High altitude balloon to lift sun-gazing telescope for highest resolution images ever taken

Posted by Rick C. Hodgin

New Mexico (USA) - A team of research scientists are engaged in a sequence of test flights for a high-altitude balloon.  It will be used to deploy a 1 meter camera capable of viewing at the Earth's main power system, the sun (which is called Sol).  It will record images with highest resolutions ever made by man.  Features as small as 30km across will be visible.  Scientists hope to get a better understanding of the nature of surface eruptions on the sun so as to predict dangerous solar flares.


The balloon itself is an unlikely candidate for high resolution imaging systems.  While balloon rides feel extremely smooth and soft to humans, the balloon itself is constantly being slammed around by air currents and periodic vectors arising from pendulum-like motions of the basket relative to the balloon's central axis.  These all affect attempts to visualize something 92 million miles away.  To correct for this the balloon carries a device called a gondola.  The gondola is a type of multi-axis, motor-driven gyroscope to maintain stability and accuracy.

Scientists are using the balloon because it is much less expensive than actual space travel.  In fact, the entire project costs about $85 million.  Scientists are also using the balloon because they do face a problem in studying the sun from Earth-ground observatories, particularly the ultra-violet (UV) portions of the spectrum.  The Earth provides a very effective UV ray blocker and smudging agent in the form of our atmosphere.  The Ozone Layer is responsible for blocking UV rays and, as anyone who's ever looked up at the stars on a hot summer's night knows, they twinkle in the heat.  The same effects are at work during the day when viewing the sun.  Scientists must launch their balloon to an altitude of 120,000 feet so they can clear enough of that effect to visualize the sun with acceptable loss or distortion.

So far, only a 10-hour test flight has been successfully carried out.  In 2009, following additional tests, the high-resolution telescope/camera will be sent up.  Scientists have been studying the sun using balloons since 1957.  This latest attempt hopes to see the smallest knowns structures on the surface of the sun, flux tubes.  These are ultra-bright magnetic filaments, of a sort.  They are constantly being pulled, plodded, plugged, perturbed, pressed and punched.  This constant tug-of-war between the filaments is believed to be the foundation of solar flares.  If scientists could better understand their nature it might be possible to predict potentially damaging solar eruptions well in advance.  Solar activity is routinely responsible for observable shifts in voltage along large power lines in the US.  Strong solar eruptions have also been known to cause localized power outages and damage to even Earth-based electrical equipment.  Effects are also much amplified in space vehicles.

The current endeavor is sponsored by an international scientific effort involving Germany, Spain, Sweden and the US.  The total projected cost will be $85 million.  The special camera being used is called the Sunrise Telescope.  When launched in 2009, the team will be based in Antarctica where, due to the tilt of the Earth, a continuous two-week mission can stay aloft focusing constantly on the sun without day/night cycles, the so-called "White Nights".  Credit for the image goes to Carlye Calvin of the University Corporation for Atmospheric Research.