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  3. For a few minutes on the afternoon of Friday April 8th millions of eyes were focused on Cape Canaveral in Florida, and shortly a

For a few minutes on the afternoon of Friday April 8th millions of eyes were focused on Cape Canaveral in Florida, and shortly a

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问题    For a few minutes on the afternoon of Friday April 8th millions of eyes were focused on Cape Canaveral in Florida, and shortly afterwards on a remote "drone" barge a couple of hundred miles downrange in a choppy Atlantic Ocean.
   【F1】The cause of all this attention was SpaceX’s launch of a heavy payload to space, with a later meeting with the International Space Station, and a critical attempt to return the 1st stage booster rocket safely to Earth.
   As reported by pretty much every media outlet across the planet, the Falcon 9 made a gloriously easy-looking powered return and landing on SpaceX’s drone ship.
   So what’s the big deal?
   【F2】First getting the biggest and costliest piece of launch hardware back in one piece offers the possibility of reusing it and lowering the expense of reaching space. Back in the last year, SpaceX had already got a Falcon 9 booster to return to within shouting distance of where it had launched from some ten minutes earlier—on a neighboring pad at Cape Canaveral.
   【F3】Although it remains to be seen how well these rockets hold up to reconditioning and relaunch, the basic idea is sound Reuse means drastically lower launch costs in the long run. It might cost $60 million to build one of SpaceX’s boosters, but on a few hundred thousand dollars to refuel it. Even if making it flight-worthy again costs several million dollars of engineering tinkering and fixing, that’s still an enormous saving.
   【F4】As Elon Musk and many others have long stated, dropping the cost per-unit-mass of launching to space is critical if our species is going to explore and utilize the solar system. It’s also the key to ensuring our long-term survival.
   Mars has a long lure, and SpaceX is in many ways built from the ground up to create the bridge to our 4th planet. 【F5】But apart from simply getting off the Earth and hauling infrastructure and people to this red world, you also have to deposit all of that safely on the surface. Mars is tricky in this respect It may be a less massive world, with a gentler gravity field, but it also has a pitifully thin atmosphere that makes landing stuff a huge challenge because there’s little to "grab onto" as you come rushing down from orbit.
   Small scientific robots and rovers are already pushing the limits of what we can get to the Martian surface in one piece. What’s really needed is the ability to bring a whole launch vehicle down, with tons and tons of payload.
【F4】
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答案埃隆-马斯克还有其他许多人早就指出，如果我们人类要探索和利用太阳系，降低每单位质量发射到太空的成本极为重要。
解析 ①本句是主从复合句。句首的As引导定语从句，修饰逗号后的整个句子，As在其中既是引导词，也充当stated“陈述。说明”的宾语。②主句本身也是一个主从复合句，主句是主系表结构，主语dropping the cost后的per-unit-mass of hunching to space可理解为后置定语，修饰cost；per-unit-mass意为“每单位质量”。③if在此引导条件状语从句。
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