NASA’s Psyche spacecraft returns unfamiliar views of a familiar world

NASA“灵神星”号探测器传回熟悉星球的陌生视角

Not quite halfway through a six-year sojourn through the Solar System, a NASA spacecraft used a close encounter with Mars last week as a dress rehearsal for its arrival at the Solar System’s largest metal asteroid in 2029. 在穿越太阳系的六年旅程中，NASA 的“灵神星”（Psyche）号探测器已走过近半路程。上周，它利用一次近距离飞掠火星的机会，为 2029 年抵达太阳系最大的金属小行星进行了“彩排”。

The Psyche mission launched more than two-and-a-half years ago, in October 2023, from Kennedy Space Center, Florida, to kick off a journey of some 2.2 billion miles (3.6 billion km) to reach its unexplored namesake, the asteroid Psyche. The robotic research mission got an initial lift from a powerful SpaceX Falcon Heavy rocket. It uses plasma engines to gradually build up the impulse needed to reach its destination in the asteroid belt, between the orbits of Mars and Jupiter. “灵神星”任务于两年半前的 2023 年 10 月从佛罗里达州肯尼迪航天中心发射升空，开启了约 22 亿英里（36 亿公里）的征程，旨在抵达其未曾探索的同名小行星——灵神星。这项机器人研究任务最初由强大的 SpaceX“猎鹰重型”火箭助推升空。它利用等离子发动机逐渐积累动力，以抵达位于火星和木星轨道之间的小行星带目的地。

A flyby of Mars last Friday gave the spacecraft its most significant boost since launch. Navigators at NASA’s Jet Propulsion Laboratory in California set up the spacecraft for a course taking it 2,864 miles (4,609 km) from the Martian surface, well above the planet’s tenuous atmosphere. Psyche used Martian gravity like a slingshot to gain enough speed to reshape its orbit around the Sun, putting the probe on a path to intercept its asteroid target. 上周五的火星飞掠为该探测器提供了自发射以来最显著的加速。位于加州的 NASA 喷气推进实验室（JPL）的导航员为探测器设定了航线，使其在距离火星表面 2864 英里（4609 公里）处掠过，远高于火星稀薄的大气层。灵神星号利用火星引力作为“弹弓”，获得了足够的加速来重塑其绕日轨道，从而使其进入拦截目标小行星的轨道。

“Although we were confident in our calculations and flight plan, monitoring the DSN’s (Deep Space Network’s) Doppler signal in real time during the flyby was still exciting,” said Don Han, Psyche’s navigation lead at JPL, in a statement. “We’ve confirmed that Mars gave the spacecraft a 1,000-mile-per-hour boost and shifted its orbital plane by about 1 degree relative to the Sun. We are now on course for arrival at the asteroid Psyche in summer 2029.” “尽管我们对计算结果和飞行计划充满信心，但在飞掠过程中实时监测深空网络（DSN）的多普勒信号依然令人兴奋，”JPL 的灵神星任务导航负责人 Don Han 在一份声明中表示。“我们已确认火星为探测器提供了每小时 1000 英里的加速，并使其轨道平面相对于太阳偏移了约 1 度。我们现在正按计划航行，将于 2029 年夏季抵达灵神星。”

The gravity assist was the main goal of the Mars flyby, but ground teams used the encounter to test the spacecraft’s three science instruments: a multispectral imager consisting of two cameras, a gamma-ray and neutron spectrometer, and a magnetometer. Similar sensors are flying on other spacecraft that are permanently studying Mars, so the real benefit of running the instruments during Psyche’s encounter was for scientists to use the flyby as a practice run for when it reaches the asteroid Psyche. 引力助推是此次火星飞掠的主要目标，但地面团队也利用这次相遇测试了探测器的三台科学仪器：由两台相机组成的多光谱成像仪、伽马射线和中子光谱仪，以及磁强计。其他长期研究火星的探测器上也搭载了类似的传感器，因此在灵神星号飞掠期间运行这些仪器的真正意义，在于让科学家们将此次飞掠作为抵达灵神星前的实战演练。

“As a bonus, it captured Mars images from a rare perspective,” NASA said in a press release. The spacecraft approached Mars from a high phase angle, or from the side opposite the Sun, making the planet appear as a thin crescent as Psyche moved in for the encounter. The wispiness of the thin Martian atmosphere was on full display, with sunlight shining through diffuse clouds of dust suspended dozens of miles over the sharp edge of the planet’s rust-colored surface. “作为额外收获，它从一个罕见的视角拍摄了火星图像，”NASA 在新闻稿中表示。探测器以高相位角（即背对太阳的一侧）接近火星，当灵神星号靠近时，火星呈现出细长的月牙状。火星稀薄大气的飘逸感展现得淋漓尽致，阳光穿过悬浮在火星锈色表面边缘上方数十英里的弥散尘云。

As Psyche zoomed past the red planet, its cameras captured a wide-angle overhead view of Mars’ southern polar ice cap. Jim Bell, who leads the Psyche imager instrument team at Arizona State University, said the spacecraft took thousands of images during the encounter. The observations will help scientists “calibrate and characterize” the performance of the cameras, Bell said. 当灵神星号疾驰掠过这颗红色星球时，其相机捕捉到了火星南极冰盖的广角俯视图。亚利桑那州立大学灵神星成像仪团队负责人 Jim Bell 表示，探测器在相遇期间拍摄了数千张图像。Bell 说，这些观测结果将有助于科学家“校准和表征”相机的性能。

Psyche’s magnetometer may have detected a signature of the solar wind interacting with Mars’ upper atmosphere or its remnant magnetic field, and its spectrometers were tuned to measure the chemical composition of the Martian surface underneath the spacecraft’s flight path. Numerous other missions are exploring Mars full-time, so there’s little chance of any major discoveries lurking in Psyche’s flyby datasets. But scientists should be able to calibrate the mission’s instruments by comparing flyby observations with archival data from other Mars missions. 灵神星号的磁强计可能探测到了太阳风与火星高层大气或其残余磁场相互作用的特征，其光谱仪也被调整为测量探测器飞行路径下方的火星表面化学成分。由于其他众多任务正在全天候探索火星，灵神星号的飞掠数据集不太可能包含任何重大发现。但科学家们可以通过将飞掠观测结果与其他火星任务的存档数据进行对比，来校准该任务的仪器。

It is always interesting to gain new perspectives, even on something familiar. You can’t see a crescent Mars from Earth. But the Psyche mission’s real payoff will come in three years, when the probe pulls in close to asteroid Psyche, an object the size of Massachusetts that is rich in iron, nickel, and likely other metals that we know only as a fuzzy blob through telescopes. It is truly uncharted territory, but the Psyche spacecraft will have more than two years to survey the asteroid, far longer than the fleeting glimpse it got of Mars last week. 即使是对熟悉的事物，获得新的视角也总是令人着迷。从地球上是无法看到月牙状火星的。但灵神星任务真正的回报将在三年后到来，届时探测器将靠近灵神星——这是一个马萨诸塞州大小、富含铁、镍及其他金属的天体，目前我们通过望远镜只能看到它模糊的轮廓。这确实是一片未知的领域，但灵神星号将有超过两年的时间来勘测这颗小行星，这远比上周对火星的匆匆一瞥要深入得多。