SLUCUBE: Innovative high performance nanosatellite science and technology demonstration mission

The Space Systems Research Laboratory (SSRL) at Saint Louis University is developing SLUCUBE nanosatellite as part of the space mission design program. The objective of the mission is to demonstrate space capability of high performance nanosatellite components that has been developed at SSRL for the past three years. The objective of the program is to provide extremely low-cost and rapid access to space for scientists and commercial exploitation using commercial-off-the-shelf components. SLUCUBE is a double CubeSat with dimensions 10×10×20 cm and a mass of 2 kg. This nanosatellite features suite of technology demonstration components to enlarge the capability of space mission for such class of spacecrafts. The primary mission of SLUCUBE is to test and demonstrate several enabling technologies by flying a number of university developed high performance components. This paper describes the new developed technologies by providing details of specific components developed along with the R&D efforts and laboratory facilities. A brief discussion about the student involvement and educational benefits will also be presented.     

Small total dose measurement system for SDS-1

The Japanese Aerospace Exploration Agency (JAXA) uses monitors on board satellites to measure and record in-flight data on ionization effects in space. A compact, total dose measurement system for the small satellite (SDS-1) was developed based on the previous system for measuring total ionizing dose effects. Especially, the sensor for SDS-1 is quite smaller than the sensor for SOHLA-1, which is presented in the last year. The sensor is 8 mm wide×3 mm high×19 mm long and weighs approximately 4 g with 500 mm its wire harness. Eight pin LCC RADFET and temperature sensor are arranged on it. Seven sensors are arranged on some components inside the SDS-1. One of the sensors is arranged on a printed board in advanced microprocessing in-ORBIT experiment equipment (AMI). The AMI demonstrate 320 MIPS microprocessor and DC–DC converter for space. The absorbed dose at the points where the sensors are arranged was evaluated before flight and will be compared with resulting flight data.     

Characterization of Lithium-Polymer batteries for CubeSat applications

With the development of several key technologies, nanosatellites are emerging as important vehicles for carrying out technology demonstrations and space science research. Nanosatellites are attractive for several reasons, the most important being that they do not involve the prohibitive costs of a conventional satellite launch. One key enabling technology is in the area of battery technology. In this paper, we focus on the characterization of battery technologies suitable for nanosatellites.Several battery chemistries are examined in order to find a type suitable for typical nanosatellite missions. As a baseline mission, we examine York University's 1U CubeSat mission for its power budget and power requirements. Several types of commercially available batteries are examined for their applicability to CubeSat missions. We also describe the procedures and results from a series of environmental tests for a set of Lithium Polymer batteries from two manufacturers.     

Flight demonstration of new thruster and green propellant technology on the PRISMA satellite

The concept of a storable liquid monopropellant blend for space applications based on ammonium dinitramide (ADN) was invented in 1997, within a co-operation between the Swedish Space Corporation (SSC) and the Swedish Defense Research Agency (FOI). The objective was to develop a propellant which has higher performance and is safer than hydrazine. The work has been performed under contract from the Swedish National Space Board and ESA. The progress of the development has been presented in several papers since 2000.ECAPS, a subsidiary of the Swedish Space Corporation was established in 2000 with the aim to develop and market the novel “high performance green propellant” (HPGP) technology for space applications. The new technology is based on several innovations and patents w.r.t. propellant formulation and thruster design, including a high temperature resistant catalyst and thrust chamber.The first flight demonstration of the HPGP propulsion system will be performed on PRISMA. PRISMA is an international technology demonstration program with Swedish Space Corporation as the Prime Contractor.This paper describes the performance, characteristics, design and verification of the HPGP propulsion system for PRISMA. Compatibility issues related to using a new propellant with COTS components is also discussed. The PRISMA mission includes two satellites in LEO orbit were the focus is on rendezvous and formation flying. One of the satellites will act as a “target” and the main spacecraft performs rendezvous and formation flying maneuvers, where the ECAPS HPGP propulsion system will provide delta-V capability.The PRISMA CDR was held in January 2007. Integration of the flight propulsion system is about to be finalized.The flight opportunity on PRISMA represents a unique opportunity to demonstrate the HPGP propulsion system in space, and thus take a significant step towards its use in future space applications. The launch of PRISMA scheduled to 2009.     

