Less than three months into its mission, NASA's Ice, Cloud and land Elevation Satellite-2, or ICESat-2, is already exceeding scientists' expectations. The satellite is measuring the height of sea ice to within an inch, tracing the terrain of previously unmapped Antarctic valleys, surveying remote ice sheets, and peering through forest canopies and shallow coastal waters.

With each pass of the ICESat-2 satellite, the mission is adding to datasets tracking Earth's rapidly changing ice. Researchers are ready to use the information to study sea level rise resulting from melting ice sheets and glaciers, and to improve sea ice and climate forecasts.

"ICESat-2 is going to be a fantastic tool for research and discovery, both for cryospheric sciences and other disciplines," said Tom Neumann, ICESat-2 project scientist at NASA's Goddard Space Flight Center in Greenbelt, Maryland.

Neumann and others with ICESat-2's science team shared the first look at the satellite's findings at the American Geophysical Union's annual meeting on Tuesday in Washington, D.C.

Filling in the gaps
In topographic maps of Transantarctic Mountains, which divide East and West Antarctica, there are places where other satellites just can't see. Some instruments don't orbit that far south, others only pick up large features or the highest points and so miss minor peaks and valleys. With an early pass of ICESat-2, scientists started to fill in those details.

"It's spectacular terrain," said Benjamin Smith, a glaciologist with the University of Washington, Seattle, and member of the ICESat-2 science team. "We're able to measure slopes that are steeper than 45 degrees, and maybe even more, all through this mountain range."

As ICESat-2 orbits over the Antarctic Ice Sheet, the photon returns reflect from the surface and show high ice plateaus, crevasses in the ice 65 feet (20 meters) deep, and the sharp edges of ice shelves dropping into the ocean. These first measurements can help fill in the gaps of Antarctic maps, Smith said, but the key science of the ICESat-2 mission is yet to come. As researchers refine knowledge of where the instrument is pointing, they can start to measure the rise or fall of ice sheets and glaciers.

"Very soon, we'll have measurements that we can compare to older measurements of surface elevation," Smith said. "And after the satellite's been up for a year, we'll start to be able to watch the ice sheets change over the seasons."

On thin ice
When sea ice first forms on polar oceans, before snow falls on it and wind smashes it into other floes, it is thin, flat and smooth. Which makes it a good place to test out how precise ICESat-2 data is, since long stretches should all be nearly the same height, said Ron Kwok, a sea ice scientist at NASA's Jet Propulsion Laboratory in Pasadena, California. So far? "The data's spectacular," Kwok said. "The fresh ice is totally flat to within a couple centimeters."

The first months of ICESat-2 data collected over Arctic and Antarctic sea ice reveal thin ice, thick ice, and features such as ice ridges. Areas of open water in the cracks between the ice floes, called leads, stand out in the data because of the difference in reflectivity between ice and water.

By comparing the height of that water surface in the leads with the height of the ice, scientists are estimating ice freeboard and thickness. With the high precision of ICESat-2, plus the satellite's six beams taking data simultaneously, researchers will have an unprecedented understanding of the thickness of sea ice, which will be used to help improve climate modeling and forecasts.

Plus, the ability to identify newly formed, thin ice will help researchers track the seasonal changes in remote polar regions, and understand the processes that drive those processes. The ice-thickness data will also help scientists improve computer models of how sea ice responds to Arctic warming, as well as forecasts of sea ice cover.

"We'll have much higher resolution of where it's ice and where it's water in the marginal ice zones, where the compact ice cover meets the ocean, during melt and freeze-up," Kwok said. "That's going to be new science to think about. "

Beyond ice
ICESat-2 is always on, taking measurements not only at the poles but also in the tropical and temperate latitudes, and what it can see has already surprised researchers.

"We were all taken aback seeing the amazing detail from ICESat-2, thanks to its detection technology," said Lori Magruder, a research scientist at the University of Texas and the ICESat-2 science team lead. "On every surface, there was some amazing feature that we weren't used to seeing with the first ICESat."

For example, photons returning from over the ocean trace individual waves. In clear coastal areas, the bathymetry is visible, sometimes as deep as 80 feet (25 meters), which could help with research including storm surge modeling, Magruder said.

