Nasa Space news - Rosetta: To Chase a Comet

Comets are among the most beautiful and least understood nomads of the night sky. To date, half a dozen of these most heavenly of heavenly bodies have been visited by spacecraft in an attempt to unlock their secrets. All these missions have had one thing in common: the high-speed flyby. Like two ships passing in the night (or one ship and one icy dirtball), they screamed past each other at hyper velocity -- providing valuable insight, but fleeting glimpses, into the life of a comet. That is, until Rosetta.

NASA is participating in the European Space Agency's Rosetta mission, whose goal is to observe one such space-bound icy dirt ball from up close -- for months on end. The spacecraft, festooned with 25 instruments between its lander and orbiter (including three from NASA), is programmed to "wake up" from hibernation on Jan. 20. After a check-out period, it will monitor comet 67P/Churyumov-Gerasimenko as it makes its nosedive into, and then climb out of, the inner solar system. Over 16 months, during which old 67P is expected to transform from a small, frozen world into a roiling mass of ice and dust, complete with surface eruptions, mini-earthquakes, basketball-sized, fluffy ice particles and spewing jets of carbon dioxide and cyanide.

"We are going to be in the cometary catbird seat on this one," said Claudia Alexander, project scientist for U.S. Rosetta from NASA's Jet Propulsion Laboratory in Pasadena, Calif.  "To have an extended presence in the neighborhood of a comet as it goes through so many changes should change our perspective on what it is to be a comet."

Since work began on Rosetta back in 1993, scientists and engineers from all over Europe and the United States have been combining their talents to build an orbiter and a lander for this unique expedition.  NASA's contribution includes three of the orbiter's instruments (an ultraviolet spectrometer called Alice; the Microwave Instrument for Rosetta Orbiter; and the Ion and Electron Sensor. NASA is also providing part of the electronics package for an instrument called the Double Focusing Mass Spectrometer, which is part of the Swiss-built Rosetta Orbiter Spectrometer for Ion and Neutral Analysis instrument. NASA is also providing U.S. science investigators for selected non-U.S. instruments and is involved to a greater or lesser degree in seven of the mission's 25 instruments. NASA's Deep Space Network provides support for ESA's Ground Station Network for spacecraft tracking and navigation.

"All the instruments aboard Rosetta and the Philae lander are designed to work synergistically," said Sam Gulkis of JPL, the principal investigator for the Microwave Instrument for Rosetta Orbiter. "They will all work together to create the most complete picture of a comet to date, telling us how the comet works, what it is made of, and what it can tell us about the origins of the solar system."

The three NASA-supplied instruments are part of the orbiter's scientific payload. Rosetta's Microwave Instrument for Rosetta Orbiter specializes in the thermal properties. The instrument combines a spectrometer and radiometer, so it can sense temperature and identify chemicals located on or near the comet's surface, and even in the dust and ices jetting out from it. The instrument will also see the gaseous activity through the dusty cloud of material.  Rosetta scientists will use it to determine how different materials in the comet change from ice to gas, and to observe how much it changes in temperature as it approaches the sun.

Like the Microwave for Rosetta Orbiter, the Alice instrument contains a spectrometer. But Alice looks at the ultraviolet portion of the spectrum. Alice will analyze gases in the coma and tail and measure the comet’s production rates of water and carbon monoxide and dioxide. It will provide information on the surface composition of the nucleus, and make a potentially key measurement of argon, which will be a big clue about what the temperature was in the primordial solar system when the comet's nucleus originally formed (more than 4.6 billion years ago).

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NASA's DSN - 'Wireless Network' Turns 50

NASA's Deep Space Network, the world's largest and most powerful communications system for "talking to" spacecraft, will reach a milestone on Dec. 24: the 50th anniversary of its official creation.

Over the past 50 years, antennas of the Deep Space Network (DSN) have communicated with just about every mission that has gone to the moon or beyond. The historic communiqués include "That's one small step for man. One giant leap for mankind"; numerous encounters with the outer planets of our solar system; images taken by rovers exploring Mars; and the data confirming that NASA's Voyager spacecraft had finally entered interstellar space.

The Deep Space Network has been so critical to so many missions over the decades, the network's team members like to use the phrase "Don't leave Earth without us."

More information about the Deep Space Network is online at: http://www.jpl.nasa.gov/dsn50/

From the very beginning of NASA's space program, it was clear that a simple, direct way to communicate with missions in deep space would be needed. For example, what is the purpose of sending a spacecraft to Mars if we can't receive data, images and other vital information from that spacecraft?

What is now known as the Deep Space Network first existed as just a few small antennas called the Deep Space Instrumentation Facility. The facility was originally operated by the U.S. Army in the 1950s and then later moved over to the jurisdiction of the newly created National Aeronautics and Space Administration (NASA).

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http://www.nasa.gov/jpl/news/dsn20131218/

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DSN's Eight Facts - Nasa Space News

Get to know the Deep Space Network (DSN)NASA's worldwide radio telescope array that communicates with spacecraft throughout the solar method.

As the World Turns: The DSN is Earth's only global spacecraft communication network

The Deep Space Network has facilities - at Goldstone, Calif.; near Madrid, Spain; and Canberra, Australia, all with multiple parabolic dish antennas, including dish each that is 230 feet (70 meters) across. Located about 120 degrees apart around Earth, the position of the complexes provides round-the-clock coverage of the solar method. (A telescope needs a direct line of sight to "speak" with a spacecraft.)

 Little Step: The DSN showed us the first moonwalk

That's little step for man. giant leap for mankind. The DSN received and relayed to the world the first TV images of astronaut Neil Armstrong setting foot on the surface of the moon in 1969.

Solar Method Ambassador: DSN relays first close-up views of other planets

The historic network enabled the world to see the first-ever picture of Mars, obtained by NASA's Mariner four spacecraft in 1965. Mariner ten returned images of Mercury's surface in 1974. NASA's twin Voyager spacecraft were the first to fly by Jupiter, Saturn, Neptune and Uranus, capturing the first close-up images of these planets, and some of their rings and moons. The DSN also relayed Voyager 1's portrait of Earth from 6 billion miles away, the iconic picture Carl Sagan called "The Pale Blue Dot," as well as the spacecraft's entry in to interstellar space.

Now Listen to This: The DSN speaks with 33 spacecraft

In the work of 1963, the DSN's first year of operation, it communicated with spacecraft. In 2013, space is a much busier place. The DSN is currently communicating with 33 spacecraft across the solar method. The DSN sends commands to spacecraft and receives telemetry, engineering and scientific knowledge.

Not NASA: The DSN relays knowledge on behalf of international space agencies

While the DSN tracks, sends commands to and receives knowledge from all NASA spacecraft beyond the moon, the network also supports spacecraft from the European Space Agency, Japanese Space Agency and Indian Space Agency.

There is Always Room for Science: The DSN is used for scientific observation

In addition to its crucial role in two-way spacecraft communication, DSN dishes make direct science observations. There is radar science, in which waves are bounced off objects such as passing asteroids to generate radar images; radio science, where changes in the steady radio link between a spacecraft and the DSN reveal the internal structure of another world; radio astronomy, which looks at naturally occurring radio sources such as pulsars and quasars; and geodetic measurements, which reveal changes in the crust of Earth by tracking how long it takes a radio signal from a quasar or other astronomical source to reach different telescopes.

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