NEEMO 7 undersea mission

The NEEMO 7 mission was the seventh in a series of NASA-coordinated missions utilizing the Aquarius undersea habitat in Florida as a human space mission analog. The primary research focus of this mission was to evaluate telementoring and telerobotic surgery technologies as potential means to deliver medical care to astronauts during spaceflight. The NEEMO 7 crewmembers received minimal pre-mission training to perform selected medical and surgical procedures. These procedures included: (1) use of a portable ultrasound to locate and measure abdominal organs and structures in a crewmember subject; (2) use of a portable ultrasound to insert a small needle and drain into a fluid-filled cystic cavity in a simulated patient; (3) surgical repair of two arteries in a simulated patient; (4) cystoscopy and use of a ureteral basket to remove a renal stone in a simulated patient; and (5) laparoscopic cholecystectomy in a simulated patient. During the actual mission, the crewmembers performed the procedures without or with telementoring and telerobotic assistance from experts located in Hamilton, Ontario. The results of the NEEMO 7 medical experiments demonstrated that telehealth interventions rely heavily on a robust broadband, high data rate telecommunication link; that certain interventional procedures can be performed adequately by minimally trained individuals with telementoring assistance; and that prior clinical experience does not always correlate with better procedural performance. As space missions become longer in duration and take place further from Earth, enhancement of medical care capability and expertise will be required. The kinds of medical technologies demonstrated during the NEEMO 7 mission may play a significant role in enabling the human exploration of space beyond low earth orbit, particularly to destinations such as the Moon and Mars.     

Very high delta-V missions to the edge of the solar system and beyond enabled by the dual-stage 4-grid ion thruster concept

A new and innovative type of gridded ion thruster, the “Dual-Stage 4-Grid” or DS4G concept, has been proposed and its predicted high performance validated under an ESA research, development and test programme. The DS4G concept is able to operate at very high specific impulse and thrust density values well in excess of conventional 3-grid ion thrusters at the expense of a higher power-to-thrust ratio. This makes it a possible candidate for ambitious missions requiring very high delta-V capability and high power. Such missions include 100 kW-level multi-ton probes based on nuclear and solar electric propulsion (SEP) to distant Kuiper Belt Object and inner Oort cloud objects, and to the Local Interstellar medium. In this paper, the DS4G concept is introduced and its application to this mission class is investigated. Benefits of using the DS4G over conventional thrusters include reduced transfer time and increased payload mass, if suitably advanced lightweight power system technologies are developed.A mission-level optimisation is performed (launch, spacecraft system design and low-thrust trajectory combined) in order to find design solutions with minimum transfer time, maximum scientific payload mass, and to explore the influence of power system specific mass. It is found that the DS4G enables an 8-ton spacecraft with a payload mass of 400 kg, equipped with a 65 kW nuclear reactor with specific mass 25 kg/kW (e.g. Topaz-type with Brayton cycle conversion) to reach 200 AU in 23 years after an Earth escape launch by Ariane 5. In this scenario, the optimum specific impulse for the mission is over 10,000 s, which is well within the capabilities of a single 65 kW DS4G thruster. It is also found that an interstellar probe mission to 200 AU could be accomplished in 25 years using a “medium-term” SEP system with a lightweight 155 kW solar array (2 kg/kW specific mass) and thruster PPU (3.7 kg/kW) and an Earth escape launch on Ariane 5. In this case, the optimum specific impulse is lower at 3500 s which is well within conventional gridded ion thruster capability.     

Group dynamics training for manned spaceflight and the CAPSULS mission: prophylactic against incompatibility and its consequences?

On February 7, 1994, four Canadian Astronauts were sealed off in a hyperbaric chamber at the Canadian Government's Defense and Civil Institute for Environmental Medicine in Toronto, Canada. This space lab training mission lasted seven days and was the first to be conducted with astronauts outside of Russia.

