After five years of trying on three continents on August 30th, Steve Fossett and his co-pilot Einar Enevoldson flew a glider high above the Andes to set a World Altitude Record of 50, 699 feet.
Their glider had released from the tow plane at 13,000 feet in a mountain wave that over a period of over four hours swept them up to their final altitude.
That such a flight could be accomplished is remarkable for many reasons. Above 40,000 feet the air is so thin and pressure so low that survival without complex life support equipment including space suites is impossible. The temperature is in the range of -50 to ?¢‚Ç¨‚Äú 70 degrees Fahrenheit, cold enough to freeze to death in short order and cold enough to eliminate the possibility of using conventional batteries.
Remember, this is a glider without any form of power generation on board! Being in the right place at the right time is also challenging since it is impossible to forecast with any precision when the necessary meteorological conditions will occur. I can testify to this having waited several years before accomplishing a high altitude glider flight in mountain wave conditions. The only difference being my flight reached 32,000 feet instead of 50,699 feet!
To understand this flight one needs to have a basic grasp of the mountain wave phenomena.
The Mountain Wave showing the air flow and the flight path exploiting the wave
In the picture above the wind is blowing against a range of mountains from the left. Under certain conditions, when the wind velocity and angle with respect to altitude and the temperature and stability indexes are just right, the flow will be disrupted on the lee side of the mountain range as shown by the white lines. At first the flow is downward on the lee side and then sharply kicks upwards with velocities that can be several thousand feet per minute. The black path shows the possible flight path of the glider, first being towed from the ground to the first deflection point, then working up through the layers of the wave finally reaching the upper limit of the rising air. Such waves have been know to exceed 60,000 feet although no glider has yet reached this altitude. The width of the wave can be as narrow as a few hundred feet or several miles. The trick is to find the core and stay in it. This is done by constantly heading into the wind and tacking to the left and right to maintain the proper position over the ground. There is another phenomenon known as the Polar Vortex that occurs during the winter that is even higher than the mountain wave. When the jet stream and Polar Vortex are in alignment it is believed to be possible to ride this wave up to altitudes as high as 100,000 feet. If you as Steve where his next adventure might be he may well say ?¢‚Ç¨?ìto ride the Polar Vortex?¢‚Ç¨¬ù.
The glider chosen is a DG-500 carbon and fiberglass two place machine, built in Europe, It originally had a retractable engine housed behind the cockpit. The engine was removed and replaced by large oxygen tanks sufficient for 14 hours and special lithium sulfur dioxide batteries to power the insulated instrumentation and provide warmth (-10 to -20 degrees vs. -60 degrees outside) for the flight suits. The plexiglass canopies have been modified with a double layer to prevent fogging in the extreme cold.
For personal survival, NASA has loaned the team two pressurized flight suites that are worn by U2 and SR71 Blackbird pilots. NASA is very interested in these flights because of the opportunity to obtain valuable atmospheric data under unique conditions.
Einar Enevoldson and Steve Fossett ready to go.
It?¢‚Ç¨‚Ñ¢s a tight fit with those pressure suits!
The flight lasted over 4 hours with an hour and a quarter above 40,000 feet! The coldest temperature was ?¢‚Ç¨‚Äú 73 F. After the flight Einar said ?¢‚Ç¨¬ùActually, the weather was far from ideal for the flight. We flew mainly to check out the suits and sailplane systems to be sure all was ready when a good day would come. On a good day we should be able to whiz right up through this altitude and keep going up up up!!?¢‚Ç¨¬ù
Way to go Steve and Einar, we wish you luck and all the best.
On final, coming home!