Spirit of Knoxville
Encyclopedia
The Spirit of Knoxville is a high altitude balloon
project run by amateur scientists and University of Tennessee
students, with the ultimate goal of successfully sending an unmanned balloon across the Atlantic Ocean
. The project is named for Charles Lindbergh
's record-breaking
Spirit of St. Louis
aircraft
.
As of November 2008, five flights have been made, of which three were intended to cross the Atlantic, a goal which has yet to be achieved.
dumping mechanisms and material, custom radio circuitry, the Distributed Tracking and Relay volunteer listening network, and command uplinking.
The first Spirit of Knoxville "SNOX" designated flight was SNOX I, reaching a stable float altitude
of approximately of 11 kilometres (36,000 feet). Launched from Knoxville Downtown Island Airport
, in December 2007, the balloon travelled over 900 kilometers southeast to land just north of the Bahamas, fulfilling the objectives of the new balloon envelope. The flight ended, however, due to the ballast system's inability to drop weight fast enough at nightfall after the loss of daytime solar heating.
The hardware and software of the ballast system was redesigned for the test flight SNOX II, to ensure a faster response to solar heat loss at sunset. SNOX II launched in January 2008, but landed in minutes just a few kilometers away in an urban home backyard. Post-flight recovery and analysis revealed that newly tested inflation procedures had caused a rip in the top of the balloon. The payload and ballast system were not damaged, however the balloon envelope was damaged beyond repair during landing.
SNOX III was assembled shortly with a new balloon envelope and the same payload and ballast system from SNOX II. Launched in January 2008, it was the first official attempt to cross the Atlantic Ocean
. The onboard GPS
failed shortly after launch, eliminating the ability for the balloon to report its position, and also preventing the ballast system from detecting changes in altitude. Crude radio direction finding attempts by volunteers did indicate the balloon followed its predicted trajectory as far as the shore of the Atlantic Ocean in Virginia.
SNOX IV was the most successful flight to date, launched on March 11, 2008 it remained in the air for over 40 hours and 5600 kilometres (3,479.7 mi), surpassing all flight duration and distance records for amateur balloons. The ballast system used all available weight on the first night, and the balloon system succumbed to the loss of solar heat on the second sunset of its flight. The landing was just a few hundred kilometers from Ireland.
The most recent flight being SNOX V, launched April 5, 2008, suffered a failure of the envelope itself, landing in southwestern Virginia
approximately 8 hours after launch.
radio transmitter, electric heater, 40 AA lithium batteries, and GPS.
Amateur radio operator
s voluntarily assist in tracking the balloons during their flights.
In order to cross the ocean, the balloon must stay within the high speed jet stream
winds the entire way from Knoxville, TN to Europe
or Africa
. These continuous winds rarely travel directly over the southeastern United States
, which restricts the number of times per year this crossing can be attempted.
High altitude balloon
High-altitude balloons are unmanned balloons, usually filled with helium or hydrogen that are released into the stratosphere, generally reaching between ....
project run by amateur scientists and University of Tennessee
University of Tennessee
The University of Tennessee is a public land-grant university headquartered at Knoxville, Tennessee, United States...
students, with the ultimate goal of successfully sending an unmanned balloon across the Atlantic Ocean
Atlantic Ocean
The Atlantic Ocean is the second-largest of the world's oceanic divisions. With a total area of about , it covers approximately 20% of the Earth's surface and about 26% of its water surface area...
. The project is named for Charles Lindbergh
Charles Lindbergh
Charles Augustus Lindbergh was an American aviator, author, inventor, explorer, and social activist.Lindbergh, a 25-year-old U.S...
's record-breaking
Flight endurance record
The flight endurance record is the longest amount of time an aircraft of a particular category spent in flight without landing. It can be a solo event, or multiple people can take turns piloting the aircraft, as long as all pilots remain in the aircraft. The limit initially was the amount of fuel...
Spirit of St. Louis
Spirit of St. Louis
The Spirit of St. Louis is the custom-built, single engine, single-seat monoplane that was flown solo by Charles Lindbergh on May 20–21, 1927, on the first non-stop flight from New York to Paris for which Lindbergh won the $25,000 Orteig Prize.Lindbergh took off in the Spirit from Roosevelt...
aircraft
Aircraft
An aircraft is a vehicle that is able to fly by gaining support from the air, or, in general, the atmosphere of a planet. An aircraft counters the force of gravity by using either static lift or by using the dynamic lift of an airfoil, or in a few cases the downward thrust from jet engines.Although...
.
As of November 2008, five flights have been made, of which three were intended to cross the Atlantic, a goal which has yet to be achieved.
History
The project began in 2005, under the direction of students from the University of Tennessee Amateur Radio Club, with a series of technology demonstrator flights dubbed the "Icarus" series. These flights tested small zero-pressure balloon designs, ballastBuoyancy compensator (aviation)
The static buoyancy of airships during a trip is not constant. It is therefore necessary to take measures to control the buoyancy and thus the altitude, the so-called buoyancy compensation.-Changes which have an effect on buoyancy:...
dumping mechanisms and material, custom radio circuitry, the Distributed Tracking and Relay volunteer listening network, and command uplinking.
