The properties and structure of electrically stressed ionic liquid menisci experiencing ion evaporation are simulated using an electrohydrodynamic model with field-enhanced thermionic emission in steady state for an axially symmetric geometry. Solutions are explored as a function of the external background field, meniscus dimension, hydraulic impedance and liquid temperature. Statically stable solutions for emitting menisci are found to be constrained to a set of conditions: a minimum hydraulic impedance, a maximum current output and a narrow range of background fields that maximizes at menisci sizes of 0.5–3 ${\rm \mu}{\rm m}$ in radius. Static stability is lost when the electric field adjacent to the electrode that holds the meniscus corresponds to an electric pressure that exceeds twice the surface tension stress of a sphere of the same size as the meniscus. Preliminary investigations suggest this limit to be universal, therefore, independent of most ionic liquid properties, reservoir pressure, hydraulic impedance or temperature and could explain the experimentally observed bifurcation of a steady ion source into two or more emission sites. Ohmic heating near the emission region increases the liquid temperature, which is found to be important to accurately describe stability boundaries. Temperature increase does not affect the current output when the hydraulic impedance is constant. This phenomenon is thought to be due to an improved interface charge relaxation enhanced by the higher electrical conductivity. Dissipated ohmic energy is mostly conducted to the electrode wall. The higher thermal diffusivity of the wall versus the liquid, allows the ion source to run in steady state without heating.

A multi-scale approach to electrospray ion source modeling has been developed. The evolution of a single-emitter electrospray plume in a pure ionic regime is simulated with a combination of electrohydrodynamic fluids and n-body particle modeling. Simulations are performed for the ionic liquid, EMI-BF4, firing in a positive pure-ion mode. The metastable nature of ion clusters is captured using an ion fragmentation model informed by molecular dynamics simulations and experimental data. Results are generated for three operating points (120, 324, and 440 nA) and are used to predict performance relevant properties, such as the divergence angle and the extractor surface impingement rate. Comparisons to experimental data recorded at similar operating points are provided.

In this era of the “big data revolution,” the desired capabilities of Earth Observing Systems are growing fast: we need ever more frequent data sets, covering a larger part of the frequency spectrum, with lower latency, and higher spatial resolution. To better address these needs, the space systems community has been exploring the value of shifting from highly monolithic architectures, in which large and isolated spacecraft carry multiple instruments with synergistic and complementary goals, toward more distributed architectures, where the functions of these large systems are partitioned into a larger number of smaller satellites. In this paper, we present an agent‐based simulation framework that can help systems engineers assess whether or not it makes sense to be able to “change system modularity during operations” by means of temporary coalitions. Systems of observing autonomous vehicles work together to perform a set of observational tasks. The vehicles can decide to form physical coalitions with other vehicles for collective sensing of a target, when no agent alone can carry out the task, or individual observation results in degraded satisfaction. The framework extends the well‐known decentralized Coupled‐Constraint Consensus‐Based Bundle Algorithm to multivehicle single‐task allocation and introduces constraints on the formation of coalitions, so that agents can create or split a coalition depending on the benefits and costs associated with these actions. The framework is described in detail and demonstrated on a case study.