The objective of this mission was to give Canadian astronauts, space scientists and the staff of the Canadian Space Agency (CSA), the opportunity to gain first hand experience on preparational and operational aspects of a typical space mission. Twenty-one scientific experiments involving six countries from several disciplines were involved in this mission.

This paper describes the goals and preliminary results of a psychological experiment/training program that used the CAPSULS mission as a test bed for its application in the manned space flight environment. The objective of this project was to enhance the understanding of small group behaviour with a view to maximizing team effectiveness and task accomplishment in teams living and working in isolation under difficult and confined conditions. The application of this model in the light of future missions is a key thesis in this paper.     

未来大规模低成本进入空间路径研究（英文）

The objective of this study is to identify the requirements of access to space for the future, the required methodology, key technologies and international cooperation mode. Firstly, the mission requirements and the challenges of current technologies to access to space are analyzed and summarized. The solutions and related key technologies to realize large-scale and low-cost access to space(L2 AS) are presented here, including the low-cost design of expendable launch vehicles and a reusable space transportation system, interface standardization, and new conceptual launchers. The mission modes based on launch vehicles to realize L2 AS and three future international collaboration modes are presented. Lastly, the relevant conclusions and suggestions are given.     

One hundred US EVAs: a perspective on spacewalks

In the 36 years between June 1965 and February 2001, the US human space flight program has conducted 100 spacewalks, or extravehicular activities (EVAs), as NASA officially calls them. EVA occurs when astronauts wearing spacesuits travel outside their protective spacecraft to perform tasks in the space vacuum environment. US EVA started with pioneering feasibility tests during the Gemini Program. The Apollo Program required sending astronauts to the moon and performing EVA to explore the lunar surface. EVA supported scientific mission objectives of the Skylab program, but may be best remembered for repairing launch damage to the vehicle and thus saving the program. EVA capability on Shuttle was initially planned to be a kit that could be flown at will, and was primarily intended for coping with vehicle return emergencies. The Skylab emergency and the pivotal role of EVA in salvaging that program quickly promoted Shuttle EVA to an essential element for achieving mission objectives, including retrieving satellites and developing techniques to assemble and maintain the International Space Station (ISS). Now, EVA is supporting assembly of ISS. This paper highlights development of US EVA capability within the context of the overarching mission objectives of the US human space flight program.     

Hyperspectral imaging—An advanced instrument concept for the EnMAP mission (Environmental Mapping and Analysis Programme)

In the upcoming generation of satellite sensors, hyperspectral instruments will play a significant role. This payload type is considered world-wide within different future planning.Our team has now successfully finalized the Phase B study for the advanced hyperspectral mission EnMAP (Environmental Mapping and Analysis Programme), Germans next optical satellite being scheduled for launch in 2012. GFZ in Potsdam has the scientific lead on EnMAP, Kayser-Threde in Munich is the industrial prime.The EnMAP instrument provides over 240 continuous spectral bands in the wavelength range between 420 and 2450 nm with a ground resolution of 30 m×30 m. Thus, the broad science and application community can draw from an extensive and highly resolved pool of information supporting the modeling and optimization process on their results. The performance of the hyperspectral instrument allows for a detailed monitoring, characterization and parameter extraction of rock/soil targets, vegetation, and inland and coastal waters on a global scale supporting a wide variety of applications in agriculture, forestry, water management and geology. The operation of an airborne system (ARES) as an element in the HGF hyperspectral network and the ongoing evolution concerning data handling and extraction procedures, will support the later inclusion process of EnMAP into the growing scientist and user communities.     

