Difference between revisions of "More information on Spitzer operations"
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It might seem, if you're just using Spitzer data (as opposed to planning observations), that you don't need to know much about Spitzer operations. But, it turns out that you do need to know a little bit about how Spitzer works in order to understand why the data look the way they do. | It might seem, if you're just using Spitzer data (as opposed to planning observations), that you don't need to know much about Spitzer operations. But, it turns out that you do need to know a little bit about how Spitzer works in order to understand why the data look the way they do. | ||
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== Spitzer is a robot == | == Spitzer is a robot == | ||
| − | Spitzer is a robot, designed to operate autonomously for 12-24 hours at a time. We at the SSC prepare schedules for the telescope, and this is done for a whole week at once. We then upload the schedule (in whole or in part) up to the spacecraft. The telescope then goes about taking data all by itself. Every 12 or 24 hours (whatever we've told it to do), it "calls home", downloads the data and gets any new instructions. This operational constraint is why we can't drop everything and make an observation of whatever you want ''right this second.'' This also means that there is NOT someone sitting with a joystick (or joystick-like-thing) at the SSC or at JPL, commanding the spacecraft in real time. All of the observations have to be planned in great detail at least 2 months in advance, usually more in advance than that. This is one way that observing from space is very different than observing from the ground. | + | Spitzer is a robot, designed to operate autonomously for 12-24 hours at a time. We at the SSC prepare schedules for the telescope, and this is done for a whole week at once. We then upload the schedule (in whole or in part) up to the spacecraft. The telescope then goes about taking data all by itself. Every 12 or 24 hours (whatever we've told it to do), it "calls home", downloads the data and gets any new instructions. We use the [http://deepspace.jpl.nasa.gov/dsn/ Deep Space Network (DSN)] to communicate with Spitzer; pretty much every other spacecraft not in Earth orbit is also competing for this limited resource. We have to plan out well in advance when we will be able to use certain dishes as part of the DSN. When there is a special event, such as an "orbital insertion" (when a spacecraft goes into orbit around another planet), then that event takes priority over all others, and we have to rearrange our uplink/downlink times accordingly. |
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| + | This operational constraint is why we can't drop everything and make an observation of whatever you want ''right this second.'' This also means that there is NOT someone sitting with a joystick (or joystick-like-thing) at the SSC or at JPL, commanding the spacecraft in real time. All of the observations have to be planned in great detail at least 2 months in advance, usually more in advance than that. This is one way that observing from space is very different than observing from the ground. | ||
Revision as of 23:36, 11 October 2007
It might seem, if you're just using Spitzer data (as opposed to planning observations), that you don't need to know much about Spitzer operations. But, it turns out that you do need to know a little bit about how Spitzer works in order to understand why the data look the way they do.
Spitzer is a robot
Spitzer is a robot, designed to operate autonomously for 12-24 hours at a time. We at the SSC prepare schedules for the telescope, and this is done for a whole week at once. We then upload the schedule (in whole or in part) up to the spacecraft. The telescope then goes about taking data all by itself. Every 12 or 24 hours (whatever we've told it to do), it "calls home", downloads the data and gets any new instructions. We use the Deep Space Network (DSN) to communicate with Spitzer; pretty much every other spacecraft not in Earth orbit is also competing for this limited resource. We have to plan out well in advance when we will be able to use certain dishes as part of the DSN. When there is a special event, such as an "orbital insertion" (when a spacecraft goes into orbit around another planet), then that event takes priority over all others, and we have to rearrange our uplink/downlink times accordingly.
This operational constraint is why we can't drop everything and make an observation of whatever you want right this second. This also means that there is NOT someone sitting with a joystick (or joystick-like-thing) at the SSC or at JPL, commanding the spacecraft in real time. All of the observations have to be planned in great detail at least 2 months in advance, usually more in advance than that. This is one way that observing from space is very different than observing from the ground.
