Re: [PSAS] staging designs, code inspection

2011-01-31 Thread David Harris
Hi Ben, What aero model are you using and how are you calculating the gravity turn and angle of attack losses? Or at this point are you just adding some margin to the delta v target figure and just approximating? David On Sun, Jan 30, 2011 at 6:03 PM, Benjamin Kaplin bkap...@pdx.edu wrote:

Re: [PSAS] staging designs, code inspection

2011-01-30 Thread Benjamin Kaplin
Ex: - m_i1 Mass of 1st stage only, including fuel - m_f2 Mass of 2nd stage only, excluding fuel This comment pointed out to me that the script was really only useful for designing a particular stage. So, to provide a more general tool, I rewrote the script. It should be a lot more

[PSAS] staging designs, code inspection

2011-01-29 Thread Benjamin Kaplin
Hi, all! I was curious to see what it would take to get a 1 kg payload into orbit, so I did some math and wrote some code! Forgive me if this duplicates work elsewhere on the wiki, but in lieu of a page on Staging, I created my own and populated it to some degree. Please, kick tires and poke

Re: [PSAS] staging designs, code inspection

2011-01-29 Thread rq17zt
Hey, Looks good! I can't check the iterative output 'cuz the stage speed (Stage Seed) is missing from the table. (Or i don't understand it, or my browser isn't rendering it, etc.) But if the stage speed was known you could just use the first equation as a simple check. -- We should (do?) have a

Re: [PSAS] staging designs, code inspection

2011-01-29 Thread Benjamin Kaplin
Total terminology gaffe on my part! stage seed refers to the weight of the stage above the stage for which we desire fuel numbers. Eg, for stage three, the seed should be 1kg, the payload weight. For stage 2, the seed should be 4 kg and some change (stage three's wet weight, you see!). the stage

Re: [PSAS] staging designs, code inspection

2011-01-29 Thread rq17zt
Thanks, that makes sense. Still not totally clear on how Dead Mass and Liftoff Mass relate to stage masses before and after separation. I might claim that Liftoff Mass is something of a misnomer. Some possible terminology: - (m_L) Payload mass - (m_p) Propellant mass - (m_i) Initial (fueled)