Accelerating change on systems engineering tenets
By Eric E. Nichols|September 10, 2018
The Systems Engineering Technical Committee supports efforts to define, develop and disseminate modern systems engineering practices.
Access to space has been limited by the ticket cost to Earth orbit since the start of the space age. Events over the past year, however, represent what may be a permanent change to the existing cost structure. While deceptively subtle, 2016 saw accelerated changes that affect how we approach two bedrock tenets of systems engineering: requirements management and standards compliance.
System requirements management and design standards matured in tandem with the aerospace industry, often in response to tragic accidents. In the 1920s, airplane construction required little more than advanced carpentry skills. Until the 1930s, rocket technology had changed little since the Congreve rocket used at Fort McHenry in 1814. World War II forced radical change to both technologies.
Integration of ever more complex systems ushered in the nascent field of systems engineering. Reliance on individual experience and intuition was replaced by operational requirements and design standards. The transition helped save countless lives but also created impediments to creative problem-solving; the culture became conservative. Radical new designs became scarce as system specifications began to reflect safe point solutions. The prevalent philosophy became: violate design standards and risk millions of dollars, years of development and loss of life.
By the 1990s, restrictive standards became the target of government reform. As cost-reduction efforts continued to stagnate, NASA attempted several programs designed to promote innovation and revitalize a commercial space sector. The Commercial Resupply Service contracts began the current trend to limited, grand-vision requirements with minimal compliance constraints. The intent was to emulate Air Mail’s impact on aviation’s early development. These contracts provided the catalyst for SpaceX and Orbital ATK to develop launch vehicles for a commercial market.
The follow-on Commercial Crew Program continued the trend to focus on “what” and not “how.” Similarly, the Ansari “X Prize,” modeled after early 20th century aviation prizes, promoted maximum creativity with minimal requirements. The simple requirements to launch a reusable crewed vehicle into space twice within two weeks became the inspiration for the space tourism market. Private ventures, including Blue Origin’s New Shepard and Virgin Galactic’s SpaceShipTwo, use these basic requirements for their suborbital spacecraft and proved there was money available for a purely commercial launch industry.
In 2016 the trend appears to have achieved critical mass with this year’s revisions to the Air Force Evolved Expendable Launch Vehicle, or EELV, documents. The new directives support the what and not how approach to launch services. With the renewed freedom, launch vehicle designers are once again questioning the existing paradigms and testing cost-saving technologies. The most visible are the reusable systems flown during the year. Less visible are the reduced recurring costs from test and integration changes. The EELV New Entrant Certification Guide accommodates providers with innovative designs and higher developmental risk. The guide recognizes possible failure as an integral part of advancing technology. This represents a radical change in launch systems engineering.
Systems engineering developed in response to the need to incorporate complex systems into advanced aerospace designs. System specifications and standards provided the written record used to pass along knowledge and generate design confidence. As the aerospace industry matured, these documents began to drive solutions toward the safe and known and discourage the risky and innovative. The new projects inspiring today’s engineers are demonstrating you can have both creative and safe. They are proving the right requirements and appropriate standards can encourage imaginative designs that reduce the ticket cost to Earth orbit.
The challenge for 2017 and beyond is to improve on the successes and work on getting the right mix of requirements and standards. ★