SP-4212
On Mars: Exploration of the Red Planet. 1958-1978

 
 
 
[434-452] Appendix C
Summary Data from Mariner, Voyager, and Viking
 

 
Abbreviations
 
CC - Coded commands for program update.
DC - Direct commands for switch closures.
PC - Processor commands for computer control.
QC - Qualitative commands for positioning and deflection maneuvers.
RCS - Reaction control system.
RF - Radio frequency.
RTC - Radioisotope thermoelectric generator.
TM - Telemetry.
TWTA - Traveling-wave-tube amplifier.
 

 

MARINER A

.

Preflight designation:

Mariner A

Flight designation:

Not flown.

Project proposed:

Study begun July 1960 at JPL.

Project approved:

15 July 1960 by T. K. Glennan.

Launch vehicle:

Atlas-Centaur

Launch date:

Canceled 30 Aug.1961 because of projected unavailability of suitable launch vehicle.

Program objectives:

Initial plan called for a flyby of Venus in 1962. Revised plan (February 1961) called for flights to Venus in 1962, 1964, and 1965.

Spacecraft shape and size:

Hexagonal frame derived from Ranger spacecraft (dimensions not available).

Weight:

Projected, 487-686 kg.

Program results:

Canceled.

Duration of flight to target:
Canceled.


 
 
MARINER B

.

Preflight designation:

Mariner B

Flight designation:

Not flown.

Project proposed:

Study begun July 1960 at JPL.

Project approved:

15 July 1960 by T. K. Glennan.

Launch vehicle:

Atlas-Centaur

Launch date:

Project deferred to Mariner-Mars 1966 on 6 May1963.

Program objectives:

Mariner B went through a series of redefinitions:
1. Initial plans called for an instrumented landing on Venus or Mars in 1964.
2. In February 1961, the Venus landing was dropped from consideration.
3. On 9 Apr. 1962, the Venus landing was again considered and the Mars landing dropped.
4. On 14 Mar.1963, mission changed to pre-Voyager checkout flight to Mars with lander.
5. Mission postponed and redesignated Mariner-Mars 1966 on 6 May 1963.

Spacecraft shape and Size

Several configurations proposed; none finalized.

Weight:

Projected, 400-600 kg.

Program results:

Redesignated Mariner-Mars 1966.

Duration of flight to target:

Redesignated Mariner-Mars 1966

 
 

 
 
 
MARINER-VENUS 1962

.

Preflight designation:

Mariner R-1 and Mariner R-2.

Flight designation:

Mariner I and Mariner 2

Project proposed:

Study started August 1961 at JPL and proposed to NASA Hq. by JPL 28 Aug. 1961.

Project approved:

30 Aug. 1961

Launch vehicle:

Atlas-Agena B

Launch date:

Mariner 1, 22 July 1962, 4:21 a.m. EST.
Mariner 2, 27 Aug. 1962, 1:53 a.m. EST.

Program objectives:

Launch 2 spacecraft to the near-vicinity of Venus in1962; establish and maintain 2-way communication with the spacecraft throughout the flight; obtain interplanetary data in space and during Venus encounter; make scientific survey of planet's characteristics.

Spacecraft shape and size:

Hexagonal magnesium-frame base, 104 cm diagonally,36cm deep. Two solar panels attached to base span 5.05 m when deployed. Aluminum tubular superstructure, mounted atop the base, supports experiments and omnidirectional antenna. High gain antenna mounted below base. Attitude-control jets mounted to base. Midcourse propulsion mounted in base compartment. Overall height, 3.66 m.

Weight:

Structures/mechanical

38.6

Electrical (RF, TM, Data)

32.2

Power

47.8

Computer command

5.1

Attitude control

22.2

Pyro and cabling

19.1

Propulsion (inert)

9.6

Thermal control

3.2

Science

18.4

Expendables

6.6

.

