How Space Shuttles Work" In its nearly 30-year history, the space shuttle program has seen exhilarating highs and devastating lows. The fleet has taken astronauts on dozens of successful missions, resulting in immeasurable scientific gains. But this success has had a serious cost. In 1986, the Challenger exploded during launch. In 2003, the Columbia broke up during re-entry over Texas. Since the Columbia accident, the shuttles have been grounded pending redesigns to improve their safety. In this article, we examine the monumental technology behind America's shuttle program, the mission it was designed to carry out, and the extraordinary efforts that NASA has made to return the shuttle to flight. First, let's look at the parts of the space shuttle and a typical mission. The space shuttle consists of the following major components: two solid rocket boosters (SRB) - critical for the launchexternal fuel tank (ET) - carries fuel for the launchorbiter - carries astronauts and payload The space shuttle flight path.
Mars, Mars Information, Red Planet Facts, News, Photos The Red Planet Mars is a small rocky body once thought to be very Earthlike. Like the other terrestrial planets—Mercury, Venus, and Earth—its surface has been changed by volcanism, impacts from other bodies, movements of its crust, and atmospheric effects such as dust storms. It has polar ice caps that grow and recede with the change of seasons; areas of layered soils near the Martian poles suggest that the planet's climate has changed more than once, perhaps caused by a regular change in the planet's orbit. Martian tectonism, the formation and change of a planet's crust, differs from Earth's. Where Earth tectonics involve sliding plates that grind against each other or spread apart in the seafloors, Martian tectonics seem to be vertical, with hot lava pushing upwards through the crust to the surface. Periodically, great dust storms engulf the entire planet. Water on Mars? Scientists believe that 3.5 billion years ago, Mars experienced the largest known floods in the solar system.
Astronomie et astrophysique Mars500 Crew 'Lands' on Mars, Begins Spacewalking the Martian Surface If you consider a meticulously curated sandpit in a Moscow suburb a destination, then the Mars500 team has finally arrived. After more than 250 days confined to a wood-paneled simulated space capsule, the international crew put down its landing craft on the "Martian" surface over the weekend and, donning Russian Orlan spacesuits, executed its first walk on the red planet today. "Today, looking at this red landscape, I can feel how inspiring it will be to look through the eyes of the first human to step foot on Mars," Italian Diego Urbina said as he began his spacewalk along with Russian Alexandr Smoleevskiy. "I salute all the explorers of tomorrow and wish them godspeed." A third crew member, China's Wang Yue, remained in the landing craft that he, Urbina, and Smoleevskiy began piloting to the Martian surface on February 8. Three more of their shipmates remain aboard the orbiting mothership, which is actually just downstairs from the lander.
Natural resources The Earth's natural resources are vital to the survival and development of the human population. These resources are limited by the Earth's capability to renew them. Although many effects of overexploitation are felt locally, the growing interdependence of nations, and international trade in natural resources, make their demand and sustainable management a global issue. Natural resources and waste — Environmental regulation and eco-innovation have increased resource efficiency through a relative decoupling of resource use, emissions and waste generation from economic growth in some areas. Biodiversity and the ecosystem services upon which we all depend are inextricably linked. Soil is a largely non-renewable natural resource that underpins a range of vital ecosystem services. Certain regions of Europe are affected by soil salinisation, acidification, landslides or desertification, with considerable economic and environmental consequences.
Mars Animation of Mars' rotation from the vantage of an observer who moves south, then north, to hover over both poles, showing the planet's major topographic features. Mars is currently host to five functioning spacecraft: three in orbit – the Mars Odyssey, Mars Express, and Mars Reconnaissance Orbiter – and two on the surface – Mars Exploration Rover Opportunity and the Mars Science Laboratory Curiosity. Defunct spacecraft on the surface include MER-A Spirit and several other inert landers and rovers such as the Phoenix lander, which completed its mission in 2008. Observations by the Mars Reconnaissance Orbiter have revealed possible flowing water during the warmest months on Mars.[25] In 2013, NASA's Curiosity rover discovered that Mars' soil contains between 1.5% and 3% water by mass (about two pints of water per cubic foot or 33 liters per cubic meter, albeit attached to other compounds and thus not freely accessible).[26] Physical characteristics Size comparison of Earth and Mars. Soil
De la vie extraterrestre derrière les surprenantes variations d'une étoile ? TRANSIT. Et voilà qu'on reparle de l'hypothèse... de la vie extraterrestre. En cause, la nouvelle trouvaille du télescope Kepler : ce chasseur d’exoplanètes repère ces astres souvent discrets lorsqu’ils transitent - autrement dit qu'ils passent - devant leur étoile hôte. Des variations difficilement explicables Sur les quatre dernières années, le comportement lumineux de l’étoile est en effet remarquable. DYSON. Soulignons que l’article publié sur arXiv ne mentionne pas cette hypothèse alternative mais l’astronome prépare un autre papier centré sur cette possibilité. Vie extraterrestre : ce qu'en dit le co-découvreur de la première exoplanète. À quoi ressemble la vie extraterrestre ? Stephen Hawking est à la recherche d'une intelligence extraterrestre.
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