Results and Prospects of Studying the Gravitationally Sensitive Systems of Plants under Conditions of Space Flight

Based on systematic studies of the impact of space flight factors on higher plants, carried out for many years both aboard orbital research stations and in the ground laboratories, we have formulated the means of solving the problem of the interaction of mankind with the plant life. The principal feasibility of the growth and development of higher plants (arabidopsis, peas, and wheat) under conditions of space flight is established, including the generative stage (arabidopsis). It is proved that the factors of space flight destabilize the macro- and microstructures of higher plants and their cellular organelles, which is an unambiguous response of cells to the changing conditions of their existence.     

Technological experiments aboard “Salyut-5”

During the flight of the Soviet orbital space complex “Salyut-5”—“Soyuz” the experiments on the space technology and materials production had been conducted amongst the versatility of various scientific research. The experiment “Diffusiya” was aimed at investigating the features of mass transfer under near-zero-gravity conditions. The experimental results had been compared with those obtained under terrestrial conditions and theoretical calculations. The experiment “Potok” was aimed at studying the gas inclusions motion dynamics in the liquid. The crystal growth from solutions was fulfilled with the aid of the “Crystal” instrument. The experiment “Sphera” had an objective to study the solidification of multicomponent metal sample with a free surface. When soldering the pipe junctions use was made of the “Reaktsiya” instrument. The experimental results contributed greatly to the creation of scientific foundations of space technology and material production.     

Excretion of amino acids by humans during space flight

We measured the urine amino acid distribution patterns before, during and after space flight on the Space Shuttle. The urine samples were collected on two separate flights of the space shuttle. The first flight lasted 9.5 days and the second flight 15 days. Urine was collected continuously on 8 subjects for the period beginning 10 d before launch to 6 d after landing. Results: In contrast to the earlier Skylab missions where a pronounced amino aciduria was found, on shuttle the urinary amino acids showed little change with spaceflight except for a marked decrease in all of the amino acids on FD (flight day) 1 (p<0.05) and a reduction in isoleucine and valine on FD3 and FD4 (p<0.05). Conclusions: (i) Amino aciduria is not an inevitable consequence of space flight. (ii) The occurrence of amino aciduria, like muscle protein breakdown is a mission specific effect rather than part of the general human response to microgravity.     

Preliminary results of Cytos 2 experiment.

Cytos 2 experiment, carried out during the French-Soviet manned flight (July 1982), has studied the antibiotics sensitivity of bacteria cultivated in vitro during the orbital flight. The results show an increase of the antibiotics resistance and a larger thickness of the cellular envelope for the inflight cells. The increase of antibiotics resistance can be related to a stimulating effect of space on the cell growth rate or to changes of the cellular envelope structure.     

THEORETICAL ANALYSIS OF InP CRYSTAL GROWTH EXPERIMENT PERFORMED ON-BOARD RUSSIAN FOTON-11 SATELLITE

Traveling heater method (THM) experiments on InP crystal growth from indium solution (SKAT-FD) were performed during the Russian FOTON-11 mission in October 1997. The aim of these experiments was to ascertain the effectiveness of controlling heat and mass transfer in the liquid phase by applying a rotating magnetic field (RMF). As an effort to understand the parameters influencing the crystal growth a mathematical model was developed for numerical simulation of these experiments. The SKAT-FD crystals were grown with RMF at an induction of 1 and 2 mT. As the calculations show, such magnetic fields influence remarkably the hydrodynamics of the melt, and consequently, the growth process. The change of the magnetic induction value (or switching off the RMF) led to an abrupt change of the growth rate, measured from artificial dopant striations produced in the growing crystals by the heat-pulse technique.     

Psychological adaptation and salutogenesis in space: Lessons from a series of studies

Individuals who adapt positively to an inhospitable or extreme environment can derive benefit from their experiences. This positive effect may include an initial improvement in mental health as someone adjusts to the environment (adaptation) as well as more sustained personal growth during the mission (salutogenesis). We review relevant findings from our prior work, including two post-mission surveys of astronauts and cosmonauts, and three studies of crewmembers during missions in a space station simulator, the Mir space station, and the International Space Station (ISS). We also present new analyses showing evidence for adaptation to ISS missions. This finding replicates our previous results from the simulation study, but this effect was not found on the Mir. A better understanding of psychological adaptation and salutogenesis during space flight should help us develop strategies to enhance crewmembers’ in-flight stress tolerance and post-flight adjustment.     

