降落在小行星贝努上

Bennu, a well-preserved, ancient asteroid, is currently more than 200 million miles (321 million kilometers) from Earth and offers scientists a window into the early solar system as it was first taking shape billions of years ago and flinging ingredients that could have helped seed life on Earth.

On Tuesday, Oct. 20, 2020, NASA’s OSIRIS-REx sample collection mission performed a successful “Touch-And-Go” (TAG) maneuver.

At 1:50 p.m. EDT, OSIRIS-REx fired its thrusters to nudge itself out of orbit around Bennu. It extended the shoulder, then elbow, then wrist of its 11-foot (3.35-meter) sampling arm, known as the Touch-And-Go Sample Acquisition Mechanism (TAGSAM), and transited across Bennu while descending about a half-mile (805 meters) toward the surface. After a four-hour descent, at an altitude of approximately 410 feet (125 meters), the spacecraft executed the “Checkpoint” burn, the first of two maneuvers to allow it to precisely target the sample collection site, known as “Nightingale.”

All spacecraft telemetry data indicates the TAG event executed as expected. However, it will take about a week for the OSIRIS-REx team to confirm how much sample the spacecraft collected.

This view of asteroid Bennu ejecting particles from its surface on January 19, 2019 was created by combining two images taken on board OSIRIS-REx spacecraft. Other image processing techniques were also applied, such as cropping and adjusting the brightness and contrast of each image.

Image Credit: NASA/Goddard/University of Arizona/Lockheed Martin

贝努（Bennu）是一个保存完好的古老小行星，目前距离地球超过2亿英里（3.21亿公里），为科学家提供了进入早期太阳系的窗口，因为它早在数十亿年前就已初具雏形，并可能为地球上孕育生命提供了原料。

2020年10月20日，星期二，NASA的OSIRIS-REx样本采集任务成功完成了“即触即走”（TAG）操作。

美国东部时间下午1点50分，OSIRIS-REx点燃了推进器，将自己推离了围绕本努的轨道。它伸展其11英尺(3.35米)取样臂的肩部、肘部、手腕，即所谓的触碰式取样装置(TAGSAM)，在向小行星表面下降约半英里(805米)的过程中穿过贝努。在大约410英尺(125米)的高度下降了4个小时后，飞船执行了“检查点燃烧”，这是两次飞行中的第一次，目的是让它精确地瞄准被称为夜莺的样本采集地点。

所有航天器遥测数据均指示按预期执行的TAG事件。但是，OSIRIS-REx团队将花费大约一周的时间来确认飞船收集了多少样品。

这张于2019年1月19日拍摄的小行星贝努从其表面喷射粒子的照片是由OSIRIS-REx飞船上拍摄的两张照片合成的。其他图像处理技术也被应用，如裁剪和调整每张图像的亮度和对比度。

影像来源：NASA/Goddard/University of Arizona/Lockheed Martin