totalitor

Continuing work after winter. I changed from ethanol to gasoline and I try first uncooled rocket engine. 6,9 bar combustion chamber pressure, thrust 35 N. All ready. Test run coming soon.

Amazing.

I am glad to be alive on this day. Well, tomorrow too but you know what I mean?

Telstar I was launched 1962 and Telstar II 1963, still orbiting earth. If I were rich collector and I want those satellites back to earth and I have rocket to catch those - could I do that? Is there a law about this?

I didn't calculate. I am using standard parts to this engine. Combustion chamber is a copper pipe 18 mm diameter. Cooling jacket is a copper pipe 22 mm diameter. Putting those together there is a cooling gap 1 mm. Smaller would be better, more speed for cooling liquid. I really don't know if this engine works. I have all ready for next year summer hot fire test. Only oxygen gas bottle to buy. When I start the engine I am sure something would happen! I made a channel on Youtube. Check this out: https://www.youtube.com/channel/UCf2lLsBevPguEq7i2YKQ4Sg

What is throat area? It seems that exit area is too large. For example 100 psi chamber pressure exit area should be about 2*throat area on sea level (info from book How to design small rocket engines). Of course if you have super large chamber pressure and vacuum optimized engine that is what it should look like. But I think you start from scratch like I do.

"We’ve just received notification from the swedish air traffic control, that they will not be able to clear the airspace above our launch area on the 23rd-24th of september. This was our last launch possibility this autumn. So no launch in 2017."

First ignition moved to year 2018. Winter break, coming back to business in May. Latest pictures of my 5,5 kg thrust rocket engine: http://imgur.com/a/fi1yO

New picture of my rocket engine project. Still thinking ignition. Otherwise all ready for test run. Coming august. http://imgur.com/a/a4c0q

I found this: http://watzlavick.com/robert/rocket/index.html This is amazing. Check it out.

Sun-synchronous near-circular orbit, altitude of 640 km, inclination = 97.8º,

June 23rd Finnish satellite Aalto-1 will be launched to orbit by Indian PSLV rocket. This is interesting: Development and demonstration of a deorbiting device for nanosatellites based on e-sail concept and measurement of its performance. More info here: https://directory.eoportal.org/web/eoportal/satellite-missions/a/aalto-1 And here is me holding model of that satellite. I find somehow cool that satellite has my name...

Definetly from Finland... That wooden rocket engine was impressive. Please do good nozzle and test more.

So I am building a rocket engine. I want to know if I can build it from ordinary stuff and can it achieve a stable combustion. Yes I can build, here is some new pictures. A rocket engine is ready and nitrogen pressure feed system is ready and tested. Still work to do. Oxygen feeding, valve controlling, ignition system, building a test stand. But I am progressing.

Back to the business, now it is summer and I can work outside. I build a fuel feeding system. I use nitrogen as a pressurant gas and 22 mm copperpipe as a fuel tank. I have integrated pressure regulator on nitrogen source, I can get 0-50 bar pressures. I am planning only short burning, up to 10 seconds. Calculated thrust is 8,9 N (2 lb) so I need only 0,02 l fuel to go. I tested system and it did worked well. But now starts difficult part. Gaseous oxygen. I hoped I could find pressure regulator up to 25 bar, but I have now only 10 bar regulator. So chamber pressure would drop much. If I suppose chamber pressure 8 bar and feeding pressure 10 bar would this be enough? How about chamber lenght? According my calculations it would be over 30 cm (chamber diameter is only 6,4 mm). With my tools I can not work with too big copper parts (I am brazing parts together). I would like to use large diameter chamber but I can't. And cooling? Do I need cooling for 10 seconds? This is very slow - but very interesting. I show pictures and videos as I am progressing. Four months and then summer is over. Maybe I can hot-fire engine this year. Advice me if you have good tips.

That was the best landing footage ever!

Check this out http://www.cientificosaficionados.com/libros/cohetes.pdf I am using this in my project.

What do you think? http://spacenews.com/finnish-company-raising-funds-for-astronaut-training-competition/

Atlas, rise! Is James Hetfield buying Atlas?

Indeed, me too. Would be interesting.

Thank you for your answers. I was thinking small, something like this: If I build a rocket 1 meter height (3 feet) and I use liquid oxygen and kerosine. Just thinking if there is enough benefit not to insulate. Weight saving would be...1 kg? Max? Is it worth? I guess not. Is it possible to use liquid oxygen boiloff instead of pressure feeding system using nitrogen or helium? Weight saving you know...

What if there is no insulation on cryogenic rocket? I know liquid oxygen would boil off but how fast? What if that rocket would be kept on container below boiling point? When fuelled and ready to launch container roof would go away and rocket would be launched. No time to boil off until the rocket is flying. A rocket small enough and fuel lets say to one minute burning - how much weight saving is possible? Or does liquids boil off too much? Think small, not big. Is this idea doomed? Are there rockets using liquid oxygen without insulation (Copenhagen Suborbital Nexo I has no insulation when flying)?

RUD-2 construction failed. I decided to build a bigger engine. RUD-3 is ready http://imgur.com/a/dkZxP Thrust: 14,35 lb (63,9 N) Isp using gaseous oxygen and 75 % alcohol about 240 so total mass flow 0,0598583 lb/sec (27,151 g/s). Mixture ratio 1.25, chamber pressure 300 psi, so fuel flow 0,0266036 lb/sec (12,067 g/s) and oxygen flow 0,0332546 lb/sec (15,084 g/s). Pressure on throat 169,2 psi, Diameter of throat 0,2 inch (5,09 mm) Chamber diameter is 0,6299 inch (16 mm) Exit diameter 0,382 inch (9,7 mm) Lenght about 4,6 inch (11,7 cm) Fuel orifice diameter 0,031 inch (0,8 mm) Oxygen orifice 0,116 inch (3 mm) I guess success in building RUD-1 was just luck. With this engine I had great difficulties in final brazing. I made two attempts and when ready fuel orifice was stucked. I had to dig feeding lines open and try again. Third time was success. My equipment cannot handle building bigger than this, brazing operation needs heating power that I don't have. And designing needs rethink, what looks easy in paper is not in practice. What next? Where I live winter is coming, I cannot do things becouse I do everything outside. Coldness stops everything. I design other components in winter and do them next summer. Maybe test firing is then. Please feel free to comment my project.

I can really now see difficulties of building such a small engine. My injector consist of one oxygen hole and one fuel hole. I calculated that fuel velocity would drop from 1189 inch/s to 153 inch/s if I use 0,8 mm hole instead of 0,3 mm hole. That's bad I guess. Ok new try with 0,3 mm hole and I definetly need a good fuel filter. Sorry if I use SI-units and imperial units together...

I was drilling 0,3 mm hole to coppertube. It did work, but when I was brazing things together that hole was blocked. Maybe brazing material melt. It was not anymore visible so I have to change way of putting things together. What if I use 0,8 mm hole for fuel (my calculations says it should be 0,3 mm)? Oxygen hole is 1 mm according calculations. Chamber pressure estimated 300 psi. Is it too fuel-rich? What will happen?