Aeronomy of ice in the mesosphere receiver/ communication lock analysis: When bad space weather is good

Abstract

The Aeronomy of Ice in the Mesosphere (AIM) spacecraft (launched on 25 April 2007) is in low-Earth polar orbit. Some days after launch, AIM began to exhibit a problem in which it would not always achieve proper receiver uplink communications lock (termed "bitlock" throughout this paper). In this context, we examined solar conditions and geomagnetic activity to search for possible connections with periods of bitlock problems. We have found that higher solar wind speeds often lead to greater geomagnetic activity and this, in turn, seems to lead to improved AIM operations. Here we present analysis of AIM bitlock to show when relative improvements or diminutions in spacecraft operations have occurred. We conclude that the spacecraft bitlock problem is related, in part, to space environment conditions (along with a gradual secular trend toward lower performance). The best indicator of "good lock" state (of all we have evaluated) is associated with a shift from low (or quiet) geomagnetic and solar wind conditions toward more disturbed conditions. Copyright © 2009 by the American Geophysical Union.