Adaptation of neuromuscular activation patterns during treadmill walking after long-duration space flight

The precise neuromuscular control needed for optimal locomotion, particularly around heel strike and toe off, is known to he compromised after short duration (8- to 15-day) space flight. We hypothesized here that longer exposure to weightlessness would result in maladaptive neuromuscular activation during postflight treadmill walking. We also hypothesized that space flight would affect the ability of the sensory-motor control system to generate adaptive neuromuscular activation patterns in response to changes in visual target distance during postflight treadmill walking. Seven crewmembers, who completed 3- to 6-month missions, walked on a motorized treadmill while visually fixating on a target placed 30 cm (NEAR) or 2 m (FAR) from the subject's eyes. Electronic foot switch data and surface electromyography were collected from selected muscles of the right lower limb. Results indicate that the phasic features of neuromuscular activation were moderately affected and the relative amplitude of activity in the tibialis anterior and rectus femoris around toe off changed after space flight. Changes also were evident after space flight in how these muscles adapted to the shift in visual target distance.     

Spaceflight effects on consecutive generations of peas grown onboard the Russian segment of the International Space Station

In the period from March 2003 to April 2005 we fulfilled five experimental cultivations of genetically marked dwarf pea species in greenhouse Lada installed in the Russian segment (RS) of the International Space Station (ISS). The purpose of this series of experiments was to make morphologic and genetic analysis of pea plants grown in successive generations.According to our results, pea growth and development over the full cycle of ontogenesis (from seed to seed) taking place in space greenhouse Lada were not different as compared with the ground control plants. In addition, four successive pea crops gathered in space flight did not loose their reproductive functions and formed viable seeds.Genetic analysis of the plants grown from the “space” and “ground” seeds produced by the first to fourth successive crops was performed using the methods of chromosomal aberrations count and Random Amplified Polymorphic DNA (molecular method). No genetic polymorphism was found either in the experimental or control crops. This can serve as a sound argument for the supposition that the genetic apparatus of plants is not impacted by exposure of several successive generations to the conditions of space flight.     

Project of the space test&fitting-out dock for solar-powered electric propulsion on-board international space station

A concept of a universal fitting-out module applicable for space flight test of a solar-powered electric propulsion (EP) as well as for the assembly and deployment of small spacecraft (S/C) from the international space station (ISS) is proposed.     

A Ticket pricing strategy for an oligopolistic space tourism market

It is important for any new launch system to develop a successful pricing strategy and to optimize launch system parameters to receive a high economic profit. A question arises, what will happen when an existing suborbital flight market (the first likely to be established in space) is interfered with by a new established orbital flight market for space tourism. There is a risk that the suborbital space tourism market could be almost instantly displaced when a product capable of reaching orbit was introduced. This is best discussed using the following three cases whose results are presented in this paper. Case A presents a ticket pricing strategy for a suborbital and orbital vehicle if the two vehicles do not compete in the same market. Case B shows the necessary ticket pricing strategy for a suborbital vehicle if there is competition from an orbital flight operator. However, the suborbital vehicle would not be able to keep up with a drop in ticket prices due to its obsolete characteristics. Thus, the suborbital vehicle would be forced to stop operation in the year when flight costs became higher than flight receipts as shown in case C.     

