航天飞机曾经北美以外的地区降落吗？Did the Space Shuttle ever land outside North America?
No, but no shuttle could launch unless appropriate landing sights were available in case of abort.
In the event of an abort during launch, the shuttle could—under certain circumstances—try for one of several alternate landing sites around the world. Only a couple of sites were available for a given mission, depending on the launch trajectory and arrangements made in advance. And advance crew from NASA had to be on site with all arrangements made ahead of the launch.
如果在发射过程中中止，则航天飞机可以在某些情况下尝试飞往全球其他几个着陆点之一。 根据发射的轨迹和事先作出的安排，给定的任务只有几个地点可用。 NASA的高级工作人员必须在发射前做好所有安排。
Mission planners could draw on a dozen US military and civilian airports and trans-oceanic sites including RAF Fairford in the UK, Lajes Air Base in Terceira island, Azores, Portugal, Zaragoza Air Base in Spain, Morón Air Base in Spain, and Istres Air Base in France, Diego Garcia in the British Indian Ocean Territory, Cologne Bonn Airport in Germany; Ben Guerir Air Base, Morocco (1988–2002), Casablanca, Morocco (till 1986), Banjul International Airport, The Gambia (1987–2002), Dakar, Senegal; Rota, Spain; and Kano, Nigeria.
任务计划者可以利用十几个美国军用和民用机场和跨洋站点，包括英国的皇家空军费尔福德，特塞拉岛的拉耶斯空军基地，亚速尔群岛，葡萄牙，西班牙的萨拉戈萨空军基地，西班牙的莫隆空军基地和伊斯特尔航空 法国基地，英属印度洋领地的迭戈·加西亚，德国科隆波恩机场； 摩洛哥本·古里尔空军基地（1988年至2002年），摩洛哥卡萨布兰卡（至1986年），冈比亚班珠尔国际机场（1987年至2002年），塞内加尔达喀尔； 西班牙罗塔; 和尼日利亚卡诺
Had an abort occurred during a launch from Vandenberg Air Force Base, Hao and Easter Islands in the Pacific Ocean would have been alternate landing sites.
是什么让NASA推迟了全女性太空行走？What happened with NASA’s delayed all-woman spacewalk?
NASA’s current spacesuit, the Extravehicular Mobility Unit (EMU) is closely derived from the Apollo A7L. Only 18 of the EMU suits were ever made. 5 were lost during missions, 1 was lost in a ground test, and 11 remain complete and functional. Of these, 4 are on the ISS.
美国宇航局当前的太空服，机动外动单位（ Extravehicular Mobility Unit ，EMU）与阿波罗的A7L宇航服关系密切。 EMU一共只生产了18件。 任务期间损失了5件，在地面测试中损失了1件，而11件仍保持完好无损。 其中有4件在国际空间站上。
The later EMUs use a modular design in which components can be swapped out to customize the fit to a particular astronaut. Some parts are easier to swap than others, however.
The biggest difference between the EMU and the Apollo era A7L is that the former has a ridged “hard upper torso unit” or HUT which is easier to don and doff and better suited for mounting tools. At the time of the planned all-female spacewalk, one suit was fitted with a medium size HUT, one with an extra-large, and two with large HUTs. There were also spare HUTs in each size on board.
EMU和Apollo时代的A7L之间的最大区别在于，前者具有脊状的“硬上躯干单元”简称HUT，它更易于穿脱，更适合安装工具。 在计划中的全女性太空行走时，一套太空服有中等大小的HUT，一套装有超大型的，而另外两套有则有大型的HUT。 船上还有各种尺寸的备用HUT。
Astronauts Anne McClain and Christina Koch were scheduled to take a spacewalk together on Friday, March 29. Koch, the smaller of the two, was going to wear the suit with the medium-size HUT, and McClain would were a large. This had been satisfactory during training in the Neutral Bouyancy Lab in Houston, but once McClain squeezed into the suit in the true weightlessness of space, she knew she could not safely operate the larger suit.
