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Stationary orbits around Mars, which are known as areostationary orbits, have similar characteristics as Earths geostationary orbits. An areostationary Relay Satellite is expected to be used for future communication network for the exploration of Mars. An areostationary Relay Satellite at 17,000 km above Mars surface is always in the same place in the sky on Mars, receiving data from the rovers/landers...
For an optical communications signal, when the noise power dominates, the capacity scales as the square of signal power over noise power. In this regime, data rate scales inversely as the 4th power of range, and the high data rate advantage of optical communications that results from a narrower transmit beam cannot be achieved. Before a received signal can be decoded, it first must be acquired from...
The1 Lunar Hydrogen Mapper (LunaH-Map) will be one of 13 CubeSats to launch on the first integrated flight of NASA's Space Launch System and Orion spacecraft in 2018. The goal of the LunaH-Map mission is to map the hydrogen content of the entire South Pole of the moon, including permanently shadowed regions at high resolution. The spacecraft is a 6 U CubeSat and the main instrument is a neutron spectrometer...
We introduce a trilateration scheme that evaluates the 3-dimensional (3-D) relative position between a reference spacecraft and a target spacecraft using raw-range measurements from a distance baseline of known locations, which we call “anchors”. The anchors can be antennas of a ground-based network (e.g., Deep Space Network (DSN) or Near Earth Network (NEN) stations), or satellites of a space-based...
In [1] and [2], we discussed automatic Repeat-reQuest (ARQ) link analysis and planning in terms of effective data rate, effective throughput, latency, and frame-error-rate (FER), under the standard assumption that the signal-to-noise ratio (SNR) remains the same throughout the ARQ communication session. In [3], we argued that the concept of constant SNR might not be valid when considering events over...
In this paper a communication system for CubeSats in formation that operate in the vicinity of the Moon is proposed. A CDMA system for the fleet of CubeSats in the vicinity of the moon to communicate with the Earth station is considered. This is an extension of our previous proposed CDMA system for a concept Constellation of CubeSats. In this paper the Doppler effects on CDMA communication system...
Current and near-term Mars relay telecommunications services are provided by a set of NASA and ESA Mars science orbiters equipped with UHF relay communication payloads employing operationally simple low-gain antennas. These have been extremely successful in supporting a series of landed Mars mission, greatly increasing data return relative to direct-to-Earth lander links. Yet their relay services...
In the last decade, great progress was made in the development of small satellites and CubeSats. Several small spacecraft were designed, fabricated, launched, and successfully operated in low Earth orbit. While more companies and space agencies are becoming interested in CubeSats and small satellite, also the mission goals for these spacecraft are gradually changing: these small spacecraft are starting...
Radio Science experiments currently rely on unmodulated continuous wave RF signal carrier for spectral purity and maximized signal-to-noise ratio. This requires missions to carefully schedule them away from periods of high rate telemetry. In the era of optical communications, currently designed systems experience the same problem. In this paper, a data processing architecture is derived that will...
In this paper a communication system for CubeSats in formation to operate in the vicinity of the Lunar Lagrangian L1 is proposed. CubeSats will collect lunar scientific data and will perform surface observations. An improved low complexity CDMA system for CubeSats for communications between the Lunar L1 and Earth station is considered. The complexity of a coded CDMA transmitter is lower than the complexity...
In1 the past, great progress has been made in the development of small satellites and CubeSats, mainly for low Earth orbit. Currently, a new technological trend is the development of technologies and strategies for potential interplanetary applications of small platforms (CubeSats/Satellites). Given the limited size, mass and power capabilities of these small platforms, one of the most interesting...
In space communications, standard link analysis assumes that messages are sent once. For a communication link that uses an error-correction coding scheme, bit-error-rate (BER) or frame-error-rate (FER), and link margins are common metrics that characterize the quality of a link, and they are used to determine the supportable data rate. With the advent of Automatic Repeat-reQuest (ARQ) protocols, when...
12Spacecraft are complex systems that involve different subsystems and multiple relationships among them. The design of a spacecraft is an evolutionary process that starts from requirements and evolves across different design phases. During this process, a lot of changes can happen and affect mass and power at component level, at subsystem level, and even at system level. Each spacecraft has to respect...
Interplanetary Cubesats would enable low-cost missions for high-quality scientific and exploration programs. In particular cubeSats in formation have been proposed to operate in the vicinity of the Lunar Lagrangian L1 to collect lunar scientific data and to perform surface observation. In this paper we present a low complexity CDMA system for CubeSats (M small spacecraft) for communications between...
Expert elicitation is increasingly applied to different research areas. Multiple approaches have been implemented, but the development of methods to quantify experts' biases and calibration represents a challenge. As a result, the integration of multiple and often conflicting opinions can be demanding, owing to the complexity of properly weighting experts' contributions. We propose an approach to...
In this paper, we describe a top-down analysis and simulation approach to size the bandwidths of a store-and-forward network for a given network topology, a mission traffic scenario, and a set of data types with different latency requirements. We use these techniques to estimate the wide area network (WAN) bandwidths of the ground links for different architecture options of the proposed Integrated...
The design of a spacecraft is an evolutionary process that starts from requirements and evolves over time across different design phases. During this process, a lot of changes can happen. They can affect mass and power at component level, at subsystem level, and even at system level. Each spacecraft has to meet overall constraints in terms of mass and power: for this reason, it's important to be sure...
Spacecraft is complex systems that involve different subsystems and multiple relationships among them. For these reasons, the design of a spacecraft is an evolutionary process that starts from requirements and evolves over time across different design phases. During this process, a lot of changes can happen. They can affect mass and power at component, subsystem, and system levels. Each spacecraft...
We introduce mixed integer programming and heuristic scheduling for space communication networks in this paper. The considered communication network consists of space and ground assets with the link dynamics between any two assets vary with respect to time, distance, and telecom configurations. One asset could be communicating with another at very high data rates at one time and at other times, communication...
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