Launch weight (total)

202.8

Control system:

10 N2 jets
3 gyros, Earth sensor
2 primary sun sensors
2 secondary sun sensors
Sungate and sensor

Electrical power:

9800 solar cells
Panels: 152 x 76 cm (2)
Total area, 2.3 m2
148 watts at Earth
222 watts at Venus
Silver-zinc battery, 1000 watts per hr.

Telecommunications:

L-band transponder, 1-watt/3-watt output
Low-gain omnidirectional antenna
Dual low-gain turnstile/dipole antennas
High-gain parabolic antenna
Science and engineering data, 8 1/3 and 33 1/3 bits per sec

Propulsion:

Monopropellant hydrazine
225 newtons thrust
Rate of velocity change, 0.2 m/sec to 60 m/sec
Total impulse, 9560 newtons per sec
4-jet vane vector control

Command system:

DC-14
QC-3 @ 1 bit per sec
CC-0

Program results:

Mariner 1 - Booster deviated from course and was destroyed by range safety officer 290 sec after launch.
Mariner 2 - First spacecraft to scan another planet; passed within 34 762 km of Venus on 14 Dec.; made 42-min instrument survey of atmosphere and surface before going into heliocentric orbit; made first comprehensive measurements of properties of solar wind. Transmissions from interplanetary experiments received until 4 Jan. 1963 from 87.4-million-km distance, establishing new communication record.

Duration of flight to target:

Mariner 1 - destroyed shortly after launch
Mariner 2 - 109 days.

.

For additional information:

JPL, Mariner-Venus 1962 Final Project Report, NASA SP-59 (Washington, 1965).

 

 


 
 
 
MARINER-MARS 1964

.

Preflight designation:

Mariner C
Mariner M (Mars)
Mariner C (Mariner 3 )
Mariner D* (Mariner 4 )

Flight designation:

Mariner 3 and Mariner 4

Project proposed:

July-August 1962

Project approved:

November 1962 (tentative); project approval document signed 1 Mar. 1963.

Launch vehicle:

Atlas-Agena SLY-3
AA- 11-Mariner 3
AA-12-Mariner 4

Launch date:

Mariner 3-5 Nov. 1964, 2:22 p.m. EST
Mariner 4-28 Nov. 1964, 9:22 a.m. EST

Program objectives:

Flyby to study surface and atmosphere of Mars, develop operational techniques, make scientific measurements of interplanetary environment, provide engineering experience in spacecraft operations during long-duration flights away from the sun.

Spacecraft shape and size:

Octagonal magnesium-frame base, 127 cm diagonally and 45.7 cm deep Four solar panels attached to top of base span 6.88 m deployed (including solar-pressure-vane extensions). High-gain dish antenna mounted atop base with low-gain antenna on top of aluminum tube. Attitude-control jets mounted at solar panel tips. Midcourse propulsion mounted on side of octagon. Overall height, 2.89 m.

Weight:

Structures/mechanical

49.4

Electrical (RF, TM, Data)

52.6

Power

61.5

Computer command

5.4

Attitude control

29.0

Pyro end cabling

15.4

Propulsion (inert)

12.8

Thermal control

6.4

Science

15.8

Expendables

12.5

Launch weight

260.8

Control system:

12 N2 jets-redundant
3 gyros, Canopus sensor
Earth sensor
Mars sensor
2 primary sun sensors
2 secondary sun sensors

Electrical power:

28 224 solar cells
Panels: 176 x 90 cm (4)
Total area, 6.3 m2
310 watts at Mars
Silver-zinc battery, 1200 watts per hr.

Telecommunications:

Dual, S-band, 7-watt cavity amp/10-watt TWTA
transmitter, single receiver
Low-gain omnidirectional antenna
High-gain parabolic antenna
Science and engineering data, 8 1/3 and 33 1/3 bits per sec
Tape recorder, 5.24 million bits

Propulsion:

Monopropellant hydrazine
225 newtons thrust
4-jet vane vector control

Command system:

DC-29
QC-3 @ 1 bit per second
CC-0

Program results:

Mariner3 - Shroud failed to jettison; battery power dropped; no evidence that solar panels opened to
replenish power supply; communications lost; in permanent heliocentric orbit.
 
