Yes, scientists are actually building an elevator to space - Fabio Pacucci

譯者: Camila Lin 審譯者: Helen Chang

Sending rockets into space requires sacrificing expensive equipment,

將火箭發射到太空中， 需要非常昂貴的設備、

burning massive amounts of fuel, and risking potential catastrophe.

燃燒巨量的燃料， 還必須冒著災害發生的風險。

So in the space race of the 21st century,

所以在這場 21 世紀的 太空競賽中，

some engineers are abandoning rockets for something much more exciting:

有些工程師已經棄火箭於不顧， 轉向更令人興奮的這個東西：

elevators.

電梯。

Okay, so maybe riding an elevator to the stars

好吧，搭電梯到其他星球去，

isn't the most thrilling mode of transportation.

可能真的不是最刺激的交通方式。

But using a fixed structure to send smaller payloads

但使用固定的建築將較小的負載量──

of astronauts and equipment into orbit

包含太空人和設備──送上軌道，

would be safer, easier, and cheaper than conventional rockets.

比傳統火箭更安全、更簡單也更便宜。

On a SpaceX Falcon 9 rocket,

以獵鷹 9 號運載火箭而言，

every kilogram of cargo costs roughly $7,500 to carry into orbit.

要將每一公斤的貨物送上軌道， 就必須花上 7500 美元。

Space elevators are projected to reduce that cost by 95%.

太空電梯預計 可減少 95% 的成本。

Researchers have been investigating this idea since 1895,

從 1895 年開始， 研究者就開始調查這個方案，

when a visit to what was then the world's tallest structure

這是俄羅斯的科學家 康斯坦丁·齊奧爾科夫斯基

inspired Russian scientist Konstantin Tsiolkovsky.

拜訪當時世界上最高的 建築物後受到的啟發。

Tsiolkovsky imagined a structure thousands of kilometers tall,

他想像出一個高數千公里的結構，

but even a century later, no known material is strong enough

但就算在一個世紀後， 也尚未發現能支撐這種建物的物質。

to support such a building.

Fortunately, the laws of physics offer a promising alternative design.

幸運的是，物理定律提供了 一個充滿希望的替代設計方案。

Imagine hopping on a fast-spinning carousel

想像你跳上一座快速運轉的旋轉木馬，

while holding a rope attached to a rock.

手上抓著一條末端綁著石頭的繩子。

As long as the carousel keeps spinning, the rock and rope will remain horizontal,

只要旋轉木馬持續旋轉， 石頭和繩子就會維持水平，

kept aloft by centrifugal force.

因為離心力而在空中飄浮。

If you're holding the rope, you'll feel this apparent, inertial acceleration

如果你抓住繩子， 就能感受到明顯的慣性加速，

pulling the rock away from the center of the rotating carousel.

正在將石頭帶離這個不停旋轉的木馬。

Now, if we replace the carousel with Earth,

現在，如果我們用地球取代旋轉木馬，

the rope with a long tether, and the rock with a counterweight,

用長拴練取代繩子，用配重取代石頭，

we have just envisioned the modern space elevator—

我們剛剛看見的就是 現代太空電梯的理想模樣：

a cable pulled into space by the physics of our spinning planet.

一條靠著地球旋轉的物理力學 被甩入太空中的電纜。

For this to work, the counterweight would need to be far enough away

要達到這個目標， 這個配重必須離地球夠遠，

that the centrifugal force generated by the Earth's spin

直到抵達因地球轉動產生的離心力

is greater than the planet's gravitational pull.

大於地球重力拉扯的地方。

These forces balance out at roughly 36,000 kilometers above the surface,

這兩股力量大概會在距離地球表面 36,000 公里的地方失去平衡，

so the counterweight should be beyond this height.

所以衡重必須在比它更遠的地方。

Objects at this specific distance are in geostationary orbit,

處在這個特定距離下的物體， 同時也處在地球同步軌道上，

meaning they revolve around Earth at the same rate the planet spins,

意味著它們繞行地球的速率 和地球自轉相同，

thus appearing motionless in the sky.

因此它們在天空中的位置 看起來靜止不動。

The counterweight itself could be anything,

衡重可以是任何事物，

even a captured asteroid.

就算是被捕獲的小行星也可以。

From here, the tether could be released down through the atmosphere

繫鏈會從衡重被放下來，穿過大氣層

and connected to a base station on the planet's surface.

和星球表面的基地連接。

To maximize centrifugal acceleration,

為了使離心加速度最大化，

this anchor point should be close to the Equator.

這個錨點應該要和赤道很接近。

And by making the loading station a mobile ocean base,

而只要將裝運站建成 移動式的海洋基地，

the entire system could be moved at will,

整個系統都能照需要移動，

allowing it to maneuver around extreme weather,

讓它在極端氣候中仍可被使用，

and dodge debris and satellites in space.

並閃避太空中的殘骸與人造衛星。

Once established, cargo could be loaded onto devices called climbers,

一旦建造完成， 貨艙就能被放上「攀升器」，

which would pull packages along the cable and into orbit.

這個設備能沿著貨艙拉起包裹， 並將它丟上軌道。

These mechanisms would require huge amounts of electricity,

這些機械裝置需要巨額電力，

which could be provided by solar panels or potentially even nuclear systems.

可以由太陽能板供給， 甚至也能用核電供應。

Current designs estimate that it would take about 8 days

依照現在的設計，預估大約需要八天

to elevate an object into geostationary orbit.

才能將一個物體拋上地球同步軌道。

And with proper radiation shielding,

而如果有適當的輻射護盾，

humans could theoretically take the ride too.

理論上人類也能搭一次太空電梯。

So, what's stopping us from building this massive structure?

所以，我們為什麼還不蓋 這個超巨大的建築物？

For one thing, a construction accident could be catastrophic.

首先，一場建築意外就會 帶來毀滅性的災害。

But the main problem lies in the cable itself.

但主要的問題是纜線。

In addition to supporting a massive amount of weight,

為了支撐這麼龐大的重量，

the cable's material would have to be strong enough

纜線的材質必須夠堅固，

to withstand the counterweight's pull.

才能承受衡重的拉力。

And because this tension and the force of gravity would vary at different points,

而因為纜線各點所受的 拉力和重力都不同，

its strength and thickness would need to vary as well.

它的強壯程度和粗細也必須隨之改變。

Engineered materials like carbon nanotubes and diamond nano-threads

工程材料如奈米碳管或奈米鑽石線

seem like our best hope for producing materials

最有希望，讓我們能製造出

夠堅固又夠輕盈、 能勝任這個工作的材料。

strong and light enough for the job.

But so far,

但到目前為止，

we've only been able to manufacture very small nanotube chains.

我們能做出的奈米管線非常小。

Another option would be to build one somewhere with weaker gravity.

另一個選擇是把電梯 蓋在重力較小的星球上。

Space elevators based on Mars or the Moon

建造於火星或月亮上的太空電梯，

are already possible with existing materials.

已可能可用現存的材料製造。

But the huge economic advantage of owning an Earth-based space elevator

但是擁有一座地球上太空電梯 帶來的巨大經濟效益，

has inspired numerous countries to try and crack this conundrum.

已經激發無數國家試著完成這個難題。

In fact, some companies in China and Japan

事實上，一些中國和日本的公司

are already planning to complete construction by 2050.

已經開始計畫在 2050 年前完成建造。