The first Spirit of Knoxville "SNOX" designated flight was SNOX I, reaching a stable float altitude
Altitude
Altitude or height is defined based on the context in which it is used . As a general definition, altitude is a distance measurement, usually in the vertical or "up" direction, between a reference datum and a point or object. The reference datum also often varies according to the context...
of approximately of 11 kilometres (36,000 feet). Launched from Knoxville Downtown Island Airport
Knoxville Downtown Island Airport
Knoxville Downtown Island Airport or Knoxville Downtown Island Home Airport , often referred to as Island Home Airport, is a general aviation airport located approximately one-half mile east of downtown Knoxville, in Knox County, Tennessee, United States.Although most U.S...
, in December 2007, the balloon travelled over 900 kilometers southeast to land just north of the Bahamas, fulfilling the objectives of the new balloon envelope. The flight ended, however, due to the ballast system's inability to drop weight fast enough at nightfall after the loss of daytime solar heating.
The hardware and software of the ballast system was redesigned for the test flight SNOX II, to ensure a faster response to solar heat loss at sunset. SNOX II launched in January 2008, but landed in minutes just a few kilometers away in an urban home backyard. Post-flight recovery and analysis revealed that newly tested inflation procedures had caused a rip in the top of the balloon. The payload and ballast system were not damaged, however the balloon envelope was damaged beyond repair during landing.
SNOX III was assembled shortly with a new balloon envelope and the same payload and ballast system from SNOX II. Launched in January 2008, it was the first official attempt to cross the Atlantic Ocean
Atlantic Ocean
The Atlantic Ocean is the second-largest of the world's oceanic divisions. With a total area of about , it covers approximately 20% of the Earth's surface and about 26% of its water surface area...
. The onboard GPS
Global Positioning System
The Global Positioning System is a space-based global navigation satellite system that provides location and time information in all weather, anywhere on or near the Earth, where there is an unobstructed line of sight to four or more GPS satellites...
failed shortly after launch, eliminating the ability for the balloon to report its position, and also preventing the ballast system from detecting changes in altitude. Crude radio direction finding attempts by volunteers did indicate the balloon followed its predicted trajectory as far as the shore of the Atlantic Ocean in Virginia.
SNOX IV was the most successful flight to date, launched on March 11, 2008 it remained in the air for over 40 hours and 5600 kilometres (3,479.7 mi), surpassing all flight duration and distance records for amateur balloons. The ballast system used all available weight on the first night, and the balloon system succumbed to the loss of solar heat on the second sunset of its flight. The landing was just a few hundred kilometers from Ireland.
The most recent flight being SNOX V, launched April 5, 2008, suffered a failure of the envelope itself, landing in southwestern Virginia
Virginia
The Commonwealth of Virginia , is a U.S. state on the Atlantic Coast of the Southern United States. Virginia is nicknamed the "Old Dominion" and sometimes the "Mother of Presidents" after the eight U.S. presidents born there...
approximately 8 hours after launch.
Overview
The project uses custom-built zero-pressure balloons from Global Western, made of very thin polyethylene, with denatured alcohol ballast dropped during cruise to maintain a constant altitude (although lift provided by solar heating is also used). The electronics comprise a flight computer, I2C temperature sensors, high frequencyHigh frequency
High frequency radio frequencies are between 3 and 30 MHz. Also known as the decameter band or decameter wave as the wavelengths range from one to ten decameters . Frequencies immediately below HF are denoted Medium-frequency , and the next higher frequencies are known as Very high frequency...
radio transmitter, electric heater, 40 AA lithium batteries, and GPS.
Amateur radio operator
Amateur radio operator
An amateur radio operator is an individual who typically uses equipment at an amateur radio station to engage in two-way personal communications with other similar individuals on radio frequencies assigned to the amateur radio service. Amateur radio operators have been granted an amateur radio...
s voluntarily assist in tracking the balloons during their flights.
In order to cross the ocean, the balloon must stay within the high speed jet stream
Jet stream
Jet streams are fast flowing, narrow air currents found in the atmospheres of some planets, including Earth. The main jet streams are located near the tropopause, the transition between the troposphere and the stratosphere . The major jet streams on Earth are westerly winds...
winds the entire way from Knoxville, TN to Europe
Europe
Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...
or Africa
Africa
Africa is the world's second largest and second most populous continent, after Asia. At about 30.2 million km² including adjacent islands, it covers 6% of the Earth's total surface area and 20.4% of the total land area...
. These continuous winds rarely travel directly over the southeastern United States
Southeastern United States
The Southeastern United States, colloquially referred to as the Southeast, is the eastern portion of the Southern United States. It is one of the most populous regions in the United States of America....
, which restricts the number of times per year this crossing can be attempted.
Spirit of Knoxville Official
Press
- Cross the Atlantic cover story on Metro PulseMetro PulseMetro Pulse is a weekly newspaper in Knoxville, Tennessee.It was founded in 1991 by Ashley Capps, Rand Pearson, Ian Blackburn, and Margaret Weston. Metro Pulse has been a member of the Association of Alternative Newsweeklies since 1993....
- Amateur radio buffs devote three years to balloon project that reaches new height Life section cover story in Knoxville News Sentinel