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domingo, 17 de abril de 2016

NASA : Mission Manager Update: Kepler Remains Stable as Health Check Continues .- Continúa Gestor de actualizaciones Misión: Kepler mantiene estable como chequeo

Hola amigos: A VUELO DE UN QUINDE EL BLOG., La nave espacial Kepler se mantiene estable ya que el proceso de devolverlo a la ciencia continúa. La causa de la anomalía, informó por primera vez el 8 de abril, sigue bajo investigación.
Desde el domingo por la mañana la nave espacial se ha mantenido de manera segura "aparcado" en una configuración en punta estable llamado Punto Resto Estado. En este estado, el consumo de combustible sigue siendo bajo y el enlace de comunicación con la Tierra es buena. A partir del martes, los ingenieros de operaciones de la misión habían enlace descendente todos los datos necesarios de Kepler de triaje la situación y planificar los pasos hacia la recuperación.
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Kepler detecting the brightening of a star

Mission Manager Update: Kepler Remains Stable as Health Check Continues

The Kepler spacecraft remains stable as the process of returning it to science continues. The cause of the anomaly, first reported on April 8, remains under investigation.

Since Sunday morning the spacecraft has remained safely "parked" in a stable pointed configuration called Point Rest State. In this state, fuel usage remains low and the communication link to Earth is good. As of Tuesday, mission operations engineers had downlinked all the necessary data from Kepler to triage the situation and plan the steps toward recovery.

The recovery to science began with a thorough assessment of the data, which took a couple days, after which the team had learned all they could about the state of the spacecraft from the data. It was then time to turn back on and test the components deemed low-risk to spacecraft health. Testing begins on the Kepler spacecraft simulator at the flight planning center at Ball Aerospace in Boulder, Colorado. With the ground-based simulation a success, we were ready to conduct the tests on Kepler, 75 million miles away. The engineers sent the instructions, along with commands for the spacecraft to protect itself and enter a safe operating mode if there was a problem, and waited for the spacecraft to report back.

The spacecraft returned a response that is the equivalent of 'so far, so good.' It did not experience any faults from switching on the components, and all the data suggest the components are working normally. The spacecraft is another step closer to returning to scientific observations for the K2 mission.

The photometer – Kepler’s camera – and the solid state recorder are powered on. The subsystem interface box, which is the interface between the spacecraft sensors and the main computer, was only briefly powered on for an initial assessment, but should be back online early next week. The team will continue recovering the components, as they are deemed safe and low-risk to the spacecraft.

Over the weekend, NASA's Deep Space Network (DSN) will remain in contact with the spacecraft while the team gets some much-needed rest. To watch the worldwide array of antennae communicate with the spacecraft, tune-in to DSN Now.

The recovery started slowly and carefully, as we initially merely tried to understand the situation and recover the systems least likely to have been the cause. Over the last day and a half, we’ve begun to turn the corner, by powering on more suspect components. With just one more to go, I expect that we will soon be on the home stretch and picking up speed towards returning to normal science operations.
Updates will be provided as information warrants.
Regards,

Charlie Sobeck​
Kepler and K2 mission manager
NASA's Ames Research Center






4/11, Update 1: Kepler Recovered from Emergency and Stable
Mission operations engineers have successfully recovered the Kepler spacecraft from Emergency Mode (EM). On Sunday morning, the spacecraft reached a stable state with the communication antenna pointed toward Earth, enabling telemetry and historical event data to be downloaded to the ground. The spacecraft is operating in its lowest fuel-burn mode.

The mission has cancelled the spacecraft emergency, returning the Deep Space Network ground communications to normal scheduling.

Once data is on the ground, the team will thoroughly assess all on board systems to ensure the spacecraft is healthy enough to return to science mode and begin the K2 mission's microlensing observing campaign, called Campaign 9. This checkout is anticipated to continue through the week.

Earth-based observatories participating in Campaign 9 will continue to make observations as Kepler's health check continues. The K2 observing opportunity for Campaign 9 will end on July 1, when the galactic center is no longer in view from the vantage point of the spacecraft.

K2's previous science campaign concluded on March 23. After data was downlinked to the ground, the spacecraft was placed in what is termed Point Rest State (PRS). While in PRS, the spacecraft antenna is pointed toward Earth and it operates in a fuel-efficient mode, with the reaction wheels at rest.

The Emergency Mode began approximately 14 hours before the planned maneuver to orient the spacecraft toward the center of the Milky Way for Campaign 9. The team has therefore ruled out the maneuver and the reaction wheels as possible causes of the EM event. An investigation into what caused the event will be pursued in parallel, with a priority on returning the spacecraft to science operations.

The anomalous EM event is the first that the Kepler spacecraft has encountered during its seven years in space. Mission operations at NASA's Ames Research Center in California's Silicon Valley, Ball Aerospace and the Laboratory for Atmospheric and Space Physics at the University of Colorado in Boulder remain vigilant.

