scholarly journals Landing Trajectory Generation and Energy Optimization for Unmanned Lunar Mission

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Md. Shofiqul Islam ◽  
Ibrahim M. Mehedi
Keyword(s):  
Algorithm Design ◽  
Trajectory Generation ◽  
Space Mission ◽  
Reference Trajectory ◽  
Human Beings ◽  
The Moon ◽  
Vehicle Trajectory ◽  
Satisfactory Answer ◽  
Lunar Descent ◽  
The Cost

The moon is recognized as an important destination for space science and exploration. To find a satisfactory answer for the mystery of the universe and to make use of the lunar resources for the welfare of human beings, several space agencies are planning manned and unmanned missions on the moon. As a result, the concept of lunar vehicles has begun with an advanced descent scheme to execute a precise and safe landing on the surface of the moon. On the contrary, the energy budget is an important issue for any space mission. To reduce the cost of a space mission, it is necessary to design the vehicle trajectory based on optimized energy resources. Fuel is the main energy in a space mission. Therefore, a fuel-optimized energy generation technique is focused on this research. The design of an algorithm that generates a real-time trajectory for the descent and landing of a lunar probe is critical to ensuring a successful lunar landing mission. A scheme of dual-step trajectory generation for lunar descent is also investigated in this paper. In the algorithm developing process, the thrust-to-mass ratio is considered as a principle variable. Algorithm design along with mathematical modeling and simulation results are described in detail. In addition, the proposed method for generating reference trajectory profiles is also analyzed for fuel consumption and robustness.

scholarly journals Design of Satellite Attitude Control Algorithm Based on the SDRE Method Using Gas Jets and Reaction Wheels

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Luiz C. G. de Souza ◽  
Victor M. R. Arena
Keyword(s):  
Attitude Control ◽  
Control Algorithm ◽  
Controller Design ◽  
Algorithm Design ◽  
Large Angle ◽  
Space Mission ◽  
Control Technique ◽  
Gas Jets ◽  
State Dependent ◽  
Highly Nonlinear

An experimental attitude control algorithm design using prototypes can minimize space mission costs by reducing the number of errors transmitted to the next phase of the project. The Space Mechanics and Control Division (DMC) of INPE is constructing a 3D simulator to supply the conditions for implementing and testing satellite control hardware and software. Satellite large angle maneuver makes the plant highly nonlinear and if the parameters of the system are not well determined, the plant can also present some level of uncertainty. As a result, controller designed by a linear control technique can have its performance and robustness degraded. In this paper the standard LQR linear controller and the SDRE controller associated with an SDRE filter are applied to design a controller for a nonlinear plant. The plant is similar to the DMC 3D satellite simulator where the unstructured uncertainties of the system are represented by process and measurements noise. In the sequel the State-Dependent Riccati Equation (SDRE) method is used to design and test an attitude control algorithm based on gas jets and reaction wheel torques to perform large angle maneuver in three axes. The SDRE controller design takes into account the effects of the plant nonlinearities and system noise which represents uncertainty. The SDRE controller performance and robustness are tested during the transition phase from angular velocity reductions to normal mode of operation with stringent pointing accuracy using a switching control algorithm based on minimum system energy. This work serves to validate the numerical simulator model and to verify the functionality of the control algorithm designed by the SDRE method.

scholarly journals Human Fetal Development And The Ways Of Asthabrata As An Idea In The Creation Of Sinjang Batik Tulis

2020 ◽  
Vol 1 (2) ◽  
pp. 96-106
Author(s):  
Danang Priyanto ◽  
FP Sri Wuryani
Keyword(s):  
Fetal Development ◽  
Human Life ◽  
Human Beings ◽  
The Moon ◽  
Development Stages ◽  
The Sublime ◽  
The Creation ◽  
The Universe ◽  
Human Fetal Development ◽  
Full Protection

