The Space Shuttle is on its final mission. NASA has announced the end of the Shuttle program. This program had 135 missions with two very unsuccessful missions that ended with the fiery death of their crews. This blog is in memorial to those astronauts that perished.
This is the latest news from NASA on STS Mission 135
Shuttle Crew Leaves Historic Flag Aboard Station for Next U.S. Crew Vehicle; Mission Status Briefing Cancelled
Sat, 16 Jul 2011 11:25:18 AM CDT
Space shuttle Atlantis astronauts brought with them a historic U.S. flag that flew aboard shuttle Columbia on America’s first shuttle flight, STS-1 in 1981. Commander Chris Ferguson will present it to the station crew as a symbol that the United States is in space to stay, with astronauts permanently living and working aboard the station for many years to come.
Ferguson said the flag will remain at the station until the next crew launched from the United States arrives at the outpost. That crew will bring the flag back to Earth, until it once again is carried into space with the first crew to launch from the United States on a journey of exploration beyond Earth orbit.
30 years have passed since the STS 1 mission started the Shuttle program. I remember that day well. I was in awe of the lift off that I witnessed on TV in Pennsylvania. I was working on hydrogen at that time and the company that I had worked with, Air Products and Chemicals, had the contract to supply the liquid hydrogen for the stage 1 rockets used to launch the shuttle, so I had a personal stake in the successful launch.
Each launch needs 384,071 gallons or 227,800 pounds of liquid hydrogen. Each pound of hydrogen gas at atmospheric pressure and room temperature occupies 191 standard cubic feet. This quantity of hydrogen can inflate and fill 87 million latex balloons like one sees at a birthday party (11 inch diameter balloons). This is a lot of hydrogen. The energy content in a pound of hydrogen is about that of half a gallon of gasoline so the hydrogen used in a launch of the shuttle is about equal to the energy in 115,000 gallons of gasoline. NASA actually has to buy significantly more liquid hydrogen for each launch as much of the hydrogen boils off as liquid hydrogen is an extremely low temperature cryogenic liquid.
NASA reports that they purchase 372,800 pounds of hydrogen for each launch. Therefore 145,000 pounds of hydrogen simply boils off before each launch. This vapor escapes into the atmosphere where it does harm to the ozone layer. In 135 launches 19.5 million pounds of hydrogen have escaped into the atmosphere. NASA pays air products about a dollar fifty cents a pound for the hydrogen so the boil-off wasted about $30 million in total over 30 years. This is a drop in the bucket as compared with the total cost of the Shuttle Program that is estimated to have cost $200 billion. I certainly do not think we gained $200 billion of value of inventions from the shuttle program and much of it was for show. The lives lost were also not worth the program. I am sure the folks at Air Products and other contractors who sold NASA a bunch of stuff for the program think the program was worth over $1.5 billion per mission.
A friend of mine named Peter told me this week that the Shuttle’s physical dimension were limited by the width of a horse’s posterior. This is because the booster rockets were fabricated in Utah and had to travel by rail to the launch pad in Florida. The width of the rail set the size of these booster rockets. The width of the rail on US railroads was set by the width of the axles on the carriage. This axle width came about from Roman times when chariot axles were given their dimension based on the width of posteriors of two horses side by side drawing the chariot. By this logic the Space Shuttle was limited in scope by the width of a horse’s behind. I am sure there were other constraints but this is probably the limiting constraint. On second thought the program may have been limited by the brain power of a rocket scientist who is far smarter than me and had money to burn.