Dawn's Schedule at Ceres

Dawn has a schedule of orbits stretching from now to December to achieve the science goals of its mission. As you probably know Dawn has an ion engine that only produces around 90mN of thrust. That is the same amount of force that a sheet of A4 paper exerts on your hand due to gravity. It can take Dawn weeks to lower its orbit to the next stage of the mission.

Currently Dawn is performing the Survey orbit at 4,430km altitude. This process began on the 6th of June and is scheduled to last until the end of the month. The framing cameras will have a resolution of 410m/pixel during the survey orbit so that is only around 17% better than OpNav 9 at 480m/pixel [link to photojournal.jpl.nasa.gov] [link to dawn.jpl.nasa.gov] Spot 5 will appear 62% bigger than it does in this OpNav 8 image [link to photojournal.jpl.nasa.gov] which is 670m/pixel.

During the survey orbit, maps of Ceres will be produced from the VIR spectrometer ( based on Rosetta's VIRTIS-M ) that may have the resolution to determine what spot 5 is made from.

After the Survey orbit is complete Dawn will continue on down to the High Altitude Mapping Orbit ( HAMO ) which it will reach by 4th August. This will give us three times better resolution at 140m/pixel. HAMO will continue until October 15th when Dawn again lowers its orbit to reach LAMO. At just 375km above the surface LAMO, which Dawn reaches in early December, will give us a visual resolution of 35m/pixel around 14x better than the OpNav9 image.

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