Journal of Space Safety Engineering最新文献

Cislunar space is a region of growing interest with nations investing resources to cultivate long presence habitations on the lunar surface. With this increased attention and expansion of missions, both crewed and uncrewed, the likelihood of a mishap or a spacecraft becoming impaired and unable to continue its mission will also increase. The present research adds to the field of cislunar mission operations and trajectory analysis by investigating search and rescue (SAR) operations via rendezvous and proximity operations (RPO) with an impaired notional spacecraft located in a Near-Rectlinear Halo Orbit (NRHO). This research compares the response times of rescuer spacecraft located in sample distant retrograde orbits (DROs) and $L_1$/$L_2$ Lyapunov orbits for the timely far rendezvous with the impaired spacecraft located in the NRHO. This will simulate a variety of far rendezvous whereby the impaired spacecraft’s location within the NRHO and the rescuer spacecraft in the $L_1$/$L_2$ Lyapunov and DRO orbit families are varied. A series of minimum time optimal control problems are posed using the circular restricted three-body problem (CR3BP) dynamics, and pseudospectral methods are used to find solutions given an example maximum $\Delta V$ constraint of 3 km/s. The results reinforces our intuition that rendezvous time of flight (TOF) between orbits within the $L_1$, $L_2$, and DRO families and the targeted NRHO correlate with proximity to the NRHO, with the shortest far rendezvous times in each family found to be approximately 6 hours, 4.5 hours, and 10 hours respectively. The results further show that a constellation of two rescue spacecraft could be positioned within the three orbit families to achieve far rendezvous with the chosen NRHO in under one day.

A number of physiological investigations focused on human cardiorespiratory system have been conducted at Vostok station in Central Antarctica during the wintering of 2019.

During the one-year expedition at the Vostok station, the cardiorespiratory system gradually adapted to the unusual conditions of life and work in the isolated, confined and extreme (ICE) environment of Central Antarctica.

We hypothesized that during a long stay in the conditions of the Central Antarctica the adaptation strategy to physical environmental conditions for representatives of two age groups will differ, which will be evident from the dynamics of indicators of the functioning of the cardiovascular system and when assessing the autonomic nervous system status.

The level of blood oxygen saturation stabilized by the second month and was in the range of 86.0-91.0%, which corresponded to a reduced partial pressure of oxygen in the inhaled air. In terms of the respiratory system, central sleep apnea was noted in all subjects throughout the study. Quantitative analysis revealed that the average number of apneas per hour was 43, and their average duration was 25.2 seconds. The maximum apnea number was recorded at the beginning and middle of wintering, while before the end of the expedition the episodes became rarer. In all age groups there was a shortening of the PQ interval, with a tendency towards normalization by the end of wintering, while in the first age group the shortening of the interval was more significant than in the second, which apparently can be explained by a more pronounced active reaction of the sympathetic nervous system of polar explorers of the first age group.

Adaptive Potential Index (API) level remained practically unchanged throughout the wintering period in 9 out of 11 members of the expedition. The API value was predominantly in the range from 2.11 to 3.20 points, which corresponds to the level of “adaptation stress”. The autonomous nervous system (ANS) status was assessed by Kerdo Index (KI) values. KI positive dynamic was noted in 90% of cases by the 5th month of wintering. A direct correlation was found between the degree of positive shift in the KI value and the age of the participant. The gained results do not allow us to state that ANS has fully adapted to the conditions of life and work at the station. The results of this investigation demonstrate stable and positive adaptation trend to the ICE environment of Central Antarctica throughout the study period, regardless of age and wintering experience.

