Category: Satellites

[/caption]
Space and the Olympics might not be synonymous in most people’s minds — although this image of the Opening Ceremony fireworks makes it look like Olympic Stadium is going supernova — but there are a few connections between the two for this year’s Summer Olympics in Beijing, China. Google Earth recently updated the satellite imagery it uses for the Beijing area to provide users with better maps. They also used satellite imagery to create a 3-D tour of all the facilities for the 2008 Olympics (see video below). Other space connections include several space explorers who carried the Olympic torch on its running tour around the world, and NASA space spinoff technology used in some of the clothing and equipment for Olympic use.

The first woman in space, Russian cosmonaut Valentina Tereshkova, one of 80 Russian runners, carried the Olympic torch during its tour of that country in early April. Sheikh Muszaphar Shukor, the first Malaysian in space, ran with the torch along the top of Kuala Lumpur Tower on April 21, just six months after his visit as a “spaceflight participant” to in International Space Station. Fittingly, several Chinese taikonauts carried the torch: Fei Junlong and Nie Haisheng, the two-man crew from China’s second spaceflight, Shenzou 6 ran with the torch when it arrived in China in May. China’s first space explorer, Yang Liwei who flew solo on Shenzou 5 in 2003, carried the torch when it first arrived in Beijing on August 6.

While no US astronauts carried the torch, NASA astronaut Scott Parazynski was at Base Camp when Chinese climbers carried the torch to the summit of Mt. Everest on May 8.

NASA developed “riblet” technology to aid in the aerodynamic properties of airplanes. Riblets are V-shaped grooves with angles that point in the direction of the air flow. They are no bigger than a scratch, and they look like very tiny ribs. Riblets help reduce “skin-friction” drag. But it also helps reduce friction from water, and riblets have been used in rowing shells in the four-oar-with-coxswain category. Swimsuits with riblets have also been used in competition at the Pan American games.

And of course, everyone is probably familiar with the lore that today’s athletic shoes use the same cushioning technology that was developed for the moon boots used in the Apollo missions to the moon.

News Sources: Collect Space, Kodak Olympic Picture of the Day, NASA Goes to the Olympics

Space junk in Earth orbit is becoming a big problem (here’s an previous UT article that illustrates the problem.) If the International Space Station or an operating communications or science satellite were struck by debris such as an old satellite, launch vehicle parts, or even something as small as a paint chip, it could mean disaster. Space debris also threatens the lives of astronauts and the launch of new satellites today, says Dr. Noam Eliaz, Head of the Biomaterials and Corrosion Laboratory at the School of Mechanical Engineering at Tel Aviv University. An expert in materials science and engineering, Dr. Eliaz is working to create and test new nano-materials and polymers to protect satellites and astronauts alike.

Eliaz is developing nano-based materials with special mechanical properties, such as high strength and wear resistance, and controllable electrical and thermal properties. “This could lead to a superior material for the external blankets of spacecraft,” says Eliaz. Some of the materials Eliaz has researched are being used by biomedical device companies and by aircraft industries worldwide.

One candidate Eliaz and his colleagues have investigated is a hybrid nano-material which incorporates small silicon-containing cages that can open and react with atomic oxygen to prevent further polymer degradation. Basically, a silicon skin would form to “patch” a puncture caused by a debris hit.

The team has also conducted space durability studies on polymers developed by the U.S. Air Force and Hybrid Plastics Inc, and the results are being reviewed by NASA and the European Space Agency (ESA). “Our simulation studies were done on Earth to determine how space debris will impact new polymers developed to protect space vehicles,” says Dr. Eliaz.

