 The first step in space exploration has been figuring out a way to get off the ground.  400B.C. – Archytas – used steam to propel a model pigeon (First rocket recorded)  100 A.D. – Chinese – used gunpowder to make rocket-propelled arrows for battle

 October 4, 1957 – Soviet Union launched the first artificial satellite, Sputnik  Was only about the size of a basketball  A month later, they launched a second capsule, Sputnik 2, this time with a dog in it (Laika)  She died a few hours after launch from overheating and stress  This was the first information we had on any living creature in space

 The Americans followed with their own satellite in 1958 with the Explorer 1  Canadians followed in 1962 with their own satellite, Aloulette 1

 Rocketry relies of a fundamental law of physics: For every action there is an equal and opposite reaction  An inflated balloon is similar to a rocket:  Release the mouth of a balloon and it will be propelled in the opposite direction of the escaping gas  See Fig. 2.7 on pg. 412

 There are three basic parts to a rocket:  Structural and Mechanical: everything from the rocket, engines, storage tanks, or fins  Fuel: mixture of various materials (oxygen, gasoline, hydrogen) that is ignited causing gases to expand and leave as exhaust  Payload: materials needed for flight, includes the crew cabins, food, water, air and people

 Three main types in use today: 1. Shuttle – for transporting personnel and equipment to orbiting spacecraft 2. Space probes – contain instrumentation for carrying out robotic exploration of space 3. Space stations – orbiting spacecrafts that have living quarters, work areas, and all the support systems needed to allow people to live and work in space for extended periods.

 If we are to visit other bodies in our solar system, technology still has a long way to go: 1. Ion Drives – engines that use xenon gas instead of chemical fuels; the thrust is x weaker than chemical fuels – but is can last a really long time  Imagine getting km/L for fuel mileage  Remember that in space there is no friction – so a little force over a long time makes for a very fast vehicle

 The European space agency's dart-shaped GOCE satellite, designed to skim through the extreme upper atmosphere using ion drives to compensate for air drag, has launched successfully in northern Russia. (March 17, 2009; SPACE Journal)

2. Solar Sails – like propelling boats with wind sails but instead of harnessing wind, the sails harness sunlight  When light energy (photons) hit the sail, the energy transmitted with cause the spacecraft to move  The material used could be as thin as plastic wrap and extend over 400m 2  It is estimated we could have this technology by 2015 and the spacecraft could travel 5x faster than now

 On June 21,2005 Cosmos 1 - the world's first solar sail spacecraft - is set to launch atop a converted ICBM from a submerged Russian submarine in the Barents Sea.  Unfortunately, the rocket failed and the spacecraft failed to reach orbit – but there have been more attempts since.

 At the core of NASA's future space exploration is a return to the moon, where they are planning to build a sustainable long term human presence.  As the space shuttle went into retirement and the International Space Station nears completion, NASA is building the next fleet of vehicles to bring astronauts back to the moon, and possibly to Mars and beyond.  More space stations will likely be established as well many private companies are planning to develop hotels and amusement parks in space or on the moon.  Humans seem ready for the next step in leaving Earth and living for extended times in space