Everything you never knew you wanted to know about the Mercury Project

Spacecraft 18

From RixWiki

Production Mercury Spacecraft

Flown Spacecraft

SC 1		9 May 1960
SC 4		29 Jul 1960
SC 3		8 Nov 1960
SC 2		21 Nov 1960
SC 2A		19 Dec 1960
SC 5		31 Jan 1961
SC 6		21 Feb 1961
SC 14		18 Mar 1961
SC 8		25 Apr 1961
SC 14A		28 Apr 1961
SC 7		5 May 1961
SC 11		21 Jul 1961
SC 8A		12 Sep 1961
SC 9		29 Nov 1961
SC 13		20 Feb 1962
SC 18		24 May 1962
SC 16		3 Oct 1962
SC 20		15-16 May 1962
Unflown Spacecraft

SC 10 SC 12
SC 15 SC 15A
SC 15B SC 17
SC 19

1 Mission
2 Flight Order
3 Disposition
4 Changes Since Prior Flight
5 Details
6 Chronology
7 Sources

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Mission

Spacecraft 18 flew on MA-7 which was also known as Aurora 7

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Flight Order

The previous production spacecraft flown was spacecraft 13. The next production spacecraft to fly was spacecraft 16.

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Disposition

Displayed at the Museum of Science and Industry in Chicago, Illinois

[http://aesp.nasa.okstate.edu/fieldguide/pages/mercury/ma-7.html Entry in Jim Gerard's AFGAS]

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Changes Since Prior Flight

From "This New Ocean NASA":

A number of changes were made to spacecraft 16 based on the experience of prior flights. These are the changes from spacecraft 13 used for John Glenn's flight on the MA-6 mission:

Weight Saving and comfort modifications
1. The sofar bombs and radar chaff recovery aids were deleted
2. The knee and chest straps on the couch were deleted for comfort
3. The red filter in the window was deleted.
4. The Earth path indicator was deleted.
5. The instrument panel camera was deleted as it was no longer needed.
Performance Changes
1. A radio frequency change in the telemetry system was made to eradicate transmission interference like that experienced on Glenn's flight.
2. The two landing-bag switches were rewired so that both had to be closed to activate the deploy signal.
3. The dutch-weave filters in the fuel lines were replaced with platinum screens, and a stainless-steel fuel line was substituted. This was intended as an "interim fix," but it became permanent in the Mercury project for the later flights.
4. A barostat was added to the drogue parachute deployment circuit to solve a problem in which Glenn's drogue chute had fired prematurely.
5. Temperature pickups were added at 28 points on the spacecraft. A "low level commutator" was added and the measurements were recorded on an on-board tape recorder."
Space suit modifications
1. Pockets were added on the upper sleeves and on the lower legs of the pressure suit for pencils, a handkerchief, and other small accessories.
2. The waterwing life vest, first carried by John Glenn, was installed on the chest beneath the parabolic mirror.
3. To add to Carpenter's comfort while he was waiting in his capsule on the launch pad, a new and more resilient liner was fitted in the couch.

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Details

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Capsule Interior

Fig C18-CI-1	Fig C18-CI-2	Fig C18-CI-3	Fig C18-CI-4
Fig C18-CI-5

Fig C18-CI-1 is a photo which shows an astronaut who appears to be Scott Carpenter in a Mercury spacecraft atop a booster. Fig C18-CI-2 is a detail from that photo.

WARNING - This photo has not been conclusively shown to be of spacecraft 18

Fig C18-CI-2 shows a closeup of the left interior wall of the spacecraft as it is on museum display.

Fig C18-CI-4 is a photo of an object in a museum which is labeled as a door used to cover the compartment left when the earth path indicator was removed from the instrument panel of spacecraft 18.

Note that this door is very similar to that on the instrument panel of the MA-8 spacecraft, but has a checklist attached. Note also the exposure recommendations on the camera checklist for "FIREFLYS" (sic). The "fireflies" seen by John Glenn were of interest on Scott Carpenter's MA-7 flight

Fig C18-CI-5 captured from video of pre-flight operations shows some details near the entrance hatch sill.

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Entrance Hatch

Fig C18-EH-1

Fig C18-EH-2

The first two figures are from video of the pre-flight preparations for MA-7 and show some details of the seal for the entrance hatch.

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Recovery Compartment

Fig C18-RC-1

Figure C-18-RC-1 shows the recovery compartment after the parachutes were loaded on the launch pad.

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Escape Tower

Fig C18-ET-1

Fig C18-ET-2

Figure C18-ET-1 is from video of the pre-launch preparations. Notice the differences in the glossiness of the finish of the black parts.

