Testing of Micro/Nano Satellites and their On-orbit Performance

Demand of an environment test facility suitable for micro/nano satellites has increased as the number of new satellite developers such as universities and small business companies has increased. In Japan, development of micro/nano satellites (10cm to 50cm) is very active since Japan Aerospace Exploration Agency (JAXA) started the piggyback program via H2A rocket in 2009. Micro/nano satellite systems and components can be developed at a small laboratory. For testing, however, expensive and special test machines such as thermal vacuum chamber and high power shaker are necessary. To reduce the burden on the micro/nano satellite developers, Center of Nanosatellite Testing (CeNT) at Kyushu Institute of Technology (KIT) was established as a comprehensive test facility for micro/nano satellite up to 50 cm in 2010. The purpose of CeNT is to provide low-cost and easy-to-use testing service for universities and small business companies. CeNT has a vibration machine (~ 33 kN), shock machines (~10000G), small and large thermal vacuum chambers (0.3 m and 1.7 m) and thermal cycle chambers. Offering the one-stop service for environment testing ensures the traceability of verification processes necessary for anomaly investigation. Since 2010, 11 satellite projects used the facility. 2 satellites were already launched in 2012 and 9 satellites will be launched in 2013. This paper describes the testing results and their on-orbit performance of the following 3 satellites. 1. Horyu-2 (Kyushu Institute of Technology, launched in 2012) Horyu-2 was launched on May 18, 2012. The satellite was developed by KIT students. The satellite’s size and weight are 30 cm cube and 7 kg. During the project, STM, EM and FM were developed from 2010 to 2012. The main mission of Horyu-2 is high voltage photovoltaic power generation. Vibration, shock and thermal vacuum were carried out for each model. JAXA set the strict test conditions for the vibration test and the shock test to avoid accidents such as dropping parts, accidental switch-on and unexpected RF emission during the launch and the fairing separation that could cause the critical damage to the main satellites. The satellite was launched without any anomaly. The temperature variation during the nominal operation matched with the prediction. We kept a detail record of the cost associated with each test. The effectiveness of each test will be reviewed. 2. FITSAT (Fukuoka Institute of Technology, launched in 2012) FITSAT was launched on October, 2012. The satellite was one of the first nano satellites released from Japan Experiment Module (JEM) on International Space Station (ISS). FITSAT was launched by HTV (H2 Transfer vehicle). It was packed within the rocket body, very different conditions from typical piggy-back satellites. The missions of FITSAT were high- speed data communication by 5.8 GHz amateur band and high power LED illumination. At CeNT, vibration and thermal vacuum test was carried out for EM and FM model. FITSAT carried a lithium-ion battery to drive the high power LED. Thermal vacuum test was necessary to ensure the safety of the battery because FITSAT was stored on ISS (International Space Station) until the satellite was released. The satellite missions were successful. 3. QSAT-EOS (Federation of universities and companies in Kyushu, launch in 2013) QSAT-EOS (Kyushu Satellite for Earth Observation System Demonstration) was developed by a consortium of universities and companies in Kyushu. The satellite is 50cm cube and 50kg weight. It will be launched in 2013 via a Dnepr rocket. QSAT-EOS was the first 50 kg satellite tested in CeNT. For QSAT-EOS, thermal vacuum test was conducted for STM and FM. In this paper, we will compare thermal vacuum test results and the on-orbit data. At the conference, the lessons learned from these environmental tests will be presented

Programmable CubeSat Interface Board to Reduce Costs and Delivery Time

A standardized interface for different CubeSat missions is one of the keys to reduce costs and delivery time. A backplane interface approach, proposed by the University of Wuerzburg in Germany as UWE-3, was implemented in three CubeSat projects at the Kyushu Institute of Technology (Kyutech) in Japan to shorten the development and assembly times. The backplane approach also helped to reduce the risk of workmanship errors associated with the harness. The proposed standard interface board, however, needed changes in every CubeSat project to comply with the mission requirements. To obtain more flexibility especially for data connections, this work introduces a novel idea of a software-configurable bus interface with the backplane board. A Complex Programmable Logic Device (CPLD) was used instead of the hardware routing so that we can reconfigure the bus interface by reprogramming the CPLD. The concept was validated by a functional test with a breadboard module. A radiation test verified that the selected CPLD has enough strength to survive total ionization dozes of more than 2 years in low Earth orbit. A new backplane board with CPLD have been integrated with Engineering Model and Flight Model of the fourth CubeSat project at Kyutech, BIRDS-3 project, and system level verification was conducted. The flight model is now ready for delivery to JAXA in February 2019 for a planned launch to International Space Station in April 2019. The initial on-orbit data will be obtained by the time of the conference in August 2019 and will be presented to the audience