Mariner 4 - Spacecraft flew by Mars 14 July 1965,with closest approach about 9844 km; discovered
densely packed lunar-style impact craters on Martian surface; ionosphere and atmosphere measured somewhat less dense than expected; carbon dioxide suggested to be major constituent in atmosphere.

Duration of flight to target:

Mariner 3-Did not reach target
Mariner 4-228 days

.

For additional information:
JPL, Mariner-Mars 1964 Final Project Report, NASA SP-139 (Washington, 1967).
 
* Mariner D was also used for a short time in the winter of 1963 to refer to an Atlas-Centaur-launched Mariner C bus with a small atmospheric capsule that was being planned for 1966.

 


 

 
 
MARINER-MARS 1966

.

Preflight designation:

Mariner E
Mariner F

Flight designation:

Not flown.

Project proposed:

May 1963

Project approved:

19 Dec. 1963

Launch vehicle:

Atlas-Centaur

Launch date:

Effectively canceled 28 July 1964; officially terminated 4 Sept. 1964.

Program objectives:

Mars flyby spacecraft with small atmospheric probe to replace more ambitious Mariner B.

Program results:

Replaced by Advanced Mariner 1969.

 
 

 
 
 
 
ADVANCED MARINER 1969

.

Preflight designation:

Mariner-Mars 1969

Flight designation:

Not flown.

Project proposed:

Initial discussions January 1964

Project approved:

Project approval document signed 2 Aug. 1964.

Launch vehicle:

Atlas-Centaur

Launch date:

Canceled 20 Nov. 1964.

Project objectives:

Combination orbiter-lander mission designed to replace Mariner-Mars 1966 Mars flyby.

Program results:

Replaced by Mariner-Mars 1969 flyby mission.

.

For additional information:

JPL, "Mariner Mars 1969 Orbiter Technical Feasibility Study," EPD-250, 16 Nov. 1964; and JPL, "Mariner Mars 1969 Lander Technical Feasibility Studv," EPD-261, 28 Dec. 1964.
 
 

 
 
 
MARINER-VENUS 1967

.

Preflight designation:

Mariner E

Flight designation:

Mariner 5

Project proposed:

By post-Voyager 1971 deferral, 25 Dec. 1965.

Project approved:

25 Dec. 1965

Launch vehicle:

Atlas-Agena SLV-3
AA-23

Launch date:

14 June 1967, 2:01 a.m. EDT.

Program objectives:

Venus flyby to within 3218 km to provide data on atmosphere, radiation, and magnetic field environment; to return data on interplanetary environment before and after planetary encounter; to provide first exercise of turnaround ranging technique of planetary distance.

Spacecraft shape and size:

Octagonal magnesium-frame base, 127 cm diagonally and 45.7 cm deep. Four solar panels attached to top of base span 5.48 m deployed. High-gain ellipse antenna mounted atop base along with low-gain omnidirectional antenna and magnetometer 3 supported by 2.23-m-long tube. Attitude-control jets mounted at solar panel tips. Midcourse propulsion mounted on side of octagon. Overall height, 289 m.

