Mitigation of Iron Irradiation-Induced Genotoxicity and Genomic Instability by Postexposure Dietary Restriction in Mice

Background and Purpose. Postexposure onset of dietary restriction (DR) is expected to provide therapeutic nutritional approaches to reduce health risk from exposure to ionizing radiation (IR) due to such as manned space exploration, radiotherapy, or nuclear accidents as IR could alleviate radiocarcinogenesis in animal models. However, the underlying mechanisms remain largely unknown. This study is aimed at investigating the effect from postexposure onset of DR on genotoxicity and genomic instability (GI) induced by total body irradiation (TBI) in mice. Materials and Methods. Mice were exposed to 2.0 Gy of accelerated iron particles with an initial energy of 500 MeV/nucleon and a linear energy transfer (LET) value of about 200 keV/μm. After TBI, mice were either allowed to free access to a standard laboratory chow or treated under DR (25% cut in diet). Using micronucleus frequency (MNF) in bone marrow erythrocytes, induction of acute genotoxicity and GI in the hematopoietic system was, respectively, determined 1 and 2 months after TBI. Results and Conclusions. TBI alone caused a significant increase in MNF while DR alone did not markedly influence the MNF. DR induced a significant decrease in MNF compared to the treatment by TBI alone. Results demonstrated that postexposure onset of DR could relieve the elevated MNF induced by TBI with high-LET iron particles. These findings indicated that reduction in acute genotoxicity and late GI may be at least a part of the mechanisms underlying decreased radiocarcinogenesis by DR.

Numerical Analysis of Smoke Behavior and Detection of Solid Combustible Fire Developed in Manned Exploration Module Based on Exploration Gravity

A fire during manned space exploration can cause serious casualties and disrupt the mission if the initial response is delayed. Therefore, measurement technology that can detect fire in the early stage of ignition is important. There have been a number of works that investigate the smoke behaviors in microgravity as the foundation for a reliable method for sensing a fire during spaceflight. For space missions to the outer planets, however, a strategy of detecting smoke as an indicator of fire should be adjusted to cover the fire scenario that can be greatly affected by changes in gravity (microgravity, lunar, Mars, and Earth gravity). Therefore, as a preliminary study on fire detectors of the manned pressurized module, the present study examined the smoke particle behavior and detection characteristics with respect to changes in gravity using numerical analysis. In particular, the effects of the combination of buoyancy and ventilation flow on the smoke particle movement pattern was investigated to further improve the understanding of the fire detection characteristics of the smoke detector, assuming that a fire occurred in different gravity environments inside the pressurized module. To this end, we modeled the internal shape of Destiny and performed a series of numerical analysis using the Fire Dynamics Simulator (FDS). The findings of this study can provide basic data for the design of a fire detection system for manned space exploration modules.

Key points for the development of antioxidant cocktails to prevent cellular stress and damage caused by reactive oxygen species (ROS) during manned space missions

Exposure to microgravity and ionizing radiation during spaceflight missions causes excessive reactive oxygen species (ROS) production that contributes to cellular stress and damage in astronauts. Average spaceflight mission time is expected to lengthen as humanity aims to visit other planets. However, longer missions or spaceflights will undoubtedly lead to an increment in microgravity, ionizing radiation and ROS production. Strategies to minimize ROS damage are necessary to maintain the health of astronauts, future space colonists, and tourists during and after spaceflight missions. An antioxidant cocktail formulated to prevent or mitigate ROS damage during space exploration could help maintain the health of space explorers. We propose key points to consider when developing an antioxidant cocktail. We discuss how ROS damages our body and organs, the genetic predisposition of astronauts to its damage, characteristics and evidence of the effectiveness of antioxidants to combat excess ROS, differences in drug metabolism when on Earth and in space that could modify antioxidant effects, and the characteristics and efficacy of common antioxidants. Based on this information we propose a workflow for assessing astronaut resistance to ROS damage, infight monitoring of ROS production, and an antioxidant cocktail. Developing an antioxidant cocktail represents a big challenge to translate current medical practices from an Earth setting to space. The key points presented in this review could promote the development of different antioxidant formulations to maintain space explorers’ health in the future.

Optimization of 110 m Aperture Fully Steerable Radio Telescope Prestressed Back Frame Structure Based on a Genetic Algorithm

Radio telescopes play an important role in lunar exploration projects, manned space flight projects, and navigation systems. China is constructing a giant 110 m aperture ground-based fully steerable radio telescope in Qitai County, Xinjiang Uygur Autonomous Region. In this paper, a 110 m aperture fully steerable radio telescope prestressed back frame structure is proposed and optimized to improve the reflector accuracy and to reduce the weight of the telescope. First, prestressed cables are introduced into the back frame structure, and three innovative cable layout schemes are presented. Second, for stress state analysis, the wind pressure distribution on the main reflector is explored using wind tunnel experiments. Third, some improvements in genetic algorithms for addressing computational complexity are explained. Finally, the effects of prestressed cables on the weight reduction and reflector accuracy improvement are analysed. Additionally, in order to evaluate the safety of the prestressed back frame structure, its strength has been checked, and the internal force and displacement under static conditions and in earthquakes are interpreted in detail.

