Europe launches space mission in defense against city-killer asteroids

PARIS — Europe launched its first spacecraft to help develop a defense against city-killer asteroids slamming into Earth.

The European Space Agency’s Hera mission, to which defense firms Thales and Leonardo contributed technology through their joint venture Thales Alenia Space, took off from Cape Canaveral on Monday riding on a SpaceX Falcon 9 rocket. The mission will study the results of a NASA experiment that was humankind’s first attempt at deflecting an asteroid.

About 30,000 asteroids measuring 100 to 300 meters travel the solar system in orbits that bring them relatively close to Earth, with one such space rock hitting the planet every 10,000 years, according to Thales. The impact of such an asteroid would be equivalent to an explosion of around 50 megatons, equal to the Soviet Union’s Tsar Bomba, the most powerful nuclear weapon ever tested.

“We currently know of more than 35 000 asteroids that come close enough to Earth for us to keep an eye on,” ESA wrote in post on X, formerly Twitter. “Hera is part of the international effort to answer the question: Could we do anything if we spotted one on a collision course?”

The Hera mission will investigate the result of NASA’s asteroid redirection test , in which the U.S. agency rammed a spacecraft into the asteroid Dimorphos in 2022 to test planetary defense capabilities. Hera will reach the binary asteroid system that includes Dimorphos in October 2026, and gathering close-up data may help turn NASA’s kinetic impact experiment into a potentially repeatable planetary defense technique, Thales said.

Mid-sized asteroids are the ones to worry about, as their impact would be devastating for a populated area, capable of destroying an entire city or create a tsunami, according to Thales. Binary systems, a term describing pairs of two orbiting each other, account for around 15% of all known asteroids, but none have ever been studied in detail, ESA says.

“Hera will provide valuable data for future asteroid deflection missions and science to help humanity’s understanding of asteroid geophysics as well as solar system formation and evolutionary processes,” SpaceX said in a post on X.

Thales Alenia Space provided the communications subsystem for the Hera mission, allowing ESA to track and control the spacecraft from a distance of up to 500 million kilometers away, Thales said. The joint venture also supplied the power unit.

ESA plans to build on the experience acquired with Hera for its future Ramses mission, which needs to launch in 2028 for a rendezvous with the asteroid Apophis, which will pass within 32,000 kilometers of Earth in April 2029.

“If we did detect an asteroid on a collision course with Earth, a reconnaissance mission like Hera or Ramses would likely be launched as soon as possible to precisely determine the object’s trajectory and rule out a false alarm,” ESA said on X.

Such as mission would also measure the asteroid’s physical properties, which would be essential to determine when and where, and with what power, a deflector mission would need to hit the asteroid to safely divert it away from Earth, according to ESA.

Rudy Ruitenberg is a Europe correspondent for Defense News. He started his career at Bloomberg News and has experience reporting on technology, commodity markets and politics.

巴黎——欧洲发射了首个航天器，旨在帮助开发防御措施，以抵御可能撞击地球的毁灭性小行星。

欧洲航天局的“赫拉”探测任务于周一从卡纳维拉尔角发射升空，由SpaceX公司的猎鹰9号火箭运载。国防企业泰雷兹和莱昂纳多通过其合资企业泰雷兹阿莱尼亚宇航公司为该任务提供了技术支持。此次任务将研究美国宇航局一项实验的结果，该实验是人类首次尝试偏转小行星轨道。

据泰雷兹公司称，大约有3万颗直径在100米到300米之间的小行星在太阳系中运行，它们的轨道会使其相对接近地球。平均每1万年就有一颗这样的太空岩石撞击地球。这种小行星撞击地球的威力相当于约5000万吨TNT当量爆炸，与苏联沙皇炸弹（有史以来威力最大的核武器）的威力相当。

欧洲航天局（ESA）在其社交媒体平台X（前身为Twitter）上发帖称：“我们目前已知有超过35000颗小行星距离地球足够近，值得我们密切关注。赫拉小行星项目是国际合作的一部分，旨在解答这样一个问题：如果我们发现一颗小行星正朝着地球撞击而来，我们能做些什么？”

“赫拉”号任务将调查美国宇航局（NASA）小行星重定向试验的结果。在2022年的这项试验中，NASA将一艘航天器撞击了小行星迪莫弗斯，以测试行星防御能力。泰雷兹公司表示，“赫拉”号将于2026年10月抵达包含迪莫弗斯的双小行星系统，近距离收集数据可能有助于将NASA的动能撞击实验转化为一种潜在的可重复的行星防御技术。

泰雷兹公司表示，中型小行星才是真正需要关注的对象，因为它们的撞击对人口稠密地区来说将是毁灭性的，足以摧毁整座城市或引发海啸。欧洲航天局称，双星系统（指两颗相互环绕的小行星）约占已知小行星总数的15%，但目前还没有对任何双星系统进行过详细研究。

SpaceX 在 X 论坛上发帖称：“Hera 将为未来的小行星偏转任务和科学研究提供宝贵的数据，以帮助人类了解小行星地球物理学以及太阳系的形成和演化过程。”

泰雷兹阿莱尼亚宇航公司表示，该公司为赫拉任务提供了通信子系统，使欧洲航天局能够从远达5亿公里的距离跟踪和控制该航天器。这家合资企业还提供了动力单元。

欧洲航天局计划利用赫拉任务获得的经验，开展未来的拉美西斯任务。该任务需要在 2028 年发射，与小行星阿波菲斯交会。阿波菲斯将于 2029 年 4 月从距离地球 32,000 公里处掠过。

欧洲航天局在X上表示：“如果我们探测到一颗小行星正朝着地球撞击，像赫拉或拉美西斯这样的侦察任务可能会尽快发射，以精确确定该物体的轨迹并排除误报的可能性。”

据欧洲航天局称，此类任务还将测量小行星的物理特性，这对于确定偏转器任务需要在何时何地以多大的力量撞击小行星，才能安全地将其偏转远离地球至关重要。

鲁迪·鲁伊滕贝格是《防务新闻》的欧洲记者。他的职业生涯始于彭博新闻社，拥有报道科技、大宗商品市场和政治方面的经验。