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The Marshall Star
March 11, 2015
The Marshall Star banner for March 11, 2014

In This Week's Star


Steam Me Up, Scotty: Booster Temps Just Right for Major Ground Test

[image-36]Steam me up, Scotty. Well before today's major ground test of the booster for NASA’s Space Launch System rocket, engineers have been warming things up so the booster will be not too hot, not too cold -- but just right for the two-minute, full-duration firing.

At Orbital ATK's test facility in Promontory, Utah, the booster was heated to 90 degrees Fahrenheit ahead of the test. The hot fire is a significant milestone for the program and will support qualification of the booster design for performance at the highest end of the booster’s accepted propellant temperature range. Two boosters, along with four RS-25 engines, will propel SLS and the Orion spacecraft atop it, to orbit as they begin the journey to deep space destinations like an asteroid and Mars.

Data and analysis from past human-rated space programs, like the Space Shuttle Program, which used a smaller version of the booster, have set the condition parameters for boosters between 40 and 90 degrees.

"The space shuttle propellant mean bulk temperature ranged from approximately 55 to 83 degrees on the launchpad, so the 90-degree mark does a good job representing what we expect to see for SLS," said Mat Bevill, deputy chief engineer in the SLS Boosters Office at NASA's Marshall Space Flight Center, where the program is managed for the agency.

"The booster is so large at 177 feet long, and other than the metal case around the propellant, it's basically made up of mostly rubber-like materials," added Bevill. "With that much mass, it takes about a month to affect the temperature and get it uniform all the way through."

The booster's propellant burn rate is temperature-dependent, so the hotter it is, the faster it burns. That propellant burn rate affects the performance of the booster both at launch and in flight.

To get the temperature to 90 degrees, the thermostat is turned up inside the test stand where the booster is housed. Sensors inside the booster measure the temperature, and analytical models also predict the time it takes for the booster to be "done" at 90 degrees. The test stand cover, which is on rails, was rolled out of the way for the test.

"Outside temperatures are something we have to watch, but just like it takes a long time to heat the booster, it takes a long time to get the temperature back down," Bevill said. "That's why we target the highest temperature condition for testing. This isn't a new concept – we've always conditioned to a certain temperature. We basically know ahead of time how the booster will respond, but we still watch and make sure it performs the way we think it will."

Some 102 design objectives were measured through more than 531 instrumentation channels on the booster. Along with temperature, the test will demonstrate that the booster meets applicable ballistic performance requirements, such as thrust and pressure. Other objectives include data gathering on vital motor upgrades, such as the new internal motor insulation and liner and the redesigned nozzle, which increases the robustness of the design.

A second booster qualification test planned for early next year will be a cold test, where the booster will be conditioned to 40 degrees -- the low-end temperature parameter for the booster.

"These two qualification tests are major steps in getting the booster certified for the first two flights of SLS and another step closer on the journey to Mars," said SLS Boosters Office Manager Alex Priskos.

The added booster segment contains more solid propellant that allows SLS to lift more weight and reach a higher altitude before the boosters separate from the core stage. The core stage, towering more than 200 feet tall with a diameter of 27.6 feet, will store cryogenic liquid hydrogen and liquid oxygen that will feed the vehicle’s RS-25 engines.

Davidson, an ASRC Federal/Analytical Services employee, supports the Office of Strategic Analysis & Communications.

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NASA Spacecraft Becomes First to Orbit a Dwarf Planet

NASA's Dawn spacecraft has become the first mission to achieve orbit around a dwarf planet. The spacecraft was approximately 38,000 miles (61,000 kilometers) from Ceres when it was captured by the dwarf planet’s gravity at about 6:39 a.m. CDT March 6.

Mission controllers at NASA’s Jet Propulsion Laboratory received a signal from the spacecraft at 7:36 a.m. CDT that Dawn was healthy and thrusting with its ion engine, the indicator Dawn had entered orbit as planned.

"Since its discovery in 1801, Ceres was known as a planet, then an asteroid and later a dwarf planet," said Marc Rayman, Dawn chief engineer and mission director at JPL. "Now, after a journey of 3.1 billion miles (4.9 billion kilometers) and 7.5 years, Dawn calls Ceres, home."

In addition to being the first spacecraft to visit a dwarf planet, Dawn also has the distinction of being the first mission to orbit two extraterrestrial targets. From 2011 to 2012, the spacecraft explored the giant asteroid Vesta, delivering new insights and thousands of images from that distant world. Ceres and Vesta are the two most massive residents of our solar system’s main asteroid belt between Mars and Jupiter.