Weight:

Structures/mechanical

49.4

Electrical (RF, TM, Data)

52.6

Power

57.4

Computer command

5.4

Attitude control

25.0

Pyro and cabling

15.4

Propulsion (inert)

12.8

Thermal control

4.5

Science

10.2

Expendables

12.2

Launch weight

244.9

Control system:

12 N2 jets-redundant
3 gyros, Canopus tracker
2 primary sun sensors
2 secondary sun sensors
Earth sensor
Venus sensor
Venus terminator sensor

Electrical power:

17 640 solar cells
Panels: 112 x 90 cm (4)
Total area, 4.0 m2
370 watts at Earth
550 watts at Venus
Silver-zinc battery 1200 watts per hr

Telecommunications:

Dual, S-band,6.5-watt/10.5-watt transmitter, single receiver
Low-gain omnidirectional antenna
High-gain 2-position parabolic antenna
Science and engineering data, 8 1/3 and 33 1/3 bits per sec
Tape recorder, 1 million bits

Propulsion:

Monopropellant hydrazine
225 newtons thrust
4-jet vane vector control

Command system:

DC-29
QC-3 @ 1 bit per sec
CC-0

Program results:

Spacecraft passed within 4000 km of Venus, provided data on atmospheric structure, radiation, and magnetic field; mass of Venus was further defined by processing flyby trajectory data; solar-wind interaction with Venus shown to be different from Earth interaction.

Duration of flight to target:

127 days

.

For additional information:

JPL, Mariner-Venus 1967 Final Project Report, NASA SP-190 (Washington, 1971).

 

 
 
 
MARINER-MARS 1969

.

Prelight designation:

Mariner F and Mariner G

Flight designation:

Mariner 6 and Mariner 7

Project proposed:

By post-Voyager 1971 deferral, 22 Dec. 1965.

Project approved:

22 Dec. 1965; project approval document signed 28 Mar. 1966.

Launch vehicle:

Altas-Centaur SLV-3C
AC20 (spacecraft 69-3) - Mariner 6
ACI9 (spacecraft 69-4) - Mariner 7

Launch date:

Mariner 6 - 24 Feb. 1969, 8:29 p.m. EST
Mariner 7 - 27 Mar. 1969, 5:22 p.m. EST

Program objectives:

Flyby of Mars at 3218 km to study surface and atmosphere to establish basis for future experiments in search for extraterrestrial life; develop technologies for future Mars missions. Demonstrate engineering concepts and technique required for long-duration flight away from sun.

Spacecraft shape and size:

Octagonal magnesium-frame base, 138.4 cm diagonally and 45.7 cm deep. Four solar panels span 5.79 m deployed. High-gain parabolic antenna mounted atop base along with low-gain omnidirectional antenna atop 2.23-m-long tube. Attitude-control jets mounted at solar panel tips. Midcourse propulsion system mounted in base compartment. Overall height, 3.35 m.

Weight:

Structures/mechanical

120.7

Electrical (RF, TM, Data)

62.1

Power

54.9

Computer command

10.9

Attitude control

37.2

Pyro and cabling

35.4

Propulsion (inert)

10.9

Thermal control

13.1

Science

57.6

Expendables

10.0

Launch weight

412.8

Control system:

2 sets of 6 N2 jets
3 gyros, Canopus tracker
2 primary sun sensors
4 secondary sun sensors

Electrical power:

17 472 solar cells
Panels: 215 x 90 cm (4)
Total area, 7.7 m2
800 watts at Earth
449 watts at Mars
Silver-zinc battery, 1200 watts per hr

Telecommunications:

Dual, S-band, 10-watt/30-watt transmitters, single receiver
Low-gain omnidirectional antenna
Engineering data, 8 1/3 and 33 1/3 bits per sec
Science data, 662/3 and 670 bits per sec
Tape recorder, 195 million bits

Propulsion:

Monopropellant hydrazine
225 newtons thrust
Total impulse 20 900 newtons per sec
4-jet vane vector control

Command system:

DC-53
QC-4 @ 1 bit per sec
CC-5

Program results:

Mariner 6 - First Mariner launched with Atlas-Centaur; performed flyby with Mariner 7; acquired data on Mars with visual imager, ultraviolet spectrometer, infrared spectrometer, and temperature sensors, obtained most detailed data on Mars to date.
 
