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We consider the problem of trajectory planning for optimal relative orbit determination in the cislunar environment. The recent interest in cislunar space has created a need to develop autonomous tracking technologies that can maintain situational awareness of this dynamically complex regime. Optical sensors provide an ideal observation platform because of their low cost and versatility in tracking both cooperative and non-cooperative space objects. The estimation performance of an optical observer can be significantly enhanced through manuevering. This work develops a trajectory planning tool, compatible with low-thrust propulsion, for tracking one or multiple targets operating in proximity to the observer. We formulate an objective function that is a convex combination of the mutual information between target states and measurements, and the low-thrust control effort. The subsequent optimal control problem is solved via direct collocation using the successive convexification algorithm, which, we argue, is well suited for a potential onboard trajectory planning application. We demonstrate the tool for several relevant scenarios with one and multiple targets operating around periodic orbits in the circular restricted three-body problem. A sequential estimator's performance is evaluated using the Cramer-Rao lower bound and, compared to a purely passive observer, we show that optimizing the observer's trajectory can decrease this bound by up to several orders of magnitude within a planning window. This investigation provides an initial proof-of-concept to future onboard planning technologies for relative tracking in the cislunar domain. 

Geoscience is plagued with structural and systemic barriers that prevent people of historically excluded groups from fully participating in, contributing to, and accruing the benefits of geosciences. A change in the culture of our learning and working environments is required to dismantle barriers and promote belonging, accessibility, justice, equity, diversity, and inclusion in our field. Inspired by a session organized at the 2020 Ocean Sciences Meeting, the goal of this paper is to provide a consolidated summary of a few innovative and broadening participation initiatives that are being led by various stakeholders in academia (e.g., students, faculty, administrative leaders) at different institutional levels (e.g., universities, professional societies). The authors hope that the strategies outlined in this paper will inspire the coastal, ocean, and marine science community to take individual and collective actions that lead to a positive culture change. 

Abstract The transport of Ca²⁺across membranes precedes the fusion and fission of various lipid bilayers. Yeast vacuoles under hyperosmotic stress become fragmented through fission events that requires the release of Ca²⁺stores through the TRP channel Yvc1. This requires the phosphorylation of phosphatidylinositol‐3‐phosphate (PI3P) by the PI3P‐5‐kinase Fab1 to produce transient PI(3,5)P₂pools. Ca²⁺is also released during vacuole fusion upontrans‐SNARE complex assembly, however, its role remains unclear. The effect of PI(3,5)P₂on Ca²⁺flux during fusion was independent of Yvc1. Here, we show that while low levels of PI(3,5)P₂were required for Ca²⁺uptake into the vacuole, increased concentrations abolished Ca²⁺efflux. This was as shown by the addition of exogenous dioctanoyl PI(3,5)P₂or increased endogenous production of by the hyperactivefab1^T2250Amutant. In contrast, the lack of PI(3,5)P₂on vacuoles from the kinase deadfab1^EEEmutant showed delayed and decreased Ca²⁺uptake. The effects of PI(3,5)P₂were linked to the Ca²⁺pump Pmc1, as its deletion rendered vacuoles resistant to the effects of excess PI(3,5)P₂. Experiments with Verapamil inhibited Ca²⁺uptake when added at the start of the assay, while adding it after Ca²⁺had been taken up resulted in the rapid expulsion of Ca²⁺. Vacuoles lacking both Pmc1 and the H⁺/Ca²⁺exchanger Vcx1 lacked the ability to take up Ca²⁺and instead expelled it upon the addition of ATP. Together these data suggest that a balance of efflux and uptake compete during the fusion pathway and that the levels of PI(3,5)P₂can modulate which path predominates.