Mars Generation - Blog Posts

Orion Launch Abort System Motor Gets Fired-up About the Journey to Mars

Applause resounded from NASA and its partners as they watched Orion’s jettison motor generate 40,000 pounds of thrust in just a blink of an eye, preparing the spacecraft for its first integrated mission with the Space Launch System rocket.  

Onlookers had just witnessed a 1.5-second jettison motor test firing at Aerojet Rocketdyne’s facility in Sacramento, California.

The Orion launch abort system (LAS) is designed to protect astronauts in the unlikely event there is an issue during launch by pulling the spacecraft away from the rocket during a mission. The jettison motor is activated during ascent to separate the launch abort system from the spacecraft after it is no longer needed during a mission.

“This test showed us that the jettison motor can quickly generate the amount of thrust needed to pull the LAS away during an Orion mission,” said Tim Larson, jettison motor principle engineer for Lockheed Martin who has been with the project since inception. “I’m very pleased with how the test went.”

The fifth firing

The jettison motor has now undergone five tests, including two test flights. Each test in the series builds upon each other, moving the nation forward on its journey to Mars.

The motor used for the fifth test was rebuilt from a previous test motor.

“We were able to recycle some of the parts from the second ground test and use it for this test,” said NASA LAS project manager Robert Decoursey. “We not only went green, but we also saved money.”

Inside and around the test motor were instruments that included strain gauges, accelerometers and pressure transducers, which feed engineers high-quality data that show whether the motor design is ready for upcoming flight tests and missions. This motor had more instruments and produced more data than any of the previous tests.

“There are many intricate details in the jettison motor design that are not obvious from the outside, and the consistent orchestration of those details are most important to obtain predictable performance,” said NASA LAS deputy project manager Deborah Crane. “Aerojet Rocketdyne has done an excellent job executing this test on schedule.”

The jettison motor bakery

Creating a jettison motor is like baking two big cakes and making enough batter for some leftover cupcakes, according to Tim Warner, NASA LAS business manager.

The jettison motor being tested in the photo above would be activated during ascent to separate the launch abort system from the spacecraft after it is no longer needed during a mission.Credits: Aerojet Rocketdyne

What’s most exciting for the team, besides the successful test, are the latest upgrades to their baking and mixing tools.

“We were using two mixing batches to make just one motor, but have recently upgraded to a larger mixing bowl, saving us time and money,” Decoursey said.

The new mixing bowl can hold up to 450 whopping gallons of cake batter, or in NASA terms, motor propellant.

The team mixes up the batter in this large mixing bowl and evenly splits the batter into two pots for a perfectly sculpted jettison motor.

Any leftover propellant is used to make small test motors. The smaller motors are used to check the propellant’s combustion capabilities before the motors are accepted for test or flight.

What’s next?

NASA and its partners are expected to perform the last flight test of the launch abort system in 2019 before they begin sending crew to deep space aboard Orion. During the final test, an uncrewed Orion capsule will launch from a modified Peacekeeper missile and demonstrate a successful abort under the highest aerodynamic loads it could experience during a mission.

The jettison motor will be used during Orion’s first integrated mission with SLS, known as Exploration Mission-1 (EM-1) in late 2018. The mission will be the second test flight for Orion, and the first for SLS. EM-1 will send Orion on a three-week journey approximately 40,000 miles beyond the moon. The test will demonstrate the integrated performance of the rocket and spacecraft before their second test flight together, Exploration Mission-2, which will carry crew.

The LAS is led out NASA’s Langley Research Center in Virginia in collaboration with NASA’s Marshall Space Flight Center in Alabama.

Sasha Ellis

NASA Langley Research Center

NASA Langley researchers and engineers are:

Playing key roles in the development of both the Space Launch System and the Orion crew capsule, which will carry astronauts beyond the moon to an asteroid, and eventually to the dusty surface of the Red Planet.

Leading the aerodynamic design of the Space Launch System by doing analysis and extensive testing in facilities such as the Unitary Plan Wind Tunnel and Transonic Dynamics Tunnel.

Performing water impact testing and doing critical aerosciences and structural analyses for the Orion crew capsule. We also assist in analyzing and practicing recovery operations for Orion.

Developing Orion's Launch Abort System, or LAS, which is designed to protect astronauts in the unlikely event a problem arises during launch.

Spearheading work on advanced entry, descent, and landing (EDL) systems for planetary robotic missions and eventual human-scale missions to the surface of Mars. Understanding the aerodynamics and heating of atmospheric entry will enable more precise landing missions, while testing of new technologies will enable much larger missions to reach the Martian surface.

Developing safe and reliable autonomous systems to supplement human operations, including mechanisms that can work in deep space to maneuver, assemble and service structures. In the 2020s, NASA plans to use this kind of technology to retrieve an asteroid.

Leading the development of materials and structures for lightweight and affordable space transportation and habitation systems.

Solving the problems of deep space radiation protection, including leadership of the Human Research Program to develop a better understanding of space radiation on crew health and safety. Langley is also building prototype designs for habitats and storm shelters for use in space.

Working on sensor systems, known as Autonomous Landing Hazard Avoidance Technology (ALHAT), that will equip future planetary landers with the ability to assess landing hazards and land safely and precisely on many different planetary surfaces, including the moon, Mars and other planetary bodies.

Developing the Hypersonic Inflatable Aerodynamic Decelerator, or HIAD, a device that could some day help cargo, or even people, land on another planet. HIAD could give NASA more options for future planetary missions, because it could allow spacecraft to carry larger, heavier scientific instruments and other tools for exploration.