HR: 0800h
AN: SA21A-0258    [Abstracts]
TI: AIM Receiver/Communication Lock Analysis; When Bad Space Weather is Good
AU: Ryan, S
AF: University of Colorado, 1234 Innovation Drive, Boulder, CO 80303, United States
AU: * Baker, D N
AF: University of Colorado, 1234 Innovation Drive, Boulder, CO 80303, United States
AU: Gehmeyr, M
AF: University of Colorado, 1234 Innovation Drive, Boulder, CO 80303, United States
AU: McCollough, J P
AF: University of Colorado, 1234 Innovation Drive, Boulder, CO 80303, United States
AU: Russell, J M
AF: Hampton University, 100 East Queen St, Hampton, VA 23669, United States
AU: Bailey, S M
AF: Virginia Institute of Technology, 213 East Eggleston, Blacksburg, VA 24061, United States
AB: The AIM (Aeronomy of Ice in the Mesosphere) spacecraft (a NASA Small Explorer satellite) was launched on 25 April 2007. Some days after launch, AIM began to exhibit a problem in which it would not always achieve proper receiver uplink communications 'lock'. During several periods in May – August 2007, the solar wind became very quiet and geomagnetic activity went to very low levels. During such times, there were several complete days without successful unlink from the ground operators to AIM. In this context, the Forecast Modeling team of the Center for Integrated Space Weather Modeling (CISM) used modeling tools to examine solar conditions and issued forecasts about geomagnetic activity. This was based on the hypothesis that higher solar wind speeds would lead to greater geomagnetic activity – and this, in turn, would improve AIM operations. Such forecasts have proven accurate: An increase in solar wind and geomagnetic activity often leads to a dramatic improvement in AIM communication uplink. We conclude that the AIM spacecraft receiver lock problem is related to space environment conditions. We have speculated that increased space weather activity helps drive the AIM receiver circuits toward a better operational state. The best predicator of 'good lock' state is a shift from low (or quiet) geomagnetic and solar wind conditions to more disturbed conditions. We have used the CISM Forecast Model tools to predict when propitious conditions should occur. We do not fully understand the mechanism(s) by which disturbed space weather improves AIM performance, but use of CISM tools has been an important, supportive adjunct to a key new NASA flight program which is now operating quite successfully and returning excellent, continuous data.
DE: 0399 General or miscellaneous
DE: 2400 IONOSPHERE (6929)
DE: 2459 Planetary ionospheres (5435, 5729, 6026)
DE: 2499 General or miscellaneous
DE: 6999 General or miscellaneous
SC: SPA-Aeronomy [SA]
MN: 2007 Fall Meeting