U. of Colorado's 'Little Satellite That Did' set for re-entry in coming days

December 01, 2003

A $5 million University of Colorado at Boulder satellite dubbed the "Little Satellite That Did" now is expected to re-enter the atmosphere and burn up in early December following a successful six-year mission.

The Student Nitric Oxide Explorer, or SNOE, is carrying instruments that have measured nitric oxide in the upper atmosphere that affects Earth's ozone layer, the intensity of X-rays from the sun and ultraviolet light from Earth's aurora. Developed at CU-Boulder's Laboratory for Atmospheric and Space Physics by students, engineers and faculty, the mission has been controlled from LASP's CU Research Park facility 24 hours a day by students and faculty since early 1998.

"The SNOE satellite has been determining the influence of the sun on Earth's upper atmosphere by measuring the amount of nitric oxide in the atmosphere," said Charles Barth, former LASP director and principal investigator of SNOE. Produced when solar X-rays are absorbed into the atmosphere, nitric oxide destroys naturally produced ozone when injected into the stratosphere 30 to 50 miles above Earth.

"NASA's latest predictions indicate that SNOE will re-enter the atmosphere on Dec. 5," he said. "However, we are anticipating more solar storms in the next few days that may cause it to come in earlier. We still are studying the effects of the solar storms on the atmosphere, so any large storms in the next several days will be good news for our scientific studies and bad news for the lifetime of the satellite."

Orbiting at more than 300 miles above Earth, SNOE has helped CU-Boulder scientists and students map the effect of global X-rays on the atmosphere. SNOE data have shown that nitric oxide levels in the mesosphere correlate with the 27-day cycle of solar X-rays coming from the sun.

In addition, the researchers discovered that when charged particles sent rocketing to Earth by solar storms slam into Earth's magnetic field and are injected into the polar regions, they produce both Aurora Borealis and Aurora Australis. "The same particles that cause the aurora also produce the nitric oxide in the upper atmosphere," said Barth.

This helps CU researchers determine how much energy is injected in the polar regions, he said.

Roughly 60 students from disciplines ranging from business, film studies and computer science have participated in the on-campus control of SNOE, said Randy Davis, LASP's mission operations director. LASP currently controls five satellites.

SNOE's design and construction phase involved more than 100 students, primarily undergraduates, said Davis. SNOE was one of three spacecraft selected for flight by the Universities Space Research Association in 1994 as part of NASA's Student Explorer Demonstration Initiative. CU's spacecraft was the first to launch.

"It is remarkable to me how successful SNOE has been," said Davis. "The reasons we built SNOE in-house was the opportunity of involving more than 100 students in the project from design and construction to satellite control and the tremendous science SNOE was capable of doing. We have extremely competent and enthusiastic students here."

From 1981 to 1989, CU students and faculty controlled the Solar Mesosphere Explorer satellite from campus, the first NASA satellite ever entirely operated and controlled by a university. SNOE was the second.

The three-foot-diameter, 220-pound spacecraft was launched on a Pegasus expendable-launch vehicle built by Orbital Sciences Corp. of Dulles, Va. The Pegasus carried the satellite to an altitude of 40,000 feet by jet aircraft and dropped into a five-second free fall. SNOE then ignited horizontally and began ascending, placing it in a circular orbit about 340 miles above Earth within 10 minutes.

CU students tapped into the expertise of engineers from Ball Aerospace Corp. -- which built the Solar Mesosphere Explorer satellite -- and the National Center for Atmospheric Research, working side by side with them in all phases of the project.

The operations were supported in part by a special excellence award from the Colorado Commission on Higher Education, said Davis.

"During the final months of SNOE's lifetime, the students formed a SNOE re-entry team to carefully monitor the satellite's performance," said Barth. "This has been a truly unique experience for CU-Boulder students to participate in from launch to re-entry."

The SNOE research team expects almost all of the satellite to burn up during re-entry, with perhaps a few small fragments falling into the ocean.
Additional information on the SNOE project can be found on the Web at http://lasp.colorado.edu/programs_missions/present/off_site/save.html.

Additional Contacts:
Randy Davis, (303) 492-6867
Jim Scott, (303) 492-3114

University of Colorado at Boulder

Related Atmosphere Articles from Brightsurf:

ALMA shows volcanic impact on Io's atmosphere
New radio images from ALMA show for the first time the direct effect of volcanic activity on the atmosphere of Jupiter's moon Io.

New study detects ringing of the global atmosphere
A ringing bell vibrates simultaneously at a low-pitched fundamental tone and at many higher-pitched overtones, producing a pleasant musical sound. A recent study, just published in the Journal of the Atmospheric Sciences by scientists at Kyoto University and the University of Hawai'i at Mānoa, shows that the Earth's entire atmosphere vibrates in an analogous manner, in a striking confirmation of theories developed by physicists over the last two centuries.

Estuaries are warming at twice the rate of oceans and atmosphere
A 12-year study of 166 estuaries in south-east Australia shows that the waters of lakes, creeks, rivers and lagoons increased 2.16 degrees in temperature and increased acidity.

What makes Saturn's atmosphere so hot
New analysis of data from NASA's Cassini spacecraft found that electric currents, triggered by interactions between solar winds and charged particles from Saturn's moons, spark the auroras and heat the planet's upper atmosphere.

Galactic cosmic rays affect Titan's atmosphere
Planetary scientists using the Atacama Large Millimeter/submillimeter Array (ALMA) revealed the secrets of the atmosphere of Titan, the largest moon of Saturn.

Physics: An ultrafast glimpse of the photochemistry of the atmosphere
Researchers at Ludwig-Maximilians-Universitaet (LMU) in Munich have explored the initial consequences of the interaction of light with molecules on the surface of nanoscopic aerosols.

Using lasers to visualize molecular mysteries in our atmosphere
Molecular interactions between gases and liquids underpin much of our lives, but difficulties in measuring gas-liquid collisions have so far prevented the fundamental exploration of these processes.

The atmosphere of a new ultra hot Jupiter is analyzed
The combination of observations made with the CARMENES spectrograph on the 3.5m telescope at Calar Alto Observatory (Almería), and the HARPS-N spectrograph on the National Galileo Telescope (TNG) at the Roque de los Muchachos Observatory (Garafía, La Palma) has enabled a team from the Instituto de Astrofísica de Canarias (IAC) and from the University of La Laguna (ULL) to reveal new details about this extrasolar planet, which has a surface temperature of around 2000 K.

An exoplanet loses its atmosphere in the form of a tail
A new study, led by scientists from the Instituto de Astrofísica de Canarias (IAC), reveals that the giant exoplanet WASP-69b carries a comet-like tail made up of helium particles escaping from its gravitational field propelled by the ultraviolet radiation of its star.

Iron and titanium in the atmosphere of an exoplanet
Exoplanets can orbit close to their host star. When the host star is much hotter than our sun, then the exoplanet becomes as hot as a star.

Read More: Atmosphere News and Atmosphere Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.