Rocket science has been around since the turn of the century, but it was World War II that brought the subject to public attention in a most sinister way. The Nazi's developed the science of thrust, payload and telemetry to the point that the German V2 rocket bombs could be launched from Germany and destroy targets thousands of miles away in England. The world has not been the same since. The fact that MAD (Muturally Assured Destruction is a phrase coined in the early 50's) has been so effective is not just the immensely powerful atomic bombs, but the fact that these weapons can be delivered to any point on the earth with deadly accuracy. Although the German scientists had made great technical advancements for that time, the basis for their success ironically was based upon the earlier work of an American.
Robert H. Goddard, is considered one of the founding fathers of modern rocketry. Goddard was inspired by H.G. Wells' science fiction classic "War Of The Worlds" (It was made into a totally cool movie, by the way.) and decided to explore just how man could reach space. He launched the world's first liquid fuel rocket in 1926, but the American public wasn't much interested. (Unfortunately, it really made a big impression in Germany where the rocketry enthusiasts essentially layed the foundation for the later V2 work.) In fact, the New York Times published an article in 1920 ridiculing Goddard's grant application to the Smithsonian in which he suggested that we could travel through the vacuum of space using rockets. The Times later printed an official apology ... just after the 1969 launch of the Apollo 11 mission to the moon. Well, better late than never.
Today, rockets are launched regularly around the world. (If you have been reading the local newspapers, you might know about Beal Aerospace's bid to put a rocket construction facility in St. Croix!) Most of the launches are for relatively small rockets carrying scientific instruments. They are called sounding rockets. The Wallop Flight Facility (WFF) is one of NASA's facilties for launching such rockets. Although some are capable of reaching heights of 800 miles above the earth's surface, sounding rockets are designed primarily to put a payload (typically filled with measuring instruments) between the maximum height that can be reached by balloons but usually below the minimum height required for orbiting satellites.
The Orion shown to the right is a typical medium-sized sounding rocket. It is about 5 m in length and will carry a 40 kg payload to a height of 90 km. Most sounding rockets are not designed to put their payloads into orbit. Instead the payloads return to earth, typically within 30 minutes of the launch.
The space shuttle launches are quite another matter. First, the payload is considerably larger. The payload is the orbiter, one of which is shown. The orbiter (there are four in the fleet) weighs about 180,000 lb and is about the size of the 757 aircraft that land at the St. Thomas airport. Secondly, the orbiter must attain a speed sufficient to stay in orbit, around 18,000 mph! This requires a lot of thrust.
As you have undoubtedly seen, the orbiter is attached to a larger external tank (ET) with two slimmer solid (fuel) rocket boosters (SRB) on either side of the ET. The SRBs burn first, taking the unit well above most of the atmosphere. When expended, the SRBs are jettisoned to be recovered and reused. Next, the ET feeds liquid oxygen and hydrogen into the Space Shuttle Main Engines (SSME) on the orbiter, bringing it into orbit typically somewhere between 200 and 300 miles above the earth's surface. The ET is jettisoned where it lands in the ocean and is not recovered. The orbiter returns to earth using the earth's atmosphere to reduce the speed until it glides into its landing.
The most recent big project for NASA is the Mars Surveyor Mission 98 project. In December of 1998, the Mars Climate Orbiter was launched with the Delta 7425 launch vehicle. The Mars Polar Lander was launched this January. Although it must send the probes all the way to Mars, the Delta "rocket" is actually much smaller than the Space Shuttle system. The payloads are much smaller. The Climate Orbiter will arrive at Mars in mid July (225 days total flight time to Mars) and the Lander will arrive shortly afterwards.
Questions:
What did Goddard do in 1907 that suprisingly didn't get him expelled from Worcester Polytechnic Institute?
What is the maximum height for weather balloons and minimum height for orbiting satellites? (Most sounding rockets are designed for this range.)
How high do the SRBs take the shuttle and external tank?
How will the Mars Climate Orbiter reduce its speed to achieve orbit around Mars?
How many pounds of thrust can be generated by the solid rocket boosters on the Delta 7425?
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Robert H. Goddard, is considered one of the founding fathers of modern rocketry. Goddard was inspired by H.G. Wells' science fiction classic "War Of The Worlds" (It was made into a totally cool movie, by the way.) and decided to explore just how man could reach space. He launched the world's first liquid fuel rocket in 1926, but the American public wasn't much interested. (Unfortunately, it really made a big impression in Germany where the rocketry enthusiasts essentially layed the foundation for the later V2 work.) In fact, the New York Times published an article in 1920 ridiculing Goddard's grant application to the Smithsonian in which he suggested that we could travel through the vacuum of space using rockets. The Times later printed an official apology ... just after the 1969 launch of the Apollo 11 mission to the moon. Well, better late than never. 
Today, rockets are launched regularly around the world. (If you have been reading the local newspapers, you might know about Beal Aerospace's bid to put a rocket construction facility in St. Croix!) Most of the launches are for relatively small rockets carrying scientific instruments. They are called sounding rockets. The 
The space shuttle launches are quite another matter. First, the payload is considerably larger. The payload is the orbiter, one of which is shown. The orbiter (there are four in the fleet) weighs about 180,000 lb and is about the size of the 757 aircraft that land at the St. Thomas airport. Secondly, the orbiter must attain a speed sufficient to stay in orbit, around 18,000 mph! This requires a lot of thrust.