Building a Robotic, LEO-to-GEO Satellite Servicing Infrastructure as an Economic Foundation for 21st-Century Space Exploration

Author(s):  
Gary A. P. Horsham ◽  
George R. Schmidt ◽  
James H. Gilland

The strategy for accomplishing civilian exploration goals and objectives is in the process of a fundamental shift toward a new approach called “Flexible Path.” In this paper, the authors present a strategically aligned, government-industry partnership focused on the commercial development of Low Earth Orbit to Geostationary Orbit (LEO-to-GEO (LTG)) space over the next quarter century. A LTG satellite-servicing infrastructure and architecture concept is presented along with a brief assessment of the key applicable technologies. The evolution of the communications satellite industry is also discussed within the context of an emerging commercial in-space servicing industry. Large-scale, robotic, LTG satellite servicing is considered an essential economic pre-condition and next parallel or sequential step on the road toward robust, capital intensive human-robotic exploration beyond LEO. Such a step might produce the necessary pre-requisite economic value that can be used by future decision makers to justify further investment in exploration. A high-level implementation plan is offered.

Author(s):  
Michael Ellims

Brake systems fitted to current production vehicles are not the relativity straightforward hydraulic systems that many people expect. Rather they have evolved into complex systems which are on their own deliberately capable of affecting the behaviour of a vehicle. Crucially they depend on computers, software and electronic sensors to allow them to form a model of how the vehicle is expected to behave on the road and how it is actually behaving. Like any artefact they can, and do fail. This paper provides a high-level overview of the braking systems currently in place, how these systems act and present some examples of how they have failed in practice. Index words: vehicles; vehicle electronics; electronic control; software; brake systems; failure modes


2021 ◽  
Author(s):  
Thomas Roddick ◽  
Benjamin Biggs ◽  
Daniel Olmeda Reino ◽  
Roberto Cipolla

1905 ◽  
Vol 2 (5) ◽  
pp. 216-219 ◽  
Author(s):  
C. Callaway
Keyword(s):  
The Road ◽  

Mr. L. Richardson, F.G.S., having informed me that he had seen gravels at a high level on the road leading from Stow-on-the-Wold to Burford, I visited the locality, accompanied by Mr. J. W. Gray, F.G.S. About 3⅓ miles north of Burford, at the corner of the turning to Tangley, we came upon a deposit of clay with northern erratics in a quarry of oolite. As the position of such a formation was unexpected, and might be important, it seems desirable to record the discovery.


2020 ◽  
Author(s):  
Baoshan Wang ◽  
Xiangfang Zeng ◽  
Jun Yang ◽  
Yuansheng Zhang ◽  
Zhenghong Song ◽  
...  

<p>Recently large-volume airgun arrays have been used to explore and monitor the subsurface structure. The airgun array can generate highly repeatable seismic signals, which can be traced to more than 200 km. And the airgun source can be ignited every 10 minutes. The airgun source makes it possible to precisely monitor subsurface changes at large scale. The spatial resolution of airgun monitoring is poor subjecting to the receiver distribution. The distributed acoustic sensing (DAS) technique provides a strategy for low-cost and high-density seismic observations. Two experiments combing DAS technique and airgun source were conducted at two sites with different settings. At the first site, a telecommunication fiber-optic cable in urban area was used. After moderate stacking, the airgun signal emerges on the 30-km DAS array at about 9 km epicentral distance. In the second experiment, a 5-km cable was deployed from the airgun source to about 2 km away. About 800-m cable was frozen into the ice above the air-gun, the rest cable was cemented on the road crossing through a fault. And the airgun has been fired continuously for more than 48 hours with one-hour interval. On the stacking multiple shots’ records, the wavefield in fault zone emerges too. These two experiments demonstrate the feasibility of using various fiber-optic cables as dense array to acquire air-gun signal in different environments and to monitor the subsurface changes.</p>


2005 ◽  
Author(s):  
Mahmood Anwar

The name of my proposing project is “air-car”. Now a day’s traffic jam is common problem of the mega city, especially in third world countries. so, if we design the traffic system such that the light vehicles like car will flies over certain height from the ground level about 100-200 ft and the heavy vehicle like bus, truck, lorry, etc. will run on the road simultaneously then the traffic jam will be minimize with a large scale. Let us introduce with the concept “air-car”. Air car is the vehicle which can run in both way of air and road. That means that it can fly over a certain height from the ground and also run in the road as usual. We know that for the car design is such the lift force is minimized than the drag force. I want to design for the car such that, when the car has to fly lift force will be increase as much as it can fly for the required height. The body of the car also be a stream line body and the flap, aileron, rudder also be added. But this should be hidden at the time of running in the road.


