EDA技术
EDA技术
Orbital Space Plane
While scientists are searching the cause of the Columbia disaster， NASA is moving ahead with plans to develop a new craft that would1 replace shuttles on space station missions by 2012 and respond quickly to space station emergencies.
The space agency released the first set of mission needs and requirements several days ago for the orbital space plane， which would be designed to transport a crew of four to and from the International Space Station.
Although it includes few specifics2， the plan stipulates the orbiter will be safer， cheaper and require less preparation time than the shuttle. It would be able to transport four crew members by 2012 – though it would be available for rescue missions by 2010. NASA says the craft should be able to transport injured or ill space station crew members to “definitive medical care3” within 24 hours.
The release of the requirements showed NASA remains focused on the long-term priorities of space exploration， even as questions linger concerning the loss of Columbia and its seven-member crew on February 1，20034.
Experts at Marshall Space Flight Center in Huntsville， Alabama， have been working for years on a successor to the shuttle. The project， known as the Space Launch Initiative， was divided last year into two parts – one focusing on a future launch vehicle， the other on a space station orbiter. The orbiter is expected to be ready sooner.
The program’s managers say NASA officials have told them not to alter Space Launch Initiative in light of the Columbiadisaster.
U.S. President George W. Bush asked Congress for about US$1 billion for Space Launch Initiative in 2004， funds that would be almost equally split between the Orbital Space Plane and Next Generation Launch Technology.
词汇
shuttle["ʃʌtl] n.（织机的）穿梭机;
initiative[ɪ"nɪʃətɪv] n.创始，倡议;
orbiter[ˈɔ:bɪtə(r)] n.轨道航天飞机
in light of 鉴于，由于
linger ["lɪŋɡə(r)]v.继续存留
注释：
1．would:这是虚拟语气的用法，表示未来可能发生的事。下面第三段出现的两个would也属这种用法。
2．few specifics:（谈到）很少细节。specific意为“详情，细节”时，一定要用复数形式的specifics o
3．"definitive medical care”：“最权威的医疗机构”
4．concerning the loss of Columbia and its seven-member crew on February l,2003:作定语，修饰linger前面的questions。The orbital space craft has been designed for____.
A:controlling the Intemational Space Station B:carrying astronauts to the International Space Station C:transporting equipment to the International Space Station D:training astronauts in space flights
Text 4
| Space enthusiasts look to the day when
ordinary people, as well as professional astronauts and members of Congress, can
leave Earth behind and head for a space station resort, or maybe a base on the
moon or Mars. The Space Transportation Association, an industry lobbying group,
recently created a division devoted to promoting space tourism, which it sees as
a viable way to spur economic development beyond Earth. The great stumbling block in this road to stars, however, is the sheer difficulty of getting anywhere in space. Merely achieving orbit is an expensive and risky proposition. Current space propulsion technologies make it a stretch to send probes to distant destinations within the solar system. Spacecraft have to follow multi-laver, indirect trajectories that loop around several planes in order to gain velocity from gravity assists. Then the craft lack the energy to come back. Sending spacecraft to other solar systems would take many centuries. Fortunately, engineers have no shortage of inventive plans for new propulsion systems that might someday expand human presence, literally or figuratively, beyond this planet. Some are radical refinements of current rockets or jet technologies. Others harness nuclear energies or would ride on powerful laser beams. Even the equivalents of "space elevators" for hoisting cargoes into orbit are on the drawing board. "Reach low orbit and you are halfway to anywhere in the Solar System," science-fiction author Robert A. Heinlein memorably wrote, and virtually all analysts agree that inexpensive access to low Earth orbit is a vital first step, because most scenarios for expanding humankind’ s reach depend on the orbital assembly of massive spacecraft or other equipment, involving multiple hunches. The need for better launch systems is already immediate, driven by private and public sector demand. Most commercial payloads are destined either for the now crowed geo-stationary orbit, where satellites jostle for elbow room 36,000 kilometers above the equator, or for low-Earth or bit, just a few hundred kilometers up. Low-Earth orbit is rapidly becoming a space enterprise zone, because satellites that close can transmit signals to desktop or even handheld receivers. Scientific payloads are also taking off in a big way. More than 50 major observatories and explorations to other solar systems’ bodies will lift off within the next decade. The pressing demand for launches has even prompted Boeing’s commercial space division to team up with RSC—Energia in Moscow and Kvaerner Maritime in Oslo to refurbish an oil rig and create a 34,000—ton displacement semi-submersible launch platform that will be towed to orbitally favorable launch sites. |
A:the development of space technology B:the obstacles and prospects of space transportation C:the public interests in space travel D:the growth of space business
The sun’s heat warms the air and makes it move. This movement is called a wind. Different parts of the Earth receive different amounts of heat. Near the equator(赤道), the sun is overhead and heats the Earth intensely (强烈). Nearer the poles, the sun’s rays strike the Earth at a low angle so the heat is not so intense.
