Search

The Moon has returned into the focus of human endeavors regarding human spaceflight, e.g., with NASA's Artemis program, ESA's Moon Village, and the Russian/Chinese International Lunar Research Station. In difference to the pathfinding missions of the Apollo -era, the goal for these future missions is to stay on the lunar surface for longer durations and inhabit the lunar environment (near-)permanently. This requires a different approach to be affordable, i.e., instead of resupply as mostly used on e.g., the International Space Station, resource management has to include recycling and in-situ utilization. The former especially calls for the application of so-called BLSS to allow providing essential life-support services to the crew without prohibitive resource consumption, which is economically not feasible to achieve with resupplies. Bio-regenerative-life-support systems have been researched for decades, yet the system complexity, technology advancements, and singular aspects as e.g., plant biology require more research, especially if combined as in a greenhouse. For instance, the understanding of how a microbiome develops in a closed environment and what implications the microbiome has on plant growth is still insufficient. Within the EDEN project, the German Aerospace Center built a lunar analogue greenhouse and operated it at the Neumayer-III research station in Antarctica for four years, testing the technology – which was not space hardware – and operations. Derived from this experience the next step in the project is to design and subsequently operate a ground test demonstrator for a lunar greenhouse, as close as possible to the actual space hardware and operations. This paper explains the current design and trade-offs that led to it. Furthermore, the concept of operations is shown to illustrate the demonstrator's utility for researching bioregenerative-life-support. Overall, the system presented is feasible and useful to close the gaps, currently still existing in this field of research, and thus a mission enabler for future long-duration human space exploration missions. • Design of an integrated greenhouse module test demonstrator. • Extensive science program definition. • Mission scenario definition for lunar greenhouse. • Discussion of benefits and open issues. [ABSTRACT FROM AUTHOR]

Satellite operators struggle to communicate with their satellites over Europe in the UHF amateur band (430–440 MHz) due to high power in-orbit interference. Statistical characterisation of the interference beyond average interference levels using in-orbit measurements is useful for the design of suitable countermeasures. Some recent studies have started to investigate both the frequency and time behaviour of the interference, but more measurements are needed to cover the whole UHF amateur band. In this paper, we use the Local Mean Envelope (LME) method to analyse the time and frequency characteristics of in-orbit radio interference from the LUME-1 satellite, measured in the 437 MHz band. Satellite measurements were performed on a TOTEM Software-Defined Radio (SDR), in orbit over Europe and Antarctica and the results were downloaded for analysis on the ground. The average power spectrum and the variability of the LME for different time windows in the 437 MHz band are presented. The data analysis also includes the coefficient of variation of the LME to study the dispersion of the interference. The results are compared to previous measurements in the 435 MHz band using the same method. The new results are found to differ compared with previous measurements on the 435 MHz band. The bandwidth of the band-limited signals measured at 435 MHz was found to be 300 kHz, and at 437 MHz, 200 kHz wide for this dataset. Also, the interference power was found to be higher for 437 MHz. In both cases the interference behaviour is highly non-Gaussian, suggesting that typical communication countermeasures will not be sufficient. Although more measurements are needed for better spatial resolution, our findings may contribute to explaining why satellite operations are difficult on these bands. A better knowledge of the time and frequency variability of the interference can indicate which mitigation techniques are required and are efficient to improve satellite communication in that band. • Average interference power and the spread in envelope was higher in the 437.28 MHz band than in the 435 MHz band. • A 200 kHz band-limited interference signal was detected at 437.28 MHz in contrast with the 300 kHz bandwidth of the signal at 435 MHz. • The interference behaviour is highly non-Gaussian. • Countermeasures assuming Additive White Gaussian Noise (AWGN) will not be realistic in this band. • Interference measured explains challenges experienced by operators of small satellites. [ABSTRACT FROM AUTHOR]

Interplanetary human missions to Mars and beyond will suppose a very demanding physical and psychological environment for future astronauts. Isolation, confinement, hypoxia or hypercapnia in a less pressurized atmosphere, darkness and other factors are expected to endanger a mission's success, directly influencing human performance. In order to study the effects of such environmental conditions on human beings, the SIMSKILL Experiment aims to investigate how spacecraft piloting performance decays over time by deploying a Soyuz flight simulator on the Antarctic research stations Halley VI and Concordia, which feature similar living conditions as those of a space mission, leading eventually to muscular atrophy, loss of cognitive capacities, and reduction of psycho-motor skills. This paper offers an analysis on the recorded data from the scientific campaigns in Antarctica, compared to those of the subjects in a control group in Stuttgart, Germany. An overall total of 69 subjects and more than one thousand approach and docking flights to the ISS performed in a Soyuz-TMA simulator have been analysed using a performance assessment methodology. The post-processed simulation dataset allows to recognize collective trends and find which are the essential parameters that affect the pilot's skill evolution. The results obtained from this analysis show how the influence of isolation, confinement and hypoxia in Antarctica is crucial to understand how differences in performance appear between subjects. The significance of the obtained results has been proven by means of statistical models, which show that a one-month training refreshing delivers satisfactory performance for a docking simulation, whereas a frequency of 3 months follows to a loss of piloting reliability. Moreover, the effect of isolation and hypoxia aggravates the loss of flight performance. • Use of a Soyuz space flight simulator for the analysis of flight performance. • International Space Station approach and docking procedures prove to be an optimal testbed for human performance analysis. • Antarctic isolation and confinement conditions cause a degradation on spacecraft piloting performance. • Training intervals of three months show a decrease on flight performance and reliability. • The hypoxic environment at the Concordia Station exacerbates the decay of piloting skills. [ABSTRACT FROM AUTHOR]