Mariner 7 - Same as above; flew at a different angle from Mariner 6; obtained same data from different areas of the planet. Together the 2 spacecraft transmitted 143 analog pictures as they approached Mars, plus 58 photos during flyby; closeups were made of 20 percent of surface. Provided daytime and nighttime surface temperatures; confirmed presence of C02, ionized C02, CO, atomic hydrogen, and very slight traces of molecular oxygen. Confirmed ablateness estimates.

Duration of flight to target:

Mariner 6 - 156 days
Mariner 7 - 133 days

For additional information:

JPL. Mariner Mars 1969 Final Project Report, JPL TR-32-1460, 3 vols. (Pasadena, 1970).

 
 

 
 
 
MARINER-MARS 1971

.

Preflight designation:

Mariner H and Mariner I
Mission A and Mission B

Flight designation:

Mariner 8 and Mariner 9

Project proposed:

November 1967 by Office of Space Science staff following cancellation of Voyager.

Project approved:

Project approval document signed 23 Aug. 1968; NASA Hq. authorized JPL to begin work on Mariner-Mars 1971 on 14 Nov. 1968

Launch vehicle:

Atlas-Centaur SLV-3C
AC-24 - Mariner 8
AC-23 - Mariner 9

Launch date:

Mariner 8 - 8 May 1971, 9:11 p.m. EDT.
Mariner 9 - 30 May 1971, 6:23 p.m. EDT.

Program objectives:

Orbit Mars for 90 days; provide 25-30 million bits of scientific data; take total of more than 5000 TV pictures; take scores of TV pictures of the 2 moons; map more than 70 percent of surface; study temperature and composition of surface, study composition and structure of atmosphere; determine pressure of atmosphere.

Spacecraft size and shape:

Octagonal magnesium-frame base, 138.4 cm diagonally and 45.7 cm deep. Four solar panels attached to top of the base span 6.89 m. High-gain parabolic antenna mounted on base along with low-gain omnidirectional antenna on 1.44-m-long tube. Attitude-control jets mounted on solar panel tips. Midcourse propulsion mounted on top. Overall height, 2.28 m.

Weight:

Structures/mechanical

155.1

Electrical (RF, TM, Data)

60.8

Power

72.6

Computer command

10.4

Attitude control

39.4

Pyro and cabling

49.4

Propulsion (inert)

98.0

Thermal control

10.0

Science

63.1

Expendables

439.1

Launch weight

997.9

Control system:

2 sets of ACS jets, 6 jets each
Canopus star tracker
Cruise sun sensor
Sun gate

Electrical power:

14 742 solar cells
Panels: 215 x 90 cm (4)
Total area, 7.7 m2
800 watts at Earth
500 watts at Mars
Nickel-cadmium battery, 20 amp-hrs.

Telecommunications:

Dual, S-band, 10-watt/20-watt transmitters, single receiver
Low-gain omnidirectional antenna
Medium-gain horn antenna
High-gain, parabolic, 2-position antenna
Engineering data, 8 1/3, and 33 1/3, bits per sec
Science data, 16.2 kilobits per sec maximum
Tape recorder, 180 million bits

Propulsion:

Monomethyl hydrazine and nitrogen tetroxide
1340 newtons thrust
5 restarts capability
Gimbaled engine ±9°

Command system:

DC-86
QC-4 @ 1 bit per sec
CC-5

Program results:

Mariner 8 - With ignition of Centaur main engine 265 sec after launch, the upper stage began to oscillate and subsequently tumbled end over end. At about 365 sec after launch, Centaur engine shut down, and upper stage and spacecraft fell into Atlantic about 560 km north of Puerto Rico.
 
Mariner 9 - Total useful lifetime was 515 days, with 349 days in Mars orbit. Transmitted total of 7329 TV pictures of Mars and its satellites and mapped 100 percent of planet; transmitted 54 billion bits of science data (contrasting with 2 billion bits from all previous Mars flights).