And as ICESat-2 orbits over forests, it can distinguish not only the tops of trees but also the inner canopies and the forest floor. While the team was unsure how clear the terrain would be under dense canopies like those found in tropical rainforests, the data turned out even better than expected. By measuring tree heights globally, the ICESat-2 mission will be able to improve estimates of how much carbon is stored in forests.

Checking the numbers, bridging the gap
As the ICESat-2 science team was analyzing the first sets of data, colleagues with NASA's Operation IceBridge were collecting data in aircraft over Antarctica - flying over the same paths that the satellite was orbiting.

Over vast plains of rippling ice, craggy peaks poking through the ice sheet, and lines of crevasses marching down glaciers, the airborne campaign measured surface elevation with the Airborne Topographic Mapper's laser altimeters, snow and ice thickness with radars, and sub-ice-shelf bathymetry with a gravimeter. For a decade, IceBridge has been surveying the region, but this fall they were also gathering data to help check the accuracy of ICESat-2.

In three separate flights, IceBridge surveyed the flat plateau along the 88-degree-south latitude line where all ICESat-2 orbits converge. Other flights tracked across glaciers, ice streams and mountains along individual satellite paths - at times right as the satellite passed overhead. To measure sea ice, the IceBridge team flew briefly at 500 feet to measure wind speed, calculated how far the ice had moved since ICESat-2 measured it, and then adjusted the flight path to survey the same patch of ice.

"Almost every flight has ICESat-2 tracks incorporated into it," said Joseph MacGregor, IceBridge project scientist at NASA Goddard. "We fly over fast-changing outlet glaciers, the slower-changing interior, and uncommon surfaces that are interesting to ICESat-2. The primary goal for IceBridge is to bridge the gap between ICESat and ICESat-2, so it's very rewarding to know that we're completing that process."

The first ICESat satellite operated between 2003 and 2009, which is when IceBridge began its campaigns. ICESat-2 launched on Sept. 15 from Vandenberg Air Force Base in California. Its laser instrument, called ATLAS (Advanced Topographic Laser Altimeter System), sends pulses of light to Earth.

It then times, to within a billionth of a second, how long it takes individual photons to return to the satellite. ATLAS has fired its laser more than 50 billion times since first turning on Sept. 30, and all the metrics from the instrument show it is working as it should, Neumann said.

Mission managers expect to release the data to the public in early 2019.

-- SPACE STORY-- microsat hg 295 25-DEC-49 MILO Institute launches a new model for space exploration MILO Institute launches a new model for space exploration milo-institute-team-hg.jpg milo-institute-team-lg.jpg milo-institute-team-bg.jpg milo-institute-team-sm.jpg The MILO team after a reception at the International Astronautical Congress in Bremen, Germany. ASU
by Madison Arnold for ASU News Tempe AZ (SPX) Dec 12, 2018 Space is daunting in its enormity and tantalizing in its mysteries, and missions to explore those mysteries are audacious and ambitious. They are also expensive.

Traditionally, governments lead most space science missions. But due to limited budgets, many good ideas never get off the ground. In fact, for every 10 missions proposed to NASA, only one is selected to proceed.

A new model is needed to increase accessibility to space science. The MILO Institute is answering that call.

Through the institute, Arizona State University, Lockheed Martin and GEOshare are pioneering a new way to fund deep-space missions that help us better understand not only our universe, but also ourselves.

Accessibility: Reducing cost and sharing knowledge
The MILO Institute takes a new approach to advancing space science. Through a consortium model, universities, industries and space agencies around the globe are able to become members of the institute. The members split the cost of the missions, allowing more access to space by making it more affordable.

"The MILO Institute has been formed to reduce the barriers of entry to space science. Our objective is essentially to open the doors and make space science accessible to more organizations," said David Thomas, executive director for the MILO Institute.

Lockheed Martin will manage the development of the missions, and ASU will oversee the science and education aspects. Member organizations can contribute instruments, satellites and satellite components, or science and education expertise.

Membership will be available at different levels. For example, some entities might pay more to acquire space in the satellites for their own instruments, such as cameras or other sensors. Other, possibly smaller or emerging organizations, could buy in at a lower level of membership and still have access to the expertise within the institute. Every member will have access to the all data collected from each mission.

Lockheed Martin has an extensive history delivering aerospace, defense, security and other technology to military, intelligence, civil and commercial customers. It has been building planetary science spacecraft for more than four decades and has produced more than all other U.S. companies combined.

