Thursday, February 2, 2012

The Space Shuttle

The space shuttles were designed as a continuation of the American space program after the Apollo program ended officially in 1975. Unlike the Apollo spaceships which were designed for a single use (most of the Apollo spacecrafts remained in space or burned in the atmosphere. The remaining capsules were distributed to several museums), the shuttles were designed to be launched as a rocket and to land just like an airplane. The first space shuttle took off in 1981. Its commander was John Young. His name is unknown to many, but he is a veteran astronaut and has a very long career at NASA. John Young was an astronaut in Gemini, two Apollo flights, one of them (Apollo 16) he commanded and landed on the moon, and was a natural choice for the first pilot of the new spacecraft. The shuttle Columbia first flight was a success.

The first flights were mainly for research purposes or for placing satellites in orbit. With the beginning of the construction of the International Space Station, most tasks were to build the station. The shuttles brought parts to the stations and the astronauts connected them to the station in space walks (known as EVA – External Vehicle Activity). With the development of the space station, more and more tasks are performed by external robots.
The first shuttle disaster was in 1986, when just seconds after the launch of the Challenger (live broadcast of course) the shuttle exploded in the air. I remember myself as a child watching the launch live and the shock that then struck everyone. After the disaster the shuttle was grounded for a few years while the investigation committee wrote long and detailed reports. A member of the investigation team was Richard Feynman, whose personal report was published as an appendix to the official reports and regarded as a masterpiece worth reading in its own right. The report revealed many flaws in NASA activities and the shuttle program resumed only after a long time.

The shuttles achieved many successes, but another disaster, the Columbia disaster which killed Ilan Ramon, was the sign of the beginning of the end. Colombia was launched successfully, but the launch video images already pointed out that there was a problem in the isolation of the shuttle. Investigation reports have shown after the disaster that there were failures in transferring the information, the decision making process of executives and complacency of "to me, it will not happen". During the return to Earth, the shuttle insulation was defect and heat generated due to large atmospheric friction dissolved the Columbia, causing an explosion. The excitement in the country during the launching mission was hard to forget, many of us saw the live launch, and the entire State of Israel was in grieve mourning. 
Seated in front are astronauts Rick D. Husband (left); Kalpana Chawla and William C. McCool. Standing are (from the left) astronauts David M. Brown, Laurel B. Clark, Michael P. Anderson, and Ilan Ramon

After grounding the shuttle program yet again, it was decided to take all shuttles out of service by 2010. After the Challenger disaster, a new shuttle was built (Endeavor), but no new shuttle was built after the Columbia disaster, and the three remaining shuttles' (Discovery, Atlantis and Endeavour) schedules changed and many missions were canceled. Today, as only 5 shuttle missions are left, the shuttles are offered for sale for a modest sum of $ 29 million (excluding transfer costs)

Another high-profile mission of the shuttle was STS-125 service mission to the Hubble Space telescope. Many modules of the telescope were outdated, and parts had to be replaced in order for the telescope to function. The mission was approved under pressure from the public, because the importance of Hubble to science and to the entire human culture in general. There has not been another telescope which has enriched our world so much. Despite the risk and cost, the mission was approved and was extremely successful mission. Hubble space telescope will now serve us at least until 2015.

The shuttles always take off from Florida from one of two launching pads (now only one is active, the other has been transformed to use for the next generation of space vehicles). The shuttle is built and integrated in a huge structure. The building is the tallest one story building in the world with the world's tallest doors. The shuttles are transported from that building to the launch pad on a special vehicle at the amazing speed of, hold tight, half a mile per hour. The shuttle is connected to a huge external fuel tank and two booster accelerators. Both the shuttle’s engines and the boosters are active during the launch to create tremendous thrust, and two and a half minutes later the boosters are cut off and fall back to the Atlantic. The shuttle continues on its engines for another eight minutes and the external fuel tank then disconnects and falls to the Indian Ocean.
After that the space shuttle carries out the tasks or connects to the space station. To land, the shuttle just slows down and begins to fall to earth (slowing of 200 mph is enough). Once this process begins it cannot be stopped. The beginning of the reentrance is determined by the exact landing location. The most desirable location is back in Florida, but this depends on the weather in California. Shuttles landing in California make their way back to Florida on a special Boeing 747 at a cost of another million dollars. Around the world there are more airports where a shuttle can theoretically land, in case there is failure requiring emergency landing immediately after launch. In practice, a landing has never taken place outside the United States.