It was the quick response and determination of the engineers throughout the weekend that led to the recovery. We are deeply appreciative of their efforts, and for the outpouring of support from the mission's fans and followers from around the world.  We also recognize the tremendous support from NASA’s Deep Space Network, managed by the Jet Propulsion Laboratory in Pasadena, California, and to NASA’s other missions that surrendered their scheduled telemetry links in order to provide us with the resources needed to protect the Kepler spacecraft.

Updates will be provided as information warrants.
Regards,

Charlie Sobeck​
Kepler and K2 mission manager
NASA's Ames Research Center






April 8, Original Report: Kepler in Emergency Mode
During a scheduled contact on Thursday, April 7, mission operations engineers discovered that the Kepler spacecraft was in Emergency Mode (EM). EM is the lowest operational mode and is fuel intensive. Recovering from EM is the team's priority at this time.

The mission has declared a spacecraft emergency, which provides priority access to ground-based communications at the agency's Deep Space Network.

Initial indications are that Kepler entered EM approximately 36 hours ago, before mission operations began the maneuver to orient the spacecraft to point toward the center of the Milky Way for the K2 mission's microlensing observing campaign.

The spacecraft is nearly 75 million miles from Earth, making the communication slow. Even at the speed of light, it takes 13 minutes for a signal to travel to the spacecraft and back.

The last regular contact with the spacecraft was on April. 4.  The spacecraft was in good health and operating as expected.

Kepler completed its prime mission in 2012, detecting nearly 5,000 exoplanets, of which, more than 1,000 have been confirmed. In 2014 the Kepler spacecraft began a new mission called K2. In this extended mission, K2 continues the search for exoplanets while introducing new research opportunities to study young stars, supernovae, and many other astronomical objects.

Updates will be provided as additional information is available.
Regards,

Charlie Sobeck​
Kepler and K2 mission manager
NASA's Ames Research Center

 

Media contact:

Michele Johnson
Ames Research Center, Moffett Field, Calif.
650-604-6982
michele.johnson@nasa.gov
Last Updated: April 15, 2016
Editor: Michele Johnson
 
Free-floating exoplanet

Searching for Far Out and Wandering Worlds


Astronomers have made great strides in discovering planets outside of our solar system, termed “exoplanets.” In fact, over the past 20 years more than 5,000 exoplanets have been detected beyond the eight planets that call our solar system home.
 
K2 and gravitational microlensing
As an exoplanet passes in front of a more distant star, its gravity causes the trajectory of the starlight to bend, and in some cases results in a brief brightening of the background star as seen by a telescope. The artistic concept illustrates this effect. This phenomenon of gravitational microlensing enables scientists to search for exoplanets that are too distant and dark to detect any other way.
Credits: NASA Ames/JPL-Caltech/T. Pyle
The majority of these exoplanets have been found snuggled up to their host star completing an orbit (or year) in hours, days or weeks, while some have been found orbiting as far as Earth is to the sun, taking one-Earth-year to circle. But, what about those worlds that orbit much farther out, such as Jupiter and Saturn, or, in some cases, free-floating exoplanets that are on their own and have no star to call home? In fact, some studies suggest that there may be more free-floating exoplanets than stars in our galaxy.

This week, NASA's K2 mission, the repurposed mission of the Kepler space telescope, and other ground-based observatories have teamed up to kick-off a global experiment in exoplanet observation. Their mission: survey millions of stars toward the center of our Milky Way galaxy in search of distant stars' planetary outposts and exoplanets wandering between the stars.

While today's planet-hunting techniques have favored finding exoplanets near their sun, the outer regions of a planetary system have gone largely unexplored. In the exoplanet detection toolkit, scientists have a technique well suited to search these farthest outreaches and the space in between the stars. This technique is called gravitational microlensing.


Gravitational Microlensing

For this experiment, astronomers rely on the effect of a familiar fundamental force of nature to help detect the presence of these far out worlds— gravity. The gravity of massive objects such as stars and planets produces a noticeable effect on other nearby objects.

But gravity also influences light, deflecting or warping, the direction of light that passes close to massive objects. This bending effect can make gravity act as a lens, concentrating light from a distant object, just as a magnifying glass can focus the light from the sun. Scientists can take advantage of the warping effect by measuring the light of distant stars, looking for a brightening that might be caused by a massive object, such as a planet, that passes between a telescope and a distant background star. Such a detection could reveal an otherwise hidden exoplanet.
"The chance for the K2 mission to use gravity to help us explore exoplanets is one of the most fantastic astronomical experiments of the decade," said Steve Howell, project scientist for NASA's Kepler and K2 missions at NASA’s Ames Research Center in California's Silicon Valley. "I am happy to be a part of this K2 campaign and look forward to the many discoveries that will be made."
 
