Long-duration firings of a Mariner Mars 1969 catalytic reactor

Two long-duration tests were conducted with a surplus Mariner Mars 1969 monopropellant hydrazine reactor in an attempt to induce the washout phenomenon. The Mariner Mars 1969 reactor was chosen because it has a long development history and thus is well characterized. No washout occurred during either of the two 1000-s tests, although slow transients were observed in the reactor operation during what were nominally steady-state conditions. The 2000-s of operating time represents nearly an order of magnitude increase over the rated life of the engine.