Duration of flight to target:

Mariner 8 - Did not reach target
Mariner 9 - 167 days

.

For additional information:

Chap. 10; and JPL, Mariner Mars 1971 Project Final Report, JPL TR-32-1550, 5 vols. (Pasadena, 1972).
 
 

 
 
 
MARINER VENUS MERCURY 1973

.

Preflight designation:

Mariner J

Flight designation:

Mariner 10

Project proposed:

June 1968 by the Space Science Board.

Project approved:

Project assigned to JPL 30 Dec. 1969.

Launch vehicle:

Atlas-Centaur SLV-3D/D1-A

Launch date:

3 Nov. 1973, 12:45 a.m. EST.

Program objectives:

Flyby of Venus and encounter with Mercury (primary target) at an altitude of 1000 km; conduct exploratory investigations by obtaining measurements of environment, atmosphere, and body characteristics for both planets. Perform experiments in the interplanetary medium; obtain experience with dual planet, gravity-assist mission.

Spacecraft size and shape:

Octagonal magnesium-frame base, 138.4 cm deep. Two solar panels attached to top of base span 6.55m. High-gain parabolic antenna mounted on top along with scan platform and one of the 2 low-gain omniantennas. Other low-gain antenna mounted on base. Attitude-control jets mounted on supports from octagon faces. Midcourse propulsion system mounted in base compartment.

Weight:

Structures/mechanical

109.4

Electrical (RF, TM, Data)

60.8

Power

63.6

Computer command

10.4

Attitude control

29.9

Pyro and cabling

30.8

Propulsion (inert)

11.3

Thermal control

9.5

Science

78.2

Expendables

29.0

Launch weight

432.9

Control system:

2 sets of 6 N2 jets
3 gyros, Canopus tracker
2 primary sun sensors
4 secondary sensors

Electrical power:

19 800 solar cells
Panels: 215 x 120 cm (2)
Total area, 5.2 m2
500 watts on Earth
820 watts on Venus
820 watts (tilted) on Mercury
Nickel-cadmium battery, 20 amp-hrs

Telecommunications:

Dual, S-band, 10-watt/20-watt transmitter, single receiver
2 low-gain omnidirectional antennas
High-gain parabolic antenna
Engineering data, 8 1/3 and 33 1/3 uncoded
Science data, 117.6 kilobits per sec maximum
Tape recorder, 180 million bits

Propulsion:

Monopropellant hydrazine
225 newtons thrust
Total impulse 20 900 newtons per sec
4-jet vane vector control

Command system:

DC-96
QC-4 @ 1 bit per sec
CC-5

Program results:

First dual-planet mission; first mission to use gravitational attraction of one planet to reach another. Venus encountered at 1:01 p.m. EDT, 5 Feb. 1974, 5800 km from surface. Some 4000 photos of Venus revealed a nearly round planet enveloped in smooth cloud layers with a slow rotational period (243 days) and only 0.05 percent of Earth's magnetic field; atmosphere mostly hydrogen, resulting from solar wind bombardment. After Venus flyby, spacecraft trajectory bent in toward sun for first exploration of Mercury. Mercury encountered at 4:47 p.m. EDT, 29 March 1974, 704 km from surface. Photos revealed intensely cratered, lunar like surface. Atmosphere, mostly helium. High-iron-rich core makes Mercury densest planet in solar system; iron core also accounts for existence of magnetic field despite planet's extremely slow spin rate. After Mercury flyby, spacecraft entered solar orbit. Flew by Mercury again 20-23 Sept. 1974, coming within 48 069 km. Photographed sun side of planet and south polar region. Photographed total of 45 percent of Mercury's surface.

Duration of flight to target:

166 days to Venus

.

For additional information:

NASA, "Mariner Venus/Mercury: A Study in Cost Control," Nov. 1973; and James A. Dunne and Eric Burgess, The Voyage of Mariner 10: Mission to Venus and Mercury, NASA SP-424 (Washington, 1978).
 
