NASA's twin Voyager probes （航天探测器） have been on a mission of exploration for decades, and they've performed admirably.Both probes have now left the solar system,providing the first direct measurements of the universe outside our little corner of it. Keeping a 42-year-old space probe working is no simple feat, though.Engineers are working to restore normal operations on Voyager 2 afterautomated fault protection routines shut off the probe's science instruments.

The first sign of trouble came on January 25th when the spacecraft failed to execute a planned maneuver（移动） to calibrate（校准）its magnetic field instrument. Voyager 2 remained in contact with Earth, but its science instruments shut off after the failed maneuver.After studying the probe's telemetry（遥测术）,the team determined that the missed spin left two high-power systems operating at the same time.That state would call for more power than the probe had, so the fault protection kicked in to turn off non-essential systems.

NASA's Jet Propulsion Laboratory （JPL）equipped Voyager 2 with a radioisotope thermoelectric generator （RTG） for power as it's too far from the Sun for solar panels to be effective. This type of power source provides a constant supply of power, but its potency drops a bit every year as the plutonium （钚）fuel decays. Engineers have slowly ratcheted down the probe's power requirements over the years.

With a full understanding of the issue,JPL staff were able to reactivate the science suite yesterday （January 28th） by flipping off one of the high-power subsystems. The team is currently working to restore normal operations, but that will take some time. This is a machine from the 1970s after all, and it's 11.5 billion miles away. Each command takes 17 hours to reach Voyager 2, and the confirmation takes 17 hours to come back. So,that's almost a day and a half just to find out if a command does what it is supposed to do.Despite the difficulties, the Voyager probes remain vital tools in our study of deep space.

阅读检测

1. What do we know about Voyager 2 according to the first paragraph?

A. It's leaving the solar system. B. It's functioning very well.

C. It needs to have a good rest. D. It was launched in the 1970s.

2. What does the underlined word “execute” in paragraph 2 mean?

A. Carry out. B. Give away.

C. Focus on. D. Bring up.

3. What does the author think of the team's working to restore normal operations?

A. Very easy. B. Puzzling.

C. Challenging. D. Meaningless.

语言学习

难句分析

Engineers are working to restore normal operations on Voyager 2 after automated fault protection routines shut off the probe's science instruments. 在“旅行者2号”探测器的自动保护程序关闭了探测器的科学仪器之后,工程师们正在努力使探测器恢复到正常运行状态。

【点石成金】本句是一个复合句。 Engineers are working to restore normal operations on Voyager 2主句，after引导时间状语从句。