Fresnel reflectors: Producing electricity on the moon at night

System for producing electricity on the Moon using reflective mirrors and a thermal engine. 

Fresnel reflectors (dark blue and grey mirrors) will concentrate solar rays into the elongated collector above. 

Beneath, there is a tube filled with fluid that transforms into a gas when heated. 

This heats the thermal mass or reservoir (grey box), which can transfer this heat to a Stirling engine (cross-shaped object) to produce electricity during the long lunar night. 

The radiator (blue) can heat rovers and crew. 

The yellow cover is a protector that prevents the heat from rapidly dissipating.

Credit: Blai Climent et al.

Scientists from the Polytechnic University of Catalonia and other international collaborators have proposed a system of mirrors, processed lunar soil and a heat engine to provide energy to vehicles and crew during the lunar night.

This would preclude the need for batteries and nuclear power sources such as those used by the Chinese rover that recently landed on the moon.

The lunar night lasts approximately 14 days, during which temperatures as low as -150 ºC have been recorded.

This complicates vehicle movement and equipment functioning on the lunar surface, requiring the transport of heavy batteries from Earth or the use of nuclear energy, as exemplified by the Chinese rover Yutu.

Now, a team of researchers from the Polytechnic University of Catalonia, along with collaborators from the USA, have studied two options for storing energy on the Moon during the day for use at night.

Michael Griffin

The details have been published in the journal Acta Astronautica, in an article featuring the participation of former NASA administrator, Michael Griffin.

"The first system consists of modifying fragments of regolith or lunar soil, incorporating elements such as aluminium, for example, such that it becomes a thermal mass," Ricard Gonzalez-Cinca, a physics researcher at the Polytechnic University of Catalonia and co-author of the study, explains to SINC.

"When the Sun's rays hit the surface, a system of mirrors reflects the light to heat the thermal mass, which later," he adds, "can transmit heat during the night to rovers and other lunar equipment."

The second system is similar, but incorporates a more sophisticated series of mirrors and a heat engine.

The mirrors are Fresnel reflectors, such as those used in some solar energy technologies on Earth, which concentrate solar rays upon a fluid-filled tube.

This heat converts the liquid into a gas, which in turn heats the thermal mass.

Afterwards, during the long lunar night, the heat is transferred to a Stirling engine to produce electricity.

"This system is better equipped than the previous model for lunar projects with greater energy needs, such as a manned mission spending the night on the moon," reports Gonzalez-Cinca.

Starting in 2020, the world's major space agencies, including NASA, the European Space Agency (ESA) and the China National Space Administration, are planning their first manned missions to our satellite.

Other countries, such as India and Japan, have also voiced their interest to send their own missions from that date onwards.

More information: Blai Climent, Oscar Torroba, Ricard Gonzalez-Cinca, Narayanan Ramachandran, Michael D. Griffin. "Heat storage and electricity generation in the Moon during the lunar night". Acta Astronautica 93: 352-358, January 2014. (Invited paper). DOI: 10.1016/j.actaastro.2013.07.024

Mars Rover Curiosity Uses Arm Camera at Night

This image of a Martian rock illuminated by white-light LEDs (light emitting diodes) is part of the first set of nighttime images taken by the Mars Hand Lens Imager (MAHLI) camera at the end of the robotic arm of NASA's Mars rover Curiosity. 

Image credit: NASA, JPL-Caltech, MSSS.

NASA's Mars rover Curiosity has for the first time used the camera on its arm to take photos at night, illuminated by white lights and ultraviolet lights on the instrument.

Scientists used the rover's Mars Hand Lens Imager (MAHLI) instrument for a close-up nighttime look at a rock target called "Sayunei," in an area where Curiosity's front-left wheel had scuffed the rock to provide fresh, dust-free materials to examine.

