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Milestone-Nomination:Mercury Spacecraft MA-6

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Docket Number: 2009-12

Proposal Link: http://www.ieeeghn.org/wiki/index.php/Milestone-Proposal:Mercury_Spacecraft_MA-6

In the space below the line, please enter your proposed citation in English, with title and text. Text absolutely limited to 70 words; 60 is preferable for aesthetic reasons. NOTE: The IEEE History Committee shall have final determination on the wording of the citation

                                           Mercury Spacecraft MA-6


Col John Glenn piloted the Mercury Spacecraft "Friendship 7" as the first USA manned orbital flight
on February 20, 1962. His spaceflight was extraordinary because of the utilization of the electrical
and electronic systems invented by McDonnell Engineers, some being members of IRE and subsequently
IEEE. Project Mercury's electronics included Navigation & Control Instruments; Auto Pilot; Rate
Stabilization & Control; and Fly-By-Wire (FBW) manual electrical systems.


Project Mercury technical drawings are shown on website:http://www.hq.nasa.gov/office/pao/History/diagrams/mercury.html


 

MA-6 (23) Flight Details
Friendship 7
Pad LC-14 ()
Atlas (6)

Crew:
John H. Glenn, Jr.

Milestones:
8/27/61 - Capsule arrived at Cape Canaveral
2/15/62 - Flight Safety Review
2/20/62 - Launch

Payload:
Spacecraft No. 13, Vehicle Number 109-D

Mission Objective:
Place a man into earth orbit, observe his reactions to the space environment and safely return him to earth to a point where he could be readily found.
The Mercury flight plan during the first orbit was to maintain optimum spacecraft attitude for radar tracking and communication checks.

Launch:
February 20, 1962. 9:47:39 am EST. Cape Canaveral Launch Complex 14. Powered flight lasted 5 minutes 1 second and was completed normally.

The mercury countdown began on 1/27/62 and was performed in two parts. Precount checks out the primary spacecraft systems, followed by a 17.5 hour hold for pyrotechnic checks, electrical connections and peroxide system servicing. Then the countdown began. The launch countdown proceeded to the T-13 minute mark and then was canceled due to adverse weather conditions. After cancellation, the mission team decided to replace the carbon dioxide absorber unit and the peroxide system had to be drained and flushed to prevent corrosion. Launch vehicle systems were then revalidated and a leak was discovered in the inner bulkhead of the fuel tank that required 4-6 days to repair. The launch was rescheduled to 2/13/62 and then to 2/14/62 to all the bulkhead work to complete. The precount picked up again on 2/13/62, 2/15/62 and 2/16/62 but was canceled each time due to adverse weather. The launch was then rescheduled for 2/20/62.

During the launch countdown on 2/20/62, all systems were energized and final overall checks were made. the count started at T-390 minutes by installing and connecting the escape-rocket igniter. The service structure was then cleared and the spacecraft was powered to verify no inadvertent pyrotechnic ignition. The personnel then returned to the service structure to prepare for static firing of the reaction control system at T-250 minutes.
The spacecraft was then prepared for boarding at T-120 minutes. The hatch was put into place at T-90 minutes. During installation a bolt was broken, and the hatch had to be removed to replace the bolt causing a 40 minute hold. From T-90 to T-55 final mechanical work and spacecraft checks were made and the servicewas evacuated and moved away from the launch vehicle. At T-45 minutes, a 15 minute hold was required to add fuel to the launch vehicle and at T-22 minutes and additional 25 minutes was required for filling the liquid-oxygen tanks as a result of a minor malfunction in the ground support equipment used to pump liquid oxygen into the launch vehicle. At approximately T-35 minutes, filling of the liquid-oxygen tanks began and final spacecraft and launch vehicle systems checks were started.

At T-10 minutes the spacecraft went on internal power. At T-6min 30 seconds, a 2 minute hold was required to make a quick check of the network computer at Bermuda. The launch vehicle went on internal power at T-3 minutes. At T-35 seconds the spacecraft umbilical was ejected and at T-0 the main engines started. Liftoff occured at T+4 seconds at 9:47:39am EST.


Orbit:
Altitude: 162.2 x 100 statute miles
Inclination: 32.54
Orbits: 3
Period: 88min 29sec
Duration: 0 Days, 4 hours, 55 min, 23 seconds
Distance: 75,679 statute miles
Velocity: 17,544 mph
Max Q: 982 psf
Max G: 7.7

Landing:
February 20, 1962. 14:43:02 am EST. 800 miles southeast of Bermuda.

Recovered by the destroyer USS Noa. Lookouts on the destroyer sighted the main parachute at an altitude of 5,000 ft from a range of 5nm. The Noa had the spacecraft aboard 21 minutes after landing and astronaut John Glenn remained in the spacecraft during pickup. Original plans had called for egress through the top hatch but Glenn was becoming uncomfortably warm and it was decided to exit by the easier egress path.
Mission Highlights:
Mission Successful. First American in orbit. Total time weightless 4 hours 48min 27sec. During the flight only two major problems were encountered: (1) a yaw attitude control jet apparently clogged at the end of the first orbit, forcing the astronaut to abandon the automatic control system for the manual-electrical fly-by-wire system; and (2) a faulty switch in the heat shield circuit indicated that the clamp holding the shield had been prematurely released- a signal later found to be false. During reentry, however, the retropack was not jettisoned but retained as a safety measure to hold the heat shield in place in the event it had loosened.

(Reference NASA - Results of the First US Manned Orbital Space Flight)
(Reference NASA SP-4201 - This New Ocean)
(Reference NASA SP-4001 - Project Mercury: A Chronology)










Please also include references and full citations, and include supporting material in an electronic format (GIF, JPEG, PNG, PDF, DOC) which can be made available on the IEEE History Center’s Web site to historians, scholars, students, and interested members of the public. All supporting materials must be in English, or if not in English, accompanied by an English translation. If you are including images or photographs as part of the supporting material, it is necessary that you list the copyright owner.

In the space below the line, please describe the historic significance of this work: its importance to the evolution of electrical and computer engineering and science and its importance to regional/national/international development.

When the request for proposals was issued by NASA, there had not been a manned spaceflight by the United States. Amazingly, James S. McDonnell, founder of the McDonnell Aircraft Company, dedicated resources and personnel to design a spacecraft capable of putting humans into space and returning them safely to earth at least two years before the signing of the Project Mercury contract. Because space flight was different than conventional air flight electrical systems had new challenges. The electrical and electronics systems had to be able to operate in a new environment including but not limited to the vacuum of space, the weightlessness of orbital flight, and the rigors of launch and recovery. McDonnell electrical and electronics engineers took extra precautions because the spacecraft had to be man rated.


 Its systems epitomize the field of interest of the IEEE Aerospace and Electronics Systems Society. Project Mercury's electronics included Navigation and control instruments; auto pilot; rate stabilization and control, manual proportional control system and Fly-By-Wire (FBW)manual-electrical system. The FBW manual-electrical systems proved critical to Friendship 7's mission success because a yaw attitude control jet apparently clogged at the end of the first orbit, forcing astronaut Glenn to abandon the automatic control system for the manual-electrical fly-by-wire system. (ref http://science.ksc.nasa.gov/history/mercury/ma-6/ma-6.html). This established the United States of America’s foundation for future manned spaceflight, eventually resulting in the landing of humans on the Moon.






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