scholarly journals Spectral Correlation for Signal Presence Detection and Frequency Acquisition of Small Satellites

Aerospace ◽  
2021 ◽  
Vol 8 (2) ◽  
pp. 57
Author(s):  
Jonas Hofmann ◽  
Andreas Knopp ◽  
Chad M. Spooner ◽  
Giovanni Minelli ◽  
James Newman

Challenges in interference-limited satellite detection arising from the low-earth orbit (LEO) and the Industrial, Scientific and Medical (ISM) frequency bands are addressed. In particular, a novel signal presence detector based on cyclostationary signal properties is proposed and analyzed for a low signal-to-noise-plus-interference ratio (SINR) regime. The performance of the proposed detector, which is applicable to various small-satellite scenarios, is evaluated on both simulated and real-world measurement data. This measurement data has been collected from the scientific satellite mission “Picosats Realizing Orbital Propagation Calibrations using Beacon Emitters” (PROPCUBE).

2021 ◽  
Author(s):  
Sukhmander Singh ◽  
Sanjeev Kumar ◽  
Shravan Kumar Meena ◽  
Sujit Kumar Saini

Technically, there are two types of propulsion systems namely chemical and electric depending on the sources of the fuel. Electrostatic thrusters are used for launching small satellites in low earth orbit which are capable to provide thrust for long time intervals. These thrusters consume less fuel compared to chemical propulsion systems. Therefore for the cost reduction interests, space scientists are interested to develop thrusters based on electric propulsion technology. This chapter is intended to serve as a general overview of the technology of electric propulsion (EP) and its applications. Plasma based electric propulsion technology used for space missions with regard to the spacecraft station keeping, rephrasing and orbit topping applications. Typical thrusters have a lifespan of 10,000 h and produce thrust of 0.1–1 N. These devices have E→×B→ configurations which is used to confine electrons, increasing the electron residence time and allowing more ionization in the channel. Almost 2500 satellites have been launched into orbit till 2020. For example, the ESA SMART-1 mission (Small Mission for Advanced Research in Technology) used a Hall thruster to escape Earth orbit and reach the moon with a small satellite that weighed 367 kg. These satellites carrying small Hall thrusters for orbital corrections in space as thrust is needed to compensate for various ambient forces including atmospheric drag and radiation pressure. The chapter outlines the electric propulsion thruster systems and technologies and their shortcomings. Moreover, the current status of potential research to improve the electric propulsion systems for small satellite has been discussed.


Aerospace ◽  
2020 ◽  
Vol 7 (6) ◽  
pp. 67 ◽  
Author(s):  
George-Cristian Potrivitu ◽  
Yufei Sun ◽  
Muhammad Wisnuh Aggriawan bin Rohaizat ◽  
Oleksii Cherkun ◽  
Luxiang Xu ◽  
...  

The age of space electric propulsion arrived and found the space exploration endeavors at a paradigm shift in the context of new space. Mega-constellations of small satellites on low-Earth orbit (LEO) are proposed by many emerging commercial actors. Naturally, the boom in the small satellite market drives the necessity of propulsion systems that are both power and fuel efficient and accommodate small form-factors. Most of the existing electric propulsion technologies have reached the maturity level and can be the prime choices to enable mission versatility for small satellite platforms in Earth orbit and beyond. At the Plasma Sources and Applications Centre/Space Propulsion Centre (PSAC/SPC) Singapore, a continuous effort was dedicated to the development of low-power electric propulsion systems that can meet the small satellites market requirements. This review presents the recent progress in the field of electric propulsion at PSAC/SPC Singapore, from Hall thrusters and thermionic cathodes research to more ambitious devices such as the rotamak-like plasma thruster. On top of that, a review of the existing vacuum facilities and plasma diagnostics used for electric propulsion testing and characterization is included in the present research.


Aerospace ◽  
2019 ◽  
Vol 6 (10) ◽  
pp. 108 ◽  
Author(s):  
Isai Fajardo ◽  
Aleksander Lidtke ◽  
Sidi Bendoukha ◽  
Jesus Gonzalez-Llorente ◽  
Rafael Rodríguez ◽  
...  

Ten-Koh is a 23.5 kg, low-cost satellite developed to conduct space environment effects research in low-Earth orbit (LEO). Ten-Koh was developed primarily by students of the Kyushu Institute of Technology (Kyutech) and launched on 29 October 2018 on-board HII-A rocket F40, as a piggyback payload of JAXA’s Greenhouse gas Observing Satellite (GOSAT-2). The satellite carries a double Langmuir probe, CMOS-based particle detectors and a Liulin spectrometer as main payloads. This paper reviews the design of the mission, specifies the exact hardware used, and outlines the implementation and operation phases of the project. This work is intended as a reference that other aspiring satellite developers may use to increase their chances of success. Such a reference is expected to be particularly useful to other university teams, which will likely face the same challenges as the Ten-Koh team at Kyutech. Various on-orbit failures of the satellite are also discussed here in order to help avoid them in future small spacecraft. Applicability of small satellites to conduct space-weather research is also illustrated on the Ten-Koh example, which carried out simultaneous measurements with JAXA’s ARASE satellite.


