Originally Posted by Sintel
Thanks for that, but what I guess im really asking was how did they design/test/know that the powered descent stage would work? Like I said I've seen the drop test
but not a test on the powered descent, I imagine it would be impossible to test on earth with the different environments, so would it have been based entirely on simulations (and a bit of luck)?
Good question, although i cant really answer that with any certainty but what i woud imagine they have tested is a mock up rig of the powered descent skycrane on earth with enough fuel, thrust etc. for earth parameters like gravity, atmospheric density etc. for testing stability for example (making sure the rockets were placed adequately for a stable landing). The calculations involved woudnt really need much practical testing as rocket science is now a proven and reliable discipline. Simulations may well suffice.
Unfortunately the only way to test the deployment of parameters with mars in mind would be just simulations based on calculations that have proven to work on earth. which is basically where rocket science knowledge obviously originates.
They would have done the same thing for the apollo lunar lander descent and ascent stages. To make sure the descent stage/ lander didnt crash into the lunar ground (exactly like making sure curiosity didnt crash into martian ground) and that the ascent stage could get back up into orbit around the moon to redock with the command module for the return trip home.