Ares V launch vehicle: An enabling capability for future space science missions

NASA's planned Ares V cargo launch vehicle offers the potential to completely change the paradigm of future space science mission architectures. Future space science telescopes desire increasingly larger telescope collecting aperture. But, current launch vehicle mass and volume constraints are a severe limit. The Ares V greatly relaxes these constraints. For example, while current launch vehicles have the ability to place a 4.5 m diameter payload with a mass of 9400 kg on to a Sun-Earth L2 transfer trajectory, the Ares V is projected to have the ability to place an 8.8 m diameter payload with a mass of approximately 60,000 kg on to the same trajectory, or 180,000 kg into Low Earth Orbit. Also the Ares V could place approximately 3000 kg (13,000 kg with a Centaur upper stage) on to a trajectory with a C3 of 106 km²/s², arriving at Saturn in 6.1 years without the use of gravity assists. This paper summarizes the current planned Ares V payload launch capability.     

Lunar precursor missions for human exploration of Mars--III: studies of system reliability and maintenance

Discussions of future human expeditions into the solar system generally focus on whether the next explorers ought to go to the Moon or to Mars. The only mission scenario developed in any detail within NASA is an expedition to Mars with a 500-day stay at the surface. The technological capabilities and the operational experience base required for such a mission do not now exist nor has any self-consistent program plan been proposed to acquire them. In particular, the lack of an Abort-to-Earth capability implies that critical mission systems must perform reliably for 3 years or must be maintainable and repairable by the crew. As has been previously argued, a well-planned program of human exploration of the Moon would provide a context within which to develop the appropriate technologies because a lunar expedition incorporates many of the operational elements of a Mars expedition. Initial lunar expeditions can be carried out at scales consistent with the current experience base but can be expanded in any or all operational phases to produce an experience base necessary to successfully and safely conduct human exploration of Mars.     

Human exploration of near earth asteroids: Mission analysis for chemical and electric propulsion

This paper presents a mission analysis comparison of human missions to asteroids using two distinct architectures. The objective is to determine if either architecture can reduce launch mass with respect to the other, while not sacrificing other performance metrics such as mission duration. One architecture relies on chemical propulsion, the traditional workhorse of space exploration. The second combines chemical and electric propulsion into a hybrid architecture that attempts to utilize the strengths of each, namely the short flight times of chemical propulsion and the propellant efficiency of electric propulsion. The architectures are thoroughly detailed, and accessibility of the known asteroid population is determined for both. The most accessible asteroids are discussed in detail. Aspects such as mission abort scenarios and vehicle reusability are also discussed. Ultimately, it is determined that launch mass can be greatly reduced with the hybrid architecture, without a notable increase in mission duration. This demonstrates that significant performance improvements can be introduced to the next step of human space exploration with realistic electric propulsion system capabilities. This leads to immediate cost savings for human exploration and simultaneously opens a path of technology development that leads to technologies enabling access to even further destinations in the future.     

How the science and engineering of spaceflight contribute to understanding the plasticity of spinal cord injury.

Space programs support experimental investigations related to the unique environment of space and to the technological developments from many disciplines of both science and engineering that contribute to space studies. Furthermore, interactions between scientists, engineers and administrators, that are necessary for the success of any science mission in space, promote interdiscipline communication, understanding and interests which extend well beyond a specific mission. NASA-catalyzed collaborations have benefited the spinal cord rehabilitation program at UCLA in fundamental science and in the application of expertise and technologies originally developed for the space program. Examples of these benefits include: (1) better understanding of the role of load in maintaining healthy muscle and motor function, resulting in a spinal cord injury (SCI) rehabilitation program based on muscle/limb loading; (2) investigation of a potentially novel growth factor affected by spaceflight which may help regulate muscle mass; (3) development of implantable sensors, electronics and software to monitor and analyze long-term muscle activity in unrestrained subjects; (4) development of hardware to assist therapies applied to SCI patients; and (5) development of computer models to simulate stepping which will be used to investigate the effects of neurological deficits (muscle weakness or inappropriate activation) and to evaluate therapies to correct these deficiencies.     

