神秘的太空飛機(jī)已經(jīng)繞地球運(yùn)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(jī)已經(jīng)繞地球運(yùn)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(wú)人駕駛的太陽(yáng)能軍用飛機(jī)，剛剛打破了其航天飛行時(shí)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(jī)被稱(chēng)為X-37B，屬于美國(guó)空軍，這是它的第五次任務(wù)，軌道試驗(yàn)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(jī)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(shí)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(shí)間10:43(美國(guó)東部時(shí)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(méi)有人確定。雖然美國(guó)空軍不回避談?wù)擄w機(jī)，但他們使用非常通用的術(shù)語(yǔ)。

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(lái)有點(diǎn)像美國(guó)宇航局舊航天飛機(jī)的小版本，美國(guó)空軍至少有兩架太陽(yáng)能飛機(jī)，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(xiàng)最新任務(wù)于2017年9月7日由SpaceX獵鷹9號(hào)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(shí)候會(huì)降落，但一旦降落，它就會(huì)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(guó)空軍的說(shuō)法，X-37B的主要目標(biāo)，是為美國(guó)未來(lái)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(cè)的實(shí)驗(yàn)。

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(méi)有透露太多關(guān)于其軌道實(shí)驗(yàn)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(guò)去，這導(dǎo)致了狂熱的猜測(cè)，軍方可能正在太空中測(cè)試一種電磁驅(qū)動(dòng)——一種假設(shè)的無(wú)燃料推進(jìn)系統(tǒng)，NASA已經(jīng)對(duì)其進(jìn)行了研究，中國(guó)聲稱(chēng)已經(jīng)在進(jìn)行測(cè)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(cè)表明，美國(guó)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(dòng)——盡管早在2010年，美國(guó)空軍否認(rèn)該計(jì)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(xiàng)目支持技術(shù)風(fēng)險(xiǎn)降低、實(shí)驗(yàn)和運(yùn)營(yíng)理念的開(kāi)發(fā)，”一位發(fā)言人當(dāng)時(shí)說(shuō)。

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(jī)的任務(wù)是什么，它最初只是為270天的軌道窗口設(shè)計(jì)的，所以事實(shí)上，它已經(jīng)能夠超過(guò)兩倍的時(shí)間，這已經(jīng)是一個(gè)太陽(yáng)能飛機(jī)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(jī)將做什么。