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Walter Sierra

Walter Sierra is a bonafide “rocket scientist” who has written six books on this topic, including the four-book Beyond the Saga of Rocket Science series. His first two books, entitled (1) Space Transportation: A Systems Approach to Analysis and Design (1999); and (2) Design Methodologies for Space Transportation Systems (2001), were intended for engineers and scientists. Both are still available from the AIAA (American Institute of Aeronautics and Astronautics) Education Series website at The author is on a team working on yet another more technical rocket science book, “International Reference Guide to Space Launch Systems” which is due to come out later in 2021.

Walter has over 45 years of progressive experience in systems engineering and integration of aerospace and defense systems, systems analysis and trade studies, formulation of system requirements, verification, and validation. He has worked in a variety of assignments from staff engineer to branch supervisor, in locations from major rocket firms in California to the halls of the Pentagon in Washington, D.C., and many places in between.

His areas of expertise include planning and executing complex projects, product definition and development, project and program requirements definition, verification planning and execution, process improvement, problem solving, optimal balancing among conflicting requirements for performance, cost, reliability, and risk. He also has expertise in building high performance work teams, and leading teams to deliver exceptional customer service.

Why did Walter write the Beyond the Saga of Rocket Science series?

Walter felt inspired to write a very interesting exposé of rocketry in all glory as a historical novel to grab the general public’s attention. A much larger audience will benefit by learning how rocket science got to where it is today, by understanding the basics of how launch and space vehicles work, and where space activities—which will increasingly impact everyone’s daily life—are headed in the future. The public is intimidated by the very words, “rocket science,” and often finds the subject boring and difficult to understand, but after reading the Beyond the Saga of Rocket Science series they will be more enlightened. Moreover, Walter explains how many historical events which everyone is familiar with—such as Watergate, the Cold War, and both World Wars—impacted the historical development of rocket science. He also ties in many seemingly unrelated events—such as the discovery of powered flight by the Wright Brothers and construction of the International Space Station—to this central theme.

Why is Walter writing under a pseudonym?

He was born in Austin, Texas on February 26, 1947 as Walter Edward Hammond. His father, Dr. John Hays Hammond, was a professor of Spanish at the University of Texas; his mother was born Carmela Sierra Abadiano in Mexico City. In 1950 the family moved to Fort Worth, Texas where Walter grew up and his father became chairman of the Foreign Language Department at TCU. Spanish was spoken as a first language in the home, and his mother imbued the family, including Walter’s sister Evelyn and brothers John and Charles, with a strong sense of Hispanic practices and culture. Carmela also had a huge family in Mexico, and everyone enjoyed extended stays in Mexico (Mexico City, Monterrey, Acapulco) every summer. Walter decided to adopt the pen name Walter Sierra in honor of his mother and many distinguished Mexican relatives.

What is Walter’s background?

Walter attended St. Andrew’s Catholic school in Fort Worth. In 1962-1963 he spent a year at St. Anthony’s Junior Seminary (since turned into a Catholic school) in San Antonio, then returned to Fort Worth and graduated from Nolan Catholic High School in 1966. He felt drawn to an engineering career, and attended the University of Texas at Arlington from 1966-1971, graduating with a degree in Aerospace Engineering. Walter’s grandfather Lee Morgan Hammond had cofounded (with William Trimble) Arlington College back in 1895, which after a succession of name changes became UTA in 1968; and Walter was glad to honor this legacy.

On August 18, 1971 Walter married the former Suzanne Adams Hammond. The couple moved to Austin where Walter attended the University of Texas, graduating with a Master’s degree in Aerospace Engineering in 1973. While finishing his degree he joined the Air Force and served a four-year stint (1972-1976), serving as an Electronic Warfare Officer on B-52s. In 1976 the family moved to Simi Valley, California so Walter could work at Rocketdyne in Canoga Park, and fly as a navigator on C-130s out of the Van Nuys airport for the California Air National Guard (1976-1979). Inclined to be a “professional student,” Walter moved the family again to College Station, Texas where Walter attended Texas A&M University (1979-1983). Four years and two degrees later (Master of Business Administration, Master of Engineering) they moved to Huntsville, Alabama so Walter could complete a one-year internship and earn a Doctor of Engineering Diploma (his fifth degree) in Industrial and Systems Engineering from TAMU (1984).

By this time, Walter’s family had grown to six (sons Scott, David, Michael; and daughter Anne). Huntsville is a great place to raise a family, so they decided to make it their home for over three decades (1983-2016); with occasional departures so Walter could pursue temporary assignments in Aerospace and Defense elsewhere [Sacramento, California at Aerojet in 1986-1987, Wheeling, West Virginia at NASA’s National Technology Transfer Center (1995), Lexington, Kentucky at M2 Technologies, Inc.(2009-2010)]. By 2005 Walter and Suzanne were facing an empty nest with all the kids grown and gone.

Over time Anne and David moved to Orlando, Florida and began their own families. By 2016–with three grandchildren, Kara, Cameron, and Michael, and more on the way—Walter and Suzanne decided to make the move to Orlando to be closer to family. Walter began his third career—as an author—in earnest. His first career was in the Air Force (active duty 1972-1976, Air Guard 1976-1979, active reserve 1979-2002); and his second career in aerospace and defense overlapped (1976-2015), with assignments with various aerospace contractors such as Teledyne Brown Engineering, Thiokol Chemical, Aerojet, Jacobs Engineering, Boeing, and Northrop Grumman.

Mt. Kilimanjaro, Tanzania

Mt. Kilimanjaro, Tanzania

What does Walter do when he’s not writing books?

There are many family activities, and Orlando is a mecca for entertainment, with five Walt Disney Parks, two Universal Studios theme parks, Sea World, and the Orlando Science Center to name a few. Walter has always been physically active. He was a varsity track athlete (long distance) at Nolan and UTA. Now he’s an avid jogger, enjoys bicycling, hiking, and mountain climbing (but not in Florida which is basically flat!). On occasion he also goes kayaking, golfing, scuba diving, and plays tennis. Travel with family is also on the menu, including trips to Mexico. So much to do, and so little time to do it!

Cerro Aconcagua, Argentina

Grand Canyon, Arizona

Everest Base Camp trek