The Mars Sample Return campaign aims to use three flight missions and one ground element to safely bring rock cores, regolith and atmospheric samples from the surface of Mars to Earth to answer key questions about the geologic and climate history of Mars, including the potential for ancient life. Since its landing in Jezero Crater in 2021, the first mission, NASA’s Mars 2020, has collected a number of samples on the crater floor and on the delta using the Perseverance rover. Subsequent missions would recover the sealed sample tubes, launch them into Mars orbit, and transport them back to Earth. The ground element would be a high-containment facility that would isolate and protect the samples during initial sample characterization, which would include sample safety assessments and time-sensitive scientific investigations. These elements are currently in the planning and design stages of development, and represent an international effort of NASA, the European Space Agency (ESA), and many industry partners. The work presented here provides an overview of the planetary protection strategy of the third flight mission, the ESA-led Earth Return Orbiter, which hosts the NASA-provided Capture, Containment, and Return System. The orbiter would detect and capture the container with up to 30 sealed tubes previously put in Martian orbit, contain them in redundant containers to ensure that no potentially hazardous Mars particles are released, and return them to Earth through an entry vehicle. Both NASA and ESA policies comply with the United Nations’ Outer Space Treaty by planning to protect Earth’s biosphere from any potential adverse effects from material returned from solar system bodies beyond the Earth-Moon system. In the conduct of Mars Sample Return, the two agencies have mutually agreed to apply approaches consistent with their own planetary protection standards to the campaign elements they each provide.

Recent years are witnessing the rapid technological development in airspace domain, actually paving the way to the development of a commercial space market. Until the recent past, space operations have been essentially performed by research centers or military agencies, in usually segregated areas to ensure third parties’ safety, governed by launch base regulations and organized in an unscheduled manner. However, with the entry of private companies into the space domain, a new market niche is being created: that of commercial space transportation. For example, a promising area is the one related to operations performed by commercial suborbital flights, whether aimed at space tourism or simply transporting things and/or passengers from one point to another on the Earth's surface. The traffic volumes are supposed to increase in next years and segregating airspace does not represent a sustainable solution for the future.

The present paper will first assess the state of the art of the regulatory framework currently applicable to operators in order to obtain authorization to perform space missions for commercial use, then propose a comparison between the United State of America and European regulatory frameworks. Main challenges related to regulatory aspects will be identified and perspectives on possible higher airspace operations integration in the medium-long term will be derived. Finally, safety considerations deriving from a seamless accommodation of higher airspace operations in current Air Traffic Management will be derived for the medium-long term. In conclusion, this work reveals that neither the United States nor Europe has formally approved a legal framework establishing certification procedures for sub-orbital space transport systems. Currently, the US legislation is the most applicable as it has comprehensive rules to allow operators to obtain flight authorization ensuring compliance with requirements through a compliance matrix periodically updated.

The space data association (SDA) has been providing reliable flight safety products for approximately 30 spacecraft operators for 14 years now. The service provides conjunction warnings and operator points of contact for around 700 spacecraft occupying all orbital regimes. The SDA's Space Data Center (SDC), built by AGI and maintained and operated by COMSPOC Corporation, has a proven track record of providing high availability space traffic coordination (STC) products since becoming operational on 15 July 2010.

Earlier this year, the SDA, and its chief technical consultant, COMSPOC Corporation, supported the U.S. Department of Commerce (DOC) Geosynchronous Earth Orbit (GEO) and Middle Earth Orbit (MEO) Pilot project by providing comprehensively fused orbit solutions, ten-day orbit ephemeris and covariance predictions, and smoothed reference ephemerides for 100 active spacecraft. Most of these spacecraft are operated by SDA members and participants, allowing the operators to collaboratively contribute their maneuver plans, GPS NavSol measurements, active ranging, and passive RF observations, and authoritative spacecraft dimensions to the DOC Pilot project. For its part, COMSPOC employed its Space Situational Awareness (SSA) Software Suite (SSS)to comprehensively fuse this diverse set of spacecraft operator observations with COMSPOC's own observations from its global network of optical sensors.

The first phase of this collaborative data fusion required the establishment of accounts, data connectivity, file transfer methods, and sensor calibration. This required about one month of technical interchange, provision of operator sensor locations and specifics, and COMSPOC SSS operator calibration of those sensors for each spacecraft.

