re hst servicing mission scheduled for days in article t nhg rpi edu strider clotho acm rpi edu greg moore writes as herny pointed out you have to develop the thruster also while much lighter you still have to lift the mass of the thruster to orbit and then the thruster lifts its own weight into a higher orbit and you take up room in the payload bay a yes but the improvement in boost orbit to the hst is significant and that means you can then carry edo packs and enough consumables so the shuttle mission can go on long enough to also fix the array tilt motors and god knows what else is going to wear out on the hst in the next months pat
