Apr 4 2017

From The Space Library

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Current revision

RELEASE 17-037 NASA’s Cassini Mission Prepares for 'Grand Finale' at Saturn

NASA's Cassini spacecraft, in orbit around Saturn since 2004, is about to begin the final chapter of its remarkable story. On Wednesday, April 26, the spacecraft will make the first in a series of dives through the 1,500-mile-wide (2,400-kilometer) gap between Saturn and its rings as part of the mission’s grand finale.

"No spacecraft has ever gone through the unique region that we'll attempt to boldly cross 22 times," said Thomas Zurbuchen, associate administrator for the Science Mission Directorate at NASA Headquarters in Washington. "What we learn from Cassini’s daring final orbits will further our understanding of how giant planets, and planetary systems everywhere, form and evolve. This is truly discovery in action to the very end."

During its time at Saturn, Cassini has made numerous dramatic discoveries, including a global ocean that showed indications of hydrothermal activity within the icy moon Enceladus, and liquid methane seas on its moon Titan.

Now 20 years since launching from Earth, and after 13 years orbiting the ringed planet, Cassini is running low on fuel. In 2010, NASA decided to end the mission with a purposeful plunge into Saturn this year in order to protect and preserve the planet's moons for future exploration – especially the potentially habitable Enceladus.

But the beginning of the end for Cassini is, in many ways, like a whole new mission. Using expertise gained over the mission's many years, Cassini engineers designed a flight plan that will maximize the scientific value of sending the spacecraft toward its fateful plunge into the planet on Sept. 15. As it ticks off its terminal orbits during the next five months, the mission will rack up an impressive list of scientific achievements.

"This planned conclusion for Cassini's journey was far and away the preferred choice for the mission's scientists," said Linda Spilker, Cassini project scientist at NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, California. "Cassini will make some of its most extraordinary observations at the end of its long life."

The mission team hopes to gain powerful insights into the planet's internal structure and the origins of the rings, obtain the first-ever sampling of Saturn's atmosphere and particles coming from the main rings, and capture the closest-ever views of Saturn's clouds and inner rings. The team currently is making final checks on the list of commands the robotic probe will follow to carry out its science observations, called a sequence, as it begins the finale. That sequence is scheduled to be uploaded to the spacecraft on Tuesday, April 11.

Cassini will transition to its grand finale orbits, with a last close flyby of Saturn's giant moon Titan, on Saturday, April 22. As it has many times over the course of the mission, Titan's gravity will bend Cassini's flight path. Cassini's orbit then will shrink so that instead of making its closest approach to Saturn just outside the rings, it will begin passing between the planet and the inner edge of its rings.

"Based on our best models, we expect the gap to be clear of particles large enough to damage the spacecraft. But we're also being cautious by using our large antenna as a shield on the first pass, as we determine whether it's safe to expose the science instruments to that environment on future passes," said Earl Maize, Cassini project manager at JPL. "Certainly there are some unknowns, but that's one of the reasons we're doing this kind of daring exploration at the end of the mission."

In mid-September, following a distant encounter with Titan, the spacecraft's path will be bent so that it dives into the planet. When Cassini makes its final plunge into Saturn's atmosphere on Sept. 15, it will send data from several instruments – most notably, data on the atmosphere's composition – until its signal is lost.

"Cassini's grand finale is so much more than a final plunge," said Spilker. "It's a thrilling final chapter for our intrepid spacecraft, and so scientifically rich that it was the clear and obvious choice for how to end the mission."

Resources on Cassini's grand finale, including images and video, are available at: [1]

An animated video about Cassini's Grand Finale is available at: [2]

The Cassini-Huygens mission is a cooperative project of NASA, ESA (European Space Agency) and the Italian Space Agency. JPL manages the mission for NASA's Science Mission Directorate. JPL designed, developed and assembled the Cassini orbiter.

More information about Cassini is at: [3] [4]

RELEASE 17-036 University Research Teams to Study Potential Aeronautical Innovations

Imagine an aircraft structure that can change its shape in flight to reduce the sonic boom noise produced by supersonics airplanes. Or imagine an airliner that can take-off and fly with a quiet and energy efficient electric propulsion system.

These are two of five examples of the transformative system-level aviation innovations NASA has selected for potential awards to university teams that will have them spend as long as five years exploring novel ideas for improving aviation, all in support of the agency’s strategic research goals for aeronautics.

“These awards further enhance the strong relationship we have with our university partners,” said Jaiwon Shin, NASA’s associate administrator for aeronautics. “We expect the awards will spur the Nation’s leading universities to take a larger leadership role in advancing the revolutionary ideas needed to transform aviation and further advance U.S. global leadership in the aviation community.”

Total value of the five research awards from NASA Aeronautics’ University Leadership Initiative (ULI) over five years is expected to be no more than $50 million.

“Potential outcomes of the research could include revolutionary technologies, operational concepts, design tools, models, or other advancements we can’t even begin to characterize today,” said Doug Rohn, director of NASA’s Transformative Aeronautics Concepts Program.

One key idea in the selection process was that NASA did not specify the research topics or disciplines for the schools to pursue, which distinguishes ULI from a standard NASA research award. Instead, universities were asked to come up on their own with the most compelling investigations, so long as that technical challenge addressed one of the agency’s main aviation research goals.

In addition to the technical challenges, another goal of ULI is to develop the ability of these university researchers to lead diverse, multi-disciplinary teams. In many cases, the teams include members from academia and industry, including those who may not have an aviation background, but whose expertise offers the potential for technology convergence. In addition, teams are encouraged to reach out broadly to universities that serve underrepresented student populations. These diverse partnerships are expected to bring different perspectives that contribute to novel, innovative approaches.

“With ULI we want to provide a forum for U.S. universities to show their leadership in innovation to contribute to our nation’s aviation community,” Rohn said.

The university teams selected for negotiations leading to a potential award are:

• University of South Carolina for research into advanced, wireless communication networks to enhance the safety and efficiency of air traffic management with both piloted aircraft and drones.
• Texas A&M Engineering Experiment Station, for research into designing commercial supersonic aircraft that could modify their shape during a flight to help minimize noise from sonic booms.
• University of Tennessee, Knoxville, for research into designing an ultra-efficient aerodynamic wing that could enable significant savings in fuel or energy consumption.
• Ohio State University, for research into electric propulsion, including areas of battery and energy storage and thermal management, among others.
• Arizona State University, for research into safely integrating the complex set of data sources that will drive future air traffic management systems.