PeTT Vacuum Chamber: Affordable Testing Facility for Lean Satellites

Satellite thermal vacuum test (TVC) is very necessary to check the functional performance of its internal subsystems within appropriate limits, subject to a given range of environmental conditions and operating modes. However, the cost of conventional TVC facilities is expensive and complex to operate and therefore is owned by a few institutions, especially in developing countries. The objective of this paper is to provide a straightforward and affordable Peltier-based Thermal Testing (PeTT) Vacuum Chamber facility for lean satellite testing. The PeTT device consists of 4 multi-stage Peltier elements sandwiched in-between a copper surface plate and water-cooled heat sink to achieve a cold temperature limit of -77 oC. The PeTT device has a mass of 3.4kg and a size 152mm length x 127mm width x 40 mm height having a maximum heat exchange capability of 400W. This paper presents the design and development, components details and cost and the demonstration of the PeTT vacuum chamber using a replica 1U CubeSat

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

BIRDS-2: Multi-Nation Cubesat Constellation Project for Learning and Capacity Building

The BIRDS project began in October, 2015 with an objective to provide hands on experience to the graduate students on satellite technology. In a BIRDS project, the students define missions, design, build, test, and operate satellite within given time frame of the project. A 1U CubeSat is built per participating country which are then released from International Space Station (ISS) into Low Earth Orbit (LEO) and operated through a ground station network, with one ground station established in each member nation. That being the first is series, the second BIRDS project or so called BIRDS-2 project started in November, 2016 with students from, Philippines, Bhutan, Malaysia and Japan. Lean philosophy is adopted for the development of CubeSats and an overlap of a year is created between successive projects so that the lessons learned and knowledge gained from each project is properly passed on. The BIRDS program targets to improve the development process of a CubeSat while maintaining/improving the reliability and reducing waste. But the true success of the program is indicated by the ability of project members to replicate what they learn from this project, at their home country after graduating

Quantitative Evaluation of SRS Similarity for Aerospace Testing Applications

The similarity between a shock response spectrum (SRS) and a target shock specification is essential in evaluating the success of a qualification test of a space component. Qualification testing facilities often utilize shock response databases for rapid testing. Traditionally, the comparison of two shocks (SRS) depends on visual evaluation, which is, at best, subjective. This paper compares five different quantitative methods for evaluating shock response similarity. This work aims to find the most suitable metric for retrieving an SRS from a pyroshock database. The five methods are the SRS difference, mean acceleration difference, average SRS ratio, dimensionless SRS coefficients, and mean square goodness-of-fit method. None of the similarity metrics account for the sign of the deviation between the target SRS and database SRS, making it challenging to satisfy the criteria for a good shock test. We propose a metric (the weighted distance) for retrieving the most similar SRS to a target SRS specification from a shock database in this work. The weighted distance outperforms the mean square goodness-of-fit and other metrics in database SRS retrieval for rapid qualification testing

CubeSat bus interface with Complex Programmable Logic Device

A standardized interface for different CubeSat missions is one of the keys to reducing costs and delivery time. A backplane interface approach, proposed by the University of Würzburg in Germany as UWE-3, was implemented in three CubeSat projects at the Kyushu Institute of Technology (Kyutech) to shorten the development and assembly times. The backplane approach also helped to reduce the risk of workmanship errors associated with the harness. However, changes to the proposed standard interface board were necessary in every CubeSat project, to comply with the mission requirements. To obtain more flexibility, especially for data connections, this work introduces a novel idea of a software-configurable bus interface with a backplane board. A Complex Programmable Logic Device (CPLD) was used instead of hardware routing so that we can reconfigure the bus interface by reprogramming the CPLD. The concept was validated by a functional test with a breadboard module. A radiation test verified that the selected CPLD has enough strength to survive total ionization doses of more than 2 years in low Earth orbit. A new backplane board with CPLD has been integrated into the engineering model of the fourth CubeSat project at Kyutech, the BIRDS-3 project, and system level verification has been conducted

Laboratory Test of Vibration of Micro/Nano Satellite for Environment Test Standardization

This paper presents the basic research for establishing the qualification test (QT) level which the units have to pass to be sold as products for space usage. A laboratory test campaign has already begun for the study how the mechanical stresses distribute within the satellite body so as to define the unit QT level. In order to achieve that we carried out random vibration tests using a dummy satellite (50cmx50cmx50cm) and measured the distribution of acceleration inside the satellite. The research focuses on the provision of the physical basis of the test conditions to be defined in the new standard. We tried to identify the range of natural frequency and acceleration in the launching environment. The main parameters taken into consideration for analysis are the resonant frequencies and amplification of acceleration. The detailed test procedure, analysis method and primary results are herein reported.The 29th International Symposium on Space Technology and Science (29th ISTS), June 2-9, 2013, Nagoya, Aich