Voyager Instrument Cooling Rapidly: Heater Turned off

To decisively reduce power consumption, mission managers have turned off a heater on part of NASA's Voyager 1 spacecraft, dropping the temperature of its ultraviolet spectrometer instrument more than 23 degrees Celsius (41 degrees Fahrenheit).

It is now operating at a temperature below minus 79 degrees Celsius (minus 110 degrees Fahrenheit), the coldest temperature that the instrument has ever endured.

This heater shut-off is a step in the careful management of the diminishing electrical power so that the Voyager spacecraft can continue to collect and transmit data through 2025.

At the moment, the spectrometer continues to collect and return data.

It was originally designed to operate at temperatures as low as minus 35 degrees Celsius (minus 31 degrees Fahrenheit), but it has continued to operate in ever chillier temperatures as heaters around it have been turned off over the last 17 years.

It was not known if the spectrometer would continue working, but since 2005, it has been operating at minus 56 degrees Celsius (69 degrees Fahrenheit.) So engineers are encouraged that the instrument has continued to operate, even after the nearby heater was turned off in December.

(The spectrometer is likely operating at a temperature somewhat lower than minus 79 degrees Celsius, or minus 110 degrees Fahrenheit, but the temperature detector does not go any lower.)

Scientists and mission managers will continue to monitor the spectrometer's performance.

It was very active during Voyager 1's encounters with Jupiter and Saturn, and since then an international team led by scientists in France has been analyzing the spectrometer's data.

This latest heater shut-off was actually part of the nearby infrared spectrometer, which itself has not been operational on Voyager 1 since 1998.

ESA BepiColumbo Mercury Mission: Surviving a Heat Sandwich - Video

Set to launch in 2014, Europe's BepiColumbo satellite pair will deliver unique imagery of Mercury during extra-close orbital passes.

The pair will contend with extreme temperatures from the nearby Sun and bright reflections from Mercury's surface.
Credit: ESA

NASA Leads Study of Unprecedented Arctic Ozone Loss

Left: Ozone in Earth's stratosphere at an altitude of approximately 12 miles (20 kilometers) in mid-March 2011, near the peak of the 2011 Arctic ozone loss. 

Right: chlorine monoxide – the primary agent of chemical ozone destruction in the cold polar lower stratosphere – for the same day and altitude.

Image credit: NASA/JPL-Caltech

A NASA-led study has documented an unprecedented depletion of Earth's protective ozone layer above the Arctic last winter and spring caused by an unusually prolonged period of extremely low temperatures in the stratosphere.

The study, published online Sunday, Oct. 2, in the journal Nature, finds the amount of ozone destroyed in the Arctic in 2011 was comparable to that seen in some years in the Antarctic, where an ozone "hole" has formed each spring since the mid-1980s.

The stratospheric ozone layer, extending from about 10 to 20 miles (15 to 35 kilometers) above the surface, protects life on Earth from the sun's harmful ultraviolet rays.

The Antarctic ozone hole forms when extremely cold conditions, common in the winter Antarctic stratosphere, trigger reactions that convert atmospheric chlorine from human-produced chemicals into forms that destroy ozone.

The same ozone-loss processes occur each winter in the Arctic. However, the generally warmer stratospheric conditions there limit the area affected and the time frame during which the chemical reactions occur, resulting in far less ozone loss in most years in the Arctic than in the Antarctic.



To investigate the 2011 Arctic ozone loss, scientists from 19 institutions in nine countries (United States, Germany, The Netherlands, Canada, Russia, Finland, Denmark, Japan and Spain) analyzed a comprehensive set of measurements.

These included daily global observations of trace gases and clouds from NASA's Aura and CALIPSO spacecraft; ozone measured by instrumented balloons; meteorological data and atmospheric models.

The scientists found that at some altitudes, the cold period in the Arctic lasted more than 30 days longer in 2011 than in any previously studied Arctic winter, leading to the unprecedented ozone loss. Further studies are needed to determine what factors caused the cold period to last so long.

"Day-to-day temperatures in the 2010-11 Arctic winter did not reach lower values than in previous cold Arctic winters," said lead author Gloria Manney of NASA's Jet Propulsion Laboratory in Pasadena, Calif., and the New Mexico Institute of Mining and Technology in Socorro.

"The difference from previous winters is that temperatures were low enough to produce ozone-destroying forms of chlorine for a much longer time. This implies that if winter Arctic stratospheric temperatures drop just slightly in the future, for example as a result of climate change, then severe Arctic ozone loss may occur more frequently."

NASA Earth Observatory: Atlantic Heat Source for Hurricane Irene

As Hurricane Irene rumbles through the Atlantic Ocean, it needs fuel to sustain itself.

Warm water is the main fuel, and there is plenty of it right now, as there usually is this time of year.

The map above shows sea surface temperatures (SST) in the Atlantic Ocean, Gulf of Mexico, and the Caribbean Sea on August 23, 2011.

The measurements come from the Advanced Microwave Scanning Radiometer (AMSR-E) on NASA’s Aqua satellite and the Moderate Resolution Imaging Spectroradiometer (MODIS) instruments on both the Terra and Aqua satellites.

The satellites measure the temperature of the top millimeter of the ocean.

Waters typically need to be above 27.8 degrees Celsius (82 Fahrenheit) to properly fuel tropical storms with warm, moist air. Red, orange, and yellow colors depict waters above the 27.8 degree mark.

The warmer the water, the more intense the storm can grow, if upper level wind patterns cooperate. In the map above, such waters dominate the Gulf of Mexico and tropical Atlantic in late August 2011.

