Recent Developments in Inflatable Airbag Impact Attenuation Systems for Mars Exploration

NASA Plum Brook's B-2 test facility-Thermal vacuum and propellant test facility

“…For similar reasons, balloon payloads including Transition Radiation Array for Cosmic Energetic Radiation (TRACER) [6] and Cosmic Ray Electron Synchrotron Telescope (CREST) have also done pre-flight thermal vacuum testing. The test chamber and cold wall were used for airbag inflation tests for the Mars Pathfinder [7] and Mars Exploration Rover (MER) [8]. FIGURE 2 shows a Centaur Stage and the TRACER test package positioned over the B-2 vacuum chamber.…”

Analytical and Experimental Investigation of Base–Extension Separation Mechanism for Spacecraft Landing

“…Nomenclature a = initial compression of L-spring in generalized-hybrid momentum exchange impact damper model, m c f = viscous damping coefficient between masses and surface of the ground, N · s∕m c f; 2 = viscous damping coefficient between base and surface of the ground, N · s∕m c f; 3 = viscous damping coefficient between upper gear and surface of the ground, N · s∕m c l = viscous damping coefficient between base and linear guide in base-extension separation mechanism model, N · s∕m d = stretched length of spring at t equal to T 2 , m E g = energy absorbed by ground damping, J E loss = energy increment of base caused by separation delay, J E 0 = initial energy of base-extension separation mechanism system, J F = maximum force of actuator in generalized-hybrid momentum exchange impact damper model, N f 1 = initial tension of spring in practical base-extension separation mechanism model (upper part of the spring), N f 2 = initial tension of spring in practical base-extension separation mechanism model (lower part of the spring), N Gs = transfer function of second-order low-pass Butterworth filter g = gravitational acceleration, m∕s 2 h r = maximum rebound height of base, m h 0 = initial fall height of base, m k f = stiffness between masses and surface of the ground, N∕m k f; 2 = stiffness between base and surface of the ground, N∕m k f; 3 = stiffness between gear and surface of the ground, N∕m k g = stiffness between gear and surface of the ground in practical base-extension separation mechanism model, N∕m k l = stiffness of L-spring in generalized-hybrid momentum exchange impact damper model, N∕m k s = spring constant in theoretical base-extension separation mechanism model, N∕m k s1 = upper part of spring constant in base-extension separation mechanism model, N∕m k s1−A = upper part of spring constant in base-extension separation mechanism model when spring is not sufficiently stretched, N∕m k s1−B = upper part of spring constant in base-extension separation mechanism model when spring is sufficiently stretched, N∕m k s2 = lower part of spring constant in base-extension separation mechanism model, N∕m k s2−A = lower part of spring constant in base-extension separation mechanism model when spring is not sufficiently stretched, N∕m k s2−B = lower part of spring constant in base-extension separation mechanism model when spring is sufficiently stretched, N∕m k u = stiffness of U-spring in generalized-hybrid momentum exchange impact damper model, N∕m l eb = length between extension and base in base-extension separation mechanism model when they are attached, m l g = gear length in base-extension separation mechanism model, m l ns = natural length of spring in base-extension separation mechanism model, m l p = length of pre-tension in base-extension separation mechanism model, m l st = stroke length of spring in base-extension separation mechanism model, m l u = natural length of U-spring in generalized-hybrid momentum exchange impact damper model, m m b = mass of body in generalized-hybrid momentum exchange impact damper model, kg m l = mass of L-damper in generalized-hybrid momentum exchange impact damper model, kg m u = mass of U-damper in generalized-hybrid momentum exchange impact damper model, kg m 1 = mass of extension in base-extension separation mechanism model, kg m 2 = mass of base in base-extension separation mechanism model, kg m 3 = mass of upper gear in base-extension separation mechanism model, kg m 4 = mass of lower gear in base-extension separation mechanism model, kg m …”

“…With the purpose of achieving the mentioned benefits, certain variables, such as the soil components, atmospheric temperature, and radiation levels, have to be measured during the exploration phase [1]. Exploration by a lander is a direct approach for acquiring these data, and many such missions have already been conducted [2][3][4][5][6][7]. The future plans of different nations suggest the importance attached to lander missions, e.g., Chang'e 4 (People's Republic of China); SELENE-2 and MELOS (Japan); Luna-GLOB (Russia); Chandorayaan 2 (India); and ExoMars (ESA) [8][9][10][11][12][13][14].…”

Deployable System for Crash—Load Attenuation

“…The specific material properties used in the model to represent the Kevlar 129 fabric are shown in Table 1. The Bakelite stanchion was represented using a linear elastic material with a density of 1.356E-4 lb-s 2 /in 4 , an elastic modulus of 1.09E+6 psi, and a Poisson's ratio of 0.25. The complete model consisted of 27,582 nodes; 16,840 hexagonal solid elements; and 8,040 BelytschkoTsay shell elements.…”

“…The first category consists of deployable devices such as hydraulic or pneumatic landing gears, vented airbags [1,2], non-vented airbags [3,4], and hybrid airbag systems [5]. Non deployable, or passive, energy absorbers belong to the second category which includes crushable honeycombs and cellular solids [6][7][8][9].…”