Novel extraterrestrial processing for space propulsion

The concept of space processing of chemicals, in general, and propellants, in particular, is explored quantitatively. The theoretical parametric calculations are supplemented by a bench scale experiment. It is seen that for several candidate space mission scenarios (recommended by several committees for the near-term future, i.e. 1990–2000 A.D.), space processing of both space resources and Earth-carried resources can make decisive differences in the mission success for a given payload. To fix ideas and to demonstrate trends, the specific case of water splitting to extract oxygen, discard (or use without storage) the resulting hydrogen, and burn Earth-carried non-cryogenic liquid fuel(s) in a simple rocket motor, designed for periodic thrusting, is treated in some detail. Experimental hardware is assembled and demonstrated to perform adequately, besides showing compactness of the space-packaged “capsule” module that is self-contained.Building upon previous studies (Ash et al., IAF-82-210, 1982), the concept of in situ propellant production (ISPP) is reexamined in light of more recent energy and materials technologies. Missions to comets and Mars Sample Return are mentioned as candidate scenarios. The mission duration, reliability-repairability of hardware, resource availability in low Earth orbit (LEO), and the thrust requirements are considered in turn. It is seen that space storage of hydrogen for extended durations (5–10 years) involves problems that require detailed studies, besides involving many presently unanswered issues. A study of the energy option in LEO and in deep space is developed in simple terms. The different solar, radioisotope, and nuclear power sources are mentioned. Storage and handling of raw and processed chemicals are considered.Applications of state-of-the-art technologies are explored using a concept of incremental small steps; this approach would decrease risk and cost yet lead toward fully autonomous energy -processing hardware for future missions. Operations in microgravity and large structure behavior are also mentioned. The paper ends with a brief summary of available options, influences of possible future technologies and breakthroughs, and an examination in light of possible future (beyond 2000 A.D.) missions.     

Power system design of ESMO

The European Student Moon Orbiter (ESMO) spacecraft is a student-built mini satellite being designed for a mission to the Moon. Designing and launching mini satellites are becoming a current trend in the space sector since they provide an economic way to perform innovative scientific experiments and in-flight demonstration of novel space technologies. The generation, storage, control, and distribution of the electrical power in a mini satellite represents unique challenges to the power engineer since the mass and volume restrictions are very stringent. Regardless of these problems, every subsystem and payload equipment must be operated within their specified voltage band whenever they required to be turned on. This paper presents the preliminary design of a lightweight, compact, and reliable power system for ESMO that can generate 720 W. Some of the key components of the EPS include ultra triple-junction (UTJ) GaAs solar cells controlled by maximum power point trackers, and high efficiency Li-ion secondary batteries recharged in parallel.     

Sumbandilasat—An operational technology demonstrator

Technology advances in sensor, digital technology and a standardised modular satellite bus are enabling a new generation of 80 kg micro-satellites with a better than 6.5 m GSD multi-spectral performance, to be specified, built and deployed with a dedicated launch within 12 months. The result of the standardised modular bus is lower cost, higher reliability and fast deployment. Operational remote sensing with a micro-satellite is thus within reach of individual organisations for dedicated missions. Sumbandilasat (pioneer in the Venda language) is a second generation satellite technology building on the expertise obtained in the Sunsat small satellite programme. The components used to build Sumbandilasat are the result of a technology development program of more than 3 years. Sumbandilasat is an operational technology demonstrator with more than 90% newly developed or improved subsystems and a compact refractive imager as a precursor to the MSMISat satellite with the same multi-spectral band set. The scalable, standardised modular satellite bus architecture enables satellites with a mass of 80–450 kg to be adapted to the specific mission requirements with minimum new engineering effort.     

TUGSAT-1/BRITE-Austria—The first Austrian nanosatellite

A nanosatellite to investigate the brightness oscillations of massive luminous stars by differential photometry is currently developed by a Canadian/Austrian team within the BRITE (Bright Target Explorer) project. The first Austrian satellite funded by the Austrian Space Program, called TUGSAT-1/BRITE-Austria, builds on the space heritage of the most successful Canadian CanX-2 and MOST missions. The satellite makes use of recent advances in miniaturized attitude determination and control systems. Precision three-axis stabilization by small reaction wheels and a star tracker provides the necessary accuracy for the photometer telescope to the arcminute level. This will provide to the astronomers photometric data of the most massive stars with unprecedented precision; data which cannot be obtained from the ground due to limitations imposed by the terrestrial atmosphere.The paper describes the spacecraft characteristics and the ground infrastructure being established in support of the BRITE mission which will consist of a constellation of up to four nearly identical satellites allowing to carry out long-term observation of stars (magnitude +3.5) not only with respect to brightness variations, but also in different spectrum ranges.     

