Concerning the impact of deorbiting spacecraft to the upper atmosphere

Author(s):  
Leonard Schulz ◽  
Karl-Heinz Glassmeier

<p>The increasing activities in space due to more and more countries with space programs, advancing commercialization, and large satellite constellation projects lead to a rising number of human-made objects in space. While many of those stay in orbit at high altitudes, objects in low Earth orbit reenter the atmosphere mostly disintegrating and injecting material into the atmosphere. The growing concern about space debris has led to policies encouraging deorbiting of satellites at the end of their lifetime. All that will increase the annual mass influx into the atmosphere by human-made (anthropogenic) objects in the future. We compare the influx of those objects to the natural mass influx of entering meteoroids of asteroidal, cometary, and planetary origin into Earth's atmosphere. We look at the mass and the elemental composition of the entering bodies also incorporating different ablation of those objects. This way, a quantitative assessment of the annual injection of aerosols and atomic remnants into the atmosphere is possible. Today, anthropogenic material makes up way less than 1 % of the overall injected mass. However, future large spacecraft constellations could increase the anthropogenic influx significantly, then contributing 4 % or more of the whole injection. As spacecraft have a high abundance of metal elements, the metal mass portion of the injection can reach up to 15 %. For some elements, the anthropogenic injection may even prevail the natural injection. This implies for future large satellite constellations that the anthropogenic injection can become significant with unknown effects on the upper atmosphere and the terrestrial habitat.</p>

2021 ◽  
Vol 6 (1) ◽  
pp. 16
Author(s):  
Peter Simon Sapaty

The threats of space debris are enormously high, which are increasing due to launch of multi-satellite constellations, especially in low-Earth orbit, with millions of pieces of junk there. Different passive and active debris removal methods are being developed like self-deorbiting of used satellites, drag sails, mechanical grasps, tethers and nets, also directed energy, lasers including. Space junk is the responsibility of the whole mankind, and the problem of managing space debris is both the international challenge and the opportunity to preserve the space environment for future space exploration missions. The paper shows how self-organized constellation networks of deorbiting satellites can organize multiple cleaning operations autonomously under the developed Spatial Grasp Technology (SGT), with cooperative involvement of the whole network and minimum interaction with costly ground antennas and stations. It also offers a unique solution where most dangerous junk items can themselves be treated as active virtual-physical items freely moving through terrestrial and celestial environments and ultimately finding, by their own initiative, the proper cleaning satellites. This can effectively organize the global junk management and removal problem, where the active junk items can keep initiative of self-removal for any time needed and using any distributed resources. A combined solution is also offered with initial global search for approximate satellite-debris matching, after which the junk is delegated its own initiative to find the absolute match by traveling around the globe as far and as long as required. The paper shows and explains different practical cleaning scenarios in the high-level Spatial Grasp Language (as key element of SGT) and possibilities of quick implementation of the approach.


2021 ◽  
Vol 11 (20) ◽  
pp. 9490
Author(s):  
Shuyi Ren ◽  
Xiaohua Yang ◽  
Ronglan Wang ◽  
Siqing Liu ◽  
Xiaojing Sun

The wide application of satellite constellations in the field of space-based global communications and remote sensing has led to a substantial increase in small-satellite launch plans, a sharp increase in the density of space objects in low-Earth orbit (LEO), and a reduction in available orbit and frequency resources. This will further aggravate the trend of deterioration of the space debris environment. Taking the Starlink constellation as an example, this paper describes the influence of the constellation from the environmental debris flux of the satellite, the evaluation of the number of evasion maneuvers, the change of risk level, the success rate of post mission disposal (PMD) and the growth rate of space objects. The simulation results show that the collision risk of the Starlink constellation is related to the orbital parameters, and the higher success rate of post-mission disposal (PMD) can reduce the collision risk of the constellation. The large constellations increases the growth rate of space objects, and even if all the satellites are disposed of after the mission, the impact of constellations on the space environment can not be offset.