The most recent images received from the spacecraft, taken on March 1 show Ceres as a crescent, mostly in shadow because the spacecraft's trajectory put it on a side of Ceres that faces away from the sun until mid-April. When Dawn emerges from Ceres' dark side, it will deliver ever-sharper images as it spirals to lower orbits around the planet.

"We feel exhilarated," said Chris Russell, principal investigator of the Dawn mission at the University of California, Los Angeles. "We have much to do over the next year and a half, but we are now on station with ample reserves, and a robust plan to obtain our science objectives."

Dawn's mission is managed by JPL for NASA's Science Mission Directorate. Dawn is a project of the directorate's Discovery Program, managed by NASA's Marshall Space Flight Center. UCLA is responsible for overall Dawn mission science. Orbital ATK Inc., in Dulles, Virginia, designed and built the spacecraft. The German Aerospace Center, Max Planck Institute for Solar System Research, Italian Space Agency and Italian National Astrophysical Institute are international partners on the mission team.

For more information about Dawn, visit here.

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Chief Engineers Office Gives Lisa Watson-Morgan a View Into Nearly Every Program at Marshall
By Kenneth Kesner

[image-52]In a sense, Dr. Lisa Watson-Morgan is an engineer of engineers.

In December 2013, Watson-Morgan became the first woman named manager of the Chief Engineers Office at NASA's Marshall Space Flight Center. A little over a year in the position has given her a unique perspective on the entire spectrum of engineers and programs at Marshall -- rocket engine and booster development, additive manufacturing, space-based lightning imaging sensors, mirrors for orbiting telescopes, environmental control and life support systems for astronauts aboard the International Space Station or on future deep-space missions, and much more.

"A good chief engineer asks a lot of questions," Watson-Morgan said. "And a good chief engineer has to know who the discipline experts are, because a chief engineer doesn't have all the answers. They have to lean on this enormous capability that this center has with outstanding engineering talent.

"Just seeing that vast amount of talent has been amazing," she said. "And the chief engineers are an outstanding group of leaders, which makes my job easier in that respect."

Her office is also a "last technical voice," adjudicating differing opinions and courses of action among chief engineers and others when there is major disagreement. Many chief engineers work on programs and projects that not only involve Marshall but also involve other NASA centers, academia, industry and other government agencies.

"I think there's an art to being a chief engineer, because you never know the problem that you're going to face that day," she said.

Watson-Morgan, 46, was born in Decatur, Alabama, and grew up in Huntsville, where she graduated from Butler High School. Her mother, Anne Watson, who worked as the manager of a small company, died before Watson-Morgan's senior year. Her father, Bill Watson, is a retired contractor who worked in graphics and publications at Marshall. He took her on "bring-your-daughter-to-work" days, and sometimes talked about how respected the engineers were, and how they were treated.

The message was not lost on Watson-Morgan. She didn't get much formal exposure to engineering in high school, but did very well in subjects that dealt with science, technology, engineering and mathematics -- today called "STEM" education. She went on to earn a bachelor's degree in industrial engineering from the University of Alabama in Tuscaloosa in 1991, and both a master's and doctoral degree in industrial and systems engineering from the University of Alabama in Huntsville, in 1994 and 2008, respectively.

Watson-Morgan always had her sights set on NASA. She worked as a cooperative education student at Marshall in 1989 and later became a full-time employee in the Missions Operations Laboratory as a data management controller for the ATLAS-3 Spacelab mission, which had a suite of science instruments that studied Earth and the atmosphere. She worked on ground operations requirements for Spacelab and later for the space shuttle and space station programs. In 2005 she was promoted to Ground Operations branch chief.

Highlights of her other experience include microsatellite development, space station payloads and serving as assistant chief engineer and acting chief engineer for the Marshall Science and Mission Systems Chief Engineers Office. Today, that breadth of programs informs her work in the Marshall Chief Engineers Office.

Mentors were very important to her professional development, and Watson-Morgan works to make sure the environment at Marshall nurtures those relationships. She makes time to speak at middle and high schools, outlining the importance of STEM education and demonstrating that engineering careers are open to women as well as men. Supporting area schools is a family matter: She and her husband, Pat Morgan, have three children -- Macie, Evan and Ethan.

“It's an exciting time to be an engineer at NASA,” Watson-Morgan said, pointing to the successful test launch, orbit and recovery of an unmanned Orion spacecraft in December, and continuing development of the most powerful deep space rocket ever made, the Space Launch System.

"Once you can build a rocket -- and obviously that's one of our core competencies -- there aren't many spacecraft or space systems that you can't build," Watson-Morgan said. "Which I think makes Marshall uniquely poised to be very useful to the space program and the nation. And it's great to be a part of it."

Kesner, an ASRC Federal/Analytical Services employee, supports the Office of Strategic Analysis & Communications.

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NASA Shaking Things Up for Space Launch System at Redstone Test Center
By Megan Davidson

[image-68]There's a whole lot of shaking going on at the Redstone Test Center for NASA's new mega rocket, the Space Launch System.

SLS will be the most powerful rocket ever built for deep space missions, including to an asteroid and eventually Mars.

NASA and The Boeing Co., prime contractor for the SLS core stage, have teamed up for thrust vector control actuator vibration testing with the Redstone Test Center's Dynamic Test Division on Redstone Arsenal. The actuators are hydraulic-powered, piston-like motors that control the RS-25 engine gimbal position to change the engine thrust angle with respect to the SLS core stage. The core stage, towering more than 200 feet, will store cryogenic liquid hydrogen and liquid oxygen that will feed the rocket’s RS-25 engines.

SLS will use actuators from the Space Shuttle Program, but with modifications.

"Vibrations from launch can significantly impact the vehicle and its systems, which is why it's important to understand and mitigate those issues before we get to the pad," said Jonathan Looser, SLS core stage main propulsion system and thrust vector control lead at NASA's Marshall Space Flight Center, where the SLS Program is managed for the agency. "The SLS vibration levels on the actuators are significantly higher than the levels the shuttle experienced. We determined in the design process that the effects of the higher vibrations can be alleviated by adding stiffer springs to the actuator's mechanical feedback."

[image-84]Development testing to evaluate the spring modification was completed in May 2014. A second phase of testing was completed in September 2014 to see how the new hardware performed under SLS flight conditions. A loaded actuator test series began in January, in which the actuator is placed onto a shaker table with up to 16,000 pounds of force added to the hardware during vibration. The test series, scheduled to conclude at the end of February, will provide data on how the actuator is affected by the vibrations and confirm its performance in the higher SLS environments.

"The size and control capability of the large shaker tables available at the Redstone Test Center provides an affordable and faster test option than if Marshall chose to develop the capability internally," said Chad Bryant, propulsion manager in the Stages Office at Marshall. "We are proud to partner with RTC to get this hardware ready for the first flight of SLS."

That first flight test will feature a configuration for a 70-metric-ton (77-ton) lift capacity and carry an uncrewed Orion spacecraft beyond low-Earth orbit to test the performance of the integrated system. As the SLS evolves, it will provide an unprecedented lift capability of 130 metric tons (143 tons) to enable missions even farther into our solar system.

For more information on SLS, click here.

Davidson, an ASRC Federal/Analytical Services employee, supports the Office of Strategic Analysis & Communications.

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NASA’s Dawn Spacecraft Makes History, Orbits Dwarf Planet Ceres

The NASA Dawn spacecraft and its historical encounter with the dwarf planet Ceres was featured in the latest edition of "This Week @NASA," a weekly video program broadcast nationwide on NASA-TV and posted online.

Dawn became the first mission to reach a dwarf planet by entering into orbit around Ceres on March 6. Ceres is the largest unexplored world of the inner solar system, located in the main asteroid belt between Mars and Jupiter.


In addition to being the first spacecraft to visit a dwarf planet, Dawn was also the first mission to orbit two extraterrestrial targets. From 2011-2012, Dawn explored the giant asteroid Vesta, delivering new insights and thousands of images. Dawn is managed by the Jet Propulsion Laboratory in Pasadena, California and is one of several projects under the Discovery Program managed by the Marshall Center for NASA's Science Mission Directorate.

View this and previous episodes at "This Week @NASA".

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The SLS booster is being heated to 90 degrees Fahrenheit.
The SLS booster was heated to 90 degrees Fahrenheit ahead of today’s qualification test at Orbital ATK's test facility in Promontory, Utah.
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Orbital ATK
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Dr. Lisa Watson-Morgan is the first woman named manager of the Chief Engineers Office at the Marshall Center.
Dr. Lisa Watson-Morgan is the first woman named manager of the Chief Engineers Office at the Marshall Center.
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NASA/MSFC/Emmett Given
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NASA Marshall's Roger Parisa and Miranda Holton get the thrust vector control actuator ready for vibration testing.
NASA Marshall's Roger Parisa and Miranda Holton get the thrust vector control actuator ready for vibration testing.
Image Credit: 
NASA/MSFC
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Location of the thrust vector control actuators on the SLS RS-25 engine.
Location of the thrust vector control actuators on the SLS RS-25 engine.
Image Credit: 
NASA/MSFC
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Page Last Updated: March 11th, 2015
Page Editor: Lee Mohon