Original News Source: American Friends of Tel Aviv University

Hard and soft. Dark and bright. High and low. Wide and thin. JAXA and NASA. And that’s just one spacecraft. Japan’s space agency, JAXA and NASA are teaming up to create a new spacecraft to study the extreme environments of the universe. NeXT, which stands for New exploration X-Ray Telescope is a next generation x-ray astronomy satellite currently under development, with launch scheduled in 2013. While Japan will provide the main spacecraft and several instruments, NASA, and in particular the Goddard Space Flight Center just announced they will be adding a new instrument to the spacecraft, the High-Resolution Soft X-Ray Spectrometer (SXS). While the spacecraft’s main instrument will be its Hard X-ray Telescope (HXTs) the addition of SXS is just one of several complementary instruments that provide a “yin and yang” aspect to NeXT’s explorations, which hope to reveal new facets of the universe.

The concept of yin and yang involves two opposing, but at the same time, complementary aspects of any one phenomenon, or comparison of any two phenomena. NeXT will employ both those aspects. With the addition of NASA’s SXS, NeXT will be observing both so-called “hard” and “soft” x-rays. Hard x-rays are the highest energy x-rays, typically having energies greater than 10,000 electron volts (or 10 keV) while the lower energy x-rays are referred to as soft x-rays, which have less energy and longer wavelengths. Different types of instruments are needed to detect each kind.

Conventional X-ray mirrors usually can just concentrate on only soft X-rays up to 10 keV. NeXT’s HXTs will use a “super mirror” which has a multi-layer coating on the reflecting surface in order to observe hard X-rays. The mission designers plan to utilize this technique to extend the energy band of the X-ray mirrors by nearly an order of magnitude. Observation of hard X-rays will enable the study of the various acceleration phenomena in the universe, such as dark energy, cosmic rays and supernova remnants, which astronomers say can never be completely understood through the observations of the thermal phenomena below 10 keV.

We have known for some time that cosmic X-rays are accelerated by supernova remnants. But some cosmic X-rays have energy levels so high that they cannot possibly come from a supernova remnant. These high-energy or hard cosmic X-rays may have been created when galaxy clusters evolved. According to this theory, when the galaxy clusters, which were small at first, were colliding and merging into large ones, shock waves were created, which greatly accelerated the particles. NeXT, may confirm or refute this theory.

NeXT will have both a soft x-ray telescope and soft x-ray spectrometer. With these instruments, the spacecraft can investigate the nature of dark matter on large scales in the universe, and can also explore how bright galaxies and clusters of galaxies form and evolve.

“We are thrilled to have the opportunity to create a powerful new x-ray spectrometer that will open up a whole new realm in high energy astrophysics in collaboration with our partners in Japan,” said Richard L. Kelley, the Principal Investigator for the SXS mission at Goddard. We have a great team in place that is anxiously waiting to start work.”

To compliment the x-ray telescopes there will also be Wide-band X-ray Imagers (WXI) to cover a wide energy range. Because it is difficult to cover such a wide energy range with a single detector, NeXT will use a hybrid detector, which consists of an upper-stage, soft X-ray detector and a lower-stage, hard X-ray detector. It will use thinned X-ray CCDs (charged coupled devices) for the upper stage, which stop only the soft X-rays and and a CdTe (cadmium telluride) pixel detector for the lower stage.

Also in the suite of instruments is a Soft Gamma-ray detector (SGD), which is still under development. It will include an ultra-low background, high-sensitivity detector in soft gamma-ray band by combining an active shield and an pixel detector.

Charles Gay, deputy associate administrator for NASA’s Science Mission Directorate in Washington said missions like SXS and NeXT “expand NASA’s science through partnerships with international and commercial organizations,” – just another complimentary aspect of a mission full of yin and yang.

Original News Source: NASA,

A Delta 2 rocket blasted off early this morning at 3:46 a.m. EDT bringing the Ocean Surface Topography Mission-Jason 2 into Earth orbit. The satellite will use a radar altimeter to precisely measure the height of ocean surfaces, which have been rising in recent years because of increasing temperatures. The data will be used to monitor effects of climate change on sea level and to improve global weather, climate and ocean forecasts. NASA said the new satellite, which is a cooperative effort between the US and France, will also improve hurricane forecasting.

