Tag Archives: Satellite

Electrical power systems for space missions require careful consideration

Requires the optimal combination of primary and secondary sources
By Maurizio Di Paolo Emilio – A satellite needs an energy source to provide perfect performance, with the battery inside it working continuously for many years. The electrical power system is, perhaps, the most fundamental requirement for the satellite payload, as power system failure results in the loss of the space mission. It’s interesting to note that many of the early satellite systems failed due to these power system failures.

Power systems cover all aspects of energy production, storage, conditioning, distribution, and conversion for all types of space applications. Missions can last from a few minutes (launchers) to decades, such as interplanetary probes or the International Space Station (ISS), and can require from a minimum of a few watts (cubes) to tens of kilowatts (large space vehicles for telecommunications such as for the ISS). The electrical loads of a satellite often vary depending on which instruments or subsystems are running at a given time.

Therefore, power systems engineering (also called the electrical power system, or EPS) for satellites requires the selection of the optimal combination of primary and secondary sources for the architecture. more>

Updates from ITU

Earth observation for weather prediction – solving the interference problem
By ITU News – “Today, several dozen satellites contribute to the accumulation of critical knowledge about the Earth’s system, enabling scientists to describe specific links between a major natural disturbance in the upper atmosphere, and changes in the weather thousands of miles away,” says Mario Maniewicz, Director of the ITU Radiocommunication Bureau.

“As accurate weather predictions need to start from the best possible estimate of the current state of the atmosphere, it is crucial that meteorologists have real-time, accurate global observations about what is happening in the Earth’s atmosphere over land and oceans. And for this, they rely on space sensing.”

Space sensing relies on the deployment of sensors to obtain data critical for Earth observation from space. Active sensors are radar systems on spaceborne platforms. They obtain data through the transmission and reception of radiowaves. Passive sensors, meanwhile, are very sensitive receivers that measure the electromagnetic energy emitted and scattered by the Earth, and the chemical constituents in the Earth’s atmosphere. They require protection from radio-frequency interference.

Spaceborne sensors measure the background natural radiative emission floor, therefore any man-made signal (e.g. communications, radars) that rises above this natural emission floor will likely interfere with the measurements. This interference can be tolerated only if its energy is well below the sensor sensitivity. more>

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NASA Memory Lane (46)

March 17, 1958.

Vanguard Satellite, 1958

NASA – One of the Vanguard satellites is checked out at Cape Canaveral, Florida in 1958. Vanguard 1, the world’s first solar-powered satellite, launched on St. Patrick’s Day (March 17) 1958.

It was designed to test the launch capabilities of a three-stage launch vehicle and the effects of the environment on a satellite and its systems in Earth orbit. Vanguard 1 was the second U.S. satellite in orbit, following Explorer 1, and remains the oldest artificial object orbiting Earth to this day. Vanguard began as a program at the Naval Research Laboratory in Washington and transferred over to NASA (along with many of its personnel) after the agency was founded by the National Aeronautics and Space Act of 1958.

NASA technology (42)

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Preparing Solar Satellite for Launchpar
Preparing Solar Satellite for LaunchNASA – VANDENBERG AFB, Calif. ‘e2’80ldblquote Technicians work on the payload fairing that will protect NASA’s Interface Region Imaging Spectrograph (IRIS) spacecraft during launch aboard an Orbital Sciences Pegasus XL rocket. Launch is currently scheduled no earlier than May 28, 2013.par
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The IRIS satellite will improve our understanding of how heat and energy move through the deepest levels of the sun’s atmosphere, thereby increasing our ability to forecast space weather. On launch day, deployment of the Pegasus from Orbital’e2’80’99s L-1011 carrier aircraft will occur at a location over the Pacific Ocean about 100 miles northwest of Vandenberg off the central coast of California south of Big Sur.par
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‘e2’80’ba About IRISpar
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Image Credit: VAFB/Randy Beaudoin

Pentagon Researches New Life For Dead Satellites

English: DARPA headquarters at 3701 N. Fairfax...

English: DARPA headquarters at 3701 N. Fairfax Drive in Arlington. (Photo credit: Wikipedia)

By Alicia Chang – It’s the latest pet project from the Pentagon‘s research wing known for its quirky and sometimes out-there ideas. The Defense Advanced Research Projects Agency is spending $180 million to test technologies that could make this possible.

DARPA thinks it can save money by repurposing in orbit.

“We’re attempting to essentially increase the return on investment … and try to find a way to really change the economics so that we can lower the cost” of military space missions, said DARPA program manager David Barnhart. more> http://tinyurl.com/atdb3tc

How I solved my broadband misery

Shropshire Star – Struggling with your broadband? Charles Denscombe reckons he has the perfect solution – bypass the providers, and plonk a giant satellite dish in the back garden.

Through his satellite internet technology which is available but not widely known about, Charles gets reliable download speeds of at least 6.5Mb per second, and up to 20Mb per second. And it is all his. The bandwidth is not shared or “contested” bandwidth, and therefore not compromised. more> http://tinyurl.com/d9m5wdg

Swiss to craft janitor satellites to grab space junk

By John Heilprin – The 10-million-franc ($11-million) satellite called CleanSpace One—the prototype for a family of such satellites—is being built by the Swiss Space Center at the Swiss Federal Institute for Technology in Lausanne, or EPFL.

The U.S. space agency NASA says over 500,000 pieces of spent rocket stages, broken satellites and other debris are being tracked as they orbit Earth.

Swiss Space Center’s director, Volker Gass, said it hopes to someday “offer and sell a whole family of ready-made systems, designed as sustainably as possible, that are able to de-orbit several different kinds of satellites.” more> http://is.gd/ld1rLf

Views from the Solar System (22)

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SPACE WATCH

Blue Marble
NASA – A ‘Blue Marble’ image of the Earth taken from the VIIRS instrument aboard NASA’s most recently launched Earth-observing satellite – Suomi NPP. This composite image uses a number of swaths of the Earth’s surface taken on January 4, 2012. The NPP satellite was renamed ‘Suomi NPP’ on January 24, 2012 to honor the late Verner E. Suomi of the University of Wisconsin.

Suomi NPP is NASA’s next Earth-observing research satellite. It is the first of a new generation of satellites that will observe many facets of our changing Earth.

Suomi NPP is carrying five instruments on board. The biggest and most important instrument is The Visible/Infrared Imager Radiometer Suite or VIIRS. Image Credit: NASA/NOAA/GSFC/Suomi NPP/VIIRS/Norman Kuring