146 research outputs found
Program Management for Sustainable University CubeSat Programs Based on the Experience of Five Generations of CubeSat Projects, BIRDS Program
BIRDS program is a university CubeSat program whose primary mission is capacity building of non-space faring countries. It has been run by Kyushu Institute of Technology, Japan, where a group of foreign and Japanese students designs, builds, tests and operates CubeSats. The program started in 2015. Roughly every year since 2017, BIRDS program delivered and launched multiple CubeSats from International Space Station. In total, the program generated 17 CubeSats in five generations. The satellites have been designed in a way so that even satellite beginners can go through the satellite system life cycles from the mission definition to the operation in two years, the duration of Master course. Subsequent generations of students overlap in the laboratory so that they can inherit the know-hows and the experience directly in-person. The satellite design has been modified based on the lessons learned in the former generations, especially during the operation phase. After going through the series of developments and operations, the satellite bus has become very mature. Currently, the initiative to open-source the BIRDS bus is also running. The program, rather than project, management aspects of university CubeSat program is discussed
CubeSat Electrical Interface Standardization for Faster Delivery and More Mission Success
In 2019, a new project to standardize the CubeSat electrical interface started based on the heritage of the small satellite related standard activities, such as ISO-19683 (testing) and ISO-TS-20991 (requirements). The project aims at registering at new work item at ISO/TC20/SC14 in summer 2021 by summer 2021 and publish the standard by fall 2024. Discussion has been made utilizing various gathering opportunities of the CubeSat community. A survey on the CubeSat interface has been distributed the CubeSat community to collect the satellite developers’ experience and desires regarding the interface, and the CubeSat vendors’ reality and desires. A research work to identify the difficulties associated integrating CubeSat components from different vendors is on-going. Initial finding suggest that clear definition of interface related information, especially the digital data communication, in the user manual is really needed. A framework of the standard has been drafted, which is mainly made of four parts. (1) Interface among components, (2) Interface between CubeSat bus (platform) and mission payloads, (3) Document specification to describe the information related to component interface, (4) Document specification to describe the information related to CubeSat bus (platform) interface
An Overview of the BIRDS-4 Satellite Project and the First Satellite of Paraguay
The Joint Global Multi-National Birds or BIRDS program, is a multinational small satellite project led by Kyushu Institute of Technology (Japan). The BIRDS program gives to non-space faring nations the opportunity to design, integrate, build, test, launch, and operate their country’s first satellite. This paper focuses on BIRDS-4, a constellation of three 1U CubeSats belonging to Paraguay (GuaraniSat-1: Paraguay’s first satellite), Philippines (Maya-2), and Japan (Tsuru). BIRDS-4 members are graduate students enrolled in Space Engineering International Course (SEIC) at Kyushu Institute of Technology. This constellation will execute nine missions such as Earth Imaging, Total Ionization Dose measurements, evaluation of Perovskite solar cell performance in space, and the use of “Satellite Structure as Antenna” for CW transmission. More importantly, the satellite will conduct a Store-and-Forward mission to test the technical viability of the chosen hardware, such that if proven successful, will be used for future satellite missions to gather data in remote areas. The satellites were launched on February 22, 2021 and deployed from the International Space Station on March 14, 2021.This paper describes the background, missions, stakeholders, lessons learned, and initial operational results after the deployment from ISS. Finally, this paper shall discuss the significance of this satellite for Paraguay, which has been a non-space-faring nation up until now
Asymmetric auxin distribution establishes a contrasting pattern of aerenchyma formation in the nodal roots of Zea nicaraguensis during gravistimulation
Auxin distribution is essential for determining root developmental patterns. The formation of lateral roots and constitutive aerenchyma, which is a gas space developed through cell death, is regulated by auxin in rice (Oryza sativa). However, it is unclear whether the involvement of auxin in constitutive aerenchyma formation is conserved in other species. In this study, we found that constitutive aerenchyma formation was regulated by auxin in the nodal roots of Zea nicaraguensis, a wild relative of maize (Zea mays ssp. mays) grown naturally on frequently flooded coastal plains. Subsequent gravistimulation (root rotation) experiments showed opposite patterns of aerenchyma and lateral root formation. Lateral root formation on the convex side of rotated roots is known to be stimulated by a transient increase in auxin level in the pericycle. We found that aerenchyma formation was accelerated in the cortex on the concave side of the rotated nodal roots of Z. nicaraguensis. A cortex-specific expression analysis of auxin-responsive genes suggested that the auxin level was higher on the concave side than on the convex side. These results suggest that asymmetric auxin distribution underlies the regulation of aerenchyma and lateral root formation in the nodal roots of Z. nicaraguensis. As aerenchyma reduces the respiratory cost of the roots, constitutive aerenchyma on the concave side of the nodal root may balance resource allocation, thereby contributing to the uptake of water and nutrients by newly formed lateral roots. Our study provides insights into auxin-dependent asymmetric root patterning such as that of gravistimulation and hydropatterning response
An ancillary study of participants in a randomized, placebo-controlled trial suggests that ingestion of bovine lactoferrin promotes expression of interferon alpha in the human colon
