The Multi-Spectral Solar Telescope Array (MSSTA) was a

sounding rocket A sounding rocket or rocketsonde, sometimes called a research rocket or a suborbital rocket, is an instrument-carrying rocket designed to take measurements and perform scientific experiments during its sub-orbital flight. The rockets are often ...

payload built by Professor Arthur B. C. Walker Jr. at

Stanford University Leland Stanford Junior University, commonly referred to as Stanford University, is a Private university, private research university in Stanford, California, United States. It was founded in 1885 by railroad magnate Leland Stanford (the eighth ...

in the 1990s to test EUV/XUV imaging of the Sun using normal incidence EUV-reflective multilayer optics. MSSTA contained a large number of individual telescopes (> 10), all trained on the Sun and all sensitive to slightly different

wavelength In physics and mathematics, wavelength or spatial period of a wave or periodic function is the distance over which the wave's shape repeats. In other words, it is the distance between consecutive corresponding points of the same ''phase (waves ...

s of ultraviolet light. Like all sounding rockets, MSSTA flew for approximately 14 minutes per mission, about 5 minutes of which were in space—just enough time to test a new technology or yield "first results" science. MSSTA is one of the last solar observing instruments to use

photographic film Photographic film is a strip or sheet of transparent film base coated on one side with a gelatin photographic emulsion, emulsion containing microscopically small light-sensitive silver halide crystals. The sizes and other characteristics of the ...

rather than a

digital camera A digital camera, also called a digicam, is a camera that captures photographs in Digital data storage, digital memory. Most cameras produced today are digital, largely replacing those that capture images on photographic film or film stock. Dig ...

system such as a CCD. MSSTA used film instead of a CCD in order to achieve the highest possible spatial resolution and to avoid the electronics difficulty presented by the large number of detectors that would have been required for its many telescopes. MSSTA and its sister rocket,

NIXT The NIXT, or Normal Incidence X-ray Telescope, was a sounding rocket payload flown in the 1990s by Professor Leon Golub (astrophysicist), Leon Golub of the Smithsonian Astrophysical Observatory, to prototype normal-incidence (conventional) optical ...

, were prototypes for normal incidence

extreme ultraviolet Extreme ultraviolet radiation (EUV or XUV) or high-energy ultraviolet radiation is electromagnetic radiation in the part of the electromagnetic spectrum spanning wavelengths shorter than the hydrogen Lyman-alpha line from 121 nm down to ...

imaging telescopes that are in use today, as well as the historic EIT instrument aboard the

SOHO SoHo, short for "South of Houston Street, Houston Street", is a neighborhood in Lower Manhattan, New York City. Since the 1970s, the neighborhood has been the location of many artists' lofts and art galleries, art installations such as The Wall ...

spacecraft, and the

TRACE Trace may refer to: Arts and entertainment Music * ''Trace'' (Son Volt album), 1995 * ''Trace'' (Died Pretty album), 1993 * Trace (band), a Dutch progressive rock band * ''The Trace'' (album), by Nell Other uses in arts and entertainment * ...

spacecraft. MSSTA flew three times: once in 1991 (NASA Sounding Rocket flight 36.049), once in 1994 (flight 36.091), and once in 2002 (flight 36.194). While Walker's 1991 telescope was the first in the series to carry the MSSTA moniker, the precursor to the MSSTA, the Stanford/MSFC Rocket Spectroheliograph (NASA Sounding Rocket flight 27.092), which carried two EUV telescopes in 1987, was the first mission to successfully obtain high-resolution, full-disk solar images utilizing normal incidence EUV optics. The MSSTA I flown in 1991 carried 14 telescopes; the MSSTA II flown in 1994 carried 19 telescopes; and the MSSTA III flown in 2002 carried 11 telescopes. Several Stanford Ph.D. degrees in Physics resulted from the MSSTA program. These include those earned by Joakim Lindblom, Maxwell J. Allen, Ray H. O'Neal, Craig Edward DeForest, Charles C. Kankelborg, Hakeem Oluseyi, Dennis S. Martinez-Galarce, and Paul F.X. Boerner.

References

See also