Princeton University attempt at a suborbital space shot?

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Yeah, I am on the Berkeley STAR rocketry team’s propulsion and airframe groups and would love to share a student’s perspective.

I see abandoning the goal of breaking the karman line to be part of maturing as a rocket team, at least until the Base11 challenge was announced. Many teams are chasing the money like lemmings. Even before it was announced, that was our goal. Since then, we’ve pretty much abandoned our plans for a space shot instead focusing on a simple IREC rocket this year, avionics development, composite fabrication and liquid engine development.

However, the other UC Berkeley team at our school is Space Enterprises at Berkeley and they are overall newer, smaller, and more focused on the goal of a space shot. However, we realize that even if we won Base11, the university is rather unlikely to award the majority of it to us, instead distributing it more widely. As such, it currently doesn’t make sense as more likely some team with greater resources would win it an we’d be out several year’s budget with little to show. That could be enough to tank the team.

We’ve recently started collaborating a bit with them in an attempt to overhaul their safety procedures and share technical information and they tend to innovate and abandon designs at a much quicker rate than we do. However, money concerns limit what we can both do as do requirements and leadership.

For example, I’d love to build an ablative engine, but our club requirements to have every a reusable engine prevents this. I’d love to investigate a film-cooled adiabatic wall engine but we currently simply don’t have the resources. We’d love to experiment with turbo pumps but that is far outside of our current capabilities. Attempting to purchase a 3-d printed engine would basically tank our budget. We used to do work with solids, but the university put a stop to that with the exception of ones designed to be used as an igniter.

Compared to teams like USC, we simply don’t have nearly the same amount of support and receive relatively little access to resource.

I agree that there is little future in ballon launched rockets, but that is something we could feasibly do with our current finding and resources (technically and economically, we don’t have the pull necessary to get permission from the FAA). I’ve met with the Stanford team and suspect that they have resources closer to us than to USC or to a lesser extent, Princeton.

The other lure of high profile projects is that companies might hear about it and it might get you more university support in addition to a certain “coolness” factor.

However, we are doing things that would look great on our resume even if they aren’t very dramatic. A little while ago we ran a test of our plumbing with analogue propellants. We ended up with several pressure anomalies and ice in the lox side. Investigating them proved to be highly educational and a wonderful experience.

We used industry standard troubleshooting methods (which looks good on a resume) and noticed some interesting check-valve behaviors. We have an over 10 page write up of just what happened and hundreds of pages of writing investigating the causes.

The pressure issue ended up being very simple (after two years of heavy use the seal on one of our valves had become worn and developed a very minor leak) the ice one was incredibly complex and interesting.

First hand knowledge of leadership, computational tools, using filament winding machines and composite fabrication is also valued, as is safety procedure and having to navigate the authorization process and work within exacting requirements and often rather unfortunate restrictions.

As such, while pushing the state-of-the-art forward is desirable, you really don’t need that to impress employers. I work in a small sat/space sciences lab at a navy research school during the summer partly as a result of my club experiences.
 
I appreciate your insight Rocket501. I would like to hear more. Do you think that rocket competitions are beneficial for students? Would collaboration with other schools be better than competing with them?
For high alt projects such as "space shots" what do you think needs to change? And, how could organizations such as TRA help?
 
Ultimately, I think that these competitions are beneficial, but could be done better. I think that both IREC and the FAR challenges are beneficial to college rocketry and students. IREC isn't cheap, but even modest college support, team dues, or crowdfunding allows you to be competitive and get into it.

Base11 isn't quite as good in my opinion. I think that a big deal is how the prize is distributed and the listed goal aren't as well consider as possible. What makes a lot more sense would be a DPF like challenge with more modest goals and prizes such as an award of 25,000-50,000 that goes direct to the rocketry team if they can launch a biprop rocket to a height of let's say 25,000 feet with multiple prizes so it isn't winner take all and can be repeated (albeit with a new rocket design) once per team per year. This can be done much more practically with a class 2 rocket and the reduction in size makes logistics easier, initial investment more achievable, and significantly reduces paperwork.

I also think it would be interesting to do paid challenges for engine development in the name of prizes for whoever builds the engine with the greatest ISP, thrust, most-innovative cooling method, thrust-to-weight, etc. given certain engineering constraints could help spur engine innovation.

While I personally want to do a space shot, I think it isn't a great goal for these liquid rocket challenges.

