字幕列表 影片播放 列印所有字幕 列印翻譯字幕 列印英文字幕 When it comes to landing spacecraft on planets, or moons, or back here on earth – Mars sucks. 對於登陸行星、衛星或地球而言,火星真的很糟糕。 There's a lower success rate landing on Mars than on Venus, the moon, the earth, even 登陸火星的成功率比金星、月球、地球、 Saturn's moon Titan. 甚至土星的衛星泰坦都要低(才登陸一次是要比三小)。 And in large part, this is because Mars's atmosphere is in the perfect goldilocks zone 主要是因為火星大氣層剛剛好處於 of being a total headache. 最棘手的區間。 On the moon (or an asteroid) you can use lightweight spacecraft made essentially out of tinfoil 在月球(或小行星)上,你可以用外殼輕薄的太空船登陸 because there's no air to cause drag or pressure or heat. 因為沒有空氣就不會造成曳力、壓力或熱。 Essentially, you save weight not having heat shields or thick walls, but need to use rockets 於是你不需要隔熱罩或厚重外殼,但需要用火箭 to land in what's called a “powered descent.” 緩衝降落,稱為「動力降落」。 On earth, or Venus, or Titan, there's enough air that you can land largely unpowered, first 在地球、金星或泰坦上, 有足夠的大氣層讓你充分減速, by slowing down with a heat shield and atmospheric drag, and then with parachutes. 先用隔熱罩和大氣層的阻力,再用降落傘減速。 So you use a lot of weight for heat shields and walls and parachutes, but don't need 於是你需要很重的隔熱罩、外殼和降落傘,但不用 big rockets or lots of fuel to land. 攜帶巨大的火箭和很多燃料。 However, the air on Mars is literally the worst of both worlds – thick enough that 但火星大氣卻比光譜兩端還要糟糕─它厚到 you actually have to deal with it with heat shields and walls, but thin enough that it 讓你必須處理隔熱罩和外殼,又薄得無法 doesn't help you slow down much and you also need to use rockets. 充分減速,讓你仍然得使用火箭。 Mars is simply a challenging place to land a spacecraft, which is why we've tried so 火星對太空船登陸而言是個大挑戰,所以我們 many different and crazy techniques for landing there: we've landed landers and rovers using 用了各種不同的瘋狂點子來登陸:包括 retrorockets, in inflatable bouncy airbags, by being lowered from a hovering sky crane 逆噴射火箭、彈性氣囊、用空中起重機懸停垂吊...... – all of which ALSO used heat shields and parachutes and rocket powered descent before 這些方法在著陸的最後階段前, the last stage of landing. 仍得搭配隔熱罩、降落傘和動力降落。 And space agencies are testing other crazy things like giant supersonic parachutes and 太空機構還在測試其他技術,例如巨大的超音速降落傘 inflatable innertubes around landers to increase their surface area and help them slow down 或在登陸器周圍加裝彈性內胎,增加其表面積 more in the thin air before landing (probably still with rockets, or sky cranes). 以便在稀薄的大氣層中更有效減速。 (可能還是要用到火箭,或空中起重機) Yes, you heard that right – it's possible that when the first humans land on Mars, we 是的你沒聽錯─也許第一個太空人上火星時, may do so in an inflatable donut. 他會待在一個充氣甜甜圈裡。 Or we'll just skim at a really low angle past the tops of mountains for a really long 或者用極低的角度不斷掠過山頂, time to slow down enough... 慢慢減速......
B1 中級 中文 火星 登陸 火箭 降落傘 外殼 大氣層 Why It's HARD To Land on Mars 45 2 Summer 發佈於 2020 年 09 月 08 日 更多分享 分享 收藏 回報 影片單字