SpaceX, an American aerospace manufacturer and space transport company founded by entrepreneur Elon Musk, did something on March 30 that really hadn’t been done before: launch a cheaper, partially-used rocket into orbit.
That may be a stride toward slashing the price tag of sending payload to space. For Musk, successfully flying reusable rockets is a crucial step toward his dream of sending people to Mars.
The rocket, carrying a telecommunications satellite, launched from the Kennedy Space Center in Florida.
Photo: EPA
照片:歐新社
Until now, rockets have almost all been single-use. Once the fuel is expended, a rocket stage plummets to Earth, a quick demise for a complex machine that cost tens of millions of dollars to build.
Musk has likened that to scrapping a 747 jet after one flight, which would make air travel impossibly expensive.
He has suggested that rocket launches could eventually be much cheaper since the cost of the rocket propellants are less than 1 percent of the full-price ticket for a launch. So, if a rocket could be simply refueled like a jetliner for another flight, the cost of space travel could drop to a fraction of what it is now.
The stresses of spaceflight on reused boosters, however, are much greater than those on jetliners. The economics will depend on how many times a booster can be flown, and how much the individual expense will be to refurbish the booster — and particularly the engines — each time.
Reusable spaceships are not a new idea. NASA’s space shuttles were the first real attempt at a reusable spaceship, but the shuttles proved more delicate than hoped, requiring an army of technicians to refurbish them between flights. As a result, they ended up being more expensive, not cheaper, than expendable rockets — close to half a billion dollars a flight.
SpaceX’s next launch for NASA, a cargo mission currently scheduled for May, will continue the reusability theme. The rocket will be entirely new, but the mission will reuse one of the capsules from one of the earlier cargo runs.
This article is an edited version of a piece that originally appeared in the New York Times
(Kenneth Chang, New York Times)
由企業家伊隆‧馬斯克所創設的SpaceX航太製造商暨太空運輸公司,在三月三十日完成了一項創舉,將一枚價格較低廉的半二手火箭發射進入軌道。
此舉有希望大幅減低太空酬載價格。對於夢想送人類上火星的馬斯克而言,成功地讓使用過的火箭再度啟航是一項關鍵進展。
這枚火箭搭載了一個通訊衛星,由美國佛羅里達州甘迺迪太空中心發射。
在此之前,火箭幾乎都是單次使用的。一旦燃料耗盡,火箭節墜落回地球,一個造價幾百萬美金的複雜機具就這樣迅速報銷了。
馬斯克把這比喻為一架七四七噴射機只飛過一次,就被報廢了,這會使搭飛機超乎想像地昂貴。
馬斯克認為未來的火箭發射會便宜許多,因為火箭推進燃料的成本其實不到發射一次的花費的百分之一。因此,如果火箭能像噴射客機一樣只需補充燃料便可再度飛行,太空航行的成本就會遠低於現在。
但噴射客機所需承受的壓力遠遠比不上太空航行對推進器產生的耗損。其經濟性端視推進器可重複使用的次數,以及每次整修所需的花費,尤其是每一次的引擎整修。
其實,太空船的重複使用並不是什麼新概念。美國太空總署的太空梭即為首次實際嘗試重複使用的太空船,但實飛結果發現,太空梭比預期中脆弱,每次飛行後都需要大批技術人員來整修,每次航行要五億美元,最後反而比消耗性火箭還要昂貴得多。
SpaceX下次為太空總署發射火箭是執行一項載運任務,目前時程訂在五月,會繼續追求重複使用機具的目標。該任務將使用全新的火箭,並搭配先前的載運任務所使用過的太空艙。
本文為編輯後的版本,英文原文已於紐約時報刊登。
(台北時報編譯林俐凱譯)
A: I want to go to Neihu to see the cherry blossoms. B: Do you want to go by YouBike? A: Well, how much does it cost? B: The Taipei City Government just announced that riders can use the bicycles for free for the first 30 minutes! A: Great! Riding bikes is also more eco-friendly than driving. A: 我想去內湖賞櫻花耶。 B: 那要不要騎YouBike微笑單車去? A: 車費怎麼算? B: 台北市政府最近宣布︰前30分鐘免費! A: 太棒了,而且也比開車更環保。 (By Eddy Chang, Taipei Times/台北時報張聖恩)
One of us is a murderer. The terrifying thought fills your head. There’s a corpse in the next room, and one of your fellow diners put it there. As the evening progresses, you learn disturbing secrets about everyone, and you’re forced to confess to a few yourself. You all have motives for the crime, but who committed it? Fortunately, it’s just a game. Murder mystery games are multiplayer role-playing games designed to be played over the course of an evening. The concept likely originated with “wink murder,” an amusing pastime that became popular in the early 1900s. In this game, a “murderer” kills
A: How does Taipei’s YouBike service charge after the free ride for the first 30 minutes? B: It’s NT$10 every 30 minutes within four hours. A: What a bargain. No wonder Taipei is listed by Britain’s “Time Out” magazine as one of the best 50 cities in the world. B: But I spotted a few English mistakes on YouBike’s Web site. A: I guess that aspect of it still has room for improvement. A: 台北市YouBike前30分鐘免費,之後怎麼算? B: 4小時內每30分鐘10元。 A: 真劃算,難怪台北市會入選英國《Time Out》雜誌全球最佳的50座城市。 B: 不過我在YouBike的網站上看到了好幾個英文錯誤。 A: 看來這個部分還有改善的空間。(By Eddy Chang, Taipei Times/ 台北時報張聖恩)
Mullet roe is a highly-priced delicacy typically served during special occasions like wedding banquets or Chinese New Year’s dinners, where families come together in celebration. The mullet roe can be prepared in various ways. It is usually pan-fried but can also be roasted or torched. To cook a pan-fried mullet roe, soak it in liquor or wine and peel off its membrane. Then, it is browned over a low fire and turned several times. Finally, the fried mullet roe is cut diagonally and is ready to be served. This dish is usually served with garlic scapes and daikon slices, but