While I think direct collaboration would be tricky, it would be amazing if in let's say a decade, we could get multiple colleges together to pool money, talent, knowledge, etc. and try to put something into orbit, I don't think this is feasible.

What would be best would be a more open sharing of information. For example, we have occasionally emailed other teams to ask if they could point us to their suppliers and been stonewalled. Also, many teams including us, have made the same sort of mistakes. More open sharing of info would benefit us all. We've already started this with Space Enterprises to a certain extent and one other college, but I'd love to make it a much bigger deal, more organized, and to a greater extent. For example, I really admire the work and guidelines that FAR has published, but it would be great to make a more comprehensive online compilation of knowledge specifically pertaining to flying liquid-rocket engines that also covers topics such as avionics design, rocket design, recovery, etc.

While I had rocketry knowledge before joining the STAR team, I would say that the majority of students do not. As such, we (even I do it) can overlook seemingly obvious things. As such, the best thing to do would be to have comprehensive engineering reports presented for analysis throughout the design phase and before flight for checking by knowledgeable individuals. Ideally this would be published publicly, but I could imagine that many teams would want to keep their design information to themselves.

Other than that, I'm not too sure what TRA should do and I think this level of work would be an overly tough burden for TRA.

One thing that I'd love to do is set up a micro-grant system for the open development of topics of interest to the community as a whole. For example, one pet project proposal of mine is to make a roughly 5kn thrust level clone of the project Morpheus engine. It is a methalox engine made from Iconel 625 and the only method of cooling is roughly 1/3 of the methane flow being used for film cooling. The isp is very low (around the 200 second mark), but the engine should be very cheap to fabricate (only requiring a slip roll, drill press and tig-welder) and have a good thrust-to-weight ratio. I calculated that a test engine would cost about $2500 to build and operate, but the proposal was rejected as we simply did't have spare money to spend on it.

Hypothetically, a group might set aside a certain amount of money to fund ideas such as this that could reduce barriers to developing these liquid rockets such as cheaper tanks, plumbing, engine, electronics, valves, etc. with the stipulation that any research must be written up and published such that everyone can use it. They wouldn't fund all ideas, but they could run a sort of contest funding what they consider to be most promising.
 
Excellent comments R501. I appreciate your interest in rocket development. It can be difficult to fund what you would like to do. I understand. Some of the things I'm working on will take years to develop.
Also, thank you for the kind words about FAR. I'm an active member there and forwarded your comments to some of the Directors. I have the opportunity to speak with many university teams and have considered the direct collaboration you mentioned. Many teams and students have similar experiences and challenges. If you would like to pursue the development of a collaborative effort, please let me know. Your call. I would ask that what ever you come up with be incremental. Many knowledgeable people that would normally be happy to help hesitate, and I hear "if they haven't demonstrated that they can do this, how can they do that?" Do you know what I mean?
So again, patience, diligence, and working simple to complex. Honestly, you may never see the end of the road but your journey will be punctuated with successes. I think you already understand that.
So let me know. I'm willing to put effort into helping. I bet others are willing as well.
 
Honestly, why not use V-BKNO3? I recently started using it and it has been an absolute joy to work with. Reliable ignition in under 100ms every time (usually about 40ms), durable, relatively safe, affordable and not even all that hard to make. I think that apogee sells it as a kit. There’s a reason the pros use it after all.

...

The safety issue of using a head end igniter might be a problem with BKNO3 ignition of upper stages, as discussed in post #530 above.

The possibility of using a heated, pressurized tube has the advantage, assuming it worked, of being applicable also for staged, sub/orbital rockets that don’t use balloon launch.

It’s also something that can be tested using small, commercial-off-the-shelf APCP motors in a small, vacuum chamber accessible to amateurs.

Bob Clark
 
The safety issue of using a head end igniter might be a problem with BKNO3 ignition of upper stages, as discussed in post #530 above.

The possibility of using a heated, pressurized tube has the advantage, assuming it worked, of being applicable also for staged, sub/orbital rockets that don’t use balloon launch.

It’s also something that can be tested using small, commercial-off-the-shelf APCP motors in a small, vacuum chamber accessible to amateurs.

Bob Clark
BKNO3 does not have the pressure/temperature issue that black powder has at altitude. It also is less sensitive to static than most pyrogens. Standard good practices for handling and arming head-end ignition are required. Sizing the amount of pyrogen, containing the pellets, and plugging the nozzle with a burst disk are all doable by amateurs and students. Design and test.
 
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