GEOshare is a subsidiary of Lockheed Martin, focused on delivering custom payloads to specific orbital locations. GEOshare provides a suite of services, from matching customer payload missions with orbital locations to facilitating construction and launch.

The idea for the MILO institute began with serial space entrepreneur Lon Levin and planetary scientist and ASU Professor Jim Bell. Levin is the president and CEO of GEOshare and has over 30 years of experience developing new space ventures. Bell is a professor in ASU's School of Earth and Space Exploration, director of ASU's Space Technology and Science (NewSpace) Initiative and chief scientist for the MILO Institute.

They are both on the board of the Planetary Society and shared a common frustration with the current funding model for space science. Bell introduced Levin to ASU President Michael Crow, and they decided ASU was the perfect place to try out a new business model to expand access and ability to do more space science. Inclusivity: Partnering for global progress

ASU, with its strong space program and focus on outreach and education, will serve as the MILO Institute's headquarters. Bell says that ASU is well positioned to be a leader in this field because of "the scientific pedigree that we've got here. We've been involved in almost every NASA robotic space mission going back to the 1960s. We know what good science is, we know how to do good science, and we know how to work with instruments and spacecraft."

According to Bell, the "entrepreneurial spirit that infuses everything" at ASU positively places the university as a leading force. Lockheed Martin will provide proven technical expertise and products for the institute. And GEOshare will assist with assembling the consortium and developing the business model.

The name for the MILO Institute comes from a play on "Venus de Milo."

"In our early days, we needed a code word for the project," said Levin. "We were working on a potential Venus mission, and chose MILO because of the famous sculpture."

The name inadvertently turned out to represent what the institute stands for.

"Traditionally, missions to the planet Venus are difficult and often fall just below the cutline of NASA funded missions," said Betsy Cantwell, CEO of the Arizona State University Research Enterprise and chair of the MILO Institute board of directors. "When the most recent mission led by ASU, Psyche, won funding from NASA, a compelling mission to Venus lost. Sometimes great ideas cannot be funded through traditional channels, and that is precisely the purpose of the MILO Institute."

Agencies, industries and universities worldwide are expressing interest in space science.

"There's a proliferation of space agencies around the world, and why is that? That's because different countries, big and small, are seeing that being a part of the space economy is important for their own economy," Levin said.

"There's a rapidly growing number of space agencies around the world. Universities have programs and departments that are focused on space," added Thomas. "Each one supports growth of the ecosystem around the space market. All are eager to fly their technology into space and demonstrate their capability to the world. The MILO Institute offers that opportunity in an inclusive way."

Innovation: A new model for global engagement
When designing its first mission, the institute considered four key focus points. The first was partner participation - allowing many partners to participate. The next was that the mission should be conducted relatively quickly, meaning less than three to five years to validate the concept. This requires the inaugural mission to stay in the inner solar system, close to Earth.

The third factor was that the mission has to be affordable, with a total cost of about $200 million to $250 million, so that the contribution from any one of the anticipated 20 to 40 member organizations would be as affordable as possible. And the last was that the science had to be compelling, as defined by consensus reports like the National Academy of Science's Planetary Decadal Survey.

The MILO Institute's first scheduled mission, slated for a launch in early 2023, is called NEOShare. NEO stands for "near earth object," as asteroids that come close to the Earth will be the focus of the mission.

"There's an alphabet soup of asteroids out there. There are dozens of types, and we've visited only six," Bell said. They are designing a mission that could focus on many kinds of asteroids that have never been seen up close before.

"I think we're in an environment where we have to think differently," said Lisa Callahan, vice president and general manager for Commercial Civil Space at Lockheed Martin. "The way we've done things in the past has a lot of value in terms of the mission success, but we're also trying to explore and experiment with different types of business models and different types of relationships. Space science is a difficult place, and I think this just helps to build more relationships to help all of us be successful - 'a rising tide lifts all boats.'"

The collaboration between ASU, Lockheed Martin and GEOshare will engage globally and increase the capacity for space science research.

"That's one of the most exciting things that we get to deliver and talk about is a globally sourced education initiative that delivers deep-space missions," Cantwell said. "Then, all of those entities get to work on the science data that comes back from that."

The MILO Institute demonstrates values that ASU holds dear: accessibility, inclusivity and innovation, not to mention impact.

"There are a lot of really interesting ways to win as this global team," said Cantwell.

Related Links
ICESat-2 at NASA
Beyond the Ice Age

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