Sleep and cognitive function of crewmembers and mission controllers working 24-h shifts during a simulated 105-day spaceflight mission

The success of long-duration space missions depends on the ability of crewmembers and mission support specialists to be alert and maintain high levels of cognitive function while operating complex, technical equipment. We examined sleep, nocturnal melatonin levels and cognitive function of crewmembers and the sleep and cognitive function of mission controllers who participated in a high-fidelity 105-day simulated spaceflight mission at the Institute of Biomedical Problems (Moscow). Crewmembers were required to perform daily mission duties and work one 24-h extended duration work shift every sixth day. Mission controllers nominally worked 24-h extended duration shifts. Supplemental lighting was provided to crewmembers and mission controllers. Participants' sleep was estimated by wrist-actigraphy recordings. Overall, results show that crewmembers and mission controllers obtained inadequate sleep and exhibited impaired cognitive function, despite countermeasure use, while working extended duration shifts. Crewmembers averaged 7.04±0.92 h (mean±SD) and 6.94±1.08 h (mean±SD) in the two workdays prior to the extended duration shifts, 1.88±0.40 h (mean±SD) during the 24-h work shift, and then slept 10.18±0.96 h (mean±SD) the day after the night shift. Although supplemental light was provided, crewmembers’ average nocturnal melatonin levels remained elevated during extended 24-h work shifts. Naps and caffeine use were reported by crewmembers during ∼86% and 45% of extended night work shifts, respectively. Even with reported use of wake-promoting countermeasures, significant impairments in cognitive function were observed. Mission controllers slept 5.63±0.95 h (mean±SD) the night prior to their extended duration work shift. On an average, 89% of night shifts included naps with mission controllers sleeping an average of 3.4±1.0 h (mean±SD) during the 24-h extended duration work shift. Mission controllers also showed impaired cognitive function during extended duration work shifts.These findings indicate that extended duration work shifts present a significant challenge to crewmembers and mission support specialists during long-duration space mission operations. Future research is needed to evaluate the efficacy of alternative work schedules and the development and implementation of more effective countermeasures will be required to maintain high levels of performance.     

Taiwan's second remote sensing satellite

FORMOSAT-2 is Taiwan's first remote sensing satellite (RSS). It was launched on 20 May 2004 with five-year mission life and a very unique mission orbit at 891 km altitude. This orbit gives FORMOSAT-2 the daily revisit feature and the capability of imaging the Arctic and Antarctic regions due to the high enough altitude. For more than three years, FORMOSAT-2 has performed outstanding jobs and its global effectiveness is evidenced in many fields such as public education in Taiwan, Earth science and ecological niche research, preservation of the world heritages, contribution to the International Charter: space and major disasters, observation of suspected North Korea and Iranian nuclear facilities, and scientific observation of the atmospheric transient luminous events (TLEs). In order to continue the provision of earth observation images from space, the National Space Organization (NSPO) of Taiwan started to work on the second RSS from 2005. This second RSS will also be Taiwan's first indigenous satellite. Both the bus platform and remote sensing instrument (RSI) shall be designed and manufactured by NSPO and the Instrument Technology Research Center (ITRC) under the supervision of the National Applied Research Laboratories (NARL). Its onboard computer (OBC) shall use Taiwan's indigenous LEON-3 central processing unit (CPU). In order to achieve cost effective design, the commercial off the shelf (COTS) components shall be widely used. NSPO shall impose the up-screening/qualification and validation/verification processes to ensure their normal functions for proper operations in the severe space environments.