Publications related to Geosynchronous orbit

Swirling against the forcing: Evidence of stable counterdirected sloshing waves in orbital-shaken reservoirs

François Gallaire, Alessandro Bongarzone, Alice Evelyne Julienne Marcotte

We investigate the response of the free liquid surface in a partially filled circular cylindrical container undergoing a planar elliptic and time-periodic orbit while maintaining fixed its orientation. For small forcing amplitudes and deep liquid layers, w ...

Amer Physical Soc2023

Microstrip patch antennas with broad beamwidth

Ismael Vico Triviño

Microstrip antennas offer a broad set of advantages such as low profile, light weight, easy fabrication and low cost. As these are desirable or even critical for a broad range of applications, there has been a large interest for these antennas in the anten ...

EPFL2023

The eta Aquilae System: Radial Velocities and Astrometry in Search of eta Aql B

Richard Irving Anderson

The classical Cepheid eta Aql was not included in past Leavitt Law work because of a presumed complicating orbit due to a known B9.8V companion. To determine the orbit of eta Aql B, we analyze a significant number of radial velocity (RV) measurements from ...

2022

Biomechanics at the workplace under hypogravity conditions

Tatiana Maillard

The main goal of my research is to establish guidelines for workplace design based on human biomechanics: specifically sitting workplaces and handling areas in 1/6G-1/3G (Moon, Mars) conditions. Such a workplace could be used in long-term space missions in ...

EPFL2022

Design of an intake and a thruster for an atmosphere-breathing electric propulsion system

Francesco Romano, Thomas Binderup Jensen

Challenging space missions include those at very low altitudes, where the atmosphere is the source of aerodynamic drag on the spacecraft, that finally defines the mission's lifetime, unless a way to compensate for it is provided. This environment is named ...

2022

Search for relativistic fractionally charged particles in space

Jennifer Maria Frieden, Chiara Perrina, Jian Wang, Zhirui Xu, Yi Zhang, Siyuan Wang, Songmei Wu, Junqiu Liu, Johan Juul Chang, Jie Chen, Cheng Zhao, Wei Li, Yong Yang, Yi Wang, Hao Liu, Xiao Wang, Shuai Liu, Wenyu Zhang, Xuan Li, Yao Zhang, Ming Gao, Arshia Ruina, Andrii Kotenko

More than a century after the performance of the oil drop experiment, the possible existence of fractionally charged particles (FCPs) still remains unsettled. The search for FCPs is crucial for some extensions of the Standard Model in particle physics. Mos ...

American Physical Society2022

Intensifying space activity calls for increased scrutiny of risks

Romain Buchs

As the pace of space activities accelerates and societies become more reliant on space-based systems, the associated risks deserve more attention. Satellites form a critical infrastructure on which military, civil and commercial entities rely. The services ...

EPFL International Risk Governance Center2021

Exploring the origin of low-metallicity stars in Milky-Way-like galaxies with the NIHAO-UHD simulations

Pascale Jablonka

The kinematics of the most metal-poor stars provide a window into the early formation and accretion history of the Milky Way (MW). Here, we use five high-resolution cosmological zoom-in simulations (similar to 5 x 10(6) star particles) of MW-like galaxies ...

OXFORD UNIV PRESS2021

X-ray pulsar-based GNC system for formation flying in high Earth orbits

Volker Gass, Camille Sébastien Pirat

In this paper, comprehensive pulsar-based Guidance, Navigation and Control (GNC) system is designed and applied to satellites formation flying. The complete autonomy of the X-ray pulsar navigation technology provides both absolute and relative positioning ...

PERGAMON-ELSEVIER SCIENCE LTD2020

Sun-synchronous repeat ground tracks and other useful orbits for future space missions

Sun Hee Kim, Luzius Gregor Kronig

The development of oceanography and meteorology has greatly benefited from satellite-based data of Earth's atmosphere and ocean. Traditional Earth observation missions have utilised Sun-synchronous orbits with repeat ground tracks due to their advantages i ...

2020

Antennas for CubeSat Communication

Miroslav Veljovic

CubeSats are a type of small satellites (< 500 kg) that weigh several kilograms and consist of multiple Units (U) measuring 100 × 100 × 113.5 mm3. CubeSats emerged as a low-cost alternative to conventional large satellites, and have since demonstrated capa ...

