1. SpaceForest is located in the Pomeranian Science & Technology Park (PPNT) in Gdynia (www.spaceforest.pl) SpaceForest creates and actively explores innovative ideas. Our company specializes in Artificial Intelligence (AI) and Video Recognition (VR) solutions, which are used in optimization of industrial processes. SpaceForest works on diverse tasks in many different areas of engineering related to electronics, IT and space-tech. the software for post-production computer aided tuning of microwave filters TrimSolutions software is applicable in tuning of very high frequency telecommunication single and multimode satellite filters up to Ka band (40 GHz)

2. 2013 SpaceForest Ltd. – All rights reserved. Purpose of building a rocket Call: ARTEMIS 2013; European Commission Project: DEWI Dependable Embedded Wireless Infrastructure (3rd place of 22 Artemis projects) Business Needs: Reduction of aircraft weight by removing wires and using WSN (Wireless Sensor Network) Domain: AERONAUTICS aeroplanes, helicopters, launchers Example: the Ariane 5 telemetry system contains of 600 to 800 sensors. Telemetry system control unit is centralized. Thousands of cables are spread all over the 40 meter launcher. 70 % of Ariane 5 avionics mass are cables.

3. 2013 SpaceForest Ltd. – All rights reserved. Purpose of building a rocket Use Case: MTL (Multilink Telemetry Logger) in Space Test, supported by Spain Demonstrator: TEST ROCKET SpaceForest as the lead partner Demonstrator of outcomes of the project – a test rocket proposed by SpaceForest - was very well received. Large of the needed demonstrator propulsion: 100 [kNs] of engine total impulse, 1 [Ton] of thrust ~50 [kg] of burned propellant

4. 2013 SpaceForest Ltd. – All rights reserved. Why hybrid propulsion? Advantages (in comparison to solid rocket engines) : - Fully legal regarding to the Polish law. This kind of engine is not a pyrotechnic or explosive material. R&D activities are not restricted. - Increased personnel safety. - Possibility of thrust control. - Possibility of emergency shut down. figure made by Paweł Surmacz Disadvantages: - More complicated. - Lower oxidizer and fuel density. - Bigger propulsion system volume. - Oxidizer losses during the rocket tank fueling.

5. 2013 SpaceForest Ltd. – All rights reserved. Our choice Nitrous Oxide N 2 O as oxidizer Advantages: - relatively inexpensive and available on the market, - easy storable in normal conditions, - auto-pressurized 51 [bar] @ 20 0 (extrusion system not needed), - non-toxic, - possibility to use typical materials like aluminum, stainless steel, Teflon. Disadvantages: - pressure tank needed (large mass), - low density of the liquid phase 0,786 [kg/dm 3 ] @ 20 0 C only, -lowest specific impulse in comparison to other oxidizers. - critical temperature 36,42 0 C

6. 2013 SpaceForest Ltd. – All rights reserved. Our choice Paraffin wax as fuel Advantages: - inexpensive and available, - non-toxic, - environmentally compatible, - high regression rate, possibility to use a single hole grain, - short combustion chamber with a single port grain, -reusable grain and easy to mix with additives. Disadvantages: - engine excitation problems, - low density 0,92 [kg/dm 3 ], - low mechanical strength. figure made by Paweł Surmacz

7. 2013 SpaceForest Ltd. – All rights reserved. Proof of concept 1.Minimal construction material cost. 2.Use of industry standard equipment. 3.Easy to transport test platform. 4.Use of safe uninhabited area for testing.

8. 2013 SpaceForest Ltd. – All rights reserved. First cold test 3,2 [kg] of N 2 O in 8,0 [dm3] 45 [bar] tank pressure 90 [mm2] injector throat Liquid: 2,54 [kg] & 0,82 [kg/dm3] Vapour: 0,66 [kg] & 0,13 [kg/dm3] 1,7 [s] dicharge time; 1,49 [kg/s] flow rate; of N2O liquid phase injector discharge coefficient C d : C d = flow rate / injector throat * (2 * liquid density * Δpressure)^0,5 C d = 0,194 Valve gear box and hydraulic system worked properly.

9. 2013 SpaceForest Ltd. – All rights reserved. First cold test

10. 2013 SpaceForest Ltd. – All rights reserved. First burn test MDF tube saturated with paraffin wax 3,3 [s] of liquid phase burn time as expected 6570 [kNs] of total impulse 1797 [Ns/kg] of specific impulse large excitation of thurst on the end of liquid phase small port diameter 30 [mm] => large oxidizer mass flux 1100 [kg/s*m2]

11. 2013 SpaceForest Ltd. – All rights reserved. First burn test MDF tube saturated with paraffin wax Grain advantages: good density 1,02 [g/cm 3 ] Grain disadvantages: - low strength -> grain damages (several cracks), - small content of paraffin wax in the grain (36 % only), - low regression rate (@ L/D = 15,4) - too big Oxidizer-to-Fuel ratio (O/F) = 8,6 N 2 O share 89,7%, - graphite nozzle throat erosion,

