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Dear GLIMS colleagues:</div>
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I have a further clarification about ASTER's future (and that of MODIS and MISR onboard Terra). There are two separate dates being floated for decommissioning. One is Sep. 30, 2026—the last day of funding for ASTER and Terra mission operations under the funding
(with a 50% cut) that is to begin on October 1, 2023. September 2026 is the decommissioning time that I mentioned yesterday. There is another possibility, and that is December 2025. That is the month when Terra's morning equator crossing will have shifted
to 9 a.m. local time. The 9 a.m. is a bit of an arbitrary cutoff, but it was thought a couple years ago that by that point the signal observed by VNIR will have decreased enough that it warrants turning ASTER off.</div>
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I have pointed out that over snow and ice targets, there is still plenty of signal. If for nothing else, imaging of snow and ice targets would be very rewarding for GLIMS and any other cryospheric studies. There presently is not a lot of enthusiasm in ASTER
Mission Ops to terminate ASTER that early. So, I suspect that Sep. 30, 2026 will stick. It would be possibly helpful, and certainly would not hurt, if we had a chorus of ASTER users to press for as late as possible of a decommissioning. ASTER is still a go-to
resource for topographic studies, and that use should not end as the orbit drifts further. Thermal is also an underutilized part of ASTER, but there are people using it for glacier and glacier lake studies, so that is another key use that would benefit from
a later decommissioning.</div>
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There is an outside hope (far outside) that with a groundswell of support for new funding and operating ASTER and Terra beyond September 30, 2026, we might be able to continue into 2027. That is me talking, not ASTER Mission Ops. A lot depends on solar activity,
since the solar wind and EUV fluffs up the atmosphere, which creates drag, and that impacts the orbit drift rate and the potential lifetime of Terra and ASTER. </div>
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So.... I am looking for emails, individually, or if groups of you want to write letters, address them to me, and I will compile the responses. You can express how you have used ASTER data (or other Terra data) and whether you feel that extracting more lifetime
out of ASTER, MODIS, or MISR will have a significant impact on science.</div>
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Please reply with "ASTER" somewhere in the subject line.</div>
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Cheers,</div>
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Jeff Kargel</div>
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