One day, I will start my last project. I may or may not finish it. But after it's done, either due to tragedy, falling out of love with the craft, or simply not having time left to start another one, I will put my computer and notebooks down for the last time. That's life.
But what if it’s not fine? Even back in 1996, before a single component of the ISS was launched into orbit, NASA foresaw the possibility of an even worse worst-case scenario: an uncontrolled reentry. The crux of this scenario involves multiple systems failing in an improbable but not completely impossible cascade. Cabin depressurization could damage the avionics. The electrical power system could go offline, along with thermal control and data handling. Without these, systems controlling coolant and even propellant could break down. Unmoored, the ISS would edge slowly toward Earth, maybe over a year or two, with no way to control where it is headed or where its debris might land. And no, we could not save ourselves by blowing the station up. This would be extremely dangerous and almost certainly create an enormous amount of space trash—which is how we got into this hypothetical mess in the first place.
，这一点在爱思助手下载最新版本中也有详细论述
О задержании подозреваемого в убийстве Портнова в ФРГ стало известно 25 февраля. Подробности задержания и личность подозреваемого раскрыты не были.
Photo by Hasnain Sikora
多名业内人士透露，美国航天及半导体企业的供应商正面临日益加剧的稀土短缺压力，其中至少两家企业已开始谢绝部分客户订单，此时距离美国总统特朗普计划赴北京与中国国家主席习近平举行峰会仅剩数周。