Mission Ranger 5

ranger 5

ranger 5 heat-sterilized rangers 3-4 had been, prevent unintended contamination of moon earth microbes. rolf halstrup, in charge of sterilization program, had vocally objected procedure convinced subjecting probes heat dosage damaging sensitive electronics in them. convinced jpl in pasadena management sterilization of ranger 4 had damaged main computer sequencer , timer , procedure needed stopped ensure reliability of spacecraft. management agreed stop sterilizing ranger probes, on ranger 8 , up, rangers 6-7 had been sterilized.

on august 20, ranger 5 began long cross-country trip state of california florida , arrived there day of mariner 2 s launch. atlas 215d , agena 6005 arrived later week , prelaunch checkouts started. initial preparations focused on launch vehicle itself, causing many problems ranger probes themselves. atlas-agena combination malfunctioned 4 out of 6 times nasa had launched , every booster delivered cape canaveral required modifications or repair work before fly. moreover, in year between ranger 1 , mariner 2, there had been no improvement whatsoever in quality control of atlas-agenas. since ranger launches had been delayed before booster problems, technicians rushed make sure nothing of sort delay ranger 5 s mission.

tracking of mariner 2 ongoing job during time , since nasa s deep space tracking networks not handle both probes @ once, decided switch attention ranger 5 short mission.

after 2 launch attempts aborted, 1 due electrical short in probe , other due weather concerns, go fly given october 18. liftoff took place @ 12:59 pm est , atlas vanished overcast gray sky. malfunction of guidance system rate beacon @ t+93 seconds resulted in noisy track rate data, unlike ranger 3, discreet commands received , issued guidance system properly. agena reached orbit , began burn place ranger 5 on translunar trajectory.

elation turned dismay once again when high temperatures detected in computer system; shortly afterwards, power generation solar panels ceased. gamma ray detector turned on, computer did not issue command align spacecraft earth. worse, telemetry receivers @ tracking stations in australia , south africa malfunctioned, returning garbled data. obvious electrical short had disabled solar panels, meant ranger 5 had few hours before run out of battery power. jpl technicians held out hope still partially salvage mission firing midcourse correction engine ensure impact moon, had before power ran out. ground controllers sent commands unfurl high-gain antenna , align probe midcourse burn, during time more electrical shorts apparently occurred because there momentary dropout telemetry transmitter. midcourse engine fired, ranger 5 exhausted batteries halfway through burn. radio transponder , telemetry signals ceased, followed uncontrolled tumbling of probe. ranger 5 passed 450 miles lunar surface en route permanent orbit around sun. signals still received tiny seismometer capsule until fading probe s distance earth became great. mission controllers tracked distance of 1.3 million km (808,000) miles.

this third attempt impact lunar surface block ii ranger spacecraft. on mission, 15 minutes after normal operation, malfunction led transfer of power solar battery power. normal operation never resumed; battery power depleted after 8 hours, , spacecraft systems died. first midcourse correction never implemented, , ranger 5 passed moon @ range of 724 kilometers on 21 october , entered heliocentric orbit. tracked distance of 1,271,381 kilometers. before loss of signal, spacecraft sent 4 hours of data gamma-ray experiment.

following failure of launch (missing moon), electronic assembly next versions rebuilt rca astro electronics division in east windsor, new jersey. satellites rebuilt rca astro worked expectations. photos returned , helped nasa determine landing sites lunar landers.