The site is near where the rover team plans to begin using Curiosity to drill into a rock in coming weeks. The images of the rock Sayunei and of MAHLI's calibration target were taken on Jan. 22 (PST) and received on Earth Jan. 23.

The MAHLI, an adjustable-focus color camera, includes its own LED (light-emitting diode) illumination sources. Images of Sayunei taken with white-LED illumination and with illumination by ultraviolet LEDs are available online here and here.

"The purpose of acquiring observations under ultraviolet illumination was to look for fluorescent minerals," said MAHLI Principal Investigator Ken Edgett of Malin Space Science Systems (MSSS), San Diego.

"These data just arrived this morning. The science team is still assessing the observations. If something looked green, yellow, orange or red under the ultraviolet illumination, that'd be a more clear-cut indicator of fluorescence."

NASA NOAA Image: Earth at Night

Credit: NASA Earth Observation/NOAA  

Almost 40 years to the day after the Apollo 17 crew snapped the famed "blue marble" image of Earth floating in space on December 7, 1972, Nasa has unveiled "black marble" views of the planet by night.

The cloud-free pictures, taken with a high-resolution visible and infrared imager aboard a NASA and National Oceanic and Atmospheric Administration satellite, capture the night lights of Earth in unprecedented detail.

Se the full range of Images at NASA Earth Observation site

NASA ISS Image: Dubai at Night

Image Credit: NASA

City lights of Dubai, United Arab Emirates, are featured in this image taken by the Expedition 30 crew aboard the International Space Station.

The City of Dubai, the largest metropolitan area within the emirate of Dubai, is a favourite subject of astronaut photography largely due to the unique artificial archipelagos situated directly offshore in the Persian Gulf, which were built such that their full design is only visible from the vantage point of an airplane or an orbiting spacecraft.

The city presents an eye-catching appearance at night that vividly displays the urban development pattern.

In this detailed image, taken with a long focal length lens and digital camera optimized for fast response and high light sensitivity, several interesting patterns can be observed.

The highways and major streets are sharply defined by yellow-orange lighting, while the commercial and residential areas are resolved into a speckle pattern of individual white, blue and yellow-orange lights.

Several large and brilliantly lit areas are large hotel and mall complexes, including the Burj Khalifa Tower, the world's tallest building at 2,717 feet, or 828 meters.

The brilliant lighting of the city contrasts sharply with both the dark Persian Gulf to the northwest, and largely undeveloped and unlit areas to the southeast.

Likewise, the clusters of lighting in the Palm Jumeira complex at bottom right correspond to the relatively small part of the archipelago that has been developed. Isolated areas of blurred city lights are due to patchy clouds.

The entire night sky

In this photograph provided by Nick Risinger of Skysurvey.org, the entire night sky is shown in a composite photograph made from more than 37,000 exposures taken in different locations all over the world.

Risinger traveled more than 60,000 miles by air and land and spent more than a year to produce the photo.

Picture: AP Photo/Skysurvey.org, Nick Risinger

NASA Shuttle Endeavour Night Launch

The US space shuttle has made its final night launch from the Kennedy Space Center in Florida.

The Endeavour orbiter soared into the Florida sky on a 13-day mission to the International Space Station.

It will be the final night launch for Nasa which plans just four further shuttle missions after this one, all in daylight hours.

For further information on the Shuttle Endeavour, click here ....

NASA Shuttle Discovery: Beauty in the Night

Image Credit: NASA/Sandra Joseph and Kevin O'Connell

Billows of smoke and steam rise above Launch Pad 39A at NASA's Kennedy Space Center in Florida alongside space shuttle Discovery as it races toward space on the STS-128 mission.

The STS-128 mission is the 30th International Space Station assembly flight and the 128th space shuttle flight.

The 13-day mission will deliver more than 7 tons of supplies, science racks and equipment, as well as additional environmental hardware to sustain six crew members on the International Space Station.

The equipment includes a freezer to store research samples, a new sleeping compartment and the COLBERT treadmill.