2011 ◽  
Vol 12 (4) ◽  
pp. 1609-1623 ◽  
Author(s):  
Kazuya Takeda ◽  
John H. L. Hansen ◽  
Pınar Boyraz ◽  
Lucas Malta ◽  
Chiyomi Miyajima ◽  
...  

Author(s):  
Yiqi Gao ◽  
Theresa Lin ◽  
Francesco Borrelli ◽  
Eric Tseng ◽  
Davor Hrovat

Two frameworks based on Model Predictive Control (MPC) for obstacle avoidance with autonomous vehicles are presented. A given trajectory represents the driver intent. An MPC has to safely avoid obstacles on the road while trying to track the desired trajectory by controlling front steering angle and differential braking. We present two different approaches to this problem. The first approach solves a single nonlinear MPC problem. The second approach uses a hierarchical scheme. At the high-level, a trajectory is computed on-line, in a receding horizon fashion, based on a simplified point-mass vehicle model in order to avoid an obstacle. At the low-level an MPC controller computes the vehicle inputs in order to best follow the high level trajectory based on a nonlinear vehicle model. This article presents the design and comparison of both approaches, the method for implementing them, and successful experimental results on icy roads.


2018 ◽  
Vol 231 ◽  
pp. 05003 ◽  
Author(s):  
Arkadiusz Matysiak ◽  
Paula Razin

The article presents the analysis of the performance of the vehicles equipped with automated driving systems (ADS) which were tested in real-life road conditions from 2015 to 2017 in the state of California. It aims at the effort to assess the impact on the road safety the continuous technological advancements in driving automation might have, based on of the first large-scale, real-life test deployments. Vehicle manufacturers and other stakeholders testing the highly automated vehicles in California are obliged to issue yearly reports which provide an insight on the test scale as well as the technology maturity. The so-called 'disengagement reports' highlight the range and number of control takeovers between the ADS and driver, which are made either based on driver's decision or information provided by the vehicle itself. The analysis of these reports allowed to investigate the development made in automated driving technology throughout the years of tests, as well as the direct or indirect influence of the external factors (e.g. various weather conditions) on the ADS performance. The results show that there is still a significant gap in reliability and safety between human drivers and highly automated vehicles which has been yet steadily decreasing due to technology advancements made while driving in the specific infrastructure and traffic conditions of California.


2009 ◽  
pp. 1087-1095
Author(s):  
Huaqun Guo ◽  
Daqing Zhang ◽  
Lek-Heng Ngoh ◽  
Song Zheng ◽  
Wai-Choong Wong

The decreasing cost of networking technology and network-enabled devices is driving the large scale deployment of such networks and devices so as to offer many new and innovative services to users in ubiquitous computing. For example, when you carry your mobile laptop or personal digital assistant (PDA) around, or drive on the road, various services have been made available, ranging from finding a local printer to print a file, to instantaneously knowing about the traffic situation from traffic-cameras and other sensors along a highway. To achieve the above, every participating network- enabled end-device must solve an interesting technical problem, i.e., to locate a particular network service or device out of hundreds of thousands of accessible services and devices. Such service advertising and discovery is important as mobile devices and mobile wireless devices proliferate on networks. For this reason, a service discovery and advertising protocol is an important tool to help these devices find services on the network wherever they connect, and to let other network users know about the services they are offering. Context-aware service discovery, on the other hand, would help users to find services that are most appropriate based on fast-changing client conditions, such as location. For example, most laptops are statically configured to print to dedicated office printers. With the help of the context-awareness, a laptop could find the nearest accessible printer attached to the network that the laptop is currently plugged into.


2014 ◽  
Vol 931-932 ◽  
pp. 676-680
Author(s):  
Arika Bridhikitti ◽  
Kanjana Thongsanit ◽  
Sunisa Chumphuthim ◽  
Patsorn Khwasui ◽  
Pawadee Nabumrung ◽  
...  

This study aims to assess possibility of health risk attributed to nuisance dust on people living and working on roadside areas nearby Mahasarakham University (MSU). Nuisance dust was measured during November 2012 to May 2013 covering a school semester and a school break. All samples for Ban Tha Kong Yang roadside area showed high level of ambient aerosol with size less than 10 micron and the level was exceeding the national ambient air quality standard of 0.12 mg m-3 . Approximately half of the samples taken for Ban Kham Riang also show the same result. This suggests significant dust problem in these areas and could potentially cause adverse human health effects. Results from personal respirable dust sampling show that construction worker was exposed to the highest respirable dust concentration among three occupations, including security guard and street-food cooker. The levels were significantly higher with longer time on the road and having earth moving activity nearby. Occupational exposure to respirable dust, however, was not exceeding the US Occupational Safety and Health Administration standard of 5 mg m-3.


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