Human beings which are wired as leaders should live based on the practice of transcendent value and total clarity on noble deeds. It functions as a guideline in living to avoid the crisis of morality that often occurs today. One of the values in this leadershipquality is the teaching of asthabrata containing the noble deeds of a leader who symbolized in the elements of the universe: the fire, the ground, the water, the air, the moon, the clouds, the sun, and the stars. The stage of human fetal development occurs from the age of one to nine months. These stages, along with the teachings of asthabrata become the base of an idea in the creation of batik art. The idea comes from the question of how to process the development stages of human fetal and ways of asthabrata as a base on creating the batik artwork which conveys sublime values about leadership. The purpose of this batik artwork creation are:incorporating the concept of human fetal development as part of human life cycle with the tradition of batik; Conveying the sublime sublime of leadership based on the asthabrata which refers to human nature as a natural born leader. The creation processcovering the method of design exploration, design process, and batik as a result of design by establishing the combination ofhuman fetal development and the asthabrata. The result shows nine sinjang batik tulis artworks, covering; Hamasesa Tan Pilih Warna (manage without seeing the color), Sukci (sacred), Hanguripi Sagung Dumadi (give strength to all life), Girise Kang Samya Miyat (be who you want to see), Sorota Hayem Angayomi (make peaceful and full protection), Jembar Tanpa Pagut(sincerity without limit), Muntir Tan Ana Pedhote (infinite rotation), Panengeraning Keblad (signpost), and Ngudi Kasampurnan(sharpening perfection). 

Dodging the Asteroids?

Impact! ◽  
1996 ◽  
Author(s):  
Gerrit L. Verschuur
Keyword(s):  
Solar System ◽  
Political Leadership ◽  
Scientific Investigation ◽  
Human Beings ◽  
The Moon ◽  
Large Problem ◽  
The Earth ◽  
Set Up ◽  
Near Earth Objects ◽  
The U.S

Finding asteroids and comets that may someday slam into our planet is the first step. What do we do then? This question is being given a whole lot of attention. In early 1993 NASA and the U.S. Congress received a report of the Near-Earth-Objects Interception Workshop (Spaceguard), the first step toward creating a program for pushing aside approaching asteroids. The report stated that “There is a clear need for continuing national and international scientific investigation and political leadership to establish a successful and broadly acceptable policy.” There are two or three options open to us to avoid being wiped out. The first is to step out of the way. This may not sound very practical, and it isn’t, at least not for a planet-load of people. However, if we plan ahead we could ship a few thousand human beings to other parts of the solar system so that if the earth were to be struck, they, at least, would survive. This would only be a privilege for a few, and getting back to earth after the cataclysm could be a rather large problem in itself. Who will welcome them back upon their return? Where would they land? If we could afford to set up colonies on the moon or Mars, the colonists could wait until after the dust had settled before attempting to return. The problem with this option is that, after a really healthy thwack, the earth’s environment would be so altered that returning human beings might find this to be an alien planet. The second way in which we could avoid getting hit would be to place an object between the onrushing comet or asteroid and ourselves. For such an emergency it might pay to place a few asteroids in geocentric orbit to be maneuvered when we need them. Then we could watch the spectacle as one asteroid slams into another, possibly showering the planet with small bits of debris that might do no more than create a spectacular display of fireballs—if we get it right, of course.

The Nursery of Life

2030 ◽  
2010 ◽  
Author(s):  
Rutger van Santen ◽  
Djan Khoe ◽  
Bram Vermeer
Keyword(s):  
Health Care ◽  
New Technology ◽  
Medical Knowledge ◽  
Human Beings ◽  
Slowing Down ◽  
Cost Of Health Care ◽  
Precise Diagnosis ◽  
Set Up ◽  
The Cost ◽  
Prompt Diagnosis

Human beings are much more complex than any technology we could devise today. How many machines are good for 80 or 90 years of service? Our immune system—set up at birth—is able to repel diseases that don’t even exist yet. Most viruses that proliferate 50 years after we were born can be defeated just as easily as maladies that have been dogging humans for generations. Effective health care means that—in most regions of the planet—we are living longer and longer. All the same, human beings are not perfect: We get sick and we wear out over time. In the wealthier regions, we spend a great deal of money trying to get as close as possible to a 100-year span. Our greatest task is to bring a long and healthy life within the reach of as many people as possible. New technology is required to hold down the cost of health care, to nip outbreaks of disease in the bud, and to ease discomfort in our old age. Scientists believe that substantial benefits can be gained by identifying abnormalities earlier. A cancerous growth measuring just a few millimeters is still relatively harmless, and an infection caught in its early stages won’t leave any scars. Although techniques for accurately diagnosing incipient abnormalities can often be very expensive, prompt diagnosis generally means that treatment will be easier, cheaper, and more likely to succeed. Thus, we can end up saving money despite the need for expensive equipment. To adequately fight the outbreak of diseases in the future, our technology must be able to respond more rapidly. This could pose a particular challenge because there is also a trend at present toward superspecialization, which is fragmenting medical knowledge and slowing down responses. Take the science of ophthalmology in which the various specializations focus on extremely specific parts of the eye. This is fine once a precise diagnosis has been made, but it could be a significant problem if the patient consults the wrong doctor at the outset. The way we currently approach diagnosis needs to change.

