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Reducing injuries to youth players is of primary importance to academies, as injuries can result in a significant loss in both training and match time, as well as negatively affecting player development. In total, 76 talented young football players were analysed over two full competitive seasons. The injury incidence and burden for all non-contact and overuse injuries were recorded. Exposure was calculated as the total number of competitive matches hours played. Somatic maturation was estimated by expressing the current height of each player as a percentage of their predicted adult height (Roche, Tyleshevski, & Rogers, 1983). The period of circa-peak height velocity (PHV) (24.5 injuries per 1000 h) was associated with a significantly higher injury incidence rate and burden compared to pre-PHV (11.5 injuries per 1000 h; RR:2.15, 95%CI:1.37-3.38, P

NASA’s planned Europa Clipper mission seeks to assess the habitability of Jupiter’s moon Europa, which exhibits strong evidence of an ocean of liquid water underneath its icy crust. The sheer number of unique instruments, all of which require quiescent environments in order to operate, compounded with Jupiter’s distance from the Sun and Earth, makes this planned mission challenging and resource-constrained. High-fidelity, mission-level simulations that model the spacecraft, ground, and environment from launch to end of mission with a given trajectory and mission plan have been employed early in the project life cycle to better understand the interactions between various components of the mission and how design changes impact the entire system. These simulations have already resulted in tangible benefits to the project by providing vital input to key spacecraft trades, assessing impacts to operability, and quantifying how well the scientific objectives of the mission can be achieved. Improvements to simulation performance and to the process by which information defining the system is gathered and built into models used by simulations have the potential to further expand the scope of their use on Europa Clipper and future missions.

This paper presents the feasibility study of the REMORA CubeSat mission concept with an integrated miniature robotic payload to prevent large debris collisions. While orbital debris poses a threat to spacecraft, a collision between the largest space debris objects is of significant concern. The DARPA Catcher's Mitt study compiled a list of the highest priority large debris objects. By annually removing 5–10 of these high priority objects, it may be possible to stabilize the medium sized debris population. Instead of deorbiting objects, REMORA would use COTS CubeSat components and secondary payload launches as a cost-effective solution for mitigating large debris collisions. The REMORA CubeSat could rendezvous with a piece of debris and use the robotic manipulator to anchor itself to the target object. Once anchored, the CubeSat could track the debris and, if needed, alter the debris object's trajectory to prevent a collision. Aspects discussed include the mission and robotic payload baseline designs. Many of the highest priority objects identified in the DARPA Catcher's Mitt study are located in the 71°-75° inclination range and in sun-synchronous orbit. An initial mission design concept targets sun-synchronous objects due to the large number of launch opportunities to this orbit. The mission was simulated with a combination of MATLAB, GMAT, and STK. A CubeSat robotic payload was designed to provide a decreased chance of collision between the CubeSat and debris object during attachment, augment the ACS during approach, and provide the ability to orient the thrust vector through the center of mass while pushing. This robotic payload includes a computing element, cameras, miniature robotic arm, and end-effector. An initial miniature arm prototype was designed and built to demonstrate feasibility and inform future designs. An end-effector trade study was performed to explore different end-effectors that could be used to for attaching to the common graspable features on large debris objects. Grasping methods, including mechanical prehension, gecko grippers, electrostatic grippers, and magnetic grippers, were investigated.

Existing characterization of Europa's environment is enabled by the Europa Clipper mission's successful predecessors: Pioneer, Voyager, Galileo, and most recently, Juno. These missions reveal high intensity energetic particle fluxes at Europa's orbit, requiring a multidimensional design challenge to ensure mission success (i.e. meeting L1 science requirements). Risk averse JPL Design Principles and the Europa Environment Requirement Document (ERD) dictate practices and policy, which if masterfully followed, are designed to protect Clipper from failure or degradation due to radiation. However, even if workmanship is flawless and no waivers are assessed, modeling errors, shielding uncertainty, and natural variation in the Europa environment are cause for residual concern. While failure and part degradation are of paramount concern, the occurrence of temporary outages, causing loss or degradation of science observations, is also a critical mission risk, left largely unmanaged by documents like the ERD. The referenced risk is monitored and assessed through a Project Systems Engineeringled mission robustness effort, which attempts balance the risk of science data loss with potential design cost and increased mission complexity required to mitigate such risk. The Science Sensitivity Model (SSM) was developed to assess mission/science robustness, with its primary goal being to ensure a high probability of achieving Level 1 (L1) science objectives. The understanding of L1 science objective achievement is folded back into the spacecraft, instrument, and mission system design requirements in an iterative fashion. The Science Sensitivity Model development is a cross-Project multidisciplinary effort leveraging, and literally linking, several novel Project products: Mission Science Traceability and Alignment Framework (M-STAF): framework for writing Level 2 (L2) science measurement requirements in an organized and cohesive manner such that a science requirement set is complete and consistent across the instruments [1]. Fault/Reliability Analysis: assesses the probability a recoverable failure occurs on the spacecraft or instrument and the time it takes for the Europa Clipper system to recover. Verification of Europa Requirements Integrating Tour and Science (VERITaS): model for assessing attainment of L2 science measurement requirements (as specified in M-STAF) for a given trajectory [2]. This tool is used to triage candidate Europa tours and to understand requirement sensitivity if the face of expected outages. Project Science Traceability and Alignment Framework (P-STAF): framework that builds upon the idea of the Science Traceability Matrix (STM) to link L2 science measurement requirements to L1 science measurement requirements, enabling the understanding of instrument dependencies and robustness [3]. This paper will tie these topics together and show how they interconnect to ensure Europa's science objectives are attained in the face of a challenge few deep space missions have encountered.

Taubes contrasts two obesity hypotheses—excess energy intake versus a “hormonal disorder.”1 It becomes clear, however, that the second theory is not about a disorder, but about excess consumption of carbohydrates causing obesity, with insulin implicated as the mechanism. A disorder normally means pathology of a particular system, or “a derangement or abnormality of function; a morbid …