"Although the day started with difficulties, it ended with a successful 1000 foot space elevator test climb to a tethered 10-foot diameter balloon - LiftPort's first really significant climb. This was supposed to be a 1 mile climb test, but the FAA-required aviation orange paint - applied at 50 foot intervals to the ribbon - contained acetone, which weakened the ribbon. The first two attempts of the day resulted in ribbon breaks due to this acetone-induced degradation. (Lesson here: test what you will use!)

With the ribbon in a weakened state, three (or even two) balloons created more lift than the ribbon could handle without breaking. Therefore, only a single balloon was used for a 1000' target altitude. We made the run back into town - about 12 miles away - and bought all the string we could find so we'd have enough for a safety line to a balloon at 1000'.

One balloon (instead of 3) means only 1/3 the buoyancy, so there was just enough margin (due to weight of lifter robot, ribbon, safety line, wind, etc.) to climb 1000', causing the robotic lifter - nicknamed Sword of Damocles (see http://en.wikipedia.org/wiki/Sword_of... ) - to actually climb horizontally for about 150 feet. Nevertheless, the test was considered a success!

Consider this: our test system climbed 1000' for this test. The tallest building in the world - the CN Tower in Canada (http://www.cntower.ca ) - is 1815 feet tall. The elevators on those buildings are not continuous. You need to stop & change elevators at certain floors. So, there is justification to say that this test system was the tallest elevator in the world at that time. At 2,063 feet, the KVLY-TV mast antenna near Fargo, North Dakota (http://www.kvlytv11.com/info/info_tower .html ), is the tallest supported structure in the world and our system was about half as high as that. A couple months later we put up a system that was about a mile high (5300') with a lifter that climbed 1500'."