The need for reducing the cost of injecting payload mass into orbit is the main stimulating factor for further modifications and creation of new launch vehicles.
降低将有效载荷送入轨道的成本的需求是刺激现有运载火箭进一步改型和新型运载火箭研制的主要因素。
Having initially connected the ornithopter using a DC power source, they realized that the device could lift 1.5 grams of payload, which was roughly the mass of the batteries required for flight.
起初给扑翼机接上一个直流电源之后,他们发现这个装置的有效载荷为1.5g,这大概可以勉强提起飞行所需的电池。
But chemical-based systems are severely limited by the fact that the vehicle mass must be made mostly of propellant, which leaves little room for the payload.
但是基于化学的推进系统被严重限制了,因为机器的质量的大部分用来给了推进剂,结果就是没怎么留下空间给装载量。
The functions of nonmetal materials to improve the parameters of satellite, reduce the mass of satellite structure and increase the effective payload of satellite were stressed.
强调了非金属材料在提高卫星性能、减轻卫星结构质量,以及增大卫星有效载荷方面的作用。
Under the conditions of the given payload and the highest launching height, the design parameters of the propulsion system are selected to minimize takeoff mass of the rocket.
在给定有效载荷、最高射高的条件下,选取动力系统的设计参数使火箭的起飞质量最小。
A rigid aeroshell for aerodynamic deceleration and landing impact will result in mass and sizes of the re_entry vehicles exceeding several times those of the payload bus.
长期以来返回式飞行器为承受再入气动载荷和着陆冲击,采用具有防热层的刚性飞行器壳体,导致返回舱的质量和外形大于有效载荷的数倍。
A rigid aeroshell for aerodynamic deceleration and landing impact will result in mass and sizes of the re_entry vehicles exceeding several times those of the payload bus.
长期以来返回式飞行器为承受再入气动载荷和着陆冲击,采用具有防热层的刚性飞行器壳体,导致返回舱的质量和外形大于有效载荷的数倍。
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