Friday, May 1, 2020

Research reveals possibly active tectonic system on the moon

Researchers have discovered a system of ridges spread across the nearside of the Moon topped with freshly exposed boulders. The ridges could be evidence of active lunar tectonic processes, the researchers say, possibly the echo of a long-ago impact that nearly tore the Moon apart. "There's this assumption that the Moon is long dead, but we keep finding that that's not the case," said Peter Schultz, a professor in Brown University's Department of Earth, Environmental and Planetary Sciences and co-author of the research, which is published in the journal Geology. "From this paper it appears that the Moon may still be creaking and cracking - potentially in the present day - and we can see the evidence on these ridges." Most of the Moon's surface is covered by regolith, a powdery blanket of ground-up rock created by the constant bombardment of tiny meteorites and other impactors. Areas free of regolith where the Moon's bedrock is exposed are vanishingly rare. But Adomas Valantinas, a graduate student at the University of Bern who led the research while a visiting scholar at Brown, used data from NASA's Lunar Reconnaissance Orbiter (LRO) to spot strange bare spots within and surrounding the lunar maria, the large dark patches on the Moon's nearside. "Exposed blocks on the surface have a relatively short lifetime because the regolith buildup is happening constantly," Schultz said. "So when we see them, there needs to be some explanation for how and why they were exposed in certain locations."


For the study, Valantinas used the LRO's Diviner instrument, which measures the temperature of the lunar surface. Just as concrete-covered cities on Earth retain more heat than the countryside, exposed bedrock and blocky surfaces on the Moon stays warmer through the lunar night than regolith-covered surfaces. Using nighttime observations from Diviner, Valantinas turned up more than 500 patches of exposed bedrock on narrow ridges following a pattern across the lunar nearside maria.

A few ridges topped with exposed bedrock had been seen before, Schultz says. But those ridges were on the edges of ancient lava-filled impact basins and could be explained by continued sagging in response to weight caused by the lava fill.

But this new study discovered that the most active ridges are related to a mysterious system of tectonic features (ridges and faults) on the lunar nearside, unrelated to both lava-filled basins and other young faults that crisscross the highlands.

"The distribution that we found here begs for a different explanation," Schultz said.

Valantinas and Schultz mapped out all of the exposures revealed in the Diviner data and found an interesting correlation. In 2014, NASA's GRAIL mission found a network of ancient cracks in the Moon's crust. Those cracks became channels through which magma flowed to the Moon's surface to form deep intrusions. Valantinas and Schultz showed that the blocky ridges seemed to line up just about perfectly with the deep intrusions revealed by GRAIL.

"It's almost a one-to-one correlation," Schultz said. "That makes us think that what we're seeing is an ongoing process driven by things happening in the Moon's interior."

Schultz and Valantinas suggest that the ridges above these ancient intrusions arestill heaving upward. The upward movement breaks the surface and enables regolith to drain into cracks and voids, leaving the blocks exposed. Because bare spots on the Moon get covered over fairly quickly, this cracking must be quite recent, possibly even ongoing today. They refer to what they've found as ANTS, for Active Nearside Tectonic System.

The researchers believe that the ANTS was actually set in motion billions of years ago with a giant impact on the Moon's farside. In previous studies, Schultz and a co-worker proposed this impact, which formed the 1500-mile South Pole Aitken Basin, shattered the interior on the opposite side, the nearside facing the Earth.

Magma then filled these cracks and controlled the pattern of dikes detected in the GRAIL mission. The blocky ridges comprising the ANTS now trace the continuing adjustments along these ancient weaknesses.

"This looks like the ridges responded to something that happened 4.3 billion years ago," Schultz said. "Giant impacts have long lasting effects. The Moon has a long memory. What we're seeing on the surface today is testimony to its long memory and secrets it still holds."

Thursday, April 30, 2020

NASA's new solar sail system to be tested on-board NanoAvionics' satellite

NanoAvionics has been selected to build a 12U nanosatellite bus for an in-orbit demonstration of NASA's Advanced Composite Solar Sail System (ACS3). This a result of a contract between NASA Ames Research Center and AST for a 12U bus to carry NASA's payload into low Earth orbit (LEO) including an approximately 800 square foot (74 square meter) composite boom and solar sail system. The aim of the ACS3 mission is to replace conventional rocket propellants by developing and testing solar sails using sunlight beams to thrust the nanosatellite. These solar sail propulsion systems are designed for future small interplanetary spacecrafts destined for low-cost deep-space and science missions requiring long-duration, low-thrust propulsion. With already more than 75 successful satellite missions and satellite-related commercial projects, NanoAvionics will assemble the 12U bus at its new Columbia facility in Illinois, while the final integration of the payload will be carried out at NASA Ames facilities. Matching NASA Ames' mission requirements, the 12U bus shares the same flight-proven subsystems as NanoAvionics' flagship M6P bus but with up to 10U payload volume. The larger volume will be necessary to provide enough room for the 4.6 kg payload that includes the composite boom and solar sail system as well as cameras to monitor the solar sail during and after deployment. "I'm tremendously proud and excited that NanoAvionics will be part of NASA's effort to validate a new beam-powered propulsion system, eventually leading to more marvelous deep-space missions following the first inter-planetary CubeSats MarCO-A and B (Mars Cube One)," said F. Brent Abbott, CEO of NanoAvionics North America.


