David Garratt Hoag (October 11, 1925 – January 19, 2015) was an American aeronautical

engineer Engineers, as practitioners of engineering, are professionals who Invention, invent, design, build, maintain and test machines, complex systems, structures, gadgets and materials. They aim to fulfill functional objectives and requirements while ...

who was Director of the

Apollo Program The Apollo program, also known as Project Apollo, was the United States human spaceflight program led by NASA, which Moon landing, landed the first humans on the Moon in 1969. Apollo followed Project Mercury that put the first Americans in sp ...

at the

Massachusetts Institute of Technology The Massachusetts Institute of Technology (MIT) is a Private university, private research university in Cambridge, Massachusetts, United States. Established in 1861, MIT has played a significant role in the development of many areas of moder ...

's Instrumentation Laboratory, later renamed the

Charles Stark Draper Laboratory Draper Laboratory is an American non-profit research and development organization, headquartered in Cambridge, Massachusetts; its official name is The Charles Stark Draper Laboratory, Inc. The laboratory specializes in the design, development, an ...

. The Program was responsible for the Apollo Primary Guidance, Navigation, and Control Systems on the Apollo command module and the lunar landing spacecrafts. The Guidance and Navigation system included an inertial measurement unit, optical alignment telescope and space sextant, and

Apollo guidance computer The Apollo Guidance Computer (AGC) was a digital computer produced for the Apollo program that was installed on board each Apollo command module (CM) and Apollo Lunar Module (LM). The AGC provided computation and electronic interfaces for guidanc ...

, which was used during the Apollo missions.

Early life and education

Hoag was born in

Boston, Massachusetts Boston is the capital and most populous city in the Commonwealth (U.S. state), Commonwealth of Massachusetts in the United States. The city serves as the cultural and Financial centre, financial center of New England, a region of the Northeas ...

on October 11, 1925 to Helen Garratt and Alden Hoag. After graduating from the Chauncy Hall School in Boston, he joined the Navy. While in the military, he attended the Massachusetts Institute of Technology, where he received a bachelor's degree in electrical communications and later a masters in aeronautical engineering instrumentation.

Career

At MIT Instrumentation Laboratory, Hoag worked on the antiaircraft fire control systems and was Chief Technical Design Engineer and Program Manager for the Polaris Fleet Ballistic Missile Program. He initially had the same role for the

before becoming Director in 1966. The program focused most of the attention on the gyroscopic units. They had to be created in a fail-safe way, as the astronaut crew would be in danger if one drifted, and needed to be carefully constructed to keep the gimbals from freezing and locking up. Adjustments were made and re-tested in preparation to handle the load for the moon landing in 1969. Hoag ensured that all the work was completed to specification.

NASA The National Aeronautics and Space Administration (NASA ) is an independent agencies of the United States government, independent agency of the federal government of the United States, US federal government responsible for the United States ...

then asked the lab to also take on the work of creating a digital flight control system. The laboratory was tasked to do the programming and test verification of both Command and Lunar Module Guidance, Navigation, and Control computer programs for all the Apollo missions. This comprised 12 missions, 6 being

moon landing A Moon landing or lunar landing is the arrival of a spacecraft on the surface of the Moon, including both crewed and robotic missions. The first human-made object to touch the Moon was Luna 2 in 1959. In 1969 Apollo 11 was the first cr ...

s. Software verification was aided by the development of both digital and hybrid simulators. Later, when the MIT Instrumentation Laboratory became the

Draper Laboratory Draper Laboratory is an American non-profit research and development organization, headquartered in Cambridge, Massachusetts; its official name is The Charles Stark Draper Laboratory, Inc. The laboratory specializes in the design, development, an ...

, he became the Head of the Advanced Systems Department, where he led activities on precision pointing and tracking, as well as orbiting surveillance systems. With Draper He worked on both NASA and Army programs. He retired as Senior Technical Advisor in 1989 and remained as a consultant for the lab until 2005.

Patents

* Electromagnetic isolator/actuator System---This invention relates to electromagnetic suspensions and, more particularly, relates to apparatus and methods for providing an electromagnetically suspended platform isolated from external vibration and motion and independently controlled in six degrees of freedom by electromagnetic inputs * Laser Pointing System---This invention relates to systems for aiming a beam of light from a moving vehicle, such as a space vehicle, in a desired direction which is specified by celestial or geographic coordinates

Awards

Hoag received the Col. Thomas L. Thurlow Award in 1969 from the Institute of Navigation, the NASA Public Service Award in 1969, the Navy Certificate of Merit in 1970, and the American Institute of Aeronautics and Astronautic's Louis W, Hill Space Transportation Award in 1972 along with Dick Battin.

References

{{DEFAULTSORT:Hoag, David 1925 births 2015 deaths NASA people Aeronautical engineers 20th-century American engineers Massachusetts Institute of Technology alumni Scientists from Boston Engineers from Massachusetts Apollo program United States Navy personnel of World War II