2026年3月10日 / 美国东部时间上午10:35 / CBS新闻
一台1300磅重的NASA探测器将于今日重返地球大气层，距离其发射升空已近14年。
美国国家航空航天局（NASA）在新闻稿中援引美国太空部队的消息称，2012年8月发射的范艾伦探测器A号（Van Allen Probe A）可能于美国东部时间周二晚上7:45左右重返地球大气层，存在24小时的不确定性区间。
NASA表示，探测器大部分结构在进入大气层时预计会燃烧殆尽，但部分组件可能会在再入过程中残存。该机构指出，地球上任何人受到伤害的概率为1/4200，风险较低。
这一探测器与其孪生航天器范艾伦探测器B号（Van Allen Probe B）被送往探测地球的永久辐射带，并确定其中带电粒子的增减机制。据NASA介绍，这些被称为范艾伦辐射带的区域是被地球磁场捕获的带电粒子环，能够阻挡宇宙辐射、太阳风暴和太阳风。
NASA称，该任务原计划持续两年，最终却运行了近七年。大多数前往辐射带的任务都较为短暂，以减少辐射损伤。
NASA表示，范艾伦探测器是首个计划在该区域长时间运行的探测器，打破了航天器在此区域的工作时长纪录。
在七年的运行期间，这两台探测器取得了多项发现。NASA称，它们收集到了首个显示第三辐射带在强烈太阳活动期间形成的数据，其观测结果已成为数百篇学术论文的研究对象。
任务于2019年因燃料耗尽而终结，探测器无法再定向朝向太阳。任务专家分析认为，探测器可能在2034年重返地球大气层，但当前活跃的太阳周期引发了强烈的太空天气事件，增加了航天器受到的大气阻力，导致它们比预期更快地被拉向地球。
探测器B号预计要到2030年代才会重返地球大气层。
1,300-pound NASA satellite set to crash down to Earth today after 14 years in space
March 10, 2026 / 10:35 AM EDT / CBS News
A 1,300-pound NASA probe is set to re-enter Earth’s atmosphere today, nearly 14 years after it was launched.
The Van Allen Probe A, which was launched in August 2012, is likely to reenter Earth’s atmosphere around 7:45 p.m. ET on Tuesday, NASA said in a news release, citing the U.S. Space Force. There is a 24-hour margin of uncertainty.
Most of the probe is expected to burn up as it reenters the atmosphere, NASA said, although some components are expected to survive re-entry. There is a 1 in 4,200 chance of anyone on Earth being harmed, NASA said, noting that the risk is low.
The probe and a twin spacecraft, Van Allen Probe B, were sent to explore Earth’s permanent radiation belts and determine how particles within them are gained and lost. The zones, known as the Van Allen belts, are rings of charged particles trapped by Earth’s magnetic field, according to NASA. They shield the planet from cosmic radiation, solar storms and solar wind.
Their mission was supposed to last two years, but ended up going for nearly seven, NASA said. Most missions to the belts are short to minimize exposure to damaging radiation.
The Van Allen probes were the first that were meant to spend a significant amount of time in the region, NASA said, and broke all records for spacecraft to function there.
An artists’ conception of two Van Allen Probes spacecraft in the Van Allen Radiation Belt. HUM Images/Universal Images Group
The probes made a number of discoveries during their seven years in operation, NASA said. They collected the first data showing the existence of a third radiation belt that can form during times of intense solar activity, and their observations have been the subject of hundreds of publications, according to NASA.
The mission ended in 2019, when the probes ran out of fuel and could no longer orient themselves toward the sun. An analysis by mission specialists found the probes would likely re-enter Earth’s atmosphere in 2034, but the current active solar cycle has triggered intense space weather events and increased atmospheric drag on the spacecraft, pulling them in faster than expected.
Probe B is not expected to re-enter Earth’s atmosphere until the 2030s.
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