Sunday, November 20, 2011

Team status updates

Most N Prize teams have been inactive on the internet, with limited or no updates. This does not automatically mean that they have not been working, but it is not a good sign. Here are some teams that have been updating regularly:

Kiwi 2 Space has started construction of their test air frame, called "Psycho."

"Psycho was intended as a first liquid rocket flying test bed, but this little beast is still yet to be flown. All plumbing has been completed, with only avionics and recovery needing to be implemented. It is hoped that this will now serve as a static test bed and hopefully fly one day soon. It is of bulkhead and stringer construction with a length of 3m and diameter of 203.2mm and originally intended for a 1334N of thurst (300lbf) lox/kero engine."

After the components are tested on this rocket, the team will go to their next stage, building a "Pickering" flight rocket. Eventually, it looks as if the N Prize rocket will have three Pickering stage 0 rockets, with a core module containing the N Prize rocket. This is one of the most reasonable plans out there right now. Can they finish the final rocket in about 300 days? That seems highly unlikely. To their credit the team has released the following statement:

"!!! News, Kiwi 2 Space is no longer seeking the N-Prize competition (September 2011) !!!

Well the prize deadline has come and gone and been extended another year but is beyond our reach, I've always known it was going to be hard but it was a good initiative to get off the couch to go do something which could make a difference. And yet still could with some ideas I've had over the years. I've always been fascinated by the pump problem that smaller rockets have, more so the complexity etc. for such a small system hence why pressure fed is what you see a lot in smaller sounding rockets. I very much like Flometrics pistonless pump and think its a great idea, but every where I look I see more and more stuff electric, which is the way the world seems to be going, and with the batteries and motors these days, you have some pretty good products on the market. Its not a new idea but a small electric turbo pump for rockets is one thing I'd like to investigate more, I'm no pump man so I'm not sure what I'm getting myself into but if someone could come up with something small and powerfull like this it could change the way for smaller nano sate launchers etc. So this is one future aspiration along with many other things. But the N-Prize has been good in opening my mind and eyes on the world of amateur experimental rocketry and space in general.

I will still continue to build my big rocket, but now at my own pace."

As I stated previously, these projects are more important than just the N Prize.


Just days after I last checked in with them, Wikisat made major progress with high-altitude balloon flights:

Not only did they make good progress testing at over 100,000 feet, but they also demonstrated a Wikisat launcher, which looks like a tiny rocket based on aluminum cans:

This is exactly the kind of little rocket that I mentioned earlier. An L motor bi-propellant rocket in a soda can would offer very high (ca .9) mass fractions and in near space, would just eat up mach numbers. But it is easy to say that, much harder to actually do it. This would be a two stage rocket, I am not exactly certain where this rocket would start (from a balloon?) If you can get L impulse in the first stage, and J in the upper, you would do well from 100,000 feet. Space certainly. Probably not orbit even under ideal circumstances.

There are a bunch of youtube videos of testing:

"This is the second burn test of the WikiSat second stage. This stage is formed by four granes inside a steel combustion chamber. The nozzle made in aluminum resisted but burned in few milliseconds. The igniter were four small bulbs with black powder inside. Safety margins were respected by WikiSat team in any moment."

Sadly, the team is using black powder in this upper stage. They are clustering four D motors inside of a soda can. This is almost the opposite of what I was discussing above. These motors have ultra-poor mass fractions, will be hard to ignite in the cold of space, and wont work well if they are burning inside of a can. Why bother burning them in a can and then pushing the exhaust through a second nozzle? It doesn't make much sense. Just getting the can to survive the pressure and heat of a good efficient burn is going to be hard, I would say basically impossible. (Maybe a layer of filament CF or FG would do it if wrapped around the outside.) But more importantly, it is not needed. Use soda cans for pressure-fed bi-propellant rockets or hybrid rockets. Or use a conventional rocket motor (such as a 54mm I motor if these stubby dimensions interest you) instead and enjoy vastly better ISP and mass fractions, not to mention reliability. Granted, igniting such a rocket at high altitude will require a burst disk of some sort and ideally a head-end ignition system.

Here is the second stage after a (failed) test:

"That was a try to measure the lateral nozzle thrust but the second stage exploded bue to a failure in the after bulkhead. The micro-valve was blocked. We decided to use cold gas for the first stage control and to use spinning stabilization for the second stage."

And a first stage test using some kind of ex propellant:

"This test was a C1 + acetone burn test inside a Cocacola ZERO can, a bulkhead and a 11 mm hole. A new bulkhead method was tested. Propellant was not solid (Like the sand). Pressure increased due to the not uniform burning area. Bulkheat exploded and propellant was blowed out. The can could be reused. No damages in the flange were found.

