Controllers at NASA's Jet Propulsion Laboratory celebrated Saturday night after receiving confirmation that the Mars Exploration Rover Spirit had landed successfully on Mars. Signals from the spacecraft's UHF antenna indicated the spacecraft had rolled to a stop right side up, simplifying the deployment procedures.
The descent appeared to go as planned. About 90 minutes before landing the spacecraft rotated so that its heat shield was forward in anticipation of the high temperatures Spirit would experience on entry. Tones from the spacecraft later indicated that its cruise stage had separated as planned, and that the heat shield separation and parachute deployment were normal.
Earlier Saturday, the flight team was able to forego an optional course correction because previous corrections had gone so well. However, controllers did adjust the planned time for deployment of the spacecraft's parachute in reaction to a dust storm on the other side of Mars from the landing site at Gusev Crater. The dust storm warmed Mars' atmosphere at certain altitudes, thinning the air. In response, controllers programmed the parachute to open 3 to 4 seconds earlier than originally planned to compensate.