EPFL2020

The BUFFALO HST Survey

Jean-Paul Richard Kneib, Pascale Jablonka, David Richard Harvey, Benjamin Yvan Alexandre Clement, Mathilde Jauzac, Huanyuan Shan, Hakim Atek, Anja Von der Linden, Matthieu Schaller, Céline Tchernin, Richard Massey, Johan Richard

The Beyond Ultra-deep Frontier Fields and Legacy Observations (BUFFALO) is a 101 orbit + 101 parallel Cycle 25 Hubble Space Telescope (HST) Treasury program taking data from 2018 to 2020. BUFFALO will expand existing coverage of the Hubble Frontier Fields ...

IOP PUBLISHING LTD2020

Guidance, Navigation and Control for Autonomous Cooperative Docking of CubeSats

Volker Gass, Camille Sébastien Pirat, Pierre-Alain Mäusli

Is it possible to dock CubeSats in Low Earth Orbit? The challenges are mainly associated with the level of miniaturisation. A docking mechanism was designed, built and tested in the laboratory. Results show that a relative precision better than 1 cm and 2 ...

2018

Periodic cellular aluminum structures for space applications : from casting to additive manufacturing

Florian Thibaut Gallien

Mass is one of the crucial parameters for hardware that has to be placed in Earth orbit. Due to its harsh environment, a material with highest specific properties is desired to achieve space missions. The rise and development of new technologies, such as a ...

EPFL2018

Guidance, Navigation and Control for Autonomous Rendezvous and Docking of Nano-Satellites

Camille Sébastien Pirat

Is it possible to dock CubeSats in Low Earth Orbit? Challenges are associated with the level of miniaturisation: the docking accuracy is driven by the docking mechanism dimensions. The achievable docking performance with the Guidance, Navigation and Contro ...

EPFL2018

Hybrid Golay-coded Brillouin optical time-domain analysis based on differential pulses

Luc Thévenaz, Marcelo Alfonso Soto Hernandez, Zhisheng Yang, Zonglei Li

Different approaches to implement unipolar Golay coding in Brillouin optical time-domain analysis based on a differential pulse pair (DPP) are investigated. The analysis points out that dedicated post-processing procedures must be followed to secure the sh ...

2018

High accuracy GNSS based navigation in GEO

Pierre-André Farine, Cyril Botteron, Vincenzo Capuano, Paul David Blunt, Endrit Shehaj

Although significant improvements in efficiency and performance of communication satellites have been achieved in the past decades, it is expected that the demand for new platforms in Geostationary Orbit (GEO) and for the On-Orbit Servicing (OOS) on the ex ...

Elsevier2017

An adaptive GNSS-based reduced dynamic approach for real time autonomous navigation from the Earth to the Moon

Pierre-André Farine, Cyril Botteron, Vincenzo Capuano, Paul David Blunt, Endrit Shehaj

In this research study we describe our last effort in further improving the achievable Global Navigation Satellite System (GNSS) based navigation performance in an Earth-Moon Transfer Orbit (MTO). The GNSS-based orbital filter we implemented previously wit ...

2017

GNSS/INS/Star Tracker Integration for Real-Time On-Board Autonomous Orbit and Attitude Determination in LEO, MEO, GEO and Beyond

Pierre-André Farine, Cyril Botteron, Vincenzo Capuano, Paul David Blunt, Endrit Shehaj

In our previous studies, we demonstrated that Global Navigation Satellite System (GNSS) signals can be processed, not only in Low Earth Orbit (LEO), but also in higher earth orbits, up to the Moon. In order to maximize the GNSSbased navigation performance, ...

2017

Availability and ranging error analysis for a GPS L1/L5 receiver navigating to the Moon

Pierre-André Farine, Cyril Botteron, Vincenzo Capuano, Paul David Blunt, Endrit Shehaj, Ban Wang

Global Navigation Satellite System (GNSS) based navigation is already adopted in Low Earth Orbit (LEO), where the presence of strong GNSS signals and the good relative geometry between the receiver and the transmitters enable precise orbit determination. H ...

Ieee2017