Bill of materials

- Cocacola can: 23.3 grams
- Bulckhead: 3 grams

Ablative material: 68.4 grams
- Cylinder 60.1 grams
- Backplate 8.3 grams

Propellant mixture: Less than 320 grams
- C1: Less than 270.4 grams
- Resine: Less than 49.6 grams

TOTAL: 330.9 grams"

I see great work with balloons and electronics, but some really confusing rocketry. This team needs to revisit their plans if they are using solid propellants (of any kind) inside of an aluminum can. The can needs to be tested to the operating pressure - hundreds of PSI in most cases, as well as the operating temperatures. The overall mass fraction, isp, and total impulse need to be very good in a satellite launcher. Even my proposed "L in a soda can" motors would not be enough to launch a satellite from a rockoon without many stages. And 4x D12 motors in a soda can, clearly burning under sub-optimal conditions, are not going to cut it. The best bet would be to custom make steel casings of proper strength and load them with high quality APCP. Or better yet, to save time and money, modify an already made CTI motor such as the N 10,000 and fly it from a rockoon. That is one of your best bets for a space flight at this time, short of using much larger and more expensive R,S, or T class motors.

Stay tuned for future updates!

Sunday, July 10, 2011

University of Brasilia now an N-prize team!

Here are some of the projects from this "hybrid team."


"The LILE Program is the first project of Hybid Team and the aim was the launch of two small sounding rockets ,began in 2005 , LILE 1 and LILE 2 the first hybrid rockets ever launched in Brazil."



"The year is 2005 and The Santos Dumont sounding rocket program begins, a program to develop large aluminum hybrid rockets capable of reaching altitudes as high as 8 km an possessing computer controlled telemetry and parachute recovery systems. The program was divided in to two stages the development of the SD-1 and the SD-2, the first one being a 500N rocket and the second one a 1500N rocket."

SD Project


"Parallel to the Santos Dumont rocket program a advanced test benches program was developed, this program was aimed in developing versatility rocket test benches capable of generating good experimental material for propulsion studies."

Modular Bench


We look forward to great things from this team!


Sunday, January 30, 2011

Team Selene

"Our Mission

Our team name, “Selene” stems both from Greek mythology and Selene, the wife of the team's founder. We have assembled a talented and enthusiastic group of Chinese and German engineers and technicians who are intent upon winning the Google Lunar X Prize. Our goal is to land a remote-controlled lunar rover on the Moon which must then travel a minimum of 500 meters over the lunar surface, while at the same time, sending high-definition images and video as well as other data back to Earth.

Another purpose of this project is to promote greater co-operation between China and Germany, and to foster the exchange of ideas, a process well underway for many centuries.

We seek to dispel the myth that China's design and engineering prowess is merely the product of reverse engineering, too. There are many young, motivated engineers in both countries who are eager to demonstrate that they can succeed in this mission while contributing innovative high technology inventions and concepts to the broader community of space science and exploration as well as providing support to the ongoing humanitarian efforts to achieve better living conditions here on Earth."

Saturday, January 29, 2011

Armadillo Aerospace going for space

"Last year we started work on a new vehicle planform, which we're calling the tube rocket. From our perspective it is a Supermod whose 36 inch spherical tanks have been replaced by 15 inch cylindrical tanks with a common bulkhead. Otherwise it is quite similar to our other vehicles; low pressure LOX/alcohol as propellant, regulated helium pressurization, the same type of engine as a Mod, the same engine gimbal and roll vane for guidance and control, and the same computer box and plumbing schematic.

From an external perspective, it's looks like a fairly large liquid fueled sounding rocket. We're using a dual parachute deployment system that would be familiar to anyone in advanced high power rocketry (HPR), adjusted for a rocket that goes rather higher and is quite a bit heavier than most HPR.

We're still definitely working toward a fully reusable VTVL human-carrying vehicle, and the tube rocket acts as a risk reduction step in that direction."


My biggest concern about these competitions is that they focus on Moon landers (a crucial step, and important to work on) but seem to skip the hardest and most important part: actually launching payloads off of the Earth into space and orbit. I suspect that Google picked the lander competition because it is bite sized and produces cool looking footage. Making an orbital challenge, possibly the most important thing Google could do with these teams, would result in lots of crashes. And when it works, the rocket just disappears. In any event, it is good to see this team working towards space.

N prize update

Wikisat has some interesting (but low rez and not expandable) images of what appears to be a wing for a flying, reusable first stage.

"I hate the thought that 80% of any rocket is not reusable. Hence, I decided to start to design a 2-stage -winged launcher. On the two pictures you can see the lower left half from two different perspectives. I try to lower the Cw as much as possible and to include the fuselage as aerodynamical element."

Space prizes is a blog that has frequent updates about progress in this and other competitions.

If you are new to the N prize, here is where it all got started over at Half Bakery.