Intro: How to Launch a Rocket to Space: Inside BURPG Part 1
This is going to be more of a blogg-ish entry about the Boston University Rocket Propulsion Group. Unfortunately, since we are building a pretty big rocket, the technical details are a little hush-hush. But we are trying to raise awareness of our project in the DIY world, hoping to inspire others to shoot for the stars (that was pretty corny). So, read up, learn about what we do, and hopefully this will be something that others out there will find cool and want to get involved in something similar.
We are also hoping the technology we are developing can be applied in the aerospace industry, supplying inexpensive flight to suborbital space for research purposes. The rocket currently in development pulls fewer than 5 Gs on takeoff, and is extremely low vibration. This would allow sensitive instruments that couldn't be flown on rockets before to be launched to space.
Also, I would like to also apologize for my lack of publishing as of recently. Most (all) of my free time has been absorbed by BURPG work. As part of us coming out to the public about our work, I thought I would share my experience with BURPG.
We are currently relying on crowd funding to complete the Mk. V rocket, which is going to be a record-breaking rocket system highlighted in future posts here on Instructables. We have partnered with Rocket Mavericks for the crowd funding. There are some cool incentives including posters and memorabilia launched into space by us up for grabs if you help us out. So check it out: http://www.rocketmavericks.com/projects/starscraper-2/
We also have a Facebook page and Twitter. Follow and like us for some cool updates, and to help spread the word about our work. Part of what we do is show the public the value in engineering, and we can't do that without some public attention. We appreciate the help!!
Webiste: currently being overhauled, so excuse any issues burocket.org
Step 1: Intro: What Is BURPG
BURPG is an entirely undergraduate group devoted to LAUNCHING A ROCKET TO SPACE BY 2015!! (I got really excited typing that sentence). We are currently the number one group (amateur or professional) in developing a functional hybrid rocket engine. When we launch the newest rocket we are building, called the Mk. V Starscraper, it will fly to about 475,000 feet. This is going to break a bunch of records:
-Highest hybrid rocket launch (amateur or professional)
-Highest amateur rocket launch
-Highest single-stage rocket launch (amateur or professional)
-Highest launch by a university group
-First university group to space
So it's going to be pretty exciting!
Up to this point, we have built 4 hybrid rocket engines as part of this program. A hybrid rocket is one that uses a solid fuel and liquid oxidizer. This means the rocket is more efficient than a solid rocket, but simpler, cheaper, and potentially more reliable than a liquid rocket. Last year saw the building and testing of the Mk. IV. Prior to that there were smaller systems intended more to test the feasibility of hybrid technology, as opposed to develop it into a fully-operational rocket system.
Step 2: 2013-2014: Mk. IV Quasar Rocket Design
This was my first year at BU, and my first year on BURPG. Most of the work revolved around the Quasar rocket system. This rocket was intended to fly to about 100,000 feet, and serve as a proof of concept for the hybrid rocket technology developed by BURPG. It also was a test bed for the engine, called the Mk. IV, so that we could get the necessary performance figures to further hone the design for the next engine iteration.
My first year saw me making my first PCB, which was rewarding. I had the task of redesigning the Flow Control Unit. This was a good foray into digital circuits, PCB design rules, and how to use Altium, an incredibly powerful PCB design software. I also got my hands dirty (literally) casting the rubber fuel grains, designing electronics mounts for inside the rocket, and overseeing the design and assembly of the Ground Support Electronics (GSE) hardcase.
Step 3: 2013-2014 Mk. IV Testing and Outcome
The Mk. IV underwent multiple static tests in order to get performance stats on the engine. The Mk. IV engine developed 99% of its calculated thrust (2600 lbs). A rocket engine performing like this is almost unheard of- generally, it's 'good' if the engine performs at 80 percent of its calculated performance. The Mk. IV was also one of the most efficient hybrid rocket engines ever ignited.
During the last test, the combustion chamber did suffer some damage. However, we joked that it was because the engine was too well designed. The injector plate that atomizes the oxidizer as it enters the combustion chamber didn't just atomize the liquid; it caused the oxidizer to prematurely decompose into its elemental components. This probably increased the efficiency of the burn, but this is also an extremely exothermic process, and it was occurring in a part of the combustion chamber not intended to handle the heat. This burned through the combustion chamber wall all the way around the rocket. This was entirely fixable, by re-machining a combustion chamber and adding more insulation. The work required to do this, then execute another test to get the flight permit, was not feasible from a money and time standpoint, since it was also finals period at BU. Besides, to build the next rocket, the Mk. V, does not require having flown the Mk IV on Quasar. For this reason, the rocket never flew.
Step 4: Onward to the Mk. V Starscraper
With the Mk. IV providing what we needed to verify our models, we felt confident to go onto the design of the Mk. V engine and accompanying Starscraper rocket. This started over the summer, when a lot of the design work was handled. Also, the electronics got a complete overhaul. I redesigned the FCU board into Hyperion, which also included the functionality of a second board, Jumpstarter, allowing electric matches to be fired from the board. This, along with my internship this summer, took up a lot of my time. I am quite proud of the result. The board can handle:
-8 servos with feedback
-4 load cells for measuring weight or force
-6 pressure transducers for measuring pressure
-16 thermocouples for measuring temperature
-6 electric matches (for various things like disconnecting gas lines with explosive bolts)
And it can be expanded through the GPIO pins for other uses. Where the FCU board I designed was more a redesign of an existing circuit, Hyperion required starting over and redesigning the circuit as well, to allow greater accuracy, reliability, and expanded use.
The Starscraper (Mk. V) is going to be handled in future instructables, so be on the lookout for that. From here on, there will be weekly updates about how the Mk. V work is going, including photos and videos. This will start next week on Monday, so be ready!