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ID:
182006
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| Summary/Abstract |
The geography of the United States is not the sole determinant of how its leaders choose to defend the homeland, but geography is certainly the first and most permanent factor. The large, fertile, and secure U.S. homeland is bounded by friendly neighbors to the north and south, and broad oceans to the east and west, leading to the preferred post–World War II U.S. defense strategy of basing its forces as far forward as possible to provide a layered defense of the homeland while securing air- and sea-based lanes of transport.1 In short, the United States relies on the blessings of its geography—a large industrial base, inland transportation infrastructure, and secure sea-based capabilities—to project its military power around the world. With threats rising against U.S. power-projection capabilities in the homeland, mainly from cruise, ballistic, and hypersonic missiles, the question is, How should the United States respond to threats against its forward-based defense strategy?
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| 2 |
ID:
148488
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| Summary/Abstract |
The rapid cost growth of flagship space missions has created a crisis for astronomy and planetary science. We have hit the funding wall. For the past 3 decades scientists have not had to think much about how space technology would change within their planning horizon. However, this time around enormous improvements in space infrastructure capabilities and, especially, costs are likely on the 20-year gestation periods for large space telescopes. Commercial space will lower launch and spacecraft costs substantially, enable cost-effective on-orbit servicing, cheap lunar landers and “interplanetary cubesats” by the early 2020s. A doubling of flagship launch rates is not implausible. On a longer timescale it will enable large structures to be assembled and constructed in space. These developments will change how we plan and design missions.
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