Jupiter Missions Research Articles

Integrated trajectory optimization for Jupiter missions with single-satellite-aided capture

Integrated trajectory optimization for Jupiter missions with single-satellite-aided capture

Jupiter missions as probes of dark matter

Jupiter, the fascinating largest planet in the solar system, has been visited by nine spacecraft, which have collected a significant amount of data about Jovian properties. In this paper, we show that one type of the in situ measurements on the relativistic electron fluxes could be used to probe dark matter (DM) and dark mediator between the dark sector and our visible world. Jupiter, with its immense weight and cool core, could be an ideal capturer for DM with masses around the GeV scale. The captured DM particles could annihilate into long-lived dark mediators such as dark photons, which subsequently decay into electrons and positrons outside Jupiter. The charged particles, trapped by the Jovian magnetic field, have been measured in Jupiter missions such as the Galileo probe and the Juno orbiter. We use the data available to set upper bounds on the cross section of DM scattering off nucleons, σχn, for dark mediators with lifetime of order mathcal{O} (0.1–1) s. The results show that data from Jupiter missions already probe regions in the parameter space un- or under-explored by existing DM searches, e.g., constrain σχn of order (10−41–10−39) cm2 for 1 GeV DM dominantly annihilating into e+e− through dark mediators. This study serves as an example and an initial step to explore the full physics potential of the large planetary datasets from Jupiter missions. We also outline several other potential directions related to secondary products of electrons, positron signals and solar axions.

Fast computation of the Jovian-moon three-body flyby map based on artificial neural networks

Multiple Jovian moon flybys are common and essential for orbital transfers in Jupiter system exploration missions. To improve the preliminary design accuracy and find low-cost transfer trajectories, the restricted three-body model is used to describe the motion during the flybys. However, the restricted three-body problem has no analytical solution and requires numerical integration for computation, which requires a long computational time for the design of complex Jupiter missions. Therefore, an artificial neural network (ANN)-based model is proposed to improve the computing efficiency. The dynamics of the Jovian-moon flybys are analyzed to facilitate the design of the ANNs. A computational efficient map between the states before and after a flyby is constructed by the ANNs. Numerical simulations verify that the trained ANN-based model can achieve high accuracy and fast computational speed.

Analysis of fusion propulsion system for Earth-to-Mars mission

The high-performance space propulsion system is required for deep space exploration, such as Mars and Jupiter missions. The fusion propulsion system has an extraordinary performance of ultra-high specific impulse, high specific power, and moderate thrust, which can reflect its advantages in future deep space exploration missions. In this study, analysis has been conducted to investigate the technical requirements of the fusion propulsion system for the Earth-to-Mars mission. An analytical model based on Williams’s assumption was adopted and solved by using the MATLAB code. Critical parameters such as specific impulse, specific power, mission time, and payload ratio for Mars rendezvous missions were analyzed. The qualitative and quantitative analysis results show that in order to reach Mars within one month with a payload ratio higher than 10 %, the specific power ranging from 5 to 15 kW/kg and the specific impulse of 10000 s is required. These parameters will take entirely inherent advantage of the fusion propulsion system. Moreover, the fusion propulsion system can operate under the optimal condition, including a wide range of the specific power (1−100 kW/kg) and the specific impulse (10000–200000 s). Based on a comprehensive analysis of the space mission performance, it is possible to provide a significant reference for the development of the fusion space propulsion system.

Optimization Design of Radiation Vault in Jupiter Orbiting Mission

In Jupiter missions, one significant challenge is the harsh environment. The radiation in Jovian orbit is much higher than that in earth bf vicinity in terms of intensity and energy level. In spacecraft (S/C) design, key electronics are packaged in an enclosed vault to help them survive through the mission. The preliminary optimization design methods of a radiation vault based on a genetic algorithm (GA) are introduced, including shield structure optimization and layout pattern of electronics optimization. In shield structure optimization, the method is combined with a total ionizing dose (TID) evaluation tool. The goal is to find the optimal multi-layer shield structure so that the TID, after the shielding, is minimal within the threshold of the total mass of the structure. In a 1-year mission with an orbit of $10\,\,R_{j}\times 25\,\,R_{j} \times 0^{\circ }$ , if the areal density is within 0.5–3 g/cm2, the optimal structure is bilayer or trilayer with high-Z material as an external layer and low-Z material as an internal layer. This structure benefits from the fact that the low-Z material is more effective in shielding energetic protons whereas the high-Z material is more effective in shielding energetic electrons. In the 1-g/cm2 situation, the optimal structure is a 0.829-mm lead layer combined with a 0.158-mm magnesium layer. Comparing with the traditional aluminum shielding structure, about 43.6% of mass can be saved. In layout pattern optimization, this method combines a packing algorithm and a 3-D TID simulation tool. Using this method, an effective design layout of the vault can be found. In this design, all avionics can survive through the mission. In addition, the mass of the vault is low enough that the layout pattern is acceptable in S/C design. As an example, 14 instruments with TID threshold of 50 krad (Si) are packaged in a vault. On the premise that one instrument’s walls are thickened to 3.5-mm aluminum, the total mass of the vault is 68.47 kg. This method is a starting point for the iterative design of the radiation vault and gives principle guidelines for the designers.

ISRO: 104 Satellites in 1 Go

On February 15, 2017, ISRO set a new world record by launching 104 satellites in a single PSLV-C37 mission. There are many records in this mission. The record countdown time of 28 hours, cost of the launch, time taken for ejecting 104 satellites without collision, engineering innovation, flaw less project management are some of them. The case study describes the ISRO’s Journey, track record, vision, PSLV-C37 project, time management, cost management of the project, ISRO Jugaad, and their future plans of manned space missions, Reusable Launch Vehicles (RLV), moon lander, Mars, Venus and Jupiter missions. The case study also highlights ISRO becoming destination for foreign companies for commercial space services at low cost.

Study of a Thermal Annealing Approach for Very High Total Dose Environments

Total dose effect remains one challenging issue for electronics systems intended to space applications. For high total dose missions, like Jupiter missions, or for scientific instruments for which functionality and precision must be guaranteed, dose effect is one of the main drawbacks. So, new solutions must be found in order to ensure the reliability of the mission. In this paper, an analysis of a thermal annealing approach is done. This approach consists of applying isothermal annealing cycles to a device such that its electrical characteristics can be regenerated after being degraded by total ionizing dose. The analysis is based on experimental results obtained on Power MOSFET and CMOS APS imager. The impact of electric field during annealing is also investigated. It is shown that thermal annealing can be applied to electronic devices in order to extend their lifetime.

Laplace-resonant triple-cyclers for missions to Jupiter

Cyclers are space trajectories that repeatedly encounter the same set of bodies indefinitely. Typically, cyclers are designed to encounter two bodies periodically, with only an occasional encounter with a third body. Because of the dynamics of the Laplace resonance in the Jupiter system, cycler trajectories that periodically return to three bodies are possible for Jupiter missions. Several cycler trajectories are proposed for purposes such as reducing mission length and increasing the number of flybys in a Jupiter system tour.