神秘的太空飛機已經(jīng)繞地球運行了719天，我們卻不知道它在干什么

Mysterious Space Plane Has Now Been Orbiting Earth For 719 Days, And We Don't Know Why

神秘的太空飛機已經(jīng)繞地球運行了719天，我們卻不知道它在干什么

An uncrewed, solar-powered military plane has just broken its spaceflight-duration record, having now spent more than 719 days in orbit around Earth.

一架無人駕駛的太陽能軍用飛機，剛剛打破了其航天飛行時間的記錄，目前已在地球軌道上飛行了719天多。

Known as the X-37B, the space plane belongs to the US Air Force, and this is its fifth mission, Orbital Test Vehicle 5 (OTV-5). However, exactly what it's achieving on its missions remains classified.

這架航天飛機被稱為X-37B，屬于美國空軍，這是它的第五次任務(wù)，軌道試驗飛行器5(OTV-5)。然而，它在其任務(wù)中的具體成果仍然是保密的。

On Monday, the plane broke the record set by the previous mission, OTV-4, which stayed in the air for a duration of 717 days, 20 hours and 42 minutes.

周一，這架飛機打破了先前任務(wù)OTV-4的記錄，它在空中停留了717天20小時和42分鐘。

OTV-5 beat that record at 10:43 UTC (06:43 EDT) on August 26. We're now nearly at the end of day 719 of the plane being in orbit.

8月26日，世界時間10:43(美國東部時間06:43)，OTV-5打破了這一紀(jì)錄。現(xiàn)在，我們已經(jīng)接近第719天的尾聲了。

So what's it doing up there?

那么它在上面做什么呢?

Well, no one's sure as yet. While the US Air Force doesn't avoid talking about the plane, they use very general terms.

嗯，目前還沒有人確定。雖然美國空軍不回避談?wù)擄w機，但他們使用非常通用的術(shù)語。

Some things we do know - X-37B looks a little like a smaller version of NASA's old space shuttle, and the US Air Force has at least two of the solar-powered aircraft, which were built by Boeing.

我們知道的一些事情——X-37B看起來有點像美國宇航局舊航天飛機的小版本，美國空軍至少有兩架太陽能飛機，由波音公司制造。

This latest mission was launched on 7 September 2017 by a SpaceX Falcon 9 rocket and is still active.

這項最新任務(wù)于2017年9月7日由SpaceX獵鷹9號火箭發(fā)射，目前仍在進(jìn)行中。

It's not clear when it'll come down, but when it does, it'll land on a runway using its wheels.

現(xiàn)在還不清楚它什么時候會降落，但一旦降落，它就會用輪子降落在跑道上。

According to the Air Force, the X-37B's primary objectives are to research reusable spacecraft technologies for America's future in space, and to conduct experiments that can be returned to, and examined, on Earth.

根據(jù)美國空軍的說法，X-37B的主要目標(biāo)，是為美國未來的太空研究可重復(fù)使用的航天器技術(shù)，并進(jìn)行可以返回地球并在地球上進(jìn)行檢測的實驗。

Beyond that, officials haven't given up much actual dirt on the specifics of its orbital experiments.

除此之外，官方并沒有透露太多關(guān)于其軌道實驗的具體細(xì)節(jié)。

In the past, that's led to fervent speculation that the military might be testing an EM Drive in space – a hypothetical fuel-less propulsion system that's been studied by NASA, and which China claims it's already testing.

在過去，這導(dǎo)致了狂熱的猜測，軍方可能正在太空中測試一種電磁驅(qū)動——一種假設(shè)的無燃料推進(jìn)系統(tǒng)，NASA已經(jīng)對其進(jìn)行了研究，中國聲稱已經(jīng)在進(jìn)行測試。

Other speculation has suggested the Air Force might be using the X-37B for weapons research or orbital surveillance operations – although back in 2010 the Air Force denied that the program involved any "offensive capabilities".

其他猜測表明，美國空軍可能正在使用X-37B進(jìn)行武器研究或軌道監(jiān)視行動——盡管早在2010年，美國空軍否認(rèn)該計劃涉及任何“進(jìn)攻能力”。

"The program supports technology risk reduction, experimentation and operational concept development," a spokesperson said at the time.

“該項目支持技術(shù)風(fēng)險降低、實驗和運營理念的開發(fā)，”一位發(fā)言人當(dāng)時說。

Regardless of what the plane's mission is, it was initially only designed for an orbit window of 270 days, so the fact that it's been able to more than double that time is a pretty big win for solar-powered aircraft.

不管這架飛機的任務(wù)是什么，它最初只是為270天的軌道窗口設(shè)計的，所以事實上，它已經(jīng)能夠超過兩倍的時間，這已經(jīng)是一個太陽能飛機相當(dāng)大的勝利。

Beyond that, we unfortunately can't tell you much, other than we'll be keeping an eye on what the space plane does next.

除此之外，不幸的是，我們不能告訴你太多，除了我們將密切關(guān)注下一步太空飛機將做什么。