Mutagenesis in bacterial spores exposed to space and simulated martian conditions: data from the EXPOSE-E spaceflight experiment PROTECT

As part of the PROTECT experiment of the EXPOSE-E mission on board the International Space Station (ISS), the mutagenic efficiency of space was studied in spores of Bacillus subtilis 168. After 1.5 years' exposure to selected parameters of outer space or simulated martian conditions, the rates of induced mutations to rifampicin resistance (Rif(R)) and sporulation deficiency (Spo(-)) were quantified. In all flight samples, both mutations, Rif(R) and Spo(-), were induced and their rates increased by several orders of magnitude. Extraterrestrial solar UV radiation (>110?nm) as well as simulated martian UV radiation (>200?nm) led to the most pronounced increase (up to nearly 4 orders of magnitude); however, mutations were also induced in flight samples shielded from insolation, which were exposed to the same conditions except solar irradiation. Nucleotide sequencing located the Rif(R) mutations in the rpoB gene encoding the β-subunit of RNA polymerase. Mutations isolated from flight and parallel mission ground reference (MGR) samples were exclusively localized to Cluster I. The 21 Rif(R) mutations isolated from the flight experiment showed all a C to T transition and were all localized to one hotspot: H482Y. In mutants isolated from the MGR, the spectrum was wider with predicted amino acid changes at residues Q469K/L/R, H482D/P/R/Y, and S487L. The data show the unique mutagenic power of space and martian surface conditions as a consequence of DNA injuries induced by solar UV radiation and space vacuum or the low pressure of Mars.     

Plasma and urine catecholamine levels in cosmonauts during long-term stay on Space Station Salyut-7.

The activity of the sympathetic adrenal system in cosmonauts exposed to a stay in space lasting for about half a year has so far been studied only by measuring catecholamine levels in plasma and urine samples taken before space flight and after landing. The device "Plasma 01", specially designed for collecting and processing venous blood from subjects during space flight on board the station Salyut-7 rendered it possible for the first time to collect and freeze samples of blood from cosmonauts in the course of a long-term 237-day space flight. A physician-cosmonaut collected samples of blood and urine from two cosmonauts over the period of days 217-219 of their stay in space. The samples were transported to Earth frozen. As indicators of the sympathetic adrenal system activity, plasma and urine concentrations of epinephrine and norepinephrine as well as urine levels of the catecholamine metabolites metanephrine, normetanephrine, and vanillylmandelic acid were determined before, during and after space flight. On days 217-219 of space flight plasma epinephrine and norepinephrine levels were slightly increased, yet not substantially different from normal. During stress situations plasma norepinephrine and epinephrine levels usually exhibit a manifold increase. On days 217-219 of space flight norepinephrine and epinephrine levels in urine were comparable with pre-flight values and the levels of their metabolites were even significantly decreased. All the parameters studied, particularly plasma norepinephrine as well as urine norepinephrine, normetanephrine, and vanillylmandelic acid, reached the highest values 8 days after landing. The results obtained suggest that, in the period of days 217-219 of the cosmonauts stay in space in the state of weightlessness, the sympathetic adrenal system is either not activated at all or there is but a slight activation induced by specific activities of the cosmonauts, whereas in the process of re-adaptation after space flight on Earth this system is considerably more markedly activated.     

Life support system development in West Germany

The delivery of fully qualified Environmental Control and Life Support System (ECLS) flight hardware for the Spacelab Flight Unit was completed in 1979, and the first Spacelab flight is scheduled for mid 1983.

With Spacelab approaching its operational stage, ESA has initiated the Follow-on Development Programme. The future evolution of Spacelab elements in a continued U.S./European cooperation is obviously linked to the U.S. STS evolution and leads from the sortie-mode improvements (Initial Step) towards pallet systems and module applications in unmanned and manned space platforms (Medium and Far Term Alternatives).

Extensive studies and design work have been accomplished on life support systems for Life Sciences Laboratories (Biorack) in Spacelab (incubators and holding units for low vertebrates).

Future long term missions require the implementation of closed loop life support systems and in order to meet the long range development cycle feasibility studies have been performed. Terrestrial applications of the life support technologies developed for space have been successfully implemented.     

