四人太空船料取代太空梭

四人太空船料取代太空梭

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　　（华盛顿美联电）美国宇航局希望，太空人在未来5年内可以不需要庞大老旧的太空梭，只要乘坐精简的“四人轿车”就能够前往国际太空站。

　　美国宇航局局长奥基菲是在哥伦比亚号太空梭2月1日出事之前，宣布了有关的轨道太空机计划。哥伦比亚号惨案进一步推动宇航局寻找更经济、简单及可靠的方式载送穿梭太空站及地球之间的太空人。

　　哥伦比亚号意外调查局也赞赏有关计划。该调查局之前指责美国还没有生产新的太空梭。

　　美国宇航局最终希望新一代的太空梭能够取代目前仍然存在的哥伦比亚号姐妹太空梭。不过，当局在未来10年内可能不会认真考虑生产太空梭。

　　目前，美国宇航局正赶紧设计、建造及测试简单的4人太空船。该太空船能够以更经济的方式，载送太空人和轻货物到太空站。

　　轨道太空机计划负责人史密斯说，该计划的关键是保持太空船的简单设计，并且利用已经开发的技术，减低成本。

　　轨道太空机下的太空船将有两大任务，既是载送太空人往返太空站及充当停放在太空站的后备救生船，以便在紧急时刻疏散太空人。

　　该计划的设计阶段预算是24亿美元，这对太空计划来说是非常低廉的。

　　美国宇航局预料将在接下来几个月内敲定设计。

　　能够运载4名乘客的新型太空船，将使美国宇航局首次能够将3名以上的太空人送上太空站。目前能够运载3名太空人的太空船是长居太空站人员的唯一逃生工具。如果添加了4人太空船，太空站就能够安全地容纳7名太空人。

NASA races to create space plane
Sunday, August 31, 2003 Posted: 10:16 PM EDT (0216 GMT)


ORBITAL SPACE PLANE
The Orbital Space Plane will transport up to four crew members to the International Space Station. The vehicle could also serve as a "life boat" for astronauts onboard the ISS in the event of an emergency.


WASHINGTON (AP) -- In just five years, astronauts may journey to the International Space Station in a stripped-down four-seater instead of the mammoth -- and aging -- space shuttle.

In effect, NASA hopes to commute to orbit in a sleek sedan instead of an 18-wheeler.

NASA Administrator Sean O'Keefe announced plans for the Orbital Space Plane before space shuttle Columbia came apart over Texas and killed seven astronauts on February 1. But the tragedy has added a powerful incentive to find a cheaper, simpler and more dependable way to ferry astronauts between the space station and Earth.

It's a plan applauded by the Columbia Accident Investigation Board, which chided the nation for not already having a new spacecraft in production.

Eventually, NASA hopes to build a next generation shuttle, a more dependable heavy-lift cargo carrier to replace Columbia's three surviving sister ships. But it may be more than a decade before such a craft gets serious consideration.

'A very ambitiously rapid schedule'
For now, the space agency is rushing to design, build, test and fly a simple four-person craft that can more cheaply haul people and light cargo to the space station.

"The focus is to keep it simple and flexible," said Dennis Smith, the Orbital Space Plane program manager at the Marshall Spaceflight Center. "We're doing everything we can to get it up by 2008."

It is, Smith admitted, "a very ambitiously rapid schedule." But he noted NASA pulled off such magic in the early days of the space program.

"Mercury, Gemini and Apollo all did things faster than that," he said.

The key to the project, Smith said, is to keep the spacecraft simple and use technology that already has been developed. That also makes it cheap.

The design phase of the program is budgeted at $2.4 billion, inexpensive by space standards. Smith said the craft will be built with existing technology and existing materials. Some earlier, more ambitious NASA programs required fundamental technical advances that never developed but cost billions.

Such a simple approach has been used in the past to create some of the classic designs in transportation. Vehicles such as the World War II jeep and the DC3, a durable air transport that flew for more than 50 years, endured because they were they were simple, flexible, durable, dependable and relatively cheap.

Resisting unnecessary bells and whistles
The space plane will have only two missions: to carry people up and down from the space station, and to act as a standby lifeboat, parked at the space station for the evacuation of astronauts if there is an emergency.

"The two biggest reasons that schedules slip and costs increase is that you change the requirements or you're counting on technology that didn't pan out," Smith said. "That's why we have a very focused set of requirements that we don't intend to change. We're going to set it up for the primary mission of crew rescue and crew transport."

He said they are resisting unnecessary bells and whistles and not holding out for "some material like 'unattainium' that isn't in existence."

Preliminary studies have settled on some candidate designs. One is flat, resembling a manta ray, with upward folded wings. Others are long and slender, with stubby wings. Those could all land on a runway, as does the space shuttle.

Another design resembles a bell-shaped capsule, rather like the craft of NASA's early days. That craft would descend by parachute, the same way the Mercury, Gemini, Apollo and Russian Soyuz spacecraft landed.

NASA expects to settle on a final design within a few months.

With a capacity of four people, the plane will make it possible for the first time to put more than three long-term residents aboard the space station. Now, the Soyuz, a three-seat craft, is the only escape vehicle available if an emergency develops on the orbiting laboratory. With four more rescue seats, the station could accommodate seven astronauts safely.

Smith said the space plane initially will be launched by either Atlas or Delta boosters. These American rockets are among the most dependable, each with decades of success. Later, NASA hopes to develop another booster system.

Unique to American spacecraft, the plane will be designed to fly either manned or unmanned. Smith said an auto guidance system will allow the plane to be flown remotely to rendezvous and dock with the Space Station, and then return to Earth. With no humans aboard, the craft could be used to haul light cargo to the orbiting lab.



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