But once the data flows, sensor calibrations, and maneuver readers were completed, the second phase drew upon a nearly continuous stream of fused observations and maneuvers to yield accurate and timely predictive ephemerides and covariance time histories. These data products are well-suited to the collision avoidance problem.

Since the late 1950s, as the mankind has been exploring space, the amount of space debris (spacecraft not removed from the orbit at the end of their service life, upper stages, as well as the fragments of spacecraft and upper stages formed as a result of deliberate or accidental collision of spacecraft and upper stages with each other or with natural space debris (meteorites)) with poorly predictable masses and velocities has created a global spacecraft safety problem.

Various countries conducting space research have adopted special standards and guidelines for space debris mitigation, which require a spacecraft to be transferred to a disposal orbit at the end of its operation. For various reasons, they are not always implemented in practice.

This paper is a continuation of the previous study conducted to systematize methods developed for debris removal from the near-Earth space up to date. It presents a set of technologies that can be used to transfer space debris to a graveyard orbit using a rigid coupling between space debris and service spacecraft.

The lunar environment presents unique challenges for human health and safety over the course of performing Extravehicular Activities (EVAs) during early Artemis missions. Medical conditions leading to an injured EVA crewmember needing assistance or rescue were analysed and correlated to established, defined consequence categories. Catastrophic conditions were identified, and three mitigation strategies were analysed to determine if there was a potential change in consequence with their application. Risk consequence across the mitigations were compared with each other and the original risk without mitigations. Mitigations were further evaluated in a broader context with prospective preventions to understand the design and risk trade space associated with an early Artemis EVA.

The next goal of human space exploration is to return to the Moon to stay, and to establish a new, more advanced space station in lunar orbit: the ‘Lunar Gateway’. The authors aim to contribute to this goal through undertaking an ongoing comprehensive survey of relevant published scientific literature to seek information regarding the risk of medical conditions that might require operative or non-operative surgical solutions during long-duration spaceflight. The intended outcome is to create a roadmap for future mission planning. To date, we have identified more than 50 such potential surgical conditions. Based on disease severity and mission duration, these can be classified into: (Category 1) Time-critical conditions requiring immediate surgery; (Category 2) Urgent surgical conditions requiring minor temporising surgical intervention or conservative care (these patients can return to Earth for definitive treatment); or (Category 3) Non-urgent, as these conditions do not require immediate surgical intervention, and definitive treatment can be delayed. The proposed Lunar Gateway will be an international collaboration. Reaching Gateway is anticipated to take around three days. Gateway will operate in microgravity conditions, and include a communications lab (ground support from Earth is still available with minimal signal delay), a scientific lab, and a habitat for astronauts. Transfers to and from the lunar surface will allow astronauts to undertake extra-vehicular activities (EVA). Habitation on Gateway will present similar physiological and psychological challenges as experienced on the International Space Station (ISS), with the addition of a slightly increased communications lag. The Moon is only within Earth's magnetosphere for approximately 25 % of the time, which will increase space radiation exposure compared to the ISS. Gravitational conditions will range from microgravity on Gateway to ⅙ of the Earth's gravity on the lunar surface. Considering the duration and distance necessary in order to undertake a lunar mission, time-critical surgical interventions (Category 1) will likely be necessary, such as treating a bowel perforation, or fixation for musculoskeletal trauma. For urgent conditions (Category 2), antibiotic treatment of responsive appendicitis, drainage of uncomplicated cholecystitis, or other conservative measures might be acceptable as a temporising measure. If a return to Earth is possible within three days, delayed surgery can be undertaken if the conservative measures are unsuccessful, or the condition recurs. In the case of non-urgent procedures that can be delayed (Category 3), planned evacuation to Earth is expected to be available, for example, if a malignancy develops or is detected. Anticipating the medical and surgical challenges a lunar mission presents, and subsequent adequate planning and preparation for possible surgical emergencies, will help ensure mission success. Creating a system for triaging of surgi