宇航员安妮·麦克莱恩（Anne McClain）和克里斯蒂娜·科赫（Christina Koch）计划于3月29日星期五一起进行太空行走。两者中较小的科赫将穿着中型HUT穿着这套衣服，而麦克莱恩则大。 在休斯敦的Neutral Bouyancy Lab进行训练时，效果令人满意的，但是，一旦McClain在真正的失重状态下穿进太空服，她便知道无法安全地操作较大的太空服。
Since it would have taken twelve hours to swap out the HUT and thrown the work schedule into a shambles, McClain and NASA controllers swapped Astronaut Nick Hague into her place and carried on with the work.
NASA is well aware that they need cheaper, more versatile spacesuits that better accommodate variations in human physique. Whether or not the current selection of components was influenced by sexism back in the 1970s and 80s (it was) when the agency has only so much money to go around, it has to make difficult choices. Had it, for example, requested a set of “small” components when the suits were being made, it might now find itself short on spares and in the position of shoehorning unplanned replacements into its budget at great expense.
On the other hand, even as a tall guy myself, I think I’d have erred on the side of more smaller suits and better support for the average measurements of both genders, even if it meant big blokes like me were excluded. Someone, when the contract was let, saw it the other way round.
为什么早期的Atlas火箭的排气火焰中有一个非常明显的火焰（或火焰中的烟雾）与其他火焰角度不同？ 我指的不是游标。 在视频中，它位于1:00到1:15喷出火焰的最右侧。Why did early Atlas rockets have a very noticeable area of flames (or smoke from flames) amongst its exhaust flames go down at an angle? I’m not referring to verniers. In the video, it’s on the right side of the exhaust from 1:00 to 1:15.
That’s the booster engine turbopump exhaust.
The turbopump it what pumps the fuel and oxidizer into the combustion chamber under pressure. In most rocket engines, it’s powered by a gas generator. The gas generator is essentially a small rocket engine, but with plumbing in place of the nozzle, and with the fuel mixture set extremely rich to reduce combustion temperature enough to keep from destroying the turbine. After passing through the turbine, the exhaust (still rich in fuel) has been cooled and decompressed enough that it’s not much use for generating any thrust.
涡轮泵在压力下将燃料和氧化剂泵入燃烧室。 在大多数火箭发动机中，都是由气体发生器为涡轮泵提供动力的。 气体发生器本质上是一台小型火箭发动机，但是用水管代替了喷嘴，并且燃料混合物的浓度非常高，足以降低燃烧温度，足以防止损坏涡轮机。 通过涡轮后，排气（仍然富含燃料）已被冷却和减压，以至于它不会产生任何推力。
On the Atlas SM-65 missile, each outboard (booster) engine had its own gas generator and turbopump, and the turbopump exhaust was dumped overboard next to each engine:
The Atlas LV-3B used for Mercury Atlas flights used a shared turbopump assembly feeding both booster engines, and its exhaust was dumped overboard through a shared duct.
The turbopump exhaust from the inboard “sustainer” engine was dumped through a plenum around the engine nozzle called an “exhausterator to help cool it. The same thing was done on the Saturn V first stage, where turbopump exhaust was ducted into a nozzle extension for additional cooling:
In the Space-X Merlin, it’s dumped overboard, like on the Atlas:
在Space-X Merlin中， 喷嘴延长管像阿特拉斯地图一样被安装在了外面：
在火星上，由于大气散射，日出是蓝色的。为什么会这样？On Mars, sunsets appear blue due to the way light is scattered in the atmosphere. How and why?
一些水星计划宇航员头盔顶部的孔的目的是什么？What was the purpose of the holes on the top of some of the Mercury astronauts’ helmets?
Those holes aren’t in the helmet, but in a pad used to protect the polycarbonate visor from scratches prior to launch. The holes are most likely there for no other reason than custom, as a soft helmet would have them for breathability, and omitting them might have looked odd.
为什么水星计划的宇航员的压力服看上去有黑色的大带子，类似于降落伞的带子？ 而这些航天器没有弹射座椅。Why did the Mercury astronauts’ pressure suits had what appears to be large black straps similar to parachute straps? There were no ejection seat in those spacecraft.
Those are anti-ballooning straps.There was a central “helmet tie-down strap”, a harness-like “H” of torso sizing straps, and straps and girdles around the wrists and hands to adjust the fit and combat the tendency of the suit to balloon when inflated.