 

 
 
 
VOYAGER

.

Preflight designation:
Voyager*
Voyager 71
Voyager 73

Flight designation:

Not flown.

Project proposed:

First mentioned in spring 1960; JPL preliminary studies 1961-1962.

Project approved:

Project approval document for preliminary studies signed 21 Nov. 1962; phase I study approved 16 Dec. 1964 and revised 14 Jan. 1965 and 15 Oct. 1965.

Launch vehicle:

Initially all studies centered on use of Saturn IB-Centaur; when Saturn IB-Centaur terminated in mid-Oct. 1965, Voyager shifted to Saturn V.

Launch date:

Saturn IB-based Voyager 1971 mission canceled 22 Dec.1965; Saturn V missions with 2 landers each for Voyager 1973 canceled 29 Aug. 1967.

Program objectives:

Originally planned as the large-weight class of spacecraft to follow the Mariner class, Voyager was scheduled to visit both Venus and Mars and release landers. Successively redefined plans called for the following missions: Venus 1967; Mars 1969, deferred in 1964 and rescheduled for 1971; Mars 1971, deferred 22 Dec. 1965 and rescheduled for 1973, Mars 1973, canceled 29 Aug. 1967.

.

For additional information:

Chap. 4; app B.

 
 
*The name Voyager was later given to 2 spacecraft launch in 1977 to fly by Jupiter, Saturn, and perhaps Uranus.
 
 

 
 
 
VIKING

.

Preflight designation:

Viking 73
Viking 75
Viking A and Viking B

Flight designation:

Viking 1 and Viking 2

Project proposed:

November 1967-January 1968

Project approved:

4 Dec. 1968 by T. O. Paine; project approval document signed 8 Feb. 1969.

Launch vehicle:

Titan IIIE-Centaur
TC4 - Viking 1 (spacecraft B), VLC-1 and VO-1
TC3 - Viking 2 (spacecraft A), VLC-2 and VO-2

Launch date:

Launch deferred from 1973 to 1975:
Viking 1 - 20 Aug. 1975, 5:22 p.m. EDT
Viking 2 - 9 Sept. 1975, 2:39 p.m. EDT

Program objectives:

Soft-land on Mars; search for presence of life; compare orbital and surface data. Orbiter: deliver lander to Mars orbit; survey and select landing sites; relay data from surface to Earth; conduct orbital science investigations. Lander: search for possibility of life forms; determine environmental of surface

Spacecraft shape and size

Orbiter: Mariner-style bus; octagonal ring 45.72 cm high with alternate 139.7-cm size: and 50.8-cm sides. Consists of 16 modular compartments, 3 on each of the 4 long sides and 1 on each of the 4 short sides; 9.75 m across from tips of extended solar panels. Overall height, 3.29 from lander attachment points on bottom to launch vehicle.
 
Lander: Hemispherical bioshield 360 cm diameter. Conical 70° half-angle aeroshell/heat shield 350 cm diameter. Triangular 3-leg lander configuration height 102 cm, width 284 cm (less instruments). High-gain S-band parabolic, UHF, and low-gain S-band antennas. Aeroshell, parachute, and terminal descent propulsion (18 nozzles) for deceleration.

Weight:

Orbiter:

Structures and mechanisms

267

Communications

57

Data processing & storage

45

Power

129

Computer command

18

Attitude control inerts

59

Pyro & cabling

61

Propulsion inerts

174

Science instruments

73

Orbiter dry weight

883

.

Propellant

1426

Gas for propulsion & attitude control

20

Total expendables

1445

.

Orbiter launch weight

2328

.

Lander:

Structures & mechanisms

132

Propulsion inerts

49

Pyro and cabling

43

Thermal control

36

Guidance and control

79

Power

103

Communications and telemetry

57

Science instruments

91

Lander dry weight

590

.

