Jack Garman
Jack Garman | |
---|---|
Houston, Texas, U.S. | |
Nationality | American |
Alma mater | University of Michigan, B.S. 1966 |
Known for | Saving Apollo 11 mission from abort |
John Royer Garman[1] (September 11, 1944 – September 20, 2016) was a computer engineer, former senior NASA executive and noted key figure of the Apollo 11 lunar landing. As a young specialist on duty during the final descent stage on 20 July 1969 he dealt with a series of computer alarms which could have caused the mission to be aborted.
Early life
Garman was born September 11, 1944, in
NASA career
In 1966, at age 21, Garman was hired by
During the
Gene Kranz told Garman: 'I want you to study and write down every possible program alarm whether they can happen or not.' Garman made a handwritten list of every computer alarm code that could occur along with the correct reaction to each of them and put it under the plexiglass on his desk.[4]
1202
A design oversight with the Apollo Lunar Module Eagle's rendezvous radar led to a near-abort during the Apollo 11 landing, according to engineer Don Eyles.[5]
The radar's Coupling Data Units (CDU), which provided the interface between the radar's hardware and the LM's
When the LM's rendezvous radar (which tracked the still-orbiting
This in turn caused the CDUs to issue interrupts to the guidance computer—12,800 interrupts per second, which consumed about 15% of the computer's available compute time. As the rest of the landing tasks were consuming about 85% of the computer's time, the computer ran out of time to process all of its queued jobs in a single cycle. As scheduled jobs in the computer failed to complete in time, the programs competed for core set memory and vector accumulator registers; eventually, one and then the other were exhausted, and the LM's guidance computer began sounding program alarms and resetting.
The first was a "1202" alarm, indicating an executive overflow and an exhaustion of core sets. Several seconds after the first alarm Neil Armstrong, with some concern apparent in his voice, said, "Give us a reading on the 1202 program alarm." Meanwhile, given his knowledge of the computer systems, Garman had already advised Steve Bales that the computer could be relied upon to function adequately so long as the alarms did not become continuous.[6] Bales, who as guidance officer had to quickly decide whether to abort the mission over these alarms, trusted Garman's judgment and informed flight director Kranz. Within seconds this decision was relayed through CAPCOM to the astronauts and the flight continued.
There were several additional alarms of the same type (both 1202 and also 1201, which indicated a vector accumulator area exhaustion), and then the crew was able to stop them from recurring by changing the landing procedure slightly to reduce the computer's tasks. Apollo 11 went on to land successfully and Garman received an award from NASA for his role in the mission. Bales later recalled, "Quite frankly, Jack, who had these things memorized said, 'that's okay', before I could even remember which group it was in.”[7] Garman’s quick reactions and in-depth knowledge led others on his team to give him the nickname "Gar-Flash".[8]
IT and senior management
After the Apollo program, Garman and center director
Later career
In 2000, Garman left NASA and became a part of the OAO Corporation. Two years later OAO was bought by Lockheed Martin and Garman became Lockheed Martin's technical director of NASA services, in charge of technical support for the company's contractual activities with NASA.[citation needed]
Personal life
For his service to the program, Garman was honored with numerous NASA awards, including two exceptional service medals. In 1970, Garman was part of the Apollo 13 team awarded the Presidential Medal of Freedom by President Richard Nixon.[10]
Garman was married to the former Susan Hallmark of Los Angeles; they had two daughters.
See also
- Margaret Hamilton
References
- ^ Association, University of Michigan Alumni (1 January 1997). "Directory of Members". B.C. Harris Publishing Company. Retrieved 22 September 2016 – via Google Books.
- ^ "Bio: Jack Garman" (PDF). Jsc.nasa.gov. Archived from the original (PDF) on 2008-03-09. Retrieved 2017-03-09.
- ISSN 0362-4331. Retrieved 2022-09-18.
- ISBN 978-0-316-34178-3.
- ^ Don Eyles, Tales From the Lunar Module Guidance Computer, doneyles.com; accessed 21 September 2016.
- ^ Console audio recording of Apollo 11 Lunar Landing, klabs.org; accessed September 21, 2016.
- ^ Lindsay, Hamish. "Apollo 11". Retrieved 11 July 2006.
- ^ "Part 3: The Navigation Computer". Moon Machines. Season 1. Episode 3. June 2008.
- ^ "JSC Features - Storytelling with Jack Garman". nasa.gov. Archived from the original on 16 February 2012. Retrieved 22 September 2016.
- ^ a b c Pearlman, Robert (September 21, 2016). "Jack Garman, NASA engineer who 'saved' Apollo 11 from alarms, dies at 72". Retrieved September 21, 2016.
- ^ Roberts, Sam (24 September 2016). "Jack Garman, Whose Judgment Call Saved Moon Landing, Dies at 72". The New York Times. Retrieved 30 January 2019 – via NYTimes.com.