re hst servicing mission scheduled for days in article apr stsci edu hathaway stsci edu writes also as implied by other posters why do you need to boost the orbit on this mission anyway you don t need to but it s desirable hst like all satellites in low earth orbit is gradually losing altitude due to air drag it was deployed in the highest orbit the shuttle could reach for that reason it needs occasional reboosting or it will eventually reenter it has no propulsion system of its own this is an excellent opportunity given that there may not be another visit for several years svr resembles a high speed collision henry spencer u of toronto zoology between svr and sunos dick dunn henry zoo toronto edu utzoo henry
