Energy-Optimal Path Planning for Solar-Powered Aircraft in Level Flight

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/76295/1/AIAA-2007-6655-400.pd

Thin Fisher Zeroes

Biskup et al. [Phys. Rev. Lett. 84 (2000) 4794] have recently suggested that the loci of partition function zeroes can profitably be regarded as phase boundaries in the complex temperature or field planes. We obtain the Fisher zeroes for Ising and Potts models on non-planar (``thin'') regular random graphs using this approach, and note that the locus of Fisher zeroes on a Bethe lattice is identical to the corresponding random graph. Since the number of states appears as a parameter in the Potts solution the limiting locus of chromatic zeroes is also accessible.Comment: 10 pages, 4 figure

Positive-Buoyancy Rover for Under Ice Mobility

A buoyant rover has been developed to traverse the underside of ice-covered lakes and seas. The rover operates at the ice/water interface and permits direct observation and measurement of processes affecting freeze- over and thaw events in lake and marine environments. Operating along the 2- D ice-water interface simplifies many aspects of underwater exploration, especially when compared to submersibles, which have difficulty in station-keeping and precision mobility. The buoyant rover consists of an all aluminum body with two aluminum sawtooth wheels. The two independent body segments are sandwiched between four actuators that permit isolation of wheel movement from movement of the central tether spool. For normal operations, the wheels move while the tether spool feeds out line and the cameras on each segment maintain a user-controlled fixed position. Typically one camera targets the ice/water interface and one camera looks down to the lake floor to identify seep sources. Each wheel can be operated independently for precision turning and adjustments. The rover is controlled by a touch- tablet interface and wireless goggles enable real-time viewing of video streamed from the rover cameras. The buoyant rover was successfully deployed and tested during an October 2012 field campaign to investigate methane trapped in ice in lakes along the North Slope of Alaska

INSPIRE: Interplanetary NanoSpacecraft Pathfinder in Relevant Environment

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/106507/1/AIAA2013-5323.pd

MarCO: Early Operations of the First CubeSats to Mars

The MarCO (Mars Cube One) spacecraft launched with the InSight mission from Vandenburg Airforce Base on May 5, 2018. These spacecraft, the first interplanetary CubeSats, serve as technology demonstrators, supporting the InSight Mars lander. During InSight’s entry, descent, and landing sequence, the MarCO spacecraft will flyby Mars, collecting transmitted data from the lander, and relaying it back to the Deep Space Network (DSN) on Earth. This serves as a demonstrator for the “carry-your-own-relay” concept that might be utilized on more challenging future missions Prior to InSight support, the mission will also demonstrate the capability for a CubeSat sized, DSN compatible deep space transponder, to independently navigate from the Earth to Mars with a small spacecraft, and flight testing for numerous commercial products. In this paper, we present a status update of the mission, an overview of early operations, and an outline for the remainder of the mission to Mars. A broad description of the planetary protection approach that MarCO utilized is provided, as well as detail of the first trajectory correction maneuver

A Fractionated Space Weather Base at L_5 using CubeSats and Solar Sails

The Sun–Earth L_5 Lagrange point is an ideal location for an operational space weather forecasting mission to provide early warning of Earth-directed solar storms (coronal mass ejections, shocks and associated solar energetic particles). Such storms can cause damage to power grids, spacecraft, communications systems and astronauts, but these effects can be mitigated if early warning is received. Space weather missions at L5 have been proposed using conventional spacecraft and chemical propulsion at costs of hundreds of millions of dollars. Here we describe a mission concept that could accomplish many of the goals at a much lower cost by dividing the payload among a cluster of interplanetary CubeSats that reach orbits around L5 using solar sails

Design and Implementation of the GPS Subsystem for the Radio Aurora Explorer

Abstract This paper presents the design and implementation of the Global Positioning System (GPS) subsystem for the Radio Aurora eXplorer (RAX) CubeSat. The GPS subsystem provides accurate temporal and spatial information necessary to satisfy the science objectives of the RAX mission. There are many challenges in the successful design and implementation of a GPS subsystem for a CubeSat-based mission, including power, size, mass, and financial constraints. This paper presents an approach for selecting and testing the individual and integrated GPS subsystem components, including the receiver, antenna, low noise amplifier, and supporting circuitry. The procedures to numerically evaluate the GPS link budget and test the subsystem components at various stages of system integration are described. Performance results for simulated tests in the terrestrial and orbital environments are provided, including start-up times, carrier-to-noise ratios, and orbital position accuracy. Preliminary on-orbit GPS results from the RAX-1 and RAX-2 spacecraft are presented to validate the design process and pre-flight simulations. Overall, this paper provides a systematic approach to aid future satellite designers in implementing and verifying GPS subsystems for resourceconstrained small satellites

Solar-Powered Aircraft: Energy-Optimal Path Planning and Perpetual Endurance

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/76439/1/AIAA-40139-801.pd

Interplanetary CubeSats: Opening the Solar System to a Broad Community at Lower Cost

Interplanetary CubeSats could enable small, low-cost missions beyond low Earth orbit. This class is defined by mass < ~ 10 kg, cost < $30 M, and durations up to 5 years. Over the coming decade, a stretch of each of six distinct technology areas, creating one overarching architecture, could enable comparatively low-cost Solar System exploration missions with capabilities far beyond those demonstrated in small satellites to date. The six technology areas are: (1) CubeSat electronics and subsystems extended to operate in the interplanetary environment, especially radiation and duration of operation; (2) Optical telecommunications to enable very small, low-power uplink/downlink over interplanetary distances; (3) Solar sail propulsion to enable high !V maneuvering using no propellant; (4) Navigation of the Interplanetary Superhighway to enable multiple destinations over reasonable mission durations using achievable !V; (5) Small, highly capable instrumentation enabling acquisition of high-quality scientific and exploration information; and (6) Onboard storage and processing of raw instrument data and navigation information to enable maximum utility of uplink and downlink telecom capacity, and minimal operations staffing. The NASA Innovative Advanced Concepts (NIAC) program in 2011 selected Interplanetary CubeSats for further investigation, some results of which are reported here for Phase 1

RV Kronprins Håkon (cruise no. 2019708) Longyearbyen – Longyearbyen 19.09. – 16.10.2019

The HACON cruise is a major component of the FRINATEK HACON project, which aims at investigating the role of the Gakkel Ridge and Arctic Ocean in biological connectivity amongst ocean basins and global biogeography of chemosynthetic ecosystems. The HACON study area is centered in the Aurora seamount and Aurora vent field