Metabolic changes in the animals subjected to space flight

The activity of the enzymes involved in aminoacid metabolism (tyrosine aminotransferase, TAT, tryptophan pyrrolase TP, serine dehydratase, SD) with rapid response to glucocorticoids and enzymes requiring for activity increase repeated administration of corticosterone (alanine aminotransferase, ALT, aspartate aminotransferase, AST) in liver, the changes of lipolysis in adipose tissue and the plasma corticosterone levels were studied in rats subjected to space flight (F), in animals from synchron model experiments (SM, simulated conditions of space flight in laboratory) and in intact controls (C). The increase of plasma corticosterone concentration and of the activity of rapidly (TAT, TP, SD) and slowly activating enzymes (ALT, AST) was found in F group 6-10 hr after space flight (18.5 days on biosatellite COSMOS 1129). This suggested the presence of acute-stress (associated primarily with the landing) and chronic stress induced hypercorticosteronemia during the flight. After the short 6-day period of recovery the plasma corticosterone concentrations and the activities of liver enzymes returned to control levels. The exposition of animals to repeated immobilization stress showed higher response of corticosterone levels in flight rats as compared to intact controls. No changes in basal lipolysis were observed in flight rats in comparison to intact controls, however the stimulation of lipolysis by norepinephrine was lower in animals from F and SM groups. This lower response of lipolytic processes to norepinephrine was found in flight animals also after six days period of recovery. These results showed that there are important changes in the regulation of lipolytic processes in adipose tissue of rats after space flight and in the conditions of model experiments.     

Analysis and modeling of information flow and distributed expertise in space-related operations

Evolving space operations requirements and mission planning for long-duration expeditions require detailed examinations and evaluations of information flow dynamics, knowledge-sharing processes, and information technology use in distributed expert networks. This paper describes the work conducted with flight controllers in the Mission Control Center (MCC) of NASA's Johnson Space Center. This MCC work describes the behavior of experts in a distributed supervisory coordination framework, which extends supervisory control/command and control models of human task performance. Findings from this work are helping to develop analysis techniques, information architectures, and system simulation capabilities for knowledge sharing in an expert community. These findings are being applied to improve knowledge-sharing processes applied to a research program in advanced life support for long-duration space flight. Additional simulation work is being developed to create interoperating modules of information flow and novice/expert behavior patterns.     

Haploid deletion strains of Saccharomyces cerevisiae that determine survival during space flight

This study identifies genes that determine survival during a space flight, using the model eukaryotic organism, Saccharomyces cerevisiae. Select strains of a haploid yeast deletion series grew during storage in distilled water in space, but not in ground based static or clinorotation controls. The survival advantages in space in distilled water include a 133-fold advantage for the deletion of PEX19, a chaperone and import receptor for newly- synthesized class I peroxisomal membrane proteins, to 77–40 fold for deletion strains lacking elements of aerobic respiration, isocitrate metabolism, and mitochondrial electron transport. Following automated addition of rich growth media, the space flight was associated with a marked survival advantage of strains with deletions in catalytically active genes including hydrolases, oxidoreductases and transferases. When compared to static controls, space flight was associated with a marked survival disadvantage of deletion strains lacking transporter, antioxidant and catalytic activity. This study identifies yeast deletion strains with a survival advantage during storage in distilled water and space flight, and amplifies our understanding of the genes critical for survival in space.     

Conditions of the Maximum Principle in the Problem of Optimal Control over an Aggregate of Dynamic Systems and Their Application to Solution of the Problems of Optimal Control of Spacecraft Motion

The necessary first-order conditions of strong local optimality (conditions of maximum principle) are considered for the problems of optimal control over a set of dynamic systems. To derive them a method is suggested based on the Lagrange principle of removing constraints in the problems on a conditional extremum in a functional space. An algorithm of conversion from the problem of optimal control of an aggregate of dynamic systems to a multipoint boundary value problem is suggested for a set of systems of ordinary differential equations with the complete set of conditions necessary for its solution. An example of application of the methods and algorithm proposed is considered: the solution of the problem of constructing the trajectories of a spacecraft flight at a constant altitude above a preset area (or above a preset point) of a planet's surface in a vacuum (for a planet with atmosphere beyond the atmosphere). The spacecraft is launched from a certain circular orbit of a planet's satellite. This orbit is to be determined (optimized). Then the satellite is injected to the desired trajectory segment (or desired point) of a flyby above the planet's surface at a specified altitude. After the flyby the satellite is returned to the initial circular orbit. A method is proposed of correct accounting for constraints imposed on overload (mixed restrictions of inequality type) and on the distance from the planet center: extended (nonpointlike) intermediate (phase) restrictions of the equality type.     

