Mechanisms and models for industry engagement in collaborative research in commercial fisheries

Data and insights from fishers are essential sources of information to advance understanding of fishery and ecosystem dynamics. Incorporating fisher and industry knowledge holds prospects for improving marine science and fisheries management. We address cooperative research in the context of collaboration between fishers, scientists, industries, universities, and agencies to develop applied research to understand marine ecosystems, inform fishery management, enhance sustainability, govern resource use, and investigate social-economic dynamics. We leverage the insights of more than 100 research scientists, fisheries managers, industry representatives, and fishers to outline actionable recommendations for effective approaches and mechanisms to integrate industry data, perspectives, and insights in fisheries science. We also highlight opportunities and address challenges and limitations to such collaboration

Navigational Challenges for a Europa Flyby Mission

Jupiter's moon Europa is a prime candidate in the search for present-day habitable environments outside of the Earth. A number of missions have provided increasingly detailed images of the complex surface of Europa, including the Galileo mission, which also carried instruments that allowed for a limited investigation of the environment of Europa. A new mission to Europa is needed to pursue these exciting discoveries using close-up observations with modern instrumentation designed to address the habitability of Europa. In all likelihood the most cost effective way of doing this would be with a spacecraft carrying a comprehensive suite of instruments and performing multiple flybys of Europa. A number of notional trajectory designs have been investigated, utilizing gravity assists from other Galilean moons to decrease the period of the orbit and shape it in order to provide a globally distributed coverage of different regions of Europa. Navigation analyses are being performed on these candidate trajectories to assess the total Delta V that would be needed to complete the mission, to study how accurately the flybys could be executed, and to determine which assumptions most significantly affect the performance of the navigation system

Orbit Determination Covariance Analysis for the Europa Clipper Mission

A new Jovian satellite tour is proposed by NASA, which would include numerous flybys of the moon Europa, and would explore its potential habitability by characterizing the existence of any water within and beneath Europa's ice shell. This paper describes the results of a covariance study that was undertaken on a sample tour to assess the navigational challenges and capabilities of such a mission from an orbit determination (OD) point of view, and to help establish a delta V budget for the maneuvers needed to keep the spacecraft on the reference trajectory. Additional parametric variations from the baseline case were also investigated. The success of the Europa Clipper mission will depend on the science measurements that it will enable. Meeting the requirements of the instruments onboard the spacecraft is an integral part of this analysis

GRAIL Orbit Determination for the Science Phase and Extended Mission

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GRAIL Orbit Determination for the Science Phase and Extended Mission

The Gravity Recovery and Interior Laboratory Mission (GRAIL) is the 11th mission of the NASA Discovery Program. Its objective is to help answer funda-mental questions about the Moon's internal structure, thermal evolution, and collisional history. GRAIL employs twin spacecraft, which fly in formation in low altitude polar orbits around the Moon. An improved global lunar gravity field is derived from high-precision range-rate measurements of the distance between the two spacecraft. The purpose of this paper is to describe the strategies used by the GRAIL Orbit Determination Team to overcome challenges posed during on-orbit operations

Gravity Recovery and Interior Laboratory Mission (GRAIL) Orbit Determination

Launched on 10 September 2011 from the Cape Canaveral Air Force Station, Florida, the twin-spacecraft Gravity Recovery and Interior Laboratory (GRAIL) has the primary mission objective of generating a lunar gravity map with an unprecedented resolution via the Ka-band Lunar Gravity Ranging System (LGRS). After successfully executing nearly 30 maneuvers on their six-month journey, Ebb and Flow (aka GRAIL-A and GRAIL-B) established the most stringent planetary formation orbit on 1 March 2012 of approximately 30 km x 90 km in orbit size. This paper describes the orbit determination (OD) filter configurations, analyses, and results during the Trans-Lunar Cruise, Orbit Period Reduction, and Transition to Science Formation phases. The maneuver reconstruction strategies and their performance will also be discussed, as well as the navigation requirements, major dynamic models, and navigation challenges. GRAIL is the first mission to generate a full high-resolution gravity field of the only natural satellite of the Earth. It not only enables scientists to understand the detailed structure of the Moon but also further extends their knowledge of the evolutionary histories of the rocky inner planets. Robust and successful navigation was the key to making this a reality

Navigational Use of Cassini Delta V Telemetry

Telemetry data are used to improve navigation of the Saturn orbiting Cassini spacecraft. Thrust induced delta V's are computed on-board the spacecraft, recorded in telemetry, and downlinked to Earth. This paper discusses how and why the Cassini Navigation team utilizes spacecraft delta V telemetry. Operational changes making this information attractive to the Navigation Team will be briefly discussed, as will spacecraft hardware and software algorithms responsible for the on-board computation. An analysis of past delta V telemetry, providing calibrations and accuracies that can be applied to the estimation of future delta V activity, is described

Flying by Titan

The Cassini spacecraft encounters the massive Titan about once every month. These encounters are essential to the mission as Titan is the only satellite of Saturn that can provide enough gravity assist to shape the orbit tour and allow outstanding science for many years. From a navigation point of view, these encounters provide many challenges, in particular those that fly close enough to the surface for the atmospheric drag to perturb the orbit. This paper discusses the dynamics models developed to successfully navigate Cassini and determine its trajectory. This includes the moon's gravity pull with its second degree zonal harmonics J2, the attitude thrust control perturbations and the acceleration of drag