2012 ◽  
Vol 2012 ◽  
pp. 1-9
Author(s):  
Francisco Miranda

In the last years the small satellites have played an important role in the technological development. The attractive short period of design and low cost of them and the capacity to solve problems that are usually considered as problems to big and expensive spacecrafts lead us to study the control problem of these satellites. Active three-axis magnetic attitude stabilization of a low Earth orbit satellite is considered in this work. The control is created by interaction between the magnetic moment generated by magnetorquers mounted on the satellite body and the geomagnetic field. This problem is quite complex and difficult to solve. To overcome this difficulty guidance control is considered, where we use ε-strategies introduced by Pontryagin in the frame of differential games theory. Qualitative analysis and results of numerical simulation are presented.


Aerospace ◽  
2020 ◽  
Vol 7 (4) ◽  
pp. 35 ◽  
Author(s):  
Farhan Abdullah ◽  
Kei-ichi Okuyama ◽  
Isai Fajardo ◽  
Naoya Urakami

The low Earth orbit (LEO) environment exposes spacecraft to factors that can degrade the dimensional stability of the structure. Carbon Fibre/Polyether Ether Ketone (CF/PEEK) can limit such degradations. However, there are limited in-orbit data on the performance of CF/PEEK. Usage of small satellite as material science research platform can address such limitations. This paper discusses the design of a material science experiment termed material mission (MM) onboard Ten-Koh satellite, which allows in situ measurements of coefficient of thermal expansion (CTE) for CF/PEEK samples in LEO. Results from ground tests before launch demonstrated the feasibility of the MM design. Analysis of in-orbit data indicated that the CTE values exhibit a non-linear temperature dependence, and there was no shift in CTE values after four months. The acquired in-orbit data was consistent with previous ground tests and in-orbit data. The MM experiment provides data to verify the ground test of CF/PEEK performance in LEO. MM also proved the potential of small satellite as a platform for conducting meaningful material science experiments.


Aviation ◽  
2021 ◽  
Vol 25 (2) ◽  
pp. 73-78
Author(s):  
Aleksandrs Urbahs ◽  
Sergey Kravchenko ◽  
Margarita Urbaha ◽  
Kristine Carjova ◽  
Natalja Panova ◽  
...  

The paper presents the air-launch system enabling the delivery of small satellites into low Earth orbit. One of the most important advantages of the concept is its cost. Generally, the paper proves that launching a carrier from an aerial platform (a movable launch pad) provides the whole range of competitive advantages. In particular, the total losses during the launch from an aerial platform will reduce by 20–35%, and the characteristic velocity of the maneuver will reduce by 4–7%.


2014 ◽  
Vol 23 (10) ◽  
pp. 1450148 ◽  
Author(s):  
DANIELE DAVALLE ◽  
RICCARDO CASSETTARI ◽  
SERGIO SAPONARA ◽  
LUCA FANUCCI ◽  
LUCA CUCCHI ◽  
...  

This paper presents a flexible Telemetry, Tracking & Command (TT&C) transponder for Earth Observation (EO) small satellites. The proposed device adds to the state-of-the-art EO TT&C transponders the possibility of scientific data transfer thanks to the high downlink data-rate (up to 40 Mbps) and in-flight reconfigurability via Telecomand (TC). The integration of these features in one single device represents a considerable optimization in terms of mass budget, which is important for EO small satellites. Furthermore, in-flight reconfigurability of communication parameters via TC is important for in-orbit link optimization, which is especially useful for Low-Earth Orbit (LEO) satellites where visibility can be as short as few hundreds of seconds. The proposed transponder is a digital radio unit working at 70 MHz intermediate frequency (IF). A new custom and configurable hardware accelerator was developed to cover intensive radio DSP functions at IF. The custom hardware is integrated in a single FPGA with a space-compliant processor core, for control, configuration and interface with the other satellite subsystems. All the quantization parameters were fine-tailored to reach a trade-off between hardware complexity and implementation loss (IL). The IF RX/TX ports require eight bits and seven bits, respectively. The IL is 0.5 dB at BER = 10-5 for the RX chain. A system proof-of-concept was implemented on the Xilinx Virtex 6 VLX75T-FF484 FPGA. The total device occupation is 82%. The power consumption of the design fitted in FPGA is less than 2 W. The power consumption of the whole demonstrator board is less than 9 W.


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