Author(s):  
Nina M. Meshchakova ◽  
Marina P. Dyakovich ◽  
Salim F. Shayakhmetov

Introduction.Methanol and its derivatives occupy one of the leading places among the main organic synthesis intermediates in terms of their importance and scale of production. According to experts, by 2027 the global demand for methanol can reach 135 million tons, the annual growth will be about 5.5%. However, there is little information regarding the assessment of working conditions and occupational risks for workers in modern methanol production and its derivatives.The aim of the studyis hygienic assessment of working conditions and the formation of health risks in workers of modern production of methanol and methylamines.Materials and methods.The assessment of the main adverse factors of production is given. When studying the state of health, objective indicators (the results of an in-depth medical examination) and subjective (the results of a quantitative assessment of the risks of the main pathological syndromes associated with health) are considered.Results.According to long-term observations, the concentration of harmful substances in the air of the working area, indicators of labor severity, parameters of physical factors met hygienic requirements, with the exception of industrial noise exceeding the maximum permissible level, as well as labor intensity of 1 degree. The General assessment of working conditions corresponds to the category of harmful 2 degrees (3.2). According to the results of the medical examination and quantitative assessment of the risks of health disorders in workers, the most significant were functional disorders and diseases of the circulatory system. The levels of somatic pathology on the part of the main body systems were significantly higher in apparatchiks compared to the engineering and technical personnel (ETP).Conclusions:In the production of methyl alcohol and methylamines, the main hygienic importance is the impact on workers of the complex of harmful substances of 1-IV hazard classes in low concentrations, increased levels of industrial noise, labor intensity of 1 degree. According to the subjective assessment of health and medical examination, the greatest prevalence of health risks in workers was observed from the circulatory system, and the levels of the revealed somatic pathology were statistically significantly higher in apparatchiks compared with the ETP.


Electronics ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 577
Author(s):  
Luca Schirru ◽  
Tonino Pisanu ◽  
Angelo Podda

Space debris is a term for all human-made objects orbiting the Earth or reentering the atmosphere. The population of space debris is continuously growing and it represents a potential issue for active satellites and spacecraft. New collisions and fragmentation could exponentially increase the amount of debris and so the level of risk represented by these objects. The principal technique used for the debris monitoring, in the Low Earth Orbit (LEO) between 200 km and 2000 km of altitude, is based on radar systems. The BIRALET system represents one of the main Italian radars involved in resident space objects observations. It is a bi-static radar, which operates in the P-band at 410–415 MHz, that uses the Sardinia Radio Telescope as receiver. In this paper, a detailed description of the new ad hoc back-end developed for the BIRALET radar, with the aim to perform slant-range and Doppler shift measurements, is presented. The new system was successfully tested in several validation measurement campaigns, the results of which are reported and discussed.


2020 ◽  
Vol 29 (1) ◽  
pp. 94-106
Author(s):  
Chongyuan Hou ◽  
Yuan Yang ◽  
Yikang Yang ◽  
Kaizhong Yang ◽  
Xiao Zhang ◽  
...  

AbstractThe increase in space debris orbiting Earth is a critical problem for future space missions. Space debris removal has thus become an area of interest, and significant research progress is being made in this field. However, the exorbitant cost of space debris removal missions is a major concern for commercial space companies. We therefore propose the debris removal using electromagnetic launcher (DREL) system, a ground-based electromagnetic launch system (railgun), for space debris removal missions. The DREL system has three components: a ground-based electromagnetic launcher (GEML), suborbital vehicle (SOV), and mass of micrometer-scale dust (MSD) particles. The average cost of removing a piece of low-earth orbit space debris using DREL was found to be approximately USD 160,000. The DREL method is thus shown to be economical; the total cost to remove more than 2,000 pieces of debris in a cluster was only approximately USD 400 million, compared to the millions of dollars required to remove just one or two pieces of debris using a conventional space debris removal mission. By using DREL, the cost of entering space is negligible, thereby enabling countries to remove their space debris in an affordable manner.


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