永利皇宫客户端:Technology: Shuttle tests the eyes of SDI

 作者:司衣诱     |      日期:2019-02-28 03:01:02
By DAN CHARLES in WASHINGTON DC Officials of the US military’s Strategic Defense Initiative got their first good look last week at the sight of a rocket firing in space. Sensors flying alongside the orbiting space shuttle detected infrared radiation from one of the engines. This latest space shuttle flight was devoted to tests of technologies for SDI, also known as Star Wars, the plan hatched by President Reagan in 1983 to protect the US from attack by nuclear missiles with a shield of high-technology weapons. The data will help a future Star Wars system to recognise nuclear missiles as they fly through space and shoot them down. This was the first shuttle flight dedicated to SDI that was not smothered by official secrecy. The Pentagon decided to allow public access as secrecy is expensive: all the data and conversations that are transmitted back and forth must be encoded and stored on special computers to avoid eavesdropping. For the main test, the shuttle crew released a satellite filled with infrared sensors and communication equipment. The satellite was manoeuvred into position 10 kilometres away from the shuttle to observe the rocket plume. ‘Until these experiments, we had no idea what a rocket plume looks like in space,’ says Rob McKinney, an official for the SDI programme. The satellite also recorded the release of several other chemicals from canisters aboard the shuttle. SDI officials said that these chemicals, including rocket propellants and neutral gases like xenon, are similar to those that a ballistic missile might disperse in flight. The shuttle crew used other instruments to collect data on light emitted from the Earth’s aurora – the northern and southern lights. These observations are important so that the SDI’s sensors can recognise and disregard the Earth’s own fireworks. Otherwise, ‘we could lose a ballistic missile in the aurora’, says McKinney. Two data recorders that were supposed to store data from several minor experiments aboard the shuttle refused to work. These instruments were monitoring sources of X-rays in space and ultraviolet emissions from the Earth’s horizon. Data were recorded from these experiments, but at a greatly reduced rate. While tests continue, future prospects for Star Wars remain uncertain and controversial. The General Accounting Office of the US Congress claimed last week that feasibility studies for much of SDI will not be finished by 1994, when the President is supposed to decide whether or not to deploy the system. The Pentagon is already paying contractors to design equipment for the so-called Brilliant Pebbles scheme for deploying thousands of small guided missiles in space. But studies of the concept by Lawrence Livermore National Laboratories, to determine whether it will work, will not be completed until 1993, says the GAO. Stephen Hadley, a Pentagon official,