12. 2013 SpaceForest Ltd. – All rights reserved. Test no.2 and no.3 Wastepaper tube saturated with paraffin wax Different tank pressure 40 [bar] and 57 [bar] Other conditions unchanged No influence on O/F ratio Visible influence on efficiency 40 [bar] - 1567 [Ns/kg] 57 [bar] - 1719 [Ns/kg] (10% more than @ 40 [bar]) Big influence on average thrust in the liquid phase 40 [bar] – 1400 [N] 57 [bar] – 2600 [N] (86% more than @ 40 [bar])

13. 2013 SpaceForest Ltd. – All rights reserved. Test no.2 and no.3 Wastepaper tube saturated with paraffin wax Stable combustion: Ox Mass Flux 410 – 550 [kg/s*m2] Grain advantages: - good grain density: 1,01 [g/cm 3 ], - good ignition and test performance, - good strength of the fuel grain. Grain disadvantages: - low paraffin saturation level - 35% only, - low availability of a thick-walled paper pipe, - low regression rate, - glue content (polyvinyl acetate + polyvinyl alcohol + kaolin), - empty spaces in spirally wound tubes – gas channels, - graphite erosion.

14. 2013 SpaceForest Ltd. – All rights reserved. Test no.5 Clean cellulose roll saturated with paraffin wax - no data, acquisition failure - impressive flame - too high regression rate - very low O/F = 3,8 N 2 O share 79 % - risk of setting the launch site on fire by scraps of cellulose - lower grain density than MDF and wastepaper tube 0,86 [g/cm 3 ] only - saturation problem, air bubbles in the grain

15. 2013 SpaceForest Ltd. – All rights reserved.

16. Test no.6 Polypropylene fiber roll saturated with paraffin wax - severed and burned injector plate - low Throat/Injector ratio T/I = 4,0 - high liquid phase average thrust L t = 3300 [N] Grain advantages: - only 30% of the PP reinforcement - easy to saturate - fuel grain unbreakable - regular port surface after burning - no risk of throwing burning PP pieces Grain disadvantages: - too low O/F = 3,8 ; N 2 O share 78 %, similar to cellulose fiber

17. 2013 SpaceForest Ltd. – All rights reserved. Test no.7 and no.8 Polypropylene fiber roll saturated with paraffin wax Repeatability verification of test results with the same test bed and engine similar test conditions: Tank pressure 50 – 51 [bar] similar test result: efficiency difference 1% only liquid phase average thrust difference 3% only

18. 2013 SpaceForest Ltd. – All rights reserved. Test no.9 and no.10 Polypropylene fiber roll saturated with paraffin wax Cold tests due to ignition failures Tank pressure 51 [bar] and 52 [bar] Combustion chamber (CC) pressure 4 - 5 [bar] only Liquid phase thrust 380 [N] only In comparison, hot tests in the same conditions: CC pressure 35 – 36 [bar] Liquid phase thrust 3300 [N] Both parameters about 8x bigger than @ cold test

19. 2013 SpaceForest Ltd. – All rights reserved. Test no.11 and no.12 Polypropylene fiber roll saturated with paraffin wax Comparison of the T/I ratio’s influence on test performance Test no. 11 new injector 21x2,5 mm T/I = 6,2 tank pressure 51 [bar] CC pressure 35 [bar] typical Isp = 1744 [Ns/kg] ideal shape of thrust characteristics Test no. 12 injector extended to 21x2,8 T/I = 4,9 tank pressure 52 [bar] CC pressure 38 [bar] lower Isp = 1666 [Ns/kg] visible excitation of thrust

20. 2013 SpaceForest Ltd. – All rights reserved. Test no.12 and no.13 Polypropylene fiber roll saturated with paraffin wax Comparison of the L/D ratio influence on test performance Test no. 12 port diameter 50 [mm]; L/D = 8,6 tank pressure 52 [bar] efficiency 1666 [Ns/kg] Ox mass flux = 830 [kg/s*m2] excitations but stable flame Test no. 13 port diameter 38 [mm]; L/D = 15,4 tank pressure 50 [bar] efficiency 1637 [Ns/kg] Ox mass flux = 1650 [kg/s*m2] excitations but extinguished flame on the end of liquide phase

21. 2013 SpaceForest Ltd. – All rights reserved. Test no.13

22. 2013 SpaceForest Ltd. – All rights reserved. Test no.14 Polypropylene fiber roll saturated with paraffin wax Check of the influence of a low T/I value on test performance Test no. 14 – injector extended to 21x3,0 mm T/I = 4,3 port diameter 50 [mm] tank pressure 52 [bar] CC pressure 42 [bar] efficiency 1708 [Ns/kg] large excitation of thrust in whole liquid phase

23. 2013 SpaceForest Ltd. – All rights reserved. Test no.15 and no. 16 Polypropylene fiber roll saturated with paraffin wax Test of a new injector type Test no. 15 new injector 36x1,5 mm T/I = 10,0 port diameter 50 [mm] tank pressure 50,5 [bar] CC pressure 42 [bar] very low Isp. 1279 and [Ns/kg] Test no. 16 injector 51x1,5 mm T/I = 7,1 port diameter 38 [mm] tank pressure 51 [bar] CC pressure 38 [bar] very low Isp. 1394 [Ns/kg] very large excitation of thrust

24. 2013 SpaceForest Ltd. – All rights reserved. Test no.17 Polypropylene fiber roll saturated with paraffin wax Test bed changes: stable trolley, loose engine, joint ball on S-cell modified injector from test 14 15 x 3,0 mm T/I = 6,0 port diameter 50 [mm] tank pressure 56 [bar] good Isp 1812 [Ns/kg] 100 Hz large excitation of thrust not eliminated What to do ???

