HI-C sounding rocket mission has finest mirrors ever made

Jul 06, 2012 By Karen C. Fox
Waiting for launch: NASA's HI-C mission, sitting in the front of this image, will launch on July 11, 2012 to observe the sun's corona in the highest detail ever captured during a 381-second flight. Credit: NASA

(Phys.org) -- On July 11, NASA scientists will launch into space the highest resolution solar telescope ever to observe the solar corona, the million degree outer solar atmosphere. The instrument, called HI-C for High Resolution Coronal Imager, will fly aboard a Black Brant sounding rocket to be launched from the White Sands Missile Range in New Mexico. The mission will have just 620 seconds for its flight, spending about half of that time high enough that Earth's atmosphere will not block ultraviolet rays from the sun. By looking at a specific range of UV light, HI-C scientists hope to observe fundamental structures on the sun, as narrow as 100 miles across.

"Other instruments in space can't resolve things that small, but they do suggest – after detailed computer analysis of the amount of light in any given pixel – that structures in the sun's atmosphere are about 100 miles across," says Jonathan Cirtain, a solar scientist at 's Marshall Space Flight Center in Huntsville, Ala. who is the project scientist for HI-C. "And we also have theories about the shapes of structures in the atmosphere, or corona, that expect that size. HI-C will be the first chance we have to see them."

The spatial resolution on HI-C is some five times more detailed than the Atmospheric Imaging Assembly (AIA) instrument on the Solar Dynamics Observatory (SDO), that can resolve structures down to 600 miles and currently sends back some of our most stunning and scientifically useful images of the sun. Of course, AIA can see the entire sun at this resolution, while HI-C will focus on an area just one-sixth the width of the sun or 135,000 miles across. Also, AIA observes the sun in ten different wavelengths, while HI-C will observe just one: 193 Angstroms. This wavelength of corresponds to material in the sun at temperatures of 1.5 million Kelvin and that wavelength is typically used to observe material in the corona.

During its ten-minute journey, HI-C will focus on the center of the sun, where a large sunspot is predicted to be – a prediction based on what the sun looked like 27 days previously, since it takes 27 days for the sun to complete a full rotation.

"We will start acquiring data at 69 seconds after launch, at a rate of roughly an image a second," says Cirtain. "We will be able to look through a secondary H-alpha telescope on the instrument in real time and re-point the main telescope as needed."

In addition to seeing the finest structures yet seen in the ’s corona, the launch of HI-C will serve as a test bed for this telescope. Often one improves telescope resolution simply by building bigger mirrors, but this is not possible when constraining a telescope to the size of a , or even a long-term satellite. So HI-C's mirror is only about nine and a half inches across, no bigger than that of AIA. However, the HI-C mirrors, made by a team at Marshall, are some of the finest ever made, says Cirtain. If one could see the surface at an atomic level, it would show no greater valleys or peaks than two atoms in either direction.

"So it's super smooth," says Cirtain.

In addition, the team created a longer focal length – that is, they increased the distance the light travels from its primary mirror to its secondary mirror, another trick to improve resolution – by creating a precise inner maze for the light to travel from mirror to mirror, rather than a simple, shorter straight line.

NASA's Marshall Space Flight Center is leading the international effort for Hi-C. Key partners include the University of Alabama at Huntsville, Smithsonian Astrophysical Observatory, University of Central Lancashire in Lancashire, England, and the Lebedev Physical Institute of the Russian Academy of Sciences.

Explore further: SpaceX making Easter delivery of station supplies (Update 2)

add to favorites email to friend print save as pdf

Related Stories

Hi-C to investigate activity in solar atmosphere

Jun 22, 2012

(Phys.org) -- NASA's Marshall Space Flight Center in Huntsville, Ala. is leading an international effort to develop and launch the High Resolution Coronal Imager, or Hi-C, on a sounding rocket from the White ...

Hinode's first light... and five more years

Nov 02, 2011

(PhysOrg.com) -- On October 28, 2006, the Hinode solar mission was at last ready. The spacecraft launched on September 22, but such missions require a handful of diagnostics before the instruments can be turned ...

Huge coronal hole is sending solar wind our way

Mar 14, 2012

An enormous triangular hole in the Sun’s corona was captured earlier today by NASA’s Solar Dynamics Observatory, seen above from the AIA 211 imaging assembly. This gap in the Sun’s atmosphere ...

Spotting ultrafine loops in the Sun's corona

Jun 12, 2012

(Phys.org) -- A key to understanding the dynamics of the sun and what causes the great solar explosions there relies on deciphering how material, heat and energy swirl across the sun's surface and rise into ...

Recommended for you

Sun emits a mid-level solar flare

20 hours ago

The sun emitted a mid-level solar flare, peaking at 9:03 a.m. EDT on April 18, 2014, and NASA's Solar Dynamics Observatory captured images of the event. Solar flares are powerful bursts of radiation. Harmful ...

Impact glass stores biodata for millions of years

22 hours ago

(Phys.org) —Bits of plant life encapsulated in molten glass by asteroid and comet impacts millions of years ago give geologists information about climate and life forms on the ancient Earth. Scientists ...

The importance of plumes

22 hours ago

The Hubble Space Telescope is famous for finding black holes. It can pick out thousands of galaxies in a patch of sky the size of a thumbprint. The most powerful space telescope ever built, the Hubble provided ...

Ceres and Vesta Converge in Virgo

Apr 18, 2014

Don't let them pass you by. Right now and continuing through July, the biggest and brightest asteroids will be running on nearly parallel tracks in the constellation Virgo and so close together they'll easily ...

User comments : 0

More news stories

Impact glass stores biodata for millions of years

(Phys.org) —Bits of plant life encapsulated in molten glass by asteroid and comet impacts millions of years ago give geologists information about climate and life forms on the ancient Earth. Scientists ...

The importance of plumes

The Hubble Space Telescope is famous for finding black holes. It can pick out thousands of galaxies in a patch of sky the size of a thumbprint. The most powerful space telescope ever built, the Hubble provided ...

Continents may be a key feature of Super-Earths

Huge Earth-like planets that have both continents and oceans may be better at harboring extraterrestrial life than those that are water-only worlds. A new study gives hope for the possibility that many super-Earth ...

Airbnb rental site raises $450 mn

Online lodging listings website Airbnb inked a $450 million funding deal with investors led by TPG, a source close to the matter said Friday.

Health care site flagged in Heartbleed review

People with accounts on the enrollment website for President Barack Obama's signature health care law are being told to change their passwords following an administration-wide review of the government's vulnerability to the ...