Sound Rocket Mission SUMI
SUMI’s instruments are designed to study magnetic fields of the sun’s chromosphere -- a thin layer of solar atmosphere sandwiched between the visible surface, photosphere and its atmosphere, the corona. Hinode, a collaborative mission of the space agencies of Japan, the United States, United Kingdom and Europe, captured these very dynamic pictures of our sun's chromosphere on Jan. 12, 2007. Image credit: JAXA/NASA

NASA will launch a sounding rocket mission called the Solar Ultraviolet Magnetograph Investigation (SUMI) on July 5, to study the solar magnetic fields that are present in a "hard-to-observe" region called the chromosphere.

SUMI, which will be launched from White Sands Missile Range in New Mexico, will study the higher layers of the chromosphere. The chromosphere area is the second of the three layers present in the Sun's atmosphere, where huge explosions of solar flares and particle eruptions known as the Coronal Mass Ejections (CME) take place.

The Sun's outermost atmosphere is called the Corona. The higher layer of the chromosphere is known as the solar transition region where the chromosphere transitions into the corona. It is in this transition region that solar material heats up forming the corona and the base of the solar wind.

Solar magnetic fields also dominate this particular transition region. Researchers believe that they will be able to understand how the corona gets heated and how solar flares erupt, by studying the structure of these magnetic fields. This will also help scientists in predicting the space weather.

There are several instruments which are used to study the magnetic fields. But those instruments collect data by looking at the infrared lights and observing the magnetic fields on a particular layer of the Sun's atmosphere or on its surface. SUMI will observe ultraviolet light and study the higher layers of chromosphere which cannot be seen through other instruments, NASA said.

"What's novel with this instrument is that it observes ultraviolet light, when all the others look at infrared or visible light," said Jonathan Cirtain, a solar scientist at NASA's Marshall Space Flight Center in Huntsville, Ala. and the principal investigator for SUMI.

"Those wavelengths of light correspond to the lowest levels in the sun's atmosphere, but SUMI will look at locations higher in the chromospheres," he added.

Earlier, the SUMI mission was launched in July 2010, but due to high gravitational force from the Sun the instrument's screws holding the main mirror were broken, and as a result SUMI could not give accurate data. The team has now strengthened the mirror.

SUMI's trip will be a test flight to check if the instrument works and if any further improvements are required. Based on the information they receive from this mission, NASA scientists intend to build a space-based instrumentation that will help them understand the formation of solar flares and CMEs.