Residual propellants at landing

22

.

Total VL weight at landing

612

.

Propellant at launch

73

.

Lander launch weight

663

.

Viking lander capsule:

- Aerodecelerator:

.

Structures

46

Parachute & mortar

56

Thermal control

4

Miscellany

3

Total

109

.

- Aeroshell:

.

Structures

120

Propulsion inerts

29

Thermal control

7

Cabling

7

Science instruments

9

Miscellany

9

Total dry weight

181

Propellants

88

Total loaded weight

269

.

- Bioshield base:

.

Structures

45

Thermal control

10

Power

15

Miscellany

4

Total

74

.

- Bioshield cap:

.

Structures

47

Thermal control

3

Miscellany

4

Total

54

.

Loaded capsule weight

1168

.

Orbiter

2328

Lander and capsule

1185

Capsule mounting adapter

14

Total launch weight

3527

Control system:

Orbiter:
2 sets of N2 ACS jets, 6 jets each
Canopus star tracker
Acquisition sun sensor
Cruise sun sensor
Sun gate
6 gyros, 2 accelerometers
 
Lander:
Inertial control
4 gyros
Aerodecelerator
Radar altimeter
Terminal descent and landing radar

Electrical power:

Orbiter:
34 800 solar cells
Panels: 157 x 123 cm (8)
Total area, 15.4 m2
1400 watts on Earth
620 watts on Mars
2 nickel-cadmium, 30-amp-hr batteries
 
Lander:
Radioisotope thermal generator
2 RTG units, 90 watts
4 nickel-cadmium, 8-amp-hr batteries

Telecommunications:

Orbiter:
S-band, 20-watt transmitter, 2 10- and 20-watt
TWTAs
High-gain antenna, 2-axis steerable
Low-gain antenna, fixed
Engineering data,81/3 and 33 1/3, kilobits per sec
Science data, 1, 2, 4, 8, and 16 kilobits per sec
2 tape recorders, 128 x 107 bits
Relay radio, 381 MHz
 
Lander:
S-band, 20-watt transmitter, 2 20-watt TWTAs
High-gain antenna, 2-axis steerable
Low-gain antenna, fixed
Engineering data, 8 1/3 and 33 1/3 kilobits per sec
Science data, 250, 500, and 1000 bits per sec
Tape recorder, 4 x 107 bits
Relay radio, 381 MHz, 30 watts, 4 and 16 kilobits per sec

Propulsion:

Orbiter:
Monomethyl hydrazine and nitrogen tetroxide
1323 newtons thrust
Rate-of-velocity-change ( Delta V) capability 1480 meters per second
Gimbaled engine ± 9°
 
Lander:
RCS/deorbit: monomethyl hydrazine,35 newtons thrust, 12 nozzles, Delta V 180 meters per sec
Terminal descent: monomethyl hydrazine, 2650 newtons maximum thrust, 3 (18-nozzle) engines

Command system:

Orbiter:
DC-171
CC-40 @ 4 bits per sec
PC- 4 operator words
 
Lander:
DC-25 @ 4 bits per sec
6000-word (maximum) for command instructions

Program results:

See chaps. 11 and 12.

Duration of flight to target:

Viking 1 - 304.1 days
Viking 2 - 332.7 days
 
 


[
451] Martin Marietta Manpower Plan

JPL Manpower Plan

Martin Marietta Manpower Plan &
JPL Manpower Plan

Shifting from a 1973 to a 1975 Viking launch brought changes in manpower levels. Martin Marietta personnel numbers were significantly lower for the 1975 mission (1650 vs. about 2200), although JPL figures were not significantly affected (538 vs. about 600). From Langley Research Center, Viking Proj. Off., "Viking Project, Resource Planning Report, July 1970." 30 July 1970.



[
452]

Martin Marietta Funding Requirement for Viking

JPL Funding Requirement for Viking

Martin Marietta