K2's Microlensing Search Area - zoom
In a global experiment in exoplanet observation, the K2 mission and Earth-based observatories on six continents will survey millions of stars toward the center of our Milky Way galaxy. Using a technique called gravitational microlensing, scientists will hunt for exoplanets that orbit far from their host star, such as Jupiter is to our sun, and for free-floating exoplanets that wander between the stars. The method allow exoplanets to be found that are up to 10 times more distant than those found by the original Kepler mission, which used the transit technique. The artistic concept illustrates the relative locations of the search areas for NASA's K2 and Kepler missions.
Credits: NASA Ames/W. Stenzel and JPL-Caltech/R. Hurt
 
This phenomenon of gravitational microlensing – “micro” because the angle by which the light is deflected is small – is the effect for which scientists will be looking during the next three months. As an exoplanet passes in front of a more distant star, its gravity causes the trajectory of the starlight to bend, and in some cases results in a brief brightening of the background star as seen by the observatory.
The lensing events caused by a free-floating exoplanet last on the order of a day or two, making the continuous gaze of the Kepler spacecraft an invaluable asset for this technique.
"We are seizing the opportunity to use Kepler's uniquely sensitive camera to sniff for planets in a different way," said Geert Barentsen, research scientist at Ames.

The ground-based observatories will record simultaneous measurements of these brief events. From their different vantage points, space and Earth, the measurements can determine the location of the lensing foreground object through a technique called parallax.
“This is a unique opportunity for the K2 mission and ground-based observatories to conduct a dedicated wide-field microlensing survey near the center of our galaxy," said Paul Hertz, director of the astrophysics division in NASA’s Science Mission Directorate at the agency’s headquarters in Washington. "This first-of-its-kind survey serves as a proof of concept for NASA’s Wide-Field Infrared Survey Telescope (WFIRST), which will launch in the 2020s to conduct a larger and deeper microlensing survey. In addition, because the Kepler spacecraft is about 100 million miles from Earth, simultaneous space- and ground-based measurements will use the parallax technique to better characterize the systems producing these light amplifications."
To understand parallax, extend your arm and hold up your thumb. Close one eye and focus on your thumb and then do the same with the other eye. Your thumb appears to move depending on the vantage point. For humans to determine distance and gain depth perception, the vantage points, our eyes, use parallax.

Flipping the Spacecraft

The Kepler spacecraft trails Earth as it orbits the sun and is normally pointed away from Earth during the K2 mission. But this orientation means that the part of the sky being observed by the spacecraft cannot generally be observed from Earth at the same time, since it is mostly in the daytime sky.

To allow simultaneous ground-based observations, flight operations engineers at Ball Aerospace and the Laboratory for Atmospheric and Space Physics at the University of Colorado in Boulder will perform a maneuver turning the spacecraft around to point the telescope in the forward velocity vector. So, instead of looking towards where it’s been, the spacecraft will look in the direction of where it’s going.

This alignment will yield a viewing opportunity of Earth and the moon as they cross the spacecraft's field of view. On April 14 at 11:50 a.m. PDT (18:50 UT), Kepler will record a full frame image. The result of that image will be released to the public archive in June once the data has been downloaded and processed. Kepler measures the change in brightness of objects and does not resolve color or physical characteristics of an observed object.

Observing from Earth

To achieve the objectives of this important path-finding research and community exercise in anticipation of WFIRST, approximately two-dozen ground-based observatories on six continents will observe in concert with K2. Each will contribute to various aspects of the experiment and will help explore the distribution of exoplanets across a range of stellar systems and distances.

These results will aid in our understanding of both planetary system architectures as well as the frequency of exoplanets throughout our galaxy.

For a complete list of participating observatories, reference the paper that defines the experiment: Campaign 9 of the K2 mission.

During the roughly 80-day observing period or campaign, astronomers hope to discover over 100 lensing events, ten or more of which may have signatures of exoplanets occupying relatively unexplored regimes of parameter space.

Ames manages the Kepler and K2 missions for NASA’s Science Mission Directorate. NASA's Jet Propulsion Laboratory in Pasadena, California, managed Kepler mission development. Ball Aerospace & Technologies Corporation operates the flight system with support from the Laboratory for Atmospheric and Space Physics at the University of Colorado in Boulder.

 
For more information about the Kepler and K2 missions, visit:

The animation depicts the phenomenon of gravitational microlensing. As an exoplanet passes in front of a more distant star, its gravity causes the trajectory of the starlight to bend, and in some cases results in a brief brightening of the background star as seen by a telescope. Teaming up on a global experiment in exoplanet observation, NASA's K2 mission and Earth-based observatories on six continents will use gravitational microlensing to search for exoplanets that are too distant and dark to detect any other way.
Credits: NASA Ames/JPL-Caltech/T. Pyle



Media contact:

Michele Johnson
Ames Research Center, Moffett Field, Calif.
650-604-6982
michele.johnson@nasa.gov
Last Updated: April 8, 2016
Editor: Michele Johnson
NASA
Guillermo Gonzalo Sánchez Achutegui
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