The first "space" vegetables have been grown in the "SVET" greenhouse using controlled environmental conditions

The paper describes the "SVET" project--a new generation of space greenhouse with small dimensions. Through the use of a minicomputer, "SVET" is fully capable of automatically operating and controlling environmental systems for higher plant growth. A number of preliminary studies have shown the radish and cabbage to be potentially important crops for CELSS (Closed Environmental Life Support System). The "SVET" space greenhouse was mounted on the "CRYSTAL" technological module docked to the Mir orbital space station on 10 June 1990. Soviet cosmonauts Balandin and Solovyov started the first experiments with the greenhouse on 15 June 1990. Preliminary results of seed cultivation over an initial 54-day period in "SVET" are presented. Morphometrical characteristics of plants brought back to Earth are given. Alteration in plant characteristics, such as growth and developmental changes, or morphological contents were noted. A crop of radish plants was harvested under microgravity conditions. Characteristics of plant environmental control parameters and an estimation of functional properties of control and regulation systems of the "SVET" greenhouse in space flight as received via telemetry data is reported.     

Predictors of immune function in space flight

Of all of the environmental conditions of space flight that might have an adverse effect upon human immunity and the incidence of infection, space radiation stands out as the single-most important threat. As important as this would be on humans engaged in long and deep space flight, it obviously is not possible to plan Earth-bound radiation and infection studies in humans. Therefore, we propose to develop a murine model that could predict the adverse effects of space flight radiation and reactivation of latent virus infection for humans. Recent observations on the effects of gamma and latent virus infection demonstrate latent virus reactivation and loss of T cell mediated immune responses in a murine model. We conclude that using this small animal method of quantitating the amounts of radiation and latent virus infection and resulting alterations in immune responses, it may be possible to predict the degree of immunosuppression in interplanetary space travel for humans. Moreover, this model could be extended to include other space flight conditions, such as microgravity, sleep deprivation, and isolation, to obtain a more complete assessment of space flight risks for humans.     

Effect of weightlessness on sympathetic-adrenomedullary activity of rats.

Three cosmic experiments were performed in which rats spent 18-20 days in space on board the biosatellites "COSMOS 782", "COSMOS 936" and "COSMOS 1129". The following indicators of the sympathetic-adrenomedullary system (SAS) activity were measured: tissue and plasma catecholamines (CA), CA-synthesizing enzymes--tyrosine hydroxylase (TH), dopamine-beta-hydroxylase (DBH), phenylethanolamine-N-methyltransferase (PNMT)--as well as CA-degrading enzymes-monoamine oxidase (MAO) and catechol-O-methyltransferase (COMT). Adrenal epinephrine (EPI) and norepinephrine (NE) as well as CA-synthesizing and degrading enzymes were not significantly changed in the animals after flight on COSMOS 782. On the other hand, a significant increase was found in heart CA, the indicator which is usually decreased after stress. 26 days after landing all values were at control levels. The results obtained, compared to our previous stress experiments on Earth, suggest that prolonged weightlessness does not appear to be a pronounced stressful stimulus for the SAS. Heart and plasma CA, mainly NE, were increased both in the group living in the state of weightlessness and the group living in a centrifuge and exposed to artificial gravitation 1 g (COSMOS 936), suggesting again that prolonged weightlessness is not an intensive stressful stimulus for the SAS. The animals exposed after space flight on COSMOS 1129 to repeated immobilization stress on Earth showed a significant decrease of adrenal EPI and an expressive increase of adrenal TH activity compared to stressed animals which were not in space. Thus, the results corroborate that prolonged state of weightlessness during space flight though not representing by itself an intensive stressful stimulus for the sympathetic-adrenomedullary system, was found to potentiate the response of "cosmic rats" to stress exposure after return to Earth.