Perlan Project
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The Perlan Project is a current research project to fly a sailplane to an altitude of 100,000 feet (30,480 meters). It was conceived by former NASA test pilot Einar Enevoldson. Piloted by record-seeking sportsman Steve Fossett and Enevoldson, a modified DG Flugzeugbau 505M sailplane will launch during very specific weather conditions. (This DG 505 is now classified as Experimental, as the motor was removed to make room for batteries and liquid oxygen.) With the below set of specific weather criteria, it is believed that the plane can ascend through the tropopause and into the stratosphere.
The significance of the project can be grasped from the fact that until now the tropopause (a permanent temperature inversion between the troposphere and the stratosphere) has represented an absolute ceiling to soaring flight. Gliders rely upon ascending air currents to gain height. The lack thereoff in the essentially stable stratosphere has relegated soaring flight to the lower layer of the atmosphere associated with weather phenomena, i.e., the troposphere.
Fair-weather thermal convection is the most common energy source in the sport of gliding. This type of convection, however, is limited to the lower troposphere. Convection inside thunderstorms can reach much higher, right up to the tropopause. Pioneering glider pilots did occasionally ride thunderstorms but this practice has been discontinued due to the uncontrollable and unnacceptable risks it entails.
Atmospheric standing waves constitute the other, and currently the exclusive, source of energy for high-altitude glider flight. Also known as mountain waves, they can extend up to the tropopause. Weaker waves exist also in the stratosphere.
The aim of the Perlan Project is to demonstrate the viability of riding in standing waves beyond the tropopause and, in particular, of making the transition into stratospheric standing waves (SMW) and ascending in them to a much higher altitude.
Based for a few years in Omarama, New Zealand, the project is currently based in Patagonia, at El Calafate, Argentina.
The conditions necessary for a successful flight are quite exceptional:
- The polar vortex overhead (occurring only in near-polar latitudes during winter)
- Prefrontal conditions
- A weak tropopause
- A gradual increase in windspeed with altitude
- Wind direction within 30° of perpendicular to the mountain ridgeline
- Cooperation of any present subtropical jet stream
- Strong low-altitude winds in a stable atmosphere
- Ridgetop winds of at least 20 knots
Phase one of the project, a proof of concept flight, has a goal of 62,000 feet (18,900 meters). Phase two, which will probably be attempted with a custom-built glider, has a goal of 100,000 feet (30,480 meters). The current open-class absolute altitude record of 14,938 meters (49,009 feet) was set over California City, California, in 1986 by Robert R. Harris with a Burkhart Grob G-102.
[edit] Press Release for August 30, 2006
Into the Stratosphere – Without an Engine New world glider altitude record set by Fossett and Enevoldson in Argentina 50,671 feet (15,447 m) achieved by 'Perlan' - the first ever glider flight into the earth's stratosphere Previous record shattered by 1,662 ft (507 m) from the Perlan Project's Website