"The technology demonstration using NanoAvionics' 12U bus will be the first ever in-orbit trial of NASA's composite booms as well as sail packing and deployment systems for a solar sail. It will guide the development of a next generation nanosatellites with solar sail propulsion system for small inter-planetary spacecraft."

As part of this agreement the company will also supply a mechanical testbed model and a FlatSat model. In addition, a team of NanoAvionics engineers will provide the support required for testing, integration and operations of the nanosatellite.

The FlaSat model has identical software functionality as the final 12U bus hardware, hosting the actual payload. It allows NASA Ames to run tests via remote network connectivity without having to ship equipment back and forth. The mechanical testbed model can be used for testing payload integration and other mechanical tests, such as the deployment of solar sails.

In 2018 AST acquired a controlling interest in NanoAvionics as part of its strategy to establish manufacturing capabilities in Europe and North America. Abel Avellan, CEO and chairman of AST serves as chairman of NanoAvionics' Board of Directors.

Wednesday, April 29, 2020

Airbus will support France and India to monitor climate change with TRISHNA

The French Space Agency (Centre National d'Etudes Spatiales, CNES) has recently signed a contract with Airbus Defence and Space for the development and manufacture of the thermal infrared instrument for the TRISHNA satellite. TRISHNA (Thermal infraRed Imaging Satellite for High resolution Natural resource Assessment) will be the latest satellite in the joint Franco-Indian satellite fleet dedicated to climate monitoring and operational applications. CNES and ISRO (Indian Space Research Organisation) are partnering on the development of an infrared observation system with high thermal resolution and high revisit capability including a satellite and associated ground segment. TRISHNA observations will enhance our understanding of the water cycle and improve management of the planet's precious water resources, to better define the impacts of climate change, especially at local levels. In the international partnership workshare, ISRO will provide the platform, the visible and short wave infrared instrument and will be the prime contractor for the satellite, while CNES is co-responsible for the mission and will provide the thermal infrared instrument, to be developed by Airbus. The ground segment is shared between both countries. For this mission, Airbus is leveraging the latest innovations and synergies from other programmes (IASI-NG, CO3D...) to offer an affordable high performance instrument, with the aim of encouraging development of a commercial market.


Measuring surface temperatures provides information on hydric stress - a lack of water - and its impact on the vegetative cycle, and this monitoring of water and energy cycles is one of the main objectives of the mission, to be applied particularly in agriculture and hydrology.

"This mission will also serve numerous other applications: surveillance of continental and coastal waters, follow up of urban heat traps, risk monitoring (fire detection and volcanic activity), study of the cryosphere (glaciers, frozen lakes) and radiation budget assessment.

TRISHNA represents a significant step forward, both in terms of resolution and refresh rate, compared with existing missions, improving research opportunities and enabling further development of applications.

While existing missions are limited in terms of resolution (above 1km) and with revisit only every few weeks, TRISHNA will image the Earth every three days, at 50m resolution, observing a wide temperature range, from approx. -20C to +30C, with high precision (0.3C).

Jean-Marc Nasr, Head of Space Systems at Airbus said: "Thanks to ambitious science missions like TRISHNA, our industry has reached a technological maturity that opens up a new era of commercial observation of the Earth and all related applications.

"France's world-leading expertise in the Earth observation export market, combined with the unmatched efficiency and ambition of the Indian Space industry is going to bring thermal infrared imagery to a new level. This will enable breakthrough applications in agriculture, urban and coastal zone management, meteorology, climate science and many commercial applications."

Tuesday, April 28, 2020

NASA CubeSat Will Shine a Laser Light on the Moon's Darkest Craters

As astronauts explore the Moon during the Artemis program, they may need to make use of the resources that already exist on the lunar surface. Take water, for instance: Because it's a heavy and therefore expensive resource to launch from Earth, our future explorers might have to seek out ice to mine. Once excavated, it can be melted and purified for drinking and used for rocket fuel. But how much water is there on the Moon, and where might we find it? This is where NASA's Lunar Flashlight comes in. About the size of a briefcase, the small satellite - also known as a CubeSat - aims to detect naturally occurring surface ice believed to be at the bottom of craters on the Moon that have never seen sunlight. "Although we have a pretty good idea there's ice inside the coldest and darkest craters on the Moon, previous measurements have been a little bit ambiguous," said Barbara Cohen, principal investigator of the mission at NASA's Goddard Space Flight Center in Greenbelt, Maryland. "Scientifically, that's fine, but if we're planning on sending astronauts there to dig up the ice and drink it, we have to be sure it exists." Managed by NASA's Jet Propulsion Laboratory in Southern California, the spacecraft is a technology demonstration: It will seek to achieve several technological firsts, including being the first mission to look for water ice using lasers. It will also be the first planetary spacecraft to use a "green" propellant, a new kind of fuel that is safer to transport and store than the commonly used spacecraft propellant hydrazine.


