Design and performance of the flash satellite “Ladybeetle-1”

Author(s):  
Xia Mu ◽  
Sihai Li ◽  
Zhenxing Zhang ◽  
Bin Xi ◽  
Mingguo Xiao

The first satellite which can flash Morse code on orbit is introduced in this paper. The design of the system includes light energy estimation, attitude mode design, elevation angle analysis and flash time design. It is a 100 kg satellite with two LED arrays on 547 km. When it flashes, the satellite points to the observation location. The LED rays flash as the rule of Morse code. The satellite was sent to the orbit in Dec 2018 and the test of flash was completed within one month after then. The photo taken by star sensor can compare the apparent magnitude by the gray level. The results of the analysis show that the satellite can achieve 0 apparent magnitude, which is consistent with the design of the system. As a meaningful scientific experiment, “Ladybeetle-1” links space technology with popular science education and also provides a reference for space applications.

2013 ◽  
Vol 117 (1197) ◽  
pp. 1075-1101 ◽  
Author(s):  
S. M. Parkes ◽  
I. Martin ◽  
M. N. Dunstan ◽  
N. Rowell ◽  
O. Dubois-Matra ◽  
...  

Abstract The use of machine vision to guide robotic spacecraft is being considered for a wide range of missions, such as planetary approach and landing, asteroid and small body sampling operations and in-orbit rendezvous and docking. Numerical simulation plays an essential role in the development and testing of such systems, which in the context of vision-guidance means that realistic sequences of navigation images are required, together with knowledge of the ground-truth camera motion. Computer generated imagery (CGI) offers a variety of benefits over real images, such as availability, cost, flexibility and knowledge of the ground truth camera motion to high precision. However, standard CGI methods developed for terrestrial applications lack the realism, fidelity and performance required for engineering simulations. In this paper, we present the results of our ongoing work to develop a suitable CGI-based test environment for spacecraft vision guidance systems. We focus on the various issues involved with image simulation, including the selection of standard CGI techniques and the adaptations required for use in space applications. We also describe our approach to integration with high-fidelity end-to-end mission simulators, and summarise a variety of European Space Agency research and development projects that used our test environment.


2002 ◽  
pp. 521-528
Author(s):  
T.W. Bradshaw ◽  
A. H. Orlowska ◽  
C. Jewell

1994 ◽  
Vol 31 (03) ◽  
pp. 231-237
Author(s):  
Malcolm S. Child ◽  
L. Alberto Cangahuala

This paper reports on the history of the Massachusetts Institute of Technology's entry in the 2nd International Human-Powered Submarine Race. The design of this entry was an evolution of the MIT design (named Icarus) from the first competition, held in 1989. Anticipating an increase in competitive entries, the new MIT entry (hereafter referred to as Sea Beaver) was designed to be more reliable and faster than Icarus. Sea Beaver was designed with a maximum diameter four inches smaller than Icarus. This change in cross section forced a change from a rotary to linear pedaling mechanism. The linear pedal motion was transferred to the drive shaft through an innovative arrangement of pulleys and one-way hub bearings. This arrangement allowed the pedals to remain independent from one another, opening up the possibility to experiment with different pedaling cadences. The propeller was designed for efficiency and to minimize the possibility of entanglement with lines along the course. The steering system was arranged to take up the least volume inside the hull as possible. In addition to taking advantage of experience gained in the design of Icarus, the MIT team also made significant advances in construction techniques. The hull, propellers, and nose cones were all fabricated from molds built by team members. Compared with the Icarus construction history, Sea Beaver was completed in less time, at less cost, with more spare parts available during the competition. For the design and construction of the propulsion system, the Sea Beaver team received the 1991 Medal of Engineering Excellence from Popular Science Magazine.


Author(s):  
Phillip Olla

This chapter will describe how space technologies can be incorporated into terrestrial 3G /4G mobile telecommunication infrastructure to provide convergent innovative applications and services. The utilization of space applications for non-military use has the potential to generate significant economic, social and environmental benefits on a global scale. The satellite infrastructure will become a key enabling factor in a growing range of mobile products such as: voice services, broadband Internet services, navigation, and observation systems. The chapter presents a framework derived from the literature to aid the development of viable business models expected from the amalgamation of mobile telecommunication and space infrastructure. The chapter also identifies the various actors involved in the delivery of these services which include: technology actors, service providers, network operators, consumers, and regulators.


2019 ◽  
Vol 26 (3) ◽  
pp. 557-565 ◽  
Author(s):  
Travis Edward Shelton ◽  
Dylan Joseph Stelzer ◽  
Carl R. Hartsfield ◽  
Gregory Richard Cobb ◽  
Ryan P. O'Hara ◽  
...  

