Systematization of Shock Response Control Based on Momentum Exchange and Energy Exchange and Its Application to Lunar/Planetary Spacecraft

Impact ◽  
2019 ◽  
Vol 2019 (10) ◽  
pp. 73-75
Author(s):  
Susumu Hara

Professor Susumu Hara is based at the Department of Aerospace Engineering, Nagoya University in Japan explains that when the Mars rover Opportunity was set to land on that planet in the first weeks of 2004, onlookers held their breath as it dropped from orbit and hurtled toward the red surface. 'Any failure in the calculations or landing systems would mean a harder than expected impact,' he highlights. 'The impacts sustained by a rover such as Opportunity can derail a mission before it even starts, damaging cargo or vital systems required to complete the mission.' Impacts occur during landing but also as the craft enters the atmosphere, when it makes sudden moves, while it is on surface or when debris strikes it. 'Therefore, a system and materials to protect a craft are vital,' outlines Hara. 'Surprisingly, the solutions to this problem are not sophisticated. In fact, most craft still employ devices resembling automobile bumpers, which absorb the energy from an impact by crumpling under the force of said impact.' Unfortunately, these cannot be reused, even during testing phases a new prototype is required after every single test run. Recent missions also employed techniques like airbags or sky cranes. While successful they too have drawbacks. 'Airbags create huge rebounds which can jostle the craft and the contents inside while sky cranes are extremely costly to develop,' Hara says. For this reason, he is dedicated to designing a new highly reliable and cost-effective shock control mechanism.

2011 ◽  
Vol 34 (6) ◽  
pp. 1828-1838 ◽  
Author(s):  
Susumu Hara ◽  
Ryosuke Ito ◽  
Masatsugu Otsuki ◽  
Yoji Yamada ◽  
Takashi Kubota ◽  
...  

2012 ◽  
Vol 78 (792) ◽  
pp. 2781-2796 ◽  
Author(s):  
Susumu HARA ◽  
Tsubasa WATANABE ◽  
Yohei KUSHIDA ◽  
Masatsugu OTSUKI ◽  
Yoji YAMADA ◽  
...  

2015 ◽  
Vol 68 ◽  
pp. 218-231 ◽  
Author(s):  
Scott M. Freeman ◽  
Dominic Alvernaz ◽  
Alexandra Tonnesen ◽  
David Linderman ◽  
Adam R. Aron

Author(s):  
Yohei KUSHIDA ◽  
Susumu HARA ◽  
Masatsugu OTSUKI ◽  
Yoji YAMADA ◽  
Tatsuaki HASHIMOTO ◽  
...  

2007 ◽  
Vol 21 (29) ◽  
pp. 2009-2017
Author(s):  
P. TRIPATHI ◽  
A. C. SHARMA

The rate of energy exchange via dynamically screened electron–electron interaction in a two-dimensional and quasi two-dimensional semiconductor is described analytically for the situation where the electron gas obeys classical statistics and is therefore applicable to many cases involving hot-electrons. It is shown that the interaction is resonantly enhanced by coupled-phonon–plasmon mode effects. The magnitudes of energy and momentum exchange rates in GaAs suggest that in cases where optical phonon scattering is not dominant, hot-electron transport will be describable in terms of drifted Maxwellian distribution. Even where optical-phonon scattering is dominant, the coupled phonon–plasmon mode enhancement of the electron–electron energy exchange rate offers substantial contribution.


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