Effects and Benefits of Space Exploration

2012 ◽  
Vol 2 (1) ◽  
pp. 49-62
Author(s):  
Norma B. Crosby
Keyword(s):  
Space Exploration ◽  
Cost Benefit ◽  
Harsh Environments ◽  
Navigation Systems ◽  
Space Technology ◽  
The Moon ◽  
Modern Life ◽  
Human Needs ◽  
Transfer Of Technology ◽  
The Cost

It has been more than half a century since humans first ventured into space. While competing in being the first to land on the Moon, they learned to utilize space for human needs on Earth (e.g., telecommunications, navigation systems). Many space technologies were later applied to basic needs on Earth. Space research and development led to the “transfer of technology” in non-space sectors and became better known as “spin-offs.” They have improved global modern life in many ways. This paper discusses the cost-benefit of space technology spin-offs, as well as the relationships between various space agencies, spin-offs, and commercial enterprises. Other benefits that have come out of space exploration such as psychological, political and environmental effects are also reviewed, as well as the potential future benefits of going to space. Technologies developed for harsh environments on Earth and for those in space benefit all and collaborating both ways is the future.

scholarly journals Respecting Human Rights: Does Treaty Ratification Lead to Compliance?

2012 ◽  
Vol 2 (2) ◽  
pp. 169-179
Author(s):  
Daniel St. Pierre
Keyword(s):  
Human Rights ◽  
International Relations ◽  
International System ◽  
Indigenous Populations ◽  
International Human Rights Law ◽  
Human Beings ◽  
Human Rights Law ◽  
State Compliance ◽  
The Cost

Since the nonbinding Universal Declaration of Human Rights, states have created treaties and conventions to outline what is or is not acceptable regarding the treatment of human beings, with the understanding that if a state signs and ratifies these documents then that state will comply with the principles outlined within it.  Time and again however, compliance, or the lack thereof, has presented as a concern amongst many states, as well as non-state actors.  The issue of compliance is a serious one because it speaks to credibility.  If states do not anticipate compliance from one another it undermines the entire international system and any structure that has been created to address the anarchic nature of international relations will dissolve.  In order to make analysis of this massive issue area manageable, I focus on state compliance with human rights law and more specifically, compliance with the Indigenous and Tribal Peoples Convention 1989, or C169.  Both Brazil and Argentina have signed and ratified C169 and both are democratic with indigenous populations.  Comparing these two states it allows us to better ascertain the circumstances under which states may comply with or defect from international human rights law.  I provide an overview on what rationalist theories suggest about compliance, followed by constructivist views.  I then outline my position before examining the results of the case study and assessing its’ impact as related to both theory and my arguments.  Ultimately, I find that notwithstanding ratification and well-developed democratic institutions that allow for a strong civil society to participate in politics, there are still circumstances wherein a state will defect from a human rights treaty because the gain of doing so outweighs the cost of non-compliance.

scholarly journals A Two-Echelon Agricultural Product Supply Chain with Freshness and Greenness Concerns: A Cost-Sharing Contract Perspective

Complexity ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Manyi Tan ◽  
Manli Tu ◽  
Bin Wang ◽  
Tianyue Zou ◽  
Hong Cheng
Keyword(s):  
Supply Chain ◽  
Cost Sharing ◽  
Agricultural Products ◽  
Sensitivity Analyses ◽  
Agricultural Product ◽  
Human Beings ◽  
Optimal Decisions ◽  
Game Theoretic ◽  
The Cost ◽  
The Impact

Agricultural products are basic needs of human beings, and whether they are cultivated in a green (or organic) manner has direct impact on environment and public health. This research incorporates product freshness and greenness into a two-echelon agricultural product supply chain (APSC). Game theoretic analyses are carried out to examine pricing, freshness, and greenness decisions of the supply chain members with and without cost-sharing for greenness investment. Subsequently, we conduct comparative and sensitivity analyses for these optimal decisions and profits of the APSC members under different cases. Numerical experiment is employed to investigate the impact of key parameters on equilibrium decisions and profitability. Analytical and experimental results show that the cost-sharing contract of greenness investment for agricultural products helps to strengthen the supply chain members’ effort in improving the greenness and freshness levels of the agricultural product, thereby enhancing both individual and channel profitability of the APSC under certain conditions. This research also reveals a widened profit gap between the producer and the retailer under the cost-sharing contract.

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