Engineer with Sputnik 1 Satellite

In Their Own Words: Steven Croopnick on Sputnik Inspiration

Steven Croopnick
Dr. Battin For Brochure
Dr. Charles Stark Draper

In October 1957, at age 14, after hearing on the radio that the Soviets launched the first artificial satellite, Sputnik, I knew exactly what field I was interested in pursuing.  Sputnik, which orbited the Earth every 90 minutes, was startling and worrisome, especially in the aftermath of WWII and the onset of the cold war, since it implied the capability to attack anywhere in the world on short notice.  

In my senior year at Brookline High, I applied and was accepted, as an undergraduate, to the MIT Aeronautics and Astronautics Department. In my sophomore year at MIT I realized I wanted to do some “hands-on” work in astronautics so, at the suggestion of a colleague, I asked to see Doc Draper, at 68 Albany Street office, to apply for a job.   “Doc” graciously invited me in, discussed my interests, and hired me on the spot…I never left nor looked back.” I joined Draper formally in 1963, and am currently a member of its staff.

The Laboratory offered me the opportunity to work on programs important to the national interest. At the beginning, I had the good fortune to work with inventors and creative people, like Hal Seward, that had the same motivation and offered me encouragement. Subsequently, I did both my undergraduate and graduate theses at Draper and had the privilege of working for Dick Battin who served as my thesis advisor. He was, in my opinion, was the modern embodiment of Newton, Copernicus, and Kepler translated to the 20th century. He was responsible for the development and application of recursive filtering for space navigation before development of the well-known Kalman filter.

While a graduate student under Battin, I had the opportunity to work on space navigation and guidance. The goal was to evaluate approaches to improve the efficiency and accuracy of trajectory determination and prediction and included enhancements to classical gravity models, and recursive filter formulations and initializations. In lay terms, it means figuring out and predicting your position and velocity in the simplest way possible while maintaining accuracy and minimizing the utilization of computer resources.

All of this helped pave the way for my work leading the team responsible for the development of the on-orbit autopilot for the Space Shuttle, and later my engagement in the laboratory’s submarine-launched ballistic missile reliability effort.