NASA Tech Briefs Insider Blog

Amnesty International uses Satellite Cameras to Monitor Darfur

Amnesty International USA is using powerful satellite cameras to monitor highly vulnerable villages in war-torn Darfur — the first-ever technological capability by human rights defenders to track possible targets of attack, prevent new atrocities, and save lives.

Unlike other online projects which only document previous destruction using older satellite images, Eyes on Darfur adds up-to-date images, which create the ongoing capacity to protect human rights by allowing activists, experts, and others to track developments on the ground as they occur in villages considered to be immediately at risk.

Amnesty International worked closely with the American Association for the Advancement of Science (AAAS), which offered expertise on satellite imagery and other cutting-edge geospatial technologies. Images from commercial satellites can reveal visual data about conditions on the ground for objects as small as two feet across.

For more information, click here.

Naval Academy Develops Satellite for NASA Instruments

A partnership between NASA and the U.S. Naval Academy is offering students the chance to build a satellite called “MidSTAR-2″ through a U.S. Department of Defense program that will carry four experiments into space in 2011 to look at different parts of Earth’s atmosphere, gamma rays, and solar winds. Scientists at NASA’s Goddard Space Flight Center in Maryland are taking advantage of the opportunity to carry promising technologies into orbit for evaluation.

The NASA experiments that will fly on MidSTAR-2 are part of the Internal Research and Development Program at NASA Goddard. The program lets NASA send instruments into space without waiting for another mission. “This is a program where everyone wins,” said Dan Powell, MidSTAR program manager at NASA Goddard. “Students get an opportunity to build and integrate a satellite bus and our scientists’ instruments get a free ride.”

One of the instruments taking that ride is the Remote Sensing of the Thermospheric Temperature instrument that will be used to take the temperature of Earth’s thermosphere to determine how much it can slow low-altitude spacecraft. The thermosphere is Earth’s outermost layer of atmosphere, located about 50 to 340 miles above the surface. Because of the thin air, scientists can’t measure temperature directly, so they measure density of the air by seeing how much drag it puts on satellites.

For information about the MidSTAR program, click here.

The European Space Agency (ESA, Paris, France) is conducting trials into helping guide airplane pilots via signals from satellites. Flight trials are being conducted to demonstrate the new possibilities offered by the European Geostationary Navigation Overlay Service (EGNOS), which has been launched by ESA, the European Commission, and Eurocontrol. The first European satellite navigation service, EGNOS will offer pilots vertical guidance information during approach and landing.

The results of the trials show that EGNOS signals allow approaches and landings that meet the safety standards that govern international air traffic. The advantage of EGNOS is that it would be available everywhere without the need for ground infrastructure. It also provides vertical guidance procedures for every runway.

For more information, click here.

At NASA, the Global Positioning System (GPS) is a vital resource for scientific research aimed at understanding and protecting Earth. NASA employs the band of GPS satellites for mapping Earth’s ionosphere and developing earthquake-prediction tools. But traditional GPS still can’t communicate beyond latitudes of 75 degrees, meaning that most of Greenland and Antarctica cannot receive GPS signals.

NASA partnered with NAVSYS Corp. of Colorado Springs, CO, to enhance the technology for better surveying of urban areas prone to signal blockages. The result of this collaboration led to a new aerial mapping and targeting system called GI-Eye, a software platform that integrates GPS with inertial and digital camera data to collect high-resolution imagery for precise visual navigation and geolocation of target coordinates.

The GI-Eye technology has been integrated into FLIR Systems’ Star SAFIRE III airborne electro-optic thermal imaging system. Currently, there are about 800 of these units on more than 35 types of aircraft. The long-distance, 360-degree, day or night scoping abilities of the System have made it popular for aerial surveillance associated with search and rescue, reconnaissance, law enforcement, border patrol, news gathering, land-use planning, and environmental monitoring.

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Georgia Tech researchers have developed a new protoype engine that uses up to 40% less fuel by running on solar power while in space and by fine-tuning exhaust velocity.

The key to the engine improvements is the ability to optimize the use of available power. A traditional chemical rocket engine (attached to a satellite ready for launch) runs at maximum exhaust velocity until it reaches orbit, i.e., first gear.

The new engine allows ground-control units to adjust the engine’s operating gear based on the immediate propulsive need of the satellite. The engine operates in first gear to maximize acceleration during orbit transfers and then shifts to fifth gear once in the desired orbit. This allows the engine to burn at full capacity only during key moments and conserve fuel.

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