Friday, November 28, 2008

Prochron Update

Prochron 0811B will be set aside at this point. The OTRAG style configuration appears to be the way to go, but it is obviously rather limited. The propulsion for Prochron and Symtex is likely to be oxykerosene blowdown pressure-fed made of ordinary steel, perhaps with some cheap hoop wrapped composite. The selection of first stage motor is still Cesaroni M4770-P V-max...this one lasts only two seconds. Everything else is open, but the assumption for the stage is that it is 10% of its full mass at burnout. The module turned out to be 151kg, sized to optimize version 3204. The ascent is 9500m/s. The numbering system works like this:

1st digit: number of modules in Stage Two
2nd digit: number of modules in Stage Three
3rd and 4th digits: 10kg units of Stage Four

Version 1000: The sounding rocket (has 4 modules in Stage One)
Total impulse is 445860Ns, lower S class and about half of the maximum allowable under FAA amateur rocketry rules. It has to carry a payload of at least 100kg in order to stay under the amateur ceiling.

Version 3104: Design point, 3kg orbital booster (10kg listed payload allows 7kg for guidance and dunnage; 4kg has been allowed for the fairing.) Gross mass is 724kg. Has 10 Stage One motors.

Version 2104: Minimal: barely makes orbit with its guidance system (700g of payload). Gross mass is 557.5kg. Has 8 Stage One motors.

Version 4104: Payload of 5kg, Gross mass is 890.2kg, has 12 Stage One motors.

Version 5204: Payload of 9.8kg, Gross mass is 1230kg, has 17 Stage One motors.

Version 6204: Payload of 11.8kg, Gross mass is 1402.8kg, has 20 Stage One motors.

Version 6210: The biggest. Payload of 13.8kg. Gross mass is 1464.8kg. Has a bigger upper stage.

Post comment or send email if you want access to the spreadsheet. I need to know your email, post like "aftercolumbia at gmail dot com" to make sure it doesn't get filtered by blogger software. Oh yeah, that's my email address if you'd rather not have any exposure in the comments section. Check out the landers shortly to be posted at


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