418 S. Schmidt et al./ Acta Astronautica 55(2004)409-420 Fig. 16. C/SiC combustion chamber on the P1.5 and during the Fig. 18. Modified C/SiC combustion chamber during the hot-firing as newly developed layer systems were carried out. The main objective of the material and component tests was to verify the long-term behaviour(>1 h) and to find out the maximum permissible component temperatures. The test time amounted to 5700 s at a combustion-chamber pressure of 1l bars Fig. 17. Modified C/SiC combustion chambers coated with different Fig. 18 shows the combustion chamber during the hot-firing test The hot-firing tests conducted since 1998 with investigating differing layer systems with regard to coated combustion chambers made of C/SiC yielded long-term deployment, comprised the main areas of important insights into the application potential of CMCs for small thrusters. The feasibility together at a combustion-chamber pressure of 10 bars. By with the positive effects on engine performance were varying the mixture ratio [o/F] in the range between verified 1.64 and 1.92, maximum wall temperatures of up to 1700C were determined. Fig. 16 illustrates the 3.5. Further developments C/SiC combustion chamber on test bench P1.5 in Lampoldshausen. In the course of developing cost-effective manu- In this year, further hot-firing tests with modified facturing methods for structural components stion chambers(Fig. 17)as well of fibre composites, in recent years various418 S. Schmidt et al. /Acta Astronautica 55 (2004) 409 – 420 Fig. 16. C/SiC combustion chamber on the P1.5 and during the hot-3ring test. Fig. 17. Modi3ed C/SiC combustion chambers coated with di;erent layers. investigating di;ering layer systems with regard to long-term deployment, comprised the main areas of e;ort. The accumulated test time amounted to 3200 s at a combustion-chamber pressure of 10 bars. By varying the mixture ratio [O=F] in the range between 1.64 and 1.92, maximum wall temperatures of up to 1700◦C were determined. Fig. 16 illustrates the C/SiC combustion chamber on test bench P1.5 in Lampoldshausen. In this year, further hot-3ring tests with modi3ed and optimized combustion chambers (Fig. 17) as well Fig. 18. Modi3ed C/SiC combustion chamber during the hot-3ring test. as newly developed layer systems were carried out. The main objective of the material and component tests was to verifythe long-term behaviour (¿ 1 h) and to 3nd out the maximum permissible component temperatures. The test time amounted to 5700 s at a combustion-chamber pressure of 11 bars. Fig. 18 shows the combustion chamber during the hot-3ring test. The hot-3ring tests conducted since 1998 with coated combustion chambers made of C/SiC yielded important insights into the application potential of CMCs for small thrusters. The feasibilitytogether with the positive e;ects on engine performance were veri3ed. 3.5. Further developments In the course of developing cost-e;ective manu￾facturing methods for structural components made of 3bre composites, in recent years various textile