12

Although space is cold, vacuum is a pretty good insulator. That means it is difficult to get rid of waste heat. Almost any action your spacecraft performs does produces heat that must be radiated away. Radiators are very sensitive to temperatures, being victims of the Tyranny of the Stefan-Boltzmann Equation. Their efficiency depends on the fourth power of ...


10

Purging is done to remove residual fuel from the lines. This is normally done using nitrogen gas. https://www.grc.nasa.gov/www/retf/textFiles/lessonsRocketEngineTesting.html Residual fuel and oxidiser represents a combustion hazard - it could leak out or evaporate and start a fire. Also, if your oxidiser is something like nitric acid or dinitrogen ...


10

Those are Mach diamonds. They form due to the interaction of the exhaust flow with its own supersonic shockwaves. All rockets and some jet engines produce them; their visibility varies with the propellant combination, mixture ratio and environmental conditions. The flow pattern doesn't appreciably affect thrust since it takes place after the exhaust has ...


9

The biggest single change in the Houston Mission Control Center (MCC) occurred in the late 1990s. This was the change from a mainframe based system architecture to a workstation based system with a client/server architecture. The project was led by John Muratore and it's discussed at some length in his oral history. Several of the papers in the Control ...


8

The in-development Prime launcher from Orbex has an uncommon arrangement: One key aspect of propane is that it remains liquid at cryogenic temperatures. That enabled a “coaxial tank” design for Prime where a central tube of propane is surrounded by an outer tank of liquid oxygen, creating structural mass savings in the rocket. (From Space News ) Others ...


6

I had the distinct honor of working for John Muratore on two distinct projects. One was the X-38. But before that, I worked on developing advanced software for his Real Time Data System project. The RTDS project started in 1986 when Muratore saw the archaic structure of Mission Control. The primary goal of the project was to transition from a single ...


5

The simple answer to "Does stress-testing a spacecraft affect its durability?" is Yes, it does, in the classical western view of test programmes. I can't answer for the James Webb Telescope specifics but a common approach is to divide a test programme conceptually into design verification and workmanship verification. As an aside, the design verification ...


4

Sutton (7th edition, but the only one online) says Hydraulic and pneumatic components (valves, pipes, expansion joints) can readily be water flow tested on flow benches and corrected for pressure drops and density (and sometimes also viscosity) to determine their pressure drop at rated flow. The fairly in-depth ...


3

Can these satellites communicate to each other and be used as data relays for communication with Earth (e.g. when a potential new spacecraft is on the far side of Mars)? What would be the approximate bandwidth? Yes. Transmission relays via Mars Orbiters are possible and are actually used. Curiosity for example uses orbiters to relay information faster ...


3

ULA presented the 6-booster "Delta Superheavy" in 2004 (archive link) as a possible upgrade path for the Delta IV. As far as I can tell, it's only a proposed design. Actually building it would likely require structural changes to the core stage to handle the additional stresses (as we've seen with Falcon Heavy), and the launch pad infrastructure would have ...


3

One possible approach has been shown by SpaceX over the past few years: Use a common engine for all stages, instead of having different engine designs for each stage. Use a common tank design for all stages. This means you only need one set of jigs and tools for all the bulkheads and only one welding installation. Design for low cost instead of ...


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