在太空自由飞翔

2020 February 9

To Fly Free in Space
Image Credit: NASA, STS-41B

Explanation: What would it be like to fly free in space? At about 100 meters from the cargo bay of the space shuttle Challenger, Bruce McCandless II was living the dream — floating farther out than anyone had ever been before. Guided by a Manned Maneuvering Unit (MMU), astronaut McCandless, pictured, was floating free in space. McCandless and fellow NASA astronaut Robert Stewart were the first to experience such an “untethered space walk” during Space Shuttle mission 41-B in 1984. The MMU worked by shooting jets of nitrogen and was used to help deploy and retrieve satellites. With a mass over 140 kilograms, an MMU is heavy on Earth, but, like everything, is weightless when drifting in orbit. The MMU was later replaced with the SAFER backpack propulsion unit.

在太空自由飞翔
影像来源: NASA, STS-41B

说明: 在太空中飞翔是一种什么样的感受？在距离挑战者号航天飞机货仓约100米处，Bruce McCandless二世觉得自己正在梦境当中——现在他比此前任何人都漂浮得更远。通过载人机动装置(MMU),图中的宇航员McCandless能够自由地悬浮在太空里。在航天飞机1984年的41-B任务中，McCandless和其同事NASA宇航员Robert Stewart首次体验了这种“无系绳太空行走”。MMU利用喷射氮气进行工作，来帮助部署和回收卫星。140千克的MMU在地面上非常沉重，但在进入轨道之后像所有其他物体一样都处于失重状态。MMU后来被更加安全的背包推进装置所代替。