科学美国人60秒:Pluto Mission Finally Calls Home

“Okay, we are in lock with carrier…stand by for telemetry.”

Alice Bowman, mission operations manager of NASA’s New Horizons flyby of Pluto. And I’m Steve Mirsky, for Scientific American’s Science Talk podcast.

Bowman is talking just after the mission control center at the Johns Hopkins University Applied Physics Laboratory in Laurel, Maryland, received radio confirmation at 8:52pm, July 14^th, that the spacecraft was still in good shape after passing Pluto. The ship had been out of communication for almost 21-and-a-half hours so that it could concentrate on gathering data. So destruction by space debris or a simple malfunction could have happened hours ago without the team’s knowledge. Now the probe was finally checking in, a message sent from so far away that at the speed of light it had taken some four-and-a-half hours to arrive.   

AB: Okay, copy that, we are in lock with telemetry with the spacecraft.

Then Bowman checks in with the team members monitoring the probe’s individual subsystems. They call Bowman “MOM,” for mission operations manager. When they say “nominal,” that’s good.

AB: Subsystems, please report your status as you get enough data.

Team: Mom, this is RF (Radio Frequency) on Pluto One.

AB: Go ahead, RF.

T: RF is reporting nominal carrier power. Nominal signal to noise ratio for the telemetry, RF is nominal.

AB: Copy that, RF nominal.

T: MOM, this is Autonomy on Pluto One.

AB: Go ahead, Autonomy.

T: Autonomy is very happy to report nominal status, no rules have fired.

T: MOM, this is C&DH (Command and Data Handling) on Pluto One.

AB: Go ahead, C&DH.

T: C&DH reports nominal status. Our SSR (Solid State Recorders) pointers are where we expect them to be, which means we have recorded the expected amount of data.

AB: Copy that. Looks like we have a good data record.

T: MOM, this is GNC (Guidance, Navigation and Control) on Pluto One.

AB: Go ahead, GNC.

T: GNC is nominal, all hardware is healthy and we have a good number of thruster counts.

AB: Copy that, GNC is healthy.

T: MOM, this is Propulsion on Pluto One.

AB: Go ahead, Prop.

T: Propulsion is nominal, tank pressure is 176.8.

AB: Copy that, Propulsion system is nominal.

T: Mom, this is Power on Pluto One.

AB: Go ahead, Power.

T: Power system, all telemetry is nominal. Hardware is healthy.

AB: Copy that, nominal for power.

T: MOM, this is Thermal on Pluto One.

AB: Go ahead, Thermal.

T: Thermal reports nominal, all temperatures green.

AB: Copy that, Thermal is nominal, all temperatures green. Okay, PI (principal investigator), MOM on Pluto One: We have a healthy spacecraft. We’ve recorded data of the Pluto system, and we’re outbound from Pluto. (Cheers and applause.) I can’t express how I feel, it’s just fantastic, just like we planned it, just like we practiced. We did it. It’s just great.