Category Archives: Solar Science

Sunjammer solar sail to fly far in 2014

The NASA funded Sunjammer Project will fly the largest solar sail ever deployed in space, a  1200 sq. meter sail built by L’Garde. Scheduled for launch on a SpaceX Falcon 9 rocket in 2014, the Sunjammer spacecraft will aim for a location 300M kilometers from earth. The goals of the project include:

1. Demonstrate segmented deployment of a solar sail with ~4X the area of that vacuum tested at Plum Brook, “cookie cut” from the center of a much larger sail.

2. Demonstrate attitude control plus passive stability and trim using beam-tip vanes.

3. Execute a navigation sequence with mission-capable accuracy.

4. Fly to and Maintain Position at L1 and pole sitter positions

Taking advantage of the sunlight force on the sail, such spacecraft should be able to achieve stable orbital locations relative to earth that would provide excellent places to detect solar  storms and send warnings back home. Sunjammer will carry two solar wind measurement  instruments built by groups in the UK:

Three years of the Sun in four minutes

NASA releases a video showing a time lapse sequence of solar images taken over three years by the  Solar Dynamics Observatory (SDO). There are 2 images per day:

Three Years of SDO Images
NASA 04.22.13:  In the three years since it first provided images of the sun in the spring of 2010, NASA’s Solar Dynamics Observatory has had virtually unbroken coverage of the sun’s rise toward solar maximum, the peak of solar activity in its regular 11-year cycle. This video shows those three years of the sun at a pace of two images per day.

SDO’s Atmospheric Imaging Assembly captures a shot of the sun every 12 seconds in 10 different wavelengths. The images shown here are based on a wavelength of 171 angstroms, which is in the extreme ultraviolet range and shows solar material at around 600,000 kelvins (about 1.08 million F). In this wavelength it is easy to see the sun’s 25-day rotation as well as how solar activity has increased over three years.

During the course of the video, the sun subtly increases and decreases in apparent size. This is because the distance between the SDO spacecraft and the sun varies over time. The image is, however, remarkably consistent and stable despite the fact that SDO orbits Earth at 6,876 mph and Earth orbits the sun at 67,062 mph.

Such stability is crucial for scientists, who use SDO to learn more about our closest star. These images have regularly caught solar flares and coronal mass ejections in the act, types of space weather that can send radiation and solar material toward Earth and interfere with satellites in space. SDO’s glimpses into the violent dance on the sun help scientists understand what causes these giant explosions — with the hopes of some day improving our ability to predict this space weather.
composite SDO image of sun from April 2012-April 2013
This image is a composite of 25 separate images spanning the period of April 16, 2012, to April 15, 2013. It uses the SDO AIA wavelength of 171 angstroms and reveals the zones on the sun where active regions are most common during this part of the solar cycle.