Figure C18-ET-2 another video grab, shows the spacecraft with it's escape tower atop Atlas 107-D

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Retropackage

Fig C18-RP-1	Fig C18-RP-2	Fig C18-RP3	Fig C18-RP4
Fig C18-RP5	Fig C18-RP6	Fig C18-RP7	Fig C18-RP8
Fig C18-RP9

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Chronology

15 December 1959: The December 1959 Edition of SEDR-104 is published containing Spacecraft 18 as a specification capsule

23 May 1961: The fourth development engineering inspection on Mercury spacecraft was held at McDonnell. Inspection activities were primarily centered on spacecraft 18, and some 45 requests for alterations were initiated.

1 November 1961: The November 1961 Edition of SEDR-104 is published containing spacecraft 18 as a specification capsule
15 November 1961: spacecraft 18 delivered to Cape Canaveral.
7 December 1961: The heatshield was X-rayed, and the center-plug dowels were determined to be acceptable^[1].
9 December 1961: The auxiliary battery for the maximum altitude sensor was added^[2].
14 December 1961: Gyros with a silicone-base lubricant were installed^[3].
18 December 1961: The cabin fan inlet duct was equipped with screens to prevent possible cabin fan fouling by foreign material^[4].
20 December 1961: The check valve was removed from the cold-plate water system^[5].
10 January 1962: The oxygen partial pressure indicator was deleted^[6].
11 January 1962: The suit compressor check valves were positively oriented and had springs to assist their closing^[7].
24 January 1962: The semi-automatic blood pressure measuring system, which included the fill and dump solenoids, was added^[8].
25 January 1962: The velocity sensor,was reset from cap-sep +5 second to cap-sep +/-5 minutes^[9].
31 January 1962: The suit circuit constant bleed orifice,was removed^[10].
1 February 1962: The February 1962 Edition of SEDR-104 is published containing spacecraft 18 as a test capsule.
13 February 1962: The C-band beacon did not respond during the Service Engineering Department Report (SEDR) 195 interrogation, a communication system radiation test, and was returned to the vendor.^[11].
14 February 1962: The cabin relative-humidity indicator was removed.^[12].
14 February 1962: The coolant quantity indicator was deleted^[13].
14 February 1962: The Sofar bombs and radar chaff were deleted from the spacecraft^[14].
2 March 1962: The oxygen partial pressure transducer was removed from the suit circuit and located in the cabin^[15].
3 March 1962: The landing bag limit switches were rewired for improved reliability of the system^[16]. This was a fix for the problem seen on the MA-6 flight when an erroneous indication that the landing bag had deployed caused much concern and led to a reentry with the retropackage retained. In the initial design of the wiring any of the switches could cause a landing bag deploy signal. I the new design all of them needed to move in order to cause the signal.
6 March 1962: The 1/4-g relay circuitry was changed to prevent drop-out of this relay during posigrade ignition^[17].
14 March 1962: The oxygen flow sensor was disabled^[18].
30 March 1962: The low frequency telemetry center frequency was raised 500 kc^[19].
2 April 1962: A maneuver switch was installed that removed roll and yaw slaving of gyros and pitch orbital precession^[20].
7 April 1962: The hand controller fly-by-wire switch rod was changed to incorporate a step to prevent travel from going over-center^[21].
9 April 1962: The instrument panel camera was deleted^[22].
12 April 1962: A dual indicator was installed for the suit and cabin steam-vent temperatures^[23].
18 April 1962: All one-pound thrusters had the Dutch weave screens removed and four platinum screens added plus a distribution plate. The six-pound thrusters had the screens added^[24].
19 April 1962: A 30-inch balloon was installed for obtaining visual acuity effects and aerodynamic drag measurements^[25].
20 April 1962: A separately-commutated temperature survey was installed using thermocouples and resistance elements^[26].
28 April 1962: Spacecraft 18 was mechanically mated to Atlas 107-D^[27].
30 April 1962: Simulated flight #1 (system)^[28].
3 May 1962: The oxygen emergency rate valve and system shut-off valve were hard link connected^[29].
4 May 1962: Zero gravity experimental apparatus was installed in the position formerly occupied by the instrument panel camera^[30].
4 May 1962: Electrical mate and aborts^[31].
4 May 1962: Special hydrogen peroxide tests^[32].
5 May 1962: Simulated flight #2 (joint FACT)^[33].
8 May 1962: Flight configuration and aborts^[34].
10 May 1962: Launch simulation^[35].
11 May 1962: The yaw manual proportional valve was replaced at the launch site after a simulated launch, since tests had revealed poor centering from left-yaw position^[36].
15 May 1962: Simulated flight #3^[37].
18 May 1962: Simulated flight #3(sic)^[38]. I assume that this is a typo and this was a fourth simulated flight.
19 May 1962: A third barostat was installed in the cabin and wired into the parachute circuitry to prevent automatic system deployment of the drogue and main parachutes at altitudes above 11,000 feet^[39].
24 May 1962: MA-7 launchedNote: .