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Sustainability in the Space Industry
Published in Mark W. McElroy, The Space Industry of the Future, 2023
Reduced costs of satellites are a factor in the increasing number of spacecraft in orbit, but launch cost is by far the majority of the overall cost of a satellite mission. Launch of a satellite using a rideshare service is now accessible to anyone with $1 million,4 which is a lot for the average person but not a lot for thousands of companies and other types of organizations around the world. The reduction in cost of launches has come about through things like rocket reusability, ridesharing, small launchers, and increased market competition. The cost of launching a payload into low Earth orbit is as low as $1,500/kg using a SpaceX Falcon Heavy rocket [185]. This constitutes a price reduction per kilogram compared to using legacy rockets in the range of a factor of four and higher depending on the rocket being compared. Additionally, due to the reusability of modern rockets, the price reduction is also accompanied by a reduction in resource demand and environmental impacts. All this while increasing opportunities for value creation in space and maintaining a profitable business model. Note that this is a prime example of the circular economy principles discussed in Chapter 2 at work.
The “System” in UAS
Published in Douglas M. Marshall, R. Kurt Barnhart, Eric Shappee, Michael Most, Introduction to Unmanned Aircraft Systems, 2016
Joshua Brungardt, Richard Kurt Barnhart
Outside of research and development, most UASs are aloft to accomplish a mission and the mission usually requires an onboard payload. The payload can be related to surveillance, weapons delivery, communications, aerial sensing, cargo or many other applications. UASs are often designed around the intended payload they will employ. As we have discussed, some UASs have multiple payloads. The size and weight of payloads are two of the largest considerations when designing a UAS. Most commercial application sUAS platforms require a relatively small payload, generally less than 5 lbs. Manufacturers of some sUAS have elected to accommodate interchangeable payloads that can be quickly removed and replaced.
Epilogue
Published in R. Kurt Barnhart, Douglas M. Marshall, Eric J. Shappee, Introduction to Unmanned Aircraft Systems, 2021
Payloads usually refer to an instrument on board the aircraft that provides imaging, video, communications, sensing devices, radar, or other instruments that provide the operator with information about a particular area of interest or phenomenon that requires observation. Electro-optical, thermal infrared, multi- and hyperspectral cameras, and laser range finders offer capabilities to record and retain images and data that are useful in a wide and ever-growing variety of applications in the civilian and scientific communities, in addition to multiple military uses.
Traffic-based quantitative risk analysis of structural fire damage to roadway tunnel linings
Published in Structure and Infrastructure Engineering, 2023
Qi Guo, Spencer E. Quiel, Clay J. Naito
Figure 13 plots the probability density of payload fraction for Sites 8280 and 2680. While Site 8280 exhibits a similar shape as Site 0199, Site 2680 has a greater concentration of vehicles with a payload fraction of 0.3 and has a lower frequency of high payload fractions since it is not part of an interstate highway. The probability distributions of payload fraction are then individually applied to the prototype tunnel for comparative evaluation. Even though the probability distribution of payload fraction is different among the three sites, Figure 14 shows little change in the probability distribution of combustible vehicle mass and the corresponding HRR generated based on the three datasets. This outcome suggests that the probability distribution of HRR for the prototype tunnel was not particularly sensitive to variations in payload fraction per the three sites in Table 12. Sensitivity or parametric evaluation of other traffic-based inputs could be performed in a similar fashion depending on the user’s objectives.
Decoding Mission Design Problem for NTP Systems for Outer Planet Robotic Missions
Published in Nuclear Technology, 2022
Saroj Kumar, L. Dale Thomas, Jason T. Cassibry
The problem tackles multiple areas such as spacecraft and NTP system design based on mission objectives. The NTP system and spacecraft design parameters are also evaluated for launch vehicle constraints. This approach makes sure that the overall design is within the limits specified by each system.24 The problem statement begins with the science mission objectives, which determines whether a mission will be a flyby, rendezvous, or round trip. This information is used toward the spacecraft and NTP system design. For the scope of this study, the spacecraft design will be considered only with respect to its total mass and dimensions. The NTP system configuration is then addressed, which is based on the expendable or nonexpendable nature of the mission along with ∆V requirements, engine thrust class, and liquid hydrogen (LH2) propellant tank sizing. The spacecraft and NTP system configurations such as Initial Mass in Low Earth Orbit (IMLEO) and payload fairing encapsulation are evaluated based on commercial launch vehicle limitations. Because this exercise is multidisciplinary in nature, the issues during the design of one system do not exist in isolation but feed upon other systems as well. This problem is solved iteratively until multiple cross-dependent parameters starting from spacecraft design to NTP systems and launch vehicle requirements are satisfied. The initial calculations on ∆V requirements and trip-time estimates are based on the patched conic analysis performed on Matlab, and finally end-to-end high-fidelity trajectory design and optimization are performed using the Systems Tool Kit Astrogator module.
Optimum conceptual design for the life support systems of manned spacecraft
Published in Cogent Engineering, 2020
M. Mahmoudi, A. B. Novinzadeh, F. Pazooki
The growing demand for space transportation and human-based in-orbit exploration missions has motivated researchers to investigate different designs of modern manned spacecraft. The special characteristics of manned missions, such as extraterrestrial environments, restrictions on the payload of the launch vehicle, the crew’s needs, and safety make the design of manned spacecraft difficult. In the conceptual design phase, where the configuration, subsystems, and technologies have to be determined, designers should make sure of meeting these requirements while controlling the weight, volume, and power. Therefore, the development of methods based on optimization will improve the design procedures and reduce the related costs.