"A technology demonstration mission like Lunar Flashlight, which is lower cost and fills a specific gap in our knowledge, can help us better prepare for an extended NASA presence on the Moon as well as test key technologies that may be used in future missions," said John Baker, Lunar Flashlight project manager at JPL.

Peering Into the Shadows

Over the course of two months, Lunar Flashlight will swoop low over the Moon's South Pole to shine its lasers into permanently shadowed regions and probe for surface ice. Found near the North and South Poles, these dark craters are thought to be "cold traps" that accumulate molecules of different ices, including water ice. The molecules may have come from comet and asteroid material impacting the lunar surface and from solar wind interactions with the lunar soil.

"The Sun moves around the crater horizon but never actually shines into the crater," said Cohen, whose team includes scientists at the University of California, Los Angeles, John Hopkins Applied Physics Laboratory and the University of Colorado. "Because these craters are so cold, these molecules never receive enough energy to escape, so they become trapped and accumulate over billions of years."

Lunar Flashlight's four-laser reflectometer will use near-infrared wavelengths that are readily absorbed by water to identify any accumulations of ice on the surface. Should the lasers hit bare rock as they shine into the South Pole's permanently shadowed regions, their light will reflect back to the spacecraft, signaling a lack of ice. But if the light is absorbed, it would mean these dark pockets do indeed contain ice. The greater the absorption, the more widespread ice may be at the surface.

While the CubeSat can provide information only about the presence of ice on the surface, and not below it, Lunar Flashlight seeks to fill a critical gap in our understanding of how much water ice these regions possess. "We will also be able to compare the Lunar Flashlight data with the great data that we already have from other Moon-orbiting missions to see if there are correlations in signatures of water ice, thereby giving us a global view of surface ice distribution," added Cohen.

The mission is detailed in a new paper published in the April 2020 issue of IEEE Aerospace and Electronic Systems Magazine.

Lunar Flashlight is funded by the Small Spacecraft Technology program within NASA's Space Technology Mission Directorate. The program is based at NASA's Ames Research Center in California's Silicon Valley. It will be one of 13 secondary payloads aboard the Artemis I mission, the first integrated flight test of NASA's Deep Space Exploration Systems, including the Orion spacecraft and Space Launch System (SLS) rocket launching from the newly upgraded Exploration Ground Systems at Kennedy Space Center in Florida.

Monday, April 27, 2020

Space Surveillance Telescope Sees First Light: through US and Australian Partnership

In partnership with the Australian Ministry of Defense, the U.S. Space Force's (USSF) Space and Missile Systems Center's (SMC) Space Surveillance Telescope (SST) Program recently achieved "first light" on March 5, 2020, reaching a key milestone after it was moved from White Sands Missile Range, New Mexico to Harold E. Holt Naval Communications Station in Western Australia. "This key Space Domain Awareness, or SDA, partnership builds on the long history of close defense space cooperation between the United States and Australia and has been a cornerstone of our continued alliance," said Gordon Kordyak, SMC Special Programs Directorate Space Domain Awareness Division chief. Moving the SST to Australia satisfied a critical objective to improve the broader USSF Space Surveillance Network's ground-based electro-optical coverage of the geosynchronous space regime. First light is a significant milestone in meeting this objective. It means that course alignment of the telescope optics with the wide field of view camera has been completed to allow the first images of objects in orbit to be seen by the telescope. "Whether it is space traffic management or the protection and defense of critical space-based capabilities, delivering sensors that continuously improve our ability to maintain real-time awareness of the space domain is essential to facilitate the broader needs of both the U.S. and Australia," said Lani Smith, SMC Special Programs Directorate deputy director. "The SST program, which is a jointly operated program, represents delivery of our next iteration of sensing capability to meet this need."


The collaboration and installation of the SST in Australia included the successful completion of an Australian purpose-built facility with mission-enabling site infrastructure and a 2-Megawatt Central Power Station for powering the telescope and the site. Moving forward, SST will undergo a comprehensive integration and testing regime before officially entering service in 2022.

Once operational, the SST will become part of the global Space Surveillance Network, providing Space Domain Awareness for the United States, Australia and their key allies. The Royal Australian Air Force will operate SST with oversight and management by the USSF 21st Space Wing once the telescope is operational.