“Global warming is causing the oceans to rise at a rate of about 3 millimeters per year, and this is a direct result of increasing the temperature of the atmosphere,” said Josh Willis an oceanographer from JPL. “That causes glaciers and ice sheets to melt, raising the levels of the ocean. But also, the ocean itself absorbs heat. And when that happens, again the water expands, stands a little taller, and this causes sea level rise as well, so the altimeter on OSTM, or Jason 2, will see both of these effects at it circles the Earth.”

Similar observations began in 1992 with a spacecraft dubbed TOPEX/Poseidon and have continued with the current Jason 1 satellite. The two Jasons will fly in tandem.

Together with Jason 1, the two spacecraft will double global data coverage. This tandem mission will improve our knowledge of tides in coastal and shallow seas and internal tides in the open ocean, while improving our understanding of ocean currents and eddies.

Jason 2 will map the sea surface highs and lows every 10 days, tracking changes and helping scientists keep tabs on climate, and even weather.

Measurements of sea-surface height, or ocean surface topography, reveal the speed and direction of ocean currents and tell scientists how much of the sun’s energy is stored by the ocean. Combining ocean current and heat storage data is key to understanding global climate variations.

OSTM/Jason 2’s five primary instruments are improved versions of those flying on Jason 1. These technological advances will allow scientists to monitor conditions in ocean coastal regions — home to about half of Earth’s population. Compared with Jason 1 measurements, OSTM/Jason 2 will have substantially increased accuracy and provide data to within 25 kilometers (15 miles) of coastlines, nearly 50 percent closer to shore than in the past. Such improvements will be welcome news for all those making their living on the sea, from sailors and fishermen to workers in offshore industries. NOAA will use the improved data to better predict hurricane intensity, which is directly affected by the amount of heat stored in the upper ocean.

Sources: NASA, JPL

When a solar flare blasts energetic particles and magnetic flux at Earth, our satellites are on the front line. As coronal mass ejections (CMEs) interact with the Earth’s magnetosphere, there is a huge injection of energetic electrons into the Earth’s radiation belts. This can have dire consequences for the satellites that we depend on for communications around the globe. All is not lost however. An international team of scientists have stumbled upon a possible, innovative solution to discharge these troublesome electrons into the atmosphere: bathe the skies in radio waves.

The magnetosphere (protective layers of geomagnetic field lines) traps energetic particles in a volume of space known as the Van Allen belt. Our satellites are constantly travelling through this high radiation environment. Most satellites are shielded from all but the worst the Van Allen belt can throw at them, but should the Sun send a high concentration of energetic particles at the Earth after a solar flare, the environment in the magnetosphere becomes a very dangerous place. Should the delicate circuitry on board the spacecraft be hit by energetic particles (a situation that possibly caused Mars Odyssey to be switched to “safe-mode”), the satellite could be irreversibly damaged.

Now, a chance discovery by French and New Zealand scientists indicate that magnetospheric electrons can be discharged into the atmosphere by using ground-based radio transmitters. This finding comes from a new paper to be published in the journal Geophysical Research Letters. Rory Gamble, a PhD student of the University of Otago in Dunedin, New Zealand, and his colleagues were analysing the data from DEMETER (Detection of Electro-Magnetic Emissions Transmitted from Earthquake Regions), a satellite sensitive to radiation changes in the magnetosphere. As the satellite passed over a military transmitter in Western Australia, they noticed that magnetospheric electrons were discharged into the atmosphere, thereby removing them from the magnetosphere.

“We were able to determine that this transmitter has a direct effect on the electrons in the radiation belts [in the magnetosphere], it caused those electrons to crash into the top of the atmosphere and be removed from the radiation belts.” – Rory Gamble

This finding is a very exciting development for the human-influenced manipulation of the levels of radiation in the magnetosphere. During periods of high solar activity, when energetic electrons are expected to populate the radiation belts in higher densities, there could be a system in place to bathe the sky in radio waves, allowing safer passage for satellites. This phenomenon has been known to exist when transmitting radio waves in space, but this is the first example of electron discharge from a ground-based transmitter.

Source: ABC