25. 2013 SpaceForest Ltd. – All rights reserved. Test no.18 Paraffin wax + PE wax + EVA Test of a paraffin grain without reinforcement, with additives the same injector as in the previous test, pre-combustion chamber used for the first time (20% shorter grain), still too low O/F ratio = 3,86 typical Isp = 1734 [Ns/kg], good grain state after burn, excitation eliminated 100Hz character of fluctuation but on an acceptable level

26. 2013 SpaceForest Ltd. – All rights reserved. Test no.19 Paraffin wax + PE wax + EVA Using post-combustion chamber mixing plates two mixing plates added into the post-cc the same injector and pre-cc 10% shorter grain ideal O/F ratio = 5,6 (85% N 2 O) flame with a visible standing wave first mixing plate damaged no excitation ! no tones into characteristic spectrum (noise character of thrust fluctuation)

27. 2013 SpaceForest Ltd. – All rights reserved. Test no.20 Paraffin wax + PE wax + EVA SpaceForest’s invention to stabilize combustion and to eliminate excitations: geometric configuration of the injector in a conical shape. new cone-shaped injector modified first mixing plate (bigger ablative thickness) the same pre-combustion chamber similar grain without reinforcement grain damaged due to defect of the cast too low O/F ratio = 3,11 (76% N 2 O) very good thrust characteristics despite the big paraffin consumption

28. 2013 SpaceForest Ltd. – All rights reserved. Know-How conclusions N 2 O tank pressure has the main influence on average thrust and on resulting specific impulse. N 2 O flow rate has no influence on O/F ratio. T/I ratio reduction increase CC pressure and thrust (the same T). The most useful type of reinforcement was polypropylene fiber. ~30% share of PP does not attenuate the paraffin regression rate. Enhancement of the paraffin wax grain with various additives gave good results, for example for hardness with PE wax and for flexibility with EVA - ethylene copolymer and vinyl acetate. Used PP fiber and additives do not prevent motor excitation. The main causes of the thrust excitation is a too big fuel share due to the high regression rate of the paraffin wax.

29. 2013 SpaceForest Ltd. – All rights reserved. Know-How conclusions Other causes of excitation during the test campaign: - injector construction based on vertically and axially located holes, - too low T/I ratio, - too large Oxidizer Mass Flux, - too large fuel share, - lack of pre-combustion chamber. Ways to eliminate excitation are: - injector with holes located away from the motor axis, - injector geometry based on cone shape as proposed by SpaceForest, - proper nozzle throat diameter ensuring T/I ratio above 6, - proper port diameter ensuring Ox Mass Flux below 1000 [kg/s*m2] - proper L/D ratio ensuring 85% share of N 2 O, - using a pre-combustion chamber, - using mixing plates inside the post-combustion chamber.

30. 2013 SpaceForest Ltd. – All rights reserved. Flight experiment Adaptation of the test engine to a rocket model RTP7 the same engine (like in test 20) with added fins aluminum tank filled with 3 [kg] of N 2 O rocket height 3,3 [m], start mass 18 [kg] Flight organized and supported by PTR Polish Rocketry Society Engine damage due to poor sealing near injector.

31. 2013 SpaceForest Ltd. – All rights reserved. Flight experiment Registered data of the engine thrust during the flight two onboard ARECORDER flight computers acquisition frequency 100 Hz 0,3 [s] of start thrust on expected level ~ 2,5 kN good start acceleration >10g

32. 2013 SpaceForest Ltd. – All rights reserved. Flight experiment 2 Launch experiment by Cracov Team of PTR K1X rocket tested in several flights, equipped first time with hybrid engine based on N2O & PE, undependent own technology, ideal ignition, impressive launch performance,

33. 2013 SpaceForest Ltd. – All rights reserved.

34. Flight experiment 2 Launch experiment by Cracov Team of PTR thrust based on flight acceleration data - above 1 [kN] possible flight altitude of 11 km with fully filled tank

35. SpaceForest Ltd. Pomeranian Science & Technology Park Al.Zwyciestwa 96/98 81-451 Gdynia Poland www.spaceforest.pl, www.ppnt.pl spaceforest@spaceforest.pl; phone: +48 58 698 21 86 ; fax: +48 58 698 21 88; R&D Department: robert.magiera@spaceforest.pl; mob: +48 608 666 164; Contacts 2013 SpaceForest Ltd. – All rights reserved.

36. Thank you for your attention 2013 SpaceForest Ltd. – All rights reserved.