Photos from the Edge of Space
Article by Peter Zack
Oklahoma State University Astro 9 and 12 Missions
A photo of the Earth and the Sun taken from 98,514 ft (30,047 m). Equipment used: Pentax K10D DSLR and DA 10-17mm lens. 169° Lateral angle of view.
Today I feel you are in for a real treat. Photography like we very rarely get to see it–from the edge of space.
Dr Andrew S. Arena Jr., Professor in Engineering, School of Mechanical and Aerospace Engineering, and Deputy Director, NASA Oklahoma Space Grant Consortium and EPSCoR Oklahoma State University, launched a balloon experiment. His aircraft design teams have won 5 international awards and have set 4 world records for unmanned flights. The mission was launched near Stillwater, Oklahoma and to primarily test a new cosmic radiation sensor. They also added a digital camera to the payload. There have been 2 flights to this point with more planned in the future.
Astro 9 launched in July, 2008 and Astro 12 in December, 2008. The camera was packed in a small box that was foam lined to cushion the impact of landing.
The first flight used a DA 18-55mm lens, set to 18mm, manual focus and taped at infinity for the flight. The second flight used a DA 10-17mm lens set up the same way.
Astro 9 prepared for launch
Astro 9 reached an altitude of 104,000 ft (31,720 m) before the balloon burst and Astro 12 reached 98,514 ft (30,047 m). The balloons launch at a diameter of about 10 ft (3 m) and expand to approximately 40-50 ft (12-15 m) before they reach peak altitude and burst. The package then descends to earth, only slowed by a small parachute to cushion the fall.
The approximate landing impact is 22 mph (35 kph). Ascent speeds are approximately 60 mph at 44,000 ft (97 kph at 13,420 m) and when it nears the peak altitude, the temperature approaches -60°F (-51℃) in a near vacuum. Both flights produced about 500 RAW digital files. The camera was attached to a timer that fired a shot every 15 seconds. Dr Arena stated, he was very pleased that with each flight, there were only 5-6 shots which were unusable, and then only because the camera fired directly at the sun and overexposed the shot. Otherwise, he had about 500 excellent images. The camera and lenses survived the flights without issues, even in the cold and wet extremes they faced. The balloon is tracked with GPS telemetry systems to follow it down wind and retrieve the equipment.
Andy Arena and Seong-Jin Lee beginning to inflate the balloon
The camera was set to Auto ISO and Shutter Priority (Tv) at 1/3000 s to freeze the motion. Most shots fired at ISO 100. The camera was set at multi-segment metering for the flight. Lithium batteries are used since other battery technologies cannot handle the extreme cold. The 15 second time lapse was accomplished using external triggering from a Pclix LT100. GPS flight data were used to track the package in the chase vehicle, which was constantly updated during the flight and computer weather models were used to predict the landing site. Astro 9’s flight lasted for 102 minutes.
Finally, before the flight, a high-altitude NOTAM is filed with the FAA. That way, air traffic control can notify aircraft of the flight. There are also certain regulations that have to be followed regarding the design and operation of the system.
Astro 9 at peak altitude using 18mm lens giving 67° Lateral angle of view
|Andy Arena||OSU Professor, MAE|
|Eric Benton||OSU Professor, Physics|
|Joe Conner||OSU PhD Student, Mechanical and Aerospace Engineering|
|Carl Johnson||OSU PhD Student, Physics|
|Cassie Latino||OSU BS Electrical and Computer Engineering student|
|Andy Lau||OSU PhD Student, Physics|
|Seong-Jin Lee||OSU PhD Student, Mechanical and Aerospace Engineering|
|Harry Mueller||Oklahoma Research Balloons, Tulsa, OK|
Links to more information involving the 2 flights:
Click on image for breathtaking larger view
Our thanks to Dr Andy Arena of Oklahoma State University for providing the information and pictures.
Cheers and good shooting –Peter Zack