The 35th Anniversary of the Launch of Mir’s First Module: Main Results of Applied Scientific Research and Experiments Carried Out Onboard the Manned Orbital Complex.

For 15 years (1986–2001) the orbital station “Mir” served as the only manned space laboratory for long-term scientific and technical experiments and human body research in space. This multipurpose international complex began to op-erate on February 20, 1986 when its base module was placed into orbit. The re-sults, obtained during that period, have made a great contribution to domestic fundamental science and today they are of great practical value for various sectors of the national economy, education, health care, and development of space vehicles.

Photobioreactor Limnospira indica Growth Model: Application From the MELiSSA Plant Pilot Scale to ISS Flight Experiment

Bioregenerative life support systems (BLSS) are the foundation stone to self-sustainable manned space missions. The MELiSSA is a BLSS concept that has evolved through a mechanistic engineering approach designed to acquire both theoretical and technical knowledge on each subsystem independently and, therefore, produces the necessary knowledge and experience needed to co-integrate all the subsystems together with a high level of control. One of the subsystems is a photobioreactor colonized by an axenic culture of the cyanobacterium Limnospira indica PCC8005 for revitalizing the air for the crew. This subsystem was extensively studied, and a mass balanced mechanistic model was developed to describe, predict, and control the photobioreactor. The model was based on a light transfer limitation model coupled to a kinetic model for the cyanobacteria growth through a Linear Thermodynamics of Irreversible Processes (LTIP) approach, including substrate limitation. The model was integrated into several hydrodynamic models adapted to several photobioreactors design and experiments, from a 100 L airlift pilot scale ground photobioreactor to a 50 ml membrane photobioreactor for ISS flight. Through this article we detail the principles of this mechanistic model and their application to different photobioreactor scales for predictive and descriptive simulations.

Chronicle of an extraordinary space journey (ballistic analysis of Soyuz T-15 flight)

35 years ago, in March 1986, a unique flight of the Soyuz T-15 transport manned vehicle was performed, including in its program the flight of the crew from one orbital station to another (from the Mir station to the Salyut-7 station) and back. In the 60-year history of manned space exploration, such a double flight continues to be the only one of its kind. The article considers the circumstances that developed at the time of the Mir station launch into orbit — the first station of the 3rd generation. The approaches adopted during the development of the ballistics profile and the operational changes required during its implementation are described in detail. In conclusion, the actual fuel consumption of all spacecraft involved in this scheme is presented. It is assumed that the experience gained during the implementation of flights can be used in future promising manned missions, both in near-Earth orbit and in the implementation of the future Lunar program. Key words: orbital station Salyut, orbital station Mir, manned vehicle, orbital flights, prospective human missions.

75th anniversary of S.P. Korolev Rocket and Space Corporation Energia

The article briefly discusses the key achievements of the enterprise over 75 years from the formation of OKB-1 headed by S.P. Korolev for producing intercontinental range missiles to the current status of RSC Energia being the country’s and world leader in manned space flight. The developed intercontinental missiles R-7 and a closed-loop oxygen-hydrocarbon liquid-propellant rocket engine provided the basis for developing integrated launch vehicles which were used to launch the world's first Earth satellite, the first cosmonaut on the Earth, automatic interplanetary stations to the Moon, Venus, Mars. The diversification of the enterprise impeded S.P. Korolev to concentrate on manned space flights, and he initiated the transfer of development and manufacture of combat missiles to Makeyev DB, integrated launch vehicles to TsSKB Progress, communication and other satellites to M.F. Reshetnev ISS, lunar and interplanetary stations to S.A.Lavochkin NPO. In the 1980s under the guidance of V.P. Glushko the Energia super-heavy launch vehicle and Energia-Buran system in unmanned configuration were developed and successfully launched on the first try. The Salyut manned single-module orbital stations, Mir multifunctional multi-module space laboratory and successfully operating upgraded manned transportation (Soyuz) and logistics (Progress) spacecraft were developed. In the hard times of 1990s, RSC Energia under the guidance of Yu.P. Semenov saved the national cosmonautics through commercial research performed on the Mir station. At present, by launching three additional modules RSC Energia is completing assembly and integration of the Russian Segment into the International Space Station. Keywords. ОKB-1, S.P.Korolev RSC Energia, V.P. Glushko, Yu.S. Semenov, integrated launch vehicle, orbital station, crew transportation spacecraft, logistics transportation spacecraft, International Space Station.