A lot of the earth’s heat is reflected back into spaces, by the atmosphere, clouds, dust in the air and by water, snow and ice. So some parts of the Earth are warm and some are cold. Warm air tends to rise and creates areas of high pressure. As warm air rises, cold air flows in and replaces it. The greater the pressure difference is, the stronger the wind blows.
A:makes the air move B:makes the air still C:makes the air cold D:reflects back into space
The sun’s heat warms the air and makes it move. This movement is called a wind. Different parts of the Earth receive different amounts of heat. Near the equator(赤道), the sun is overhead and heats the Earth intensely (强烈). Nearer the poles, the sun’s rays strike the Earth at a low angle so the heat is not so intense.
A lot of the earth’s heat is reflected back into spaces, by the atmosphere, clouds, dust in the air and by water, snow and ice. So some parts of the Earth are warm and some are cold. Warm air tends to rise and creates areas of high pressure. As warm air rises, cold air flows in and replaces it. The greater the pressure difference is, the stronger the wind blows.
A:makes the air move B:makes the air still C:makes the air cold D:reflects back into space
The sun’s heat warms the air and makes it move. This movement is called a wind. Different parts of the Earth receive different amounts of heat. Near the equator(赤道), the sun is overhead and heats the Earth intensely (强烈). Nearer the poles, the sun’s rays strike the Earth at a low angle so the heat is not so intense.
A lot of the earth’s heat is reflected back into spaces, by the atmosphere, clouds, dust in the air and by water, snow and ice. So some parts of the Earth are warm and some are cold. Warm air tends to rise and creates areas of high pressure. As warm air rises, cold air flows in and replaces it. The greater the pressure difference is, the stronger the wind blows.
The sun’s heat______.
A:makes the air move B:makes the air still C:makes the air cold D:reflects back into space
阅读下列短文，然后根据短文的内容从每小题的四个选项中选出最佳的一项。
A
| The sun’s heat warms the air and makes
it move. This movement is called a wind. Different parts of the Earth receive
different amounts of heat. Near the equator(赤道), the sun is overhead and heats
the Earth intensely (强烈). Nearer the poles, the sun’s rays strike the Earth at a
low angle so the heat is not so intense. A lot of the earth’s heat is reflected back into spaces, by the atmosphere, clouds, dust in the air and by water, snow and ice. So some parts of the Earth are warm and some are cold. Warm air tends to rise and creates areas of high pressure. As warm air rises, cold air flows in and replaces it. The greater the pressure difference is, the stronger the wind blows. |
A:makes the air move B:makes the air still C:makes the air cold D:reflects back into space
Over the past two decades gee—engineering began to include other ways of fixing climate-including new spins on the Pinatubo effect. Using sulfur dioxide(二氧化硫) or other materials, they aim to reflect sunlight back into outer space. One would boost a series of mirrors into orbit, shading Earth from sunlight, but at a cost that would likely bankrupt the planet. In the 1990s, the controversial inventor of the hydrogen bomb, Edward Teller, proposed floating reflective particles of metal in the atmosphere, adding a Dr. Strangelove air to the gee-engineering field.
Various kinds of materials are used in gee-engineering to
A:bankrupt the earth. B:reflect sunlight back into space. C:boost mirrors into orbit. D:make hydrogen bombs.
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