re space manuevering tug was hst servicing mission in article c dvgh aph news cso uiuc edu jbh uxa cso uiuc edu josh hopkins writes prb access digex net pat writes i wrote prb access digex net pat writes my data shows that the oms engines hold kg of propellant of that a substantial fraction is going to be used for the first oms burn the reentry burn and the reserve so pat tell us how much fuel the altitude change is going to take and how much the edo pallet bus and extra parts are going mass if you can make the numbers work out then i ll be interested after you show us that it can be done then tell us how much the edo pallet bus and extra equipment is going to cost i don t know does anyone in nasa land know how much fuel is budgeted for the altitude change henry any figures on the mass full for the edo pallet plus it s dry weight how about for the dry mass of bus it was being de classified as i checked last also i need current orbital parameters of hst projected orbital parameters after re boost discovery s dry weight hst s dry weight i somehow think they could train up a new eva in months first while astronauts certainly have done evas with minimal planning that was because they had to they don t like to do that as a general rule so how long do they need to train a year years somehow i think moths should be adequate second remember why they had to improvise during intelsat they were trying to attach a motor to a piece of hardware that wasn t designed to do that trying to shortcut the training is only going to make a repeat more likely also because they significantly lacked on orbit eva experience the hst is designed for on orbit servicing it should be a lot easier third they don t have eight months they have however much time is left after someone comes up with a plan shows it can work and gets it approved you may think i have a pessimistic attitude i think it s realistic i m not saying that the engineering task is impossible few engineering tasks are what i m saying is that this is neither cost effective nor feasible under nasa management there comes a time in every project to kill the management they can if neccessary re schedule the hst mission december is not a drop dead date unlike say the ldef retrieval mission all they have to do is soup it up just what does that mean i suspect the bus may not have enough basic thrust for the hst re boost it mayu need bigger tanks or bigger thrusters my understanding is the second hst servicing mission is not a contingency my understanding is the mission needs both a new foc and work on the electrical system plus another re boost if the smt can avoid a second servicing mission that s million saved no pat that s million minus the cost of the new hardware minus the cost of the extra struff you want to bring along minus development and mangement costs minus extra operating costs tanstaafl somehow i think the cost of an expendable smt will be less then million and the extra stuff is real cheap nasa has lots of suits mmu s and the edo pallets are re usable oh one double magnum of champagne now there s a couple hundred bucks pat not only is this messy and less reliable than a device that s made to perform this task it also ignores the point there is a desire to have astronauts available so that if the door fails to open something can be done about it unless you can provide a very reliable way of reopening the door you haven t solved the problem that door has cycled x times already once after massive g loading i somehow think they can work ou reliability methods to ensure the door works also please tell me how some sort of sublimated material like co or h o would manage to contaminate the mirror anything that goes to vapor state shouldn t adhere to the mirror somehow the door problem can be worked maybe they can put a one time spring on it what do they do now if the door hangs up that door is part of a intrument safing mechanism if it hangs up tomorrow it ll be months until someone gets up there witha crowbar to fix it pat