Purpose For many applications, including space applications, the usability and performance of a component is dependent on the surface topology of the additively manufactured part. The purpose of this paper is to present an investigation into minimizing the residual surface roughness of direct metal laser sintering (DMLS) samples by manipulating the input process parameters. Design/methodology/approach First, the ability to manipulate surface roughness by modifying processing parameters was explored. Next, the surface topography was characterized to quantify roughness. Finally, microthruster nozzles were created both additively and conventionally for flow testing and comparison. Findings Surface roughness of DMLS samples was found to be highly dependent on the laser power and scan speed. Because of unintended partially sintered particles adhering to the surface, a localized laser fluence mechanism was explored. Experimental results show that surface roughness is influenced by the varied parameters but is not a completely fluence driven process; therefore, a relationship between laser fluence and surface roughness can be incorporated but not completely assumed. Originality/value This paper serves as an aid in understanding the importance of surface roughness and the mechanisms associated with DMLS. Rather than exploring a more common global energy density, a localized laser fluence was initiated. Moreover, the methodology and conclusions can be used when optimizing parts via metal additive manufacturing.


Author(s):  
Nicolas Vayas Tobar ◽  
Pavolas N. Christidis ◽  
Nathaniel J. O'Connor ◽  
Michal Talmor ◽  
Jamal Seyed-Yagoobi

As modern day electronics develop, electronic devices become smaller, more powerful, and are expected to operate in more diverse configurations. However, the thermal control systems that help these devices maintain stable operation must advance as well to meet the demands. One such demand is the advent of flexible electronics for wearable technology, medical applications, and biology-inspired mechanisms. This paper presents the design and performance characteristics of a proof of concept for a flexible Electrohydrodynamic (EHD) pump, based on EHD conduction pumping technology in macro- and meso-scales. Unlike mechanical pumps, EHD conduction pumps have no moving parts, can be easily adjusted to the micro-scale, and have been shown to generate and control the flow of refrigerants for electronics cooling applications. However, these pumping devices have only been previously tested in rigid configurations unsuitable for use with flexible electronics. In this work, for the first time, the net flow generated by flexible EHD conduction pumps is measured on a flat-plane and in various bending configurations. In this behavioral characteristics study, the results show that the flexible EHD conduction pumps are capable of generating significant flow velocities in all size scales considered in this study, with and without bending. This study also proves the viability of screen printing as a manufacturing method for these pumps. EHD conduction pumping technology shows potential for use in a wide range of terrestrial and space applications, including thermal control of rigid as well as flexible electronics, flow generation and control in micro-scale heat exchangers and other thermal devices, as well as cooling of high power electrical systems, soft robotic actuators, and medical devices.


2018 ◽  
Vol 1 (9) ◽  
pp. 9-42
Author(s):  
Jakub Kościukiewicz

The article was based on a fragment of the author’s doctoral dissertation entitled The birth of cello as a solo instrument – instruments, practice, and selected literature examples (Academy of Music in Łódź, chapter The evolution of cello in the 17th century) and consists of two parts. The first part outlines of the evolution of cello from its birth in the 16th century to the 18th century (the text is supplemented with illustrations), whereas the second part describes the role and use of cello in music of that period. The introduction to the article includes a critical reference to the list of academic and popular science publications therein, in Polish and other languages, touching on the cello issue in the 17th and 18th centuries. The historical part touches on the circumstances of how the violin family emerged with a special attention paid to bass representatives of that group of instruments. Following a detailed analysis of preserved instruments, their reliable copies, luthier publications, illustrations and treatises from that period, the author discussed the construction of the earlies cellos. Apart from data concerning sizes and scale length of these instruments, the article includes information about their body, neck, fingerboard (with slope angle), bridge and tailpiece, materials they were made of, and types and gauge of strings used at that time. It also describes cello tuning methods. Moreover, the author mentions different types of cello (piccolo, da spalla, basse de violon) and different ways of how it was held. A separate issue are the bows, especially types of bows, their evolution and ways of holding. This part of the article is concluded with a list of different names of bass variants of the violin used in the 16th and 17th centuries before the name cello/violoncello finally settled. The second part of the article elaborates on the most important functions of cello: as a consort instrument, a universal continuo instrument or a solo instrument. Cello (along with viola da gamba or dulcian/bassoon) managed especially well as a melodic instrument co-rendering the continuo parts, and the result was that the basso continuo became the most important domain of cello in the Baroque, having a significant influence on the shape of playing technique and performance practice of that instrument. As one of melodic bass instruments, cello performed an important role in shaping the concertante style, along with the violin, shawm/oboe, cornet or flute. It was that practice combined with the improvisation practice developed simultaneously (which also influenced the development of the instrument itself) that the idea to write first autonomous compositions for the cello (solo, chamber or with basso continuo) emerged from at the end of the 17th century. Continuation of this article, which shall be devoted to Baroque works for the cello and their composers, will be published in the following issue of “Notes Muzyczny”.


Author(s):  
L. Simone ◽  
M.C. Comparini ◽  
F. Marchetti ◽  
M. D'Attilia ◽  
S. Cocchi ◽  
...  

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