A large number of pyroshock devices are employed in spacecraft and rockets to realize stage separation and appendage deployment.Release of pyroshock devices induces high-level transient shock responses which tend to c...A large number of pyroshock devices are employed in spacecraft and rockets to realize stage separation and appendage deployment.Release of pyroshock devices induces high-level transient shock responses which tend to cause fatal damages in electronic equipment made of crystals and brittle materials.This paper aims to provide methods to isolate pyroshock and guarantee the safety of such equipment against high-frequency shocks.Firstly,stress wave transmission mechanism in stepped rods is investigated,upon which optimal area rate for shock isolation is achieved.Then,two spacecraft-rocket interface structures for pyroshock isolation,namely isolation hole and interim segment,are proposed.Both numerical simulations and experiments are carried out to validate the two shock isolation strategies.It is revealed that the interim segment structure shows better pyroshock isolation performance at the cost of increasing the weight of launching system whereas isolation hole is an optimal choice to reduce pyroshock response without causing weight increase.展开更多
In the near future, humans will go to Mars. During these interplanetary journeys, astronaut safety will be paramount. This study aims to determine whether the astronauts will be able to launch safely from Mars in a sp...In the near future, humans will go to Mars. During these interplanetary journeys, astronaut safety will be paramount. This study aims to determine whether the astronauts will be able to launch safely from Mars in a space shuttle taking off perpendicularly. This study used kinematics along with equations for calculating atmospheric density and total force on the spacecraft to evaluate these values for each atmospheric layer. Approximations were made for the spacecraft’s dimensions to find the cross-sectional front-view area of the spacecraft and the drag coefficient where verifiable data was unavailable. Although there is data for the dimensions of the spacecraft’s front view, there isn’t any on its area. The total force was found to be significantly lower than 3Gs which ensures a safe take-off for the astronauts and reduces manufacturing costs for assembling new rockets.展开更多
基金supports from National Natural Science Foundation of China(No.11902286 and 11972204)。
文摘A large number of pyroshock devices are employed in spacecraft and rockets to realize stage separation and appendage deployment.Release of pyroshock devices induces high-level transient shock responses which tend to cause fatal damages in electronic equipment made of crystals and brittle materials.This paper aims to provide methods to isolate pyroshock and guarantee the safety of such equipment against high-frequency shocks.Firstly,stress wave transmission mechanism in stepped rods is investigated,upon which optimal area rate for shock isolation is achieved.Then,two spacecraft-rocket interface structures for pyroshock isolation,namely isolation hole and interim segment,are proposed.Both numerical simulations and experiments are carried out to validate the two shock isolation strategies.It is revealed that the interim segment structure shows better pyroshock isolation performance at the cost of increasing the weight of launching system whereas isolation hole is an optimal choice to reduce pyroshock response without causing weight increase.
文摘In the near future, humans will go to Mars. During these interplanetary journeys, astronaut safety will be paramount. This study aims to determine whether the astronauts will be able to launch safely from Mars in a space shuttle taking off perpendicularly. This study used kinematics along with equations for calculating atmospheric density and total force on the spacecraft to evaluate these values for each atmospheric layer. Approximations were made for the spacecraft’s dimensions to find the cross-sectional front-view area of the spacecraft and the drag coefficient where verifiable data was unavailable. Although there is data for the dimensions of the spacecraft’s front view, there isn’t any on its area. The total force was found to be significantly lower than 3Gs which ensures a safe take-off for the astronauts and reduces manufacturing costs for assembling new rockets.