They also run up the southeastern coast of the United States, following the Gulf Stream to Cape Hatteras before giving way to slightly cooler waters (shades of blue) in the Middle and North Atlantic.

As of 5 p.m. Eastern Daylight Time on August 24, 2011, the NOAA National Hurricane Center reported Irene had maximum sustained winds of 195 kilometers (120 miles) per hour and was located at 23.1 degrees North and 74.7 degrees West, about 45 kilometers (30 miles) east-southeast of Long Island in the Bahamas.

The forecasted path had the hurricane sweeping over nearly all Bahaman islands, then turning toward the North Carolina coast and eventually New England. Forecasts are updated roughly every six hours.

Irene is the first hurricane of the Atlantic season, and potentially the first to make landfall in the United States in several years.


Further Reading

1. National Hurricane Center. (2011, August 24). Hurricane Irene. National Weather Service. Accessed August 24, 2011.
2. NASA Earth Observatory. (n.d.). Global Maps: Sea Surface Temperature. Accessed August 24, 2011.

Solar Kitchen Restaurant in Helsinki

Chef Antto Melasniemi is seen at the Lapin Kulta Solar Kitchen Restaurant in Helsinki, where cooking is done using purely solar energy.

Headed by Chef Antto Melasniemi, the unusual restaurant will be following the sun through Europe this summer.

To produce its food the kitchen relies on concentrated solar discs.

Apparently, unlike traditional ways of cooking solar heat affects the taste and texture of the dish.

This is partly due to the fact the sun heats all of the food simultaneously instead of just directing heat to the top or bottom of a pot or pan.

When the sun is at its peak dishes can be cooked in a matter of minutes, but less sunshine equals slower cooking times.

Picture: Lehtikuva OY / Rex Features

Heat Shield of Multi Purpose Crew Vehicle (MPCV)

Work on the heat shield and thermal protection backshell of the Multi Purpose Crew Vehicle ground test article, or GTA, was completed in preparation for environmental testing.

This image is of the crew vehicle at the Lockheed Martin Vertical Test Facility in Colorado. The crew vehicle will undergo rigorous testing to confirm its ability to safely fly astronauts through all the harsh environments of deep space exploration missions.

Image Credit: Lockheed Martin

NASA: Thermal control and Electronic Cooling pump

The more advanced the electronics, the more power they use. The more power they use, the hotter they get.

The hotter they get, the more likely they’ll overheat. It doesn’t take a rocket scientist to understand what typically happens next: The electronics fry.

In the world of electronics, thermal control is always one of the limiting factors -- particularly in space where there is no air to help cool down electronic components.

However, Jeffrey Didion, a thermal engineer at the NASA Goddard Space Flight Center in Greenbelt, Md., and Dr. Jamal Seyed-Yagoobi, a professor at the Illinois Institute of Technology in Chicago, Ill., have collaborated to develop a technology that may overcome current limitations. They have formed technical partnerships with the U.S. Air Force and National Renewable Energy Laboratory to address the thermal-control concerns.

Called electrohydrodynamic (EHD)-based thermal control, the technology promises to make it easier and more efficient to remove heat from small spaces -- a particular challenge for engineers building advanced space instruments and microprocessors that could fail if the heat they generate is not removed.

"Today, higher-power computer chips are available, but they generate too much heat," said Didion, who is leading the technology-development effort also involving Matthew Showalter, associate branch chief of Goddard’s Advanced Manufacturing Branch, and Mario Martins of Edge Space Systems, an engineering company specializing in thermal systems in Glenelg, Md. "If I can carry away more heat, engineers will be able to use higher-power components. In other words, they will be able to do more things."

The project, a joint activity between NASA Goddard and its partners, received support from the Goddard Internal Research and Development (IRAD) program, which funds the development of promising new technologies that could advance NASA’s scientific and exploration goals. It is being demonstrated in June on a Terrier-Improved Orion sounding rocket mission, which also is flying the Small Rocket/Spacecraft Technology (SMART) platform, a microsatellite also developed at Goddard. This new microsatellite measures about 16 inches in diameter and was specifically designed to give scientific users less expensive access to space. (Read the related press release.)

Enceladus Heat radiation: Warm fissure of Saturn's icy moon

The right-hand image shows a dramatically improved view of heat radiation from a warm fissure near the south pole of Saturn's icy moon Enceladus. It was obtained by NASA's Cassini spacecraft during its Nov. 21, 2009, flyby of that moon. The fissure, named Baghdad Sulcus, is one of four so-called "tiger stripe" features that emit jets of water vapor and ice particles.

The tiger stripe runs from the upper left to the lower right of the image. The infrared map, obtained by Cassini's composite infrared spectrometer, is nearly 10 times more detailed than the image on the left, which was the best previous map of heat from the fissures. That image was obtained in March 2008.

The new data show that broad swaths of heat previously detected by the composite infrared spectrometer are confined to a narrow, intense region no more than a kilometer (half a mile) wide along the fracture.

The thermal image also reveals that the strength of the signal varies considerably along the length of this fissure segment. The composite infrared spectrometer data indicate that the temperature along Baghdad Sulcus reached more than 180 Kelvin (about minus 140 degrees Fahrenheit).

The new map shows how the surface glows at 10 to 16 micron wavelengths of radiation along a 40-kilometer (25-mile) length of Baghdad Sulcus. This covers a region about 10 kilometers to 5 kilometers (6 miles to 3 miles) in width, with the smallest features on the thermal map measuring less than 1 kilometer (half a mile) across.