AbstractStudies using animal models have demonstrated that ingestion of bovine lactoferrin (bLF) is able to induce cytokine expression in the intestine and inhibit carcinogenesis in the colon and other organs of experimental animals. Consequently, a clinical trial was conducted in the National Cancer Center Hospital, Tokyo, Japan to determine whether ingestion of bLF affected the growth of colorectal polyps in humans. The Tokyo-trial found that ingestion of 3.0 g bLF suppressed the growth of colorectal polyps and increased the level of serum human lactoferrin in participants 63 years old or younger. The present study is a complementary study to the Tokyo-trial to determine if a change in the expression of one or more cytokines could be detected in the colon of the Tokyo-trial participants after ingesting bLF. We found that daily ingestion of 3.0 g bLF promoted the expression of interferon alpha in the colon of the Tokyo-trial participants
Diagnostic Role of 18F-Fluorodeoxyglucose Positron Emission Tomography in Gastric Mesenchymal Tumors
There have been no comparative studies investigating the results of 18F-fluorodeoxyglucose (FDG)-positron emission tomography (PET) in patients with gastric mesenchymal tumors, including leiomyomas, leiomyosarcomas, schwannomas, and gastrointestinal stromal tumors (GISTs). We retrospectively reviewed the data of 142 patients with pathologically diagnosed gastric mesenchymal tumors treated at 11 institutions. We analyzed the correlation between the maximum standardized uptake value (SUVmax) evaluated using fluorodeoxyglucose-positron emission tomography (FDG-PET) and the tumor size. The correlation between the SUVmax and mitotic index was also investigated in GISTs. The SUVmax (mean +/- standard deviation) was 0.5 +/- 0.6 in very low-risk GISTs (n = 42), 2.1 +/- 0.7 in low-risk GISTs (n = 26), 4.9 +/- 0.8 in intermediate-risk GISTs (n = 22), 12.3 +/- 0.8 in high-risk GISTs (n = 20), 1.0 +/- 1.0 in leiomyomas (n = 15), 6.9 +/- 1.2 in schwannomas (n = 10), and 3.5 in a leiomyosarcoma (n = 1). The SUVmax of GISTs with an undetermined risk classification was 4.2 +/- 1.3 (n = 8). Linear associations were observed between the SUVmax and tumor size in GISTs, leiomyomas, and schwannomas. The SUVmax of GISTs with a high mitotic index was significantly higher than that of GISTs with a low mitotic index (9.6 +/- 7.6 vs. 2.4 +/- 4.2). In conclusion, we observed positive correlations between the SUVmax and tumor size in GISTs, leiomyomas, and schwannomas. The SUVmax also positively correlated with the mitotic index and risk grade in GISTs. Schwannomas showed a higher FDG uptake than GISTs and leiomyomas
Development of precision Wolter mirrors for future solar x-ray observations
Taro Sakao, Satoshi Matsuyama, Ayumi Kime, Takumi Goto, Akihiko Nishihara, Hiroki Nakamori, Kazuto Yamauchi, Yoshiki Kohmura, Akira Miyake, Hirokazu Hashizume, Tadakazu Maezawa, Yoshinori Suematsu, and Noriyuki Narukage "Development of precision Wolter mirrors for future solar x-ray observations", Proc. SPIE 9603, Optics for EUV, X-Ray, and Gamma-Ray Astronomy VII, 96030U (4 September 2015); https://doi.org/10.1117/12.2188905
Overview of Project SPATIUM – Space Precision Atomic-clock Timing Utility Mission
The ionosphere contains large amounts of ionized plasma which is affecting the propagation of radio waves. The perturbation in ionospheric plasma significantly influences modern infrastructures that rely on radio and satellite communication. Hence, it is essential to develop a reliable platform for ionospheric plasma density monitoring. The Space Precision Atomic-clock TIming Utility Mission (SPATIUM) presents a new approach for ionospheric plasma mapping using a constellation of nanosatellites equipped with a high precision timing reference, double Langmuir probe and UHF inter-satellite ranging payloads. SPATIUM mission utilizes the breakthrough chip-scale atomic clock to generate highly stable and accurate clock signal for each satellite in order to determine the phase-shift in satellite signal. The ionosphere total electron content could be derived from ranging signals among satellites along the inter-satellite path. The pathfinder satellite, SPATIUM-I, was developed and successfully released from International Space Station on 6 October 2018. The main objective of this 2U CubeSat is to validate the clocking performance of a commercial off-the-shelf chip-scale atomic clock and demonstrate other key enabling technologies in orbit. The satellite is working well since deployment and the analysis of the captured satellite data is on-going
Improvement of Communication System for 1U CubeSat
The Joint Global Multi-Nation Birds Satellite project abbreviated as BIRDS” project started with a first-generation constellation of five 1U satellites in October 2015. Currently, BIRDS project is on its fourth-generation of CubeSat constellation. The 1U CubeSats in each generation follow the heritage of the previous satellites. The Communication subsystem has undergone multiple iterations to improve the performance on orbit. Until the second-generation of satellites (BIRDS2 CubeSat constellation), the two-way communication between the satellite in orbit and the ground station was difficult even though the ground test results seemed promising. BIRDS3 satellites went through major changes and succeeded in establishing a strong link between the satellite and the ground station. This paper describes findings that were made based on the on-orbit test results of the previous satellites that caused difficulty in the communication and some of the major changes that were made on both the BIRDS3 satellite side and the ground station side to improve the communication. BIRDS3 satellites have been operating exceptionally better in the orbit. The orbital link measurement resultis also included in this paper
Development of precision Wolter mirrors for solar x-ray observations
Taro Sakao, Satoshi Matsuyama, Takumi Goto, Jumpei Yamada, Shuhei Yasuda, Kazuto Yamauchi, Yoshiki Kohmura, Ayumi Kime, Akira Miyake, Tadakazu Maezawa, Hirokazu Hashizume, Yoshinori Suematsu, Noriyuki Narukage, and Shin-nosuke Ishikawa "Development of precision Wolter mirrors for solar x-ray observations", Proc. SPIE 10386, Advances in X-Ray/EUV Optics and Components XII, 103860E (23 August 2017); https://doi.org/10.1117/12.2273507
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