “P” impulse at 40,961 Ns and up to 889,600 Ns (the point at which the FAA stops considering you an amateur), are considerably rare and require detailed individualized documentation to be submitted to the FAA for each individual flight. As such, clubs cannot obtain Class 3 waivers for their flyers, and the sheer scale of these builds often preclude flying at a majority of sites. NAR offers no support for Class 3 flights, but a select few Tripoli clubs are able to support these often edge-of-space bound rockets through extra approval and assistance given by the Tripoli Class 3 Review Committee (C3RC).

The odd one out in this whole process, and incidentally my local site, is the Friends of Amateur Rocketry, located in the Mojave Desert, CA. FAR is not a TRA or NAR club (and has occasionally come at odds with both). FAR is also, in contrast to practically every other club, an established and improved site featuring hardened bunkers, test stands, and fixed launch pads. Due to its location surrounded by the R-2508 restricted airspace complex around Edwards AFB, FAR also enjoys a “standing waiver” of up to 250,000 feet and a special exemption allowing “P” class motors up to 81,920 Ns to be flown under Class 2 rules. Class 3 flights from FAR have reached 411,000 feet – well into space. Due to its use of bunkers and California Fire Marshal-certified pyrotechnic operators on site, FAR has practically no motor restrictions, and also supports extensive liquid-powered rocketry tests and flights, making it completely unique. More or less, you can just show up to FAR with almost anything and fly it, certified flyer or not.

Now that you know essentially everything there is to know about rocketry certifications, we can begin to define the purpose of this project itself.

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If you already know the story behind amateur rocketry certifications, skip to here.

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Time to define some requirements and ground rules.

The name-and-game of this project is to get Level 3 certified with Tripoli. While I could build a L3-class rocket and fly it at FAR with much less paperwork, I want to use it as an opportunity to develop a few project skills, and having the certification is definitely cooler than not having it.

I may work at a rocket company, but I’m not an engineer. I don’t really have my hands on the rocket often, but someday I’d like to. I figure the best way to get started down that path is the same way I’ve done anything else in my life – fake it until you make it. Except on a considerably smaller rocket this time.

As such, I’m treating Ascension to the greatest extent like I see the real launch campaign I work with being treated. I’ll be developing thorough procedures and an issue tracking system for any and all work done on the rocket. Any parts, work, or designs will be documented, signed off on if required, and carefully tracked. This far and beyond exceeds the requirements for L3 documentation, but I figure it’s a good exercise in proper project management, process control, and risk management.

So we have the background down. What else?

An L3 cert rocket must fly with a motor that has at least 5,121 Ns of impulse – i.e., at least an M-class motor. This essentially means the available motors** are 75 or 98mm (~3-4 in), all at least a couple hundred bucks, and with a considerable amount of kick behind them. I’d like to avoid making this rocket too big in the hopes I can get as much of the work done in my apartment as possible, but too small and the technical difficulty of such a build rises quickly. Put another way, I’d rather this thing not breach Mach 2 or 20,000 feet if I can help it.

**Yes, I know about the 54mm M1378. Shut up. That one is getting veto’d.

Launch site selection is also an issue. L3 certs at FAR have historically been tricky due to the NAR/TRA safety codes having no provision for the use of bunkers, making FAR otherwise nearly too small for people to stand far back enough from an M-class motor (500 feet). This is also ignoring the politics of FAR-TRA relations, which are an entire other can of worms. Due to CA rules, FAR is also the only site that can support anything over an M, so that constrains our motor selection to M motors only (probably for the best).

For the Mojave area, this leaves the Rocketry Organization of California and MDARS. ROC is by far the most established of the two, but has a waiver limited to 7,000 feet – a genuine challenge to stay under for an L3. MDARS, a small Tripoli club south of FAR, can handle 15,000. So that’d be preferable.

Furthermore, an L3 build requires two completely separate and redunant flight computers controlling separate sets of pyrotechnic charges for deployment of the rocket’s drogue and main parachutes. Due to the pretty significant altitudes involved, it’d also be nice if one or both of these supported some form of tracking, whether it be via GPS or radio beacon.

Taking this, plus a few other notes from the Tripoli L3 page, we can begin to build out a requirements matrix:

ID	REQUIREMENT	RATIONALE
L3-0XX	Vehicle definition
L3-001	Motor impulse must be M-class (5,121-10,240 Ns)	At least M to meet L3 requirements, <N to limit performance and CSFM compliance
L3-002	Rocket must use dual-redundant flight computers for pyrotechnics	Tripoli requirement, ensure safe recovery even in the event of a single computer failure
L3-003	Flight ceiling must be 15,000 ft AGL	Ease of recovery, permit flight at MDARS
L3-004	Rocket must be aerodynamically stable (>10% vehicle length between CP/CG, displayed on vehicle)	Ensure sufficient margin to maintain stable flight
L3-005	Maximum velocity not to exceed Mach 2	Ensure sufficient structural and aerothermal margin to avoid in-flight vehicle failure
L3-1XX	Tripoli Procedural Compliance
L3-101	Identify two local Tripoli TAP members to oversee project	Ensure proper project oversight
L3-102	Provide and recieve sign-offs from TAP members on project documentation before initiating build	Ensure design has no glaring flaws before build
L3-103	Document build process including photographic evidence of self working on project	Ensure traceability of any work done on vehicle
L3-104	No external direct assistance with physically building the rocket	Ensure certification is fairly awarded
L3-105	Provide a thorough pre-flight checklist detailing assembly, motor installation, and system arming	Ensure day-of-launch operations are conducted safely and methodically
L3-106	Ensure TAP member physically present at flight	Confirm success of certification flight
L3-107	Submit TAP Pre-Flight Data Capture Form	Document expected outcome of flight
L3-108	Fly rocket with a stable ascent and controlled descent and recover intact	Ensure certification awarded for a successful flight
L3-2XX	Self – Procedural Requirements
L3-201	Develop, review, and release adequate procedures for any and all work to build and operate the rocket	Ensure traceability and repeatability of processes
L3-202	Log and inventory all components and parts used to build the rocket within procedures	Ensure traceability and repeatability of processes
L3-203	All work not to original procedure must be documented via use of an issue tracking system	Establish clear rationale for deviation from procedure for traceability and to inform future operations
L3-204	Any significant risks to mission or personnel must be tracked via use of a risk tracking system	Ensure safety of vehicle operators and increase probability of mission success
L3-205	Open issues and risks must be dispositioned, closed, and/or mitigated in a timely manner with gating operations identified	Prevent normalization of deviance and increase probability of mission success
L3-206	Vehicle design work should be documented and reviewed for compliance with requirements before proceeding with build operations	Ensure rocket meets established requirements for certification
L3-207	Provide regular photo and text updates on project status via blog and other platforms	Document project progress for public visibility

This is still not an exhaustive list, and I’ll be working to finalize Ascension’s requirements pretty soon, as well as some additional nice-to-haves and other odds and ends. Hopefully this was a pretty good introduction to what an L3 certification is and high-power rocketry in general – because we’re gonna be hitting the ground running with LOG 002 – a first look into Ascension’s design.

See y’all then.

-lavie