Members Can Post Anonymously On This Site
-
Similar Topics
-
By NASA
The NESC Mechanical Systems TDT provides broad support across NASA’s mission directorates. We are a diverse group representing a variety of sub-disciplines including bearings, gears, metrology, lubrication and tribology, mechanism design, analysis and testing, fastening systems, valve engineering, actuator engineering, pyrotechnics, mechatronics, and motor controls. In addition to providing technical support, the
TDT owns and maintains NASA-STD-5017, “Design and Development Requirements for Space Mechanisms.”
Mentoring the Next Generation
The NESC Mechanical Systems TDT actively participates in the Structures, Loads & Dynamics, Materials, and Mechanical Systems (SLAMS) Early Career Forum that mentors early-career engineers. The TDT sent three members to this year’s forum at WSTF, where early-career engineers networked with peers and NESC mentors, gave presentations on tasks they worked on at their home centers, and attended splinter sessions where they collaborated with mentors.
New NASA Valve Standard to Reduce Risk and Improve Design and Reliability
Valve issues have been encountered across NASA’s programs and continue to compromise mission performance and increase risk, in many cases because the valve hardware was not qualified in the environment as specified in NASA-STD-5017. To help address these issues, the Mechanical Systems TDT is developing a NASA standard for valves. The TDT assembled a team of subject matter experts from across the Agency representing several disciplines including mechanisms, propulsion, environmental control and life support systems, spacesuits, active thermal control systems, and materials and processes. The team has started their effort by reviewing lessons learned and best practices for valve design and hope to have a draft standard ready by the end of 2025.
Bearing Life Testing for Reaction Wheel Assemblies
The Mechanical Systems TDT just concluded a multiyear bearing life test on 40 motors, each containing a pair of all steel bearings of two different conformities or a pair of hybrid bearings containing silicon nitride balls. The testing confirmed that hybrid bearings outperformed their steel counterparts, and bearings with higher conformity (54%) outperformed bearings with lower conformity (52%). The team is disassembling and inspecting the bearings, and initial results have been surprising. The TDT was able to “recover” some of the bearings that failed during the life test and get them running as well as they did when testing began. Some bearings survived over five billion revolutions and appeared like new when they were disassembled and inspected. These results will be published once analysis is complete.
X-57 Design Assessment
The Mechanical Systems TDT was asked by the Aeronautics Mission Directorate to assess the design of the electric cruise motors installed on X-57. The team responded quickly to meet the Project’s schedule, making an onsite visit and attending numerous technical interchange meetings. After careful review of the design, the TDT identified areas for higher-level consideration and risk assessment and attended follow-on reviews to provide additional comments and advice.
CLARREO Pathfinder Inner Radial Bearing Anomaly
The Climate Absolute Radiance and Refractivity Observatory (CLARREO) Pathfinder was designed to take highly accurate measurements of reflected solar radiation to better-understand Earth’s climate. During payload functional testing, engineers detected a noise as the HySICS pointing system was rotated from its normal storage orientation. Mechanical Systems TDT members reviewed the design and inspection reports after disassembly of the inner bearing unit, noticing contact marks on the bore of the inner ring and the shaft that confirmed that the inner ring of the bearing was moving on the shaft with respect to the outer ring. Lubricant applied to this interface resolved the noise problem and allowed the project to maintain schedule without any additional costs.
JPL Wheel Drive Actuator Extended Life Test Independent Review Team
A consequence of changes to its mission on Mars will require the Perseverance Rover to travel farther than originally planned. Designed to drive 20 km, the rover will now need to drive ~91 km to rendezvous and support Mars sample tube transfer to the Sample Retrieval Lander. The wheel drive actuators with integral brakes had only been life tested to 40 km, so a review was scheduled to discuss an extended life test. The OCE Science Mission Directorate Chief Engineer assembled an independent review team (IRT) that included NESC Mechanical Systems TDT members. This IRT issued findings and guidance that questioned details of the JPL assumptions and plan. Several important recommendations were made that improved the life test plan and led to the identification of brake software issues that were reducing brake life. The life test has achieved 40 km of its 137 km goal and is ongoing. In addition, software updates were sent to the rover to improve brake life.
Orion Crew Module Hydrazine Valve
When an Orion crew module hydrazine valve failed to close, the production team asked the Mechanical Systems TDT for help. A TDT member attended two meetings and then visited the valve manufacturer, where it was determined this valve was a scaled-down version of the 12-inch SLS prevalve that was the subject of a previous NESC assessment and shared similar issues. The Orion Program requested NESC materials and mechanical systems support. The Mechanical Systems TDT member then worked closely with a Lockheed Martin (LM) Fellow for Mechanisms to review all the valve vendor’s detailed drawings and assembly procedures and document any issues. A follow-on meeting was held to brief both the LM and NASA Technical Fellows for Propulsion that a redesign and requalification was recommended. These recommendations have now been elevated to the LM Vice President for Mission Success and the LM Chief Engineer for Orion.
NASA’s Perseverance Mars rover selfie taken in July 2024.
View the full article
-
-
By NASA
3 min read
Preparations for Next Moonwalk Simulations Underway (and Underwater)
Latha Balijepalle, a senior database administrator at NASA Ames, encourages others to take a risk and pursue challenges in their work, like trying something new that might open doors to a new opportunity.NASA/Brandon Torres Navarrete When Madhavi Latha Balijepalle noticed that her morning commute took her past NASA Ames Research Center in California’s Silicon Valley, she set a new career goal for herself: working for NASA.
“I started manifesting it, thinking about it every day as I drove by. When I started looking for a new job, I saw an opening and decided to apply,” said Balijepalle, a senior database administrator working at the Airspace Operations Laboratory (AOL) at NASA Ames.
Eight and a half years later, she supports the researchers and developers who research next-generation solutions to advance aircraft technology and air traffic management.
A journey into the unknown
Balijepalle’s journey to NASA started thousands of miles away. She grew up in a small town in southern India, studying electrical engineering in college and establishing a career in information technology, working in C++ and Python.
When her husband found a job opportunity in the United States, Balijepalle’s life took an unexpected turn.
“I never planned to move to America,” said Balijepalle. “It was not easy to come here, even though my husband had a job. I stayed in India for almost nine months, before he found a different job that would help us with my visa and documentation.”
After settling into her new country, growing her family, and developing in her new career, Balijepalle began to ponder her dream job at NASA. She and her younger daughter, a fellow space fan, enjoyed talking about the agency’s work in space, and when a Linux administrator position opened up, she jumped at the chance.
A dream job becomes reality
At the lab, Balijepalle was initially responsible for managing the lab’s Linux servers and applications. Today, she also supports researchers and developers with development, automation, and deployment of their work.
“Latha is the lifeblood of the lab,” said Jeff Homola, co-leader of the Airborne Operations Laboratory at NASA Ames. “Without her unwavering dedication to making sure our systems are safe, secure, up to date, and running smoothly, we would not be able to do what we do in the lab.”
One of Balijepalle’s proudest achievements during her NASA career is her language skills. Growing up, she spoke Telugu and Hindi, and learned English, but communication was still a challenge when she arrived at NASA.
“I spoke English when I came to America, but not as well, and not using the technical language we use at NASA,” said Balijepalle. “I’m proud that I’ve improved my communications skills.”
“Step outside your comfort zone”
Looking back on the commute that changed her life, Balijepalle says she owes it all to being up to the challenge.
“I wasn’t a risk taker, I didn’t think about stepping outside my comfort zone, but as I drove by NASA Ames each day, I started to think about astronauts. They step outside their comfort zone and leave the planet, so maybe I could take a risk, too.”
For those who also dream of working at NASA one day, Balijepalle has some advice: try doing it her way.
“Start thinking about it and manifesting your dream. Maybe it will come true, and maybe it won’t, but you might as well try.”
Share
Details
Last Updated Dec 23, 2024 Related Terms
Ames Research Center General Explore More
16 min read NASA Ames Astrogram – December 2024
Article 3 days ago 5 min read NASA’s Ames Research Center Celebrates 85 Years of Innovation
Article 3 days ago 3 min read NASA’s Webb Reveals Smallest Asteroids Yet Found in Main Asteroid Belt
Article 3 days ago Keep Exploring Discover More Topics From NASA
Missions
Humans in Space
Climate Change
Solar System
View the full article
-
By NASA
NASA Goddard MODIS Rapid Response Team During the morning of March 20, 2015, a total solar eclipse was visible from parts of Europe, and a partial solar eclipse from northern Africa and northern Asia. NASA’s Terra satellite passed over the Arctic Ocean on March 20 at 10:45 UTC (6:45 a.m. EDT) and captured the eclipse’s shadow over the clouds in the Arctic Ocean.
Terra launched 25 years ago on Dec. 18, 1999. Approximately the size of a small school bus, the Terra satellite carries five instruments that take coincident measurements of the Earth system: Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER), Clouds and Earth’s Radiant Energy System (CERES), Multi-angle Imaging Spectroradiometer (MISR), Measurements of Pollution in the Troposphere (MOPITT), and Moderate Resolution Imaging Spectroradiometer (MODIS).
On Nov. 28, 2024, one of Terra’s power-transmitting shunt units failed. A response team reviewed Terra’s status and discussed potential impacts and options. Consequently, the team placed ASTER into Safe Mode. As a result, ASTER data are not currently being collected. All other instruments continue uninterrupted.
Image Credit: NASA Goddard MODIS Rapid Response Team
View the full article
-
By NASA
5 min read
Preparations for Next Moonwalk Simulations Underway (and Underwater)
It’s a new year on Mars, and while New Year’s means winter in Earth’s northern hemisphere, it’s the start of spring in the same region of the Red Planet. And that means ice is thawing, leading to all sorts of interesting things. JPL research scientist Serina Diniega explains. NASA/JPL-Caltech Instead of a winter wonderland, the Red Planet’s northern hemisphere goes through an active — even explosive — spring thaw.
While New Year’s Eve is around the corner here on Earth, Mars scientists are ahead of the game: The Red Planet completed a trip around the Sun on Nov. 12, 2024, prompting a few researchers to raise a toast.
But the Martian year, which is 687 Earth days, ends in a very different way in the planet’s northern hemisphere than it does in Earth’s northern hemisphere: While winter’s kicking in here, spring is starting there. That means temperatures are rising and ice is thinning, leading to frost avalanches crashing down cliffsides, carbon dioxide gas exploding from the ground, and powerful winds helping reshape the north pole.
“Springtime on Earth has lots of trickling as water ice gradually melts. But on Mars, everything happens with a bang,” said Serina Diniega, who studies planetary surfaces at NASA’s Jet Propulsion Laboratory in Southern California.
Mars’ wispy atmosphere doesn’t allow liquids to pool on the surface, like on Earth. Instead of melting, ice sublimates, turning directly into a gas. The sudden transition in spring means a lot of violent changes as both water ice and carbon dioxide ice — dry ice, which is much more plentiful on Mars than frozen water — weaken and break.
“You get lots of cracks and explosions instead of melting,” Diniega said. “I imagine it gets really noisy.”
Using the cameras and other sensors aboard NASA’s Mars Reconnaissance Orbiter (MRO), which launched in 2005, scientists study all this activity to improve their understanding of the forces shaping the dynamic Martian surface. Here’s some of what they track.
Frost Avalanches
In 2015, MRO’s High-Resolution Imaging Science Experiment (HiRISE) camera captured a 66-foot-wide (20-meter-wide) chunk of carbon dioxide frost in freefall. Chance observations like this are reminders of just how different Mars is from Earth, Diniega said, especially in springtime, when these surface changes are most noticeable.
Martian spring involves lots of cracking ice, which led to this 66-foot-wide (20-meter-wide) chunk of carbon dioxide frost captured in freefall by the HiRISE camera aboard NASA’s Mars Reconnaissance Orbiter in 2015NASA/JPL-Caltech/University of Arizona “We’re lucky we’ve had a spacecraft like MRO observing Mars for as long as it has,” Diniega said. “Watching for almost 20 years has let us catch dramatic moments like these avalanches.”
Gas Geysers
Diniega has relied on HiRISE to study another quirk of Martian springtime: gas geysers that blast out of the surface, throwing out dark fans of sand and dust. These explosive jets form due to energetic sublimation of carbon dioxide ice. As sunlight shines through the ice, its bottom layers turn to gas, building pressure until it bursts into the air, creating those dark fans of material.
As light shines through carbon dioxide ice on Mars, it heats up its bottom layers, which, rather than melting into a liquid, turn into gas. The buildup gas eventually results in explosive geysers that toss dark fans of debris on to the surface.light shines through carbon dioxide ice on Mars But to see the best examples of the newest fans, researchers will have to wait until December 2025, when spring starts in the southern hemisphere. There, the fans are bigger and more clearly defined.
Spiders
Another difference between ice-related action in the two hemispheres: Once all the ice around some northern geysers has sublimated in summer, what’s left behind in the dirt are scour marks that, from space, look like giant spider legs. Researchers recently re-created this process in a JPL lab.
Sometimes, after carbon dioxide geysers have erupted from ice-covered areas on Mars, they leave scour marks on the surface. When the ice is all gone by summer, these long scour marks look like the legs of giant spiders.NASA/JPL-Caltech/University of Arizona Powerful Winds
For Isaac Smith of Toronto’s York University, one of the most fascinating subjects in springtime is the Texas-size ice cap at Mars’ north pole. Etched into the icy dome are swirling troughs, revealing traces of the red surface below. The effect is like a swirl of milk in a café latte.
“These things are enormous,” Smith said, noting that some are a long as California. “You can find similar troughs in Antarctica but nothing at this scale.”
As temperatures rise, powerful winds kick up that carve deep troughs into the ice cap of Mars’ north pole. Some of these troughs are as long as California, and give the Martian north pole its trademark swirls. This image was captured by NASA’s now-inactive Mars Global Surveyor.NASA/JPL-Caltech/MSSS Fast, warm wind has carved the spiral shapes over eons, and the troughs act as channels for springtime wind gusts that become more powerful as ice at the north pole starts to thaw. Just like the Santa Ana winds in Southern California or the Chinook winds in the Rocky Mountains, these gusts pick up speed and temperature as they ride down the troughs — what’s called an adiabatic process.
Wandering Dunes
The winds that carve the north pole’s troughs also reshape Mars’ sand dunes, causing sand to pile up on one side while removing sand from the other side. Over time, the process causes dunes to migrate, just as it does with dunes on Earth.
This past September, Smith coauthored a paper detailing how carbon dioxide frost settles on top of polar sand dunes during winter, freezing them in place. When the frost all thaws away in the spring, the dunes begin migrating again.
Surrounded by frost, these Martian dunes in Mars’ northern hemisphere were captured from above by NASA’s Mars Reconnaissance Orbiter using its HiRISE camera on Sept. 8, 2022. NASA/JPL-Caltech/University of Arizona Each northern spring is a little different, with variations leading to ice sublimating faster or slower, controlling the pace of all these phenomena on the surface. And these strange phenomena are just part of the seasonal changes on Mars: the southern hemisphere has its own unique activity.
More About MRO
The University of Arizona, in Tucson, operates HiRISE, which was built by Ball Aerospace & Technologies Corp., in Boulder, Colorado. NASA’s Jet Propulsion Laboratory, a division of Caltech in Pasadena, California, manages the Mars Reconnaissance Orbiter Project for NASA’s Science Mission Directorate, Washington.
For more information, visit:
https://science.nasa.gov/mission/mars-reconnaissance-orbiter
News Media Contacts
Andrew Good
Jet Propulsion Laboratory, Pasadena, Calif.
818-393-2433
andrew.c.good@jpl.nasa.gov
Karen Fox / Molly Wasser
NASA Headquarters, Washington
202-358-1600
karen.c.fox@nasa.gov / molly.l.wasser@nasa.gov
2024-177
Share
Details
Last Updated Dec 20, 2024 Related Terms
Mars Reconnaissance Orbiter (MRO) Jet Propulsion Laboratory Mars Explore More
5 min read Cutting-Edge Satellite Tracks Lake Water Levels in Ohio River Basin
Article 3 days ago 5 min read NASA Mars Orbiter Spots Retired InSight Lander to Study Dust Movement
Article 4 days ago 5 min read NASA’s Perseverance Rover Reaches Top of Jezero Crater Rim
Article 1 week ago Keep Exploring Discover Related Topics
Missions
Humans in Space
Climate Change
Solar System
View the full article
-
-
Check out these Videos
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.