LUNAR TRAJECTORIES

During the last 50 years, the Moon has developed a dual role in human thought. As the Apollo explorations and other relevant missions have shown, the Moon is a scientifically important body. It preserves a unique history of planetary formation and early development, and also serves as a probe that has recorded the space environment and cosmic radiation for billions of years. Because of its closeness to Earth, the Moon is also an obvious target for long-term human exploration beyond Earth. Knowledge of the Moon’s characteristics, especially its potential usefulness and resources, has become critical for planning the human future in space. Although the computation of precision lunar trajectories can only be done by numerical integration of the equations of motion due to the great number of external factors that may affect the trajectory, the present work can easily be applied to gain some insight into the great complexity of the orbital mechanics of a lunar mission

Simulation of the Landing Buffer of a Three-Legged Jumping Robot

In recent years, the research of planetary exploration robots has become an active field. The jumping robot has become a hot spot in this field. This paper presents a work modelling and simulating a three-legged jumping robot, which has a powerful force, high leaping performance, and good flexibility. In particular, the jumping of the robot was simulated and the landing buffer of the robot was analyzed. Because this jumping robot lacks landing buffer, this paper verifies a method of absorbing landing kinetic energy to improve landing stability and storing it as the energy for the next jump in the simulation. Through the landing simulation, the factors affecting the landing energy absorption are identified. Moreover, the simulation experiment verifies that the application of the intermediate axis theorem helps to absorb more energy and adjust the landing attitude of the robot. The simulation results in this paper can be applied to the optimal design of robot prototypes and provide a theoretical basis for subsequent research

Technology Challenges of SURROUND: A Constellation of Small Satellites Around the Sun for Tracking Solar Radio Bursts

The SURROUND mission proposes the operational monitoring and forecasting of space weather events using a constellation of five small satellites in orbit around the Sun. This unique mission concept would enable the localisation and tracking of solar events with unprecedented accuracy. The small payload combined with high launch requirements makes this an ideal candidate mission for a distributed constellation of small spacecraft and provides an opportunity for technical development in the areas of deep space communication, propulsion, and survivability. The baseline configuration for SURROUND proposes the deployment of spacecraft to Earth-Sun Lagrange points L1, L4, and L5, and two additional spacecraft in Earth leading (\u3c 1AU) and trailing (\u3e 1AU) orbits. However, the development and realisation of such a constellation in deep space presents a number of challenges, particularly when the use of small spacecraft is considered. This paper presents the conceptual design for the proposed SURROUND constellation, principally focusing on the key technical challenges of deploying the spacecraft into their desired locations around the Sun and subsequently communicating the collected data back to Earth. In addition to the key propulsion system and communications architecture trades, additional technological challenges of the mission are also considered, including attitude control, radiation hardening, and electromagnetic compatibility

Solar activity simulation and forecast with a flux-transport dynamo

We present the assessment of a diffusion-dominated mean field axisymmetric dynamo model in reproducing historical solar activity and forecast for solar cycle 25. Previous studies point to the Sun's polar magnetic field as an important proxy for solar activity prediction. Extended research using this proxy has been impeded by reduced observational data record only available from 1976. However, there is a recognised need for a solar dynamo model with ample verification over various activity scenarios to improve theoretical standards. The present study aims to explore the use of helioseismology data and reconstructed solar polar magnetic field, to foster the development of robust solar activity forecasts. The research is based on observationally inferred differential rotation morphology, as well as observed and reconstructed polar field using artificial neural network methods via the hemispheric sunspot areas record. Results show consistent reproduction of historical solar activity trends with enhanced results by introducing a precursor rise time coefficient. A weak solar cycle 25, with slow rise time and maximum activity $-14.4 \%$ ($\pm 19.5\%$) with respect to the current cycle 24 is predicted.Comment: 13 pages, 15 figures. Accepted by MNRAS 18 June 201

CLOVER Robot: A Minimally Actuated Jumping Robotic Platform

Robots have been critical instruments to space exploration by providing access to environments beyond human limitations. Jumping robot concepts are attractive solutions to negotiate complex terrain. However, among the engineering challenges to overcome to enable jumping robot concepts for sustained operation, reduction of mechanical failure modes is one of the most fundamental. This study set out to develop a jumping robot with focus on minimal actuation for reduced mechanism maintenance. We present the synthesis of a Sarrus-style linkage to constraint the system to a single translational degree of freedom without the use of typical synchronising gears. We delimit the present research to vertical solid jumps to assess the performance of the fundamental main-drive linkage. A laboratory demonstrator assists the transfer of theoretical concepts and approaches. The laboratory demonstrator performs jumps with 63% potential-to-kinetic energy conversion efficiency, with a theoretical maximum of 73%. Satisfactory operation opens up design optimisation and directional jump capability towards the development of a jumping robotic platform for space exploration