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MidSTAR-1 Proves a Tiny Chemical Detector and Heat-Controlling Film!
02.19.08
 
Dr Billy Smith inspects MidSTAR 1 for damage after vibration testing at the Naval Research Laboratory. Dr. Billy R. Smith Jr., director of the USNA Small Satellite Program and MidSTAR-1 program manager, inspects MidSTAR-1 for damage after vibration testing at the Naval Research Laboratory. This test demonstrated that the satellite could survive the rigors of launch and retain functionality. High-efficiency, triple-junction gallium arsenide solar cells cover the sides; the S-band transmit antenna is visible at the upper right. The external neutron detector for the MicroDosimeter Instrument (MiDN) is visible on the top. Credit: USNA
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Imagine a tiny sensor that can check for harmful chemicals and a special "film" that can control heat. These two new technologies were launched on board a U.S. Naval Academy satellite called MidSTAR-1, and they have proven successful in their tests in space.

These technologies were developed between NASA’s Goddard Space Flight Center, Greenbelt, Md., NASA’s Ames Research Center, Moffett Field, Calif., and Eclipse Energy Systems Inc.

The tiny sensor is the size of a quarter, and it can sense chemicals and gases that may be harmful to astronauts. That's what the "Nano Chemsensor Unit" can do. "This sensor is like a smoke detector that would fit on the end of an eraser," said Dan Powell, Lead Nanotechnologist for NASA Goddard. The Nanosensor was developed by Dr. Jing Li of NASA Ames.

The sensor on board the Mid-STAR-1 satellite was designed to detect trace amount of nitrogen dioxide (NO2), which is usually given-off as an air pollutant from many sources. Because of the sensor's tiny size, small amount of power it uses, and small amount of heat it creates, it will be very helpful to many industries on Earth. It may even help U.S. Homeland Security to detect even trace-amounts of explosives.

"If you had a sensor like this, the size of a postage stamp, you could lick and stick it to monitor chemicals and environmental constituents anywhere," Powell said. "NASA wants to put this in the International Space Station (ISS) to monitor contaminants, and the Federal Aviation Administration may build hand-held NCSU systems so aircraft crews could detect explosives and/or harmful gases in aircraft," Powell said.

The NCSU uses a network of tiny carbon nanotubes that are about 10,000-times thinner than a human-hair, to sense the different gases and their concentrations.

MidSTAR 1 sits aboard an Atlas 5 rocket the night before launch at Cape Canaveral Air Force Station in Florida. MidSTAR-1 sits aboard an Atlas 5 rocket the night before launch at Cape Canaveral Air Force Station in Florida. Credit: United Launch Alliance
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NCSU's successful operation aboard MidSTAR-1 proved that it senses target chemicals both accurately and repeatedly in space. Since MidSTAR-1 was launched in March, 2007, the sensor has been improved and can now detect and identify more than 15 different chemicals, including ammonia, hydrogen peroxide, hydrogen chloride, and formaldehyde.

The second successful experiment on MidSTAR-1 is called a "Variable Emissivity Film." By flying onboard MidSTAR-1, it showed how a special film (the thickness of an empty Ziploc bag) can be made to accurately control the temperature on a spacecraft. This film is a big breakthrough as the technology has never been successfully demonstrated in space until MIDSTAR-1. Until now, the difficulty has been to make a film that could survive the harsh conditions of space.

The science behind this is called "electrochromics." You can think of electrochromics in terms of "photochromic" sunglasses that go from clear to dark in the Sun. The film works by changing, in a controllable fashion, the ability of the film to radiate waste heat into space or keep heat in a spacecraft. The effect is accomplished by changing the electricity applied to the film. Very little power is needed, and the process is reversible.

There are many benefits of using the film on a spacecraft. It can reduce launch weight, make future thermal design easier, reduce power consumption, and allow more accurate control of the spacecraft's inside temperature. The film will enable more payloads, such as scientific instruments or astronauts, to be loaded onto a spacecraft. It can also be used on satellites, space antennas, astronaut suits and visors, and future robotic systems that will be placed on the Moon and other planets.

The United Launch Alliance booster shot into the night sky on 8 March 2007 The United Launch Alliance booster shot into the night sky above Florida's Cape Canaveral Air Force Station on March 8, 2007 at 10:10 p.m. EST, carrying MidSTAR-1 into orbit. Credit: United Launch Alliance
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There are many applications for this technology beyond space. It can be used to cover buildings and homes to reduce solar heat gain in the summer, and decrease heat loss in the winter. Additionally, imagine being able to control the tint of the windows in your car at the press of a button.

The film was made by Eclipse Energy Systems, Inc., of St. Petersburg, Fla. and other locations around the U.S., with joint financial sponsorship from NASA Goddard and the U.S. Air Force.

Both experiments were able to go into space because of the U.S. Naval Academy's MidSTAR satellite program. The Naval Academy built the MidSTAR-1 satellite and placed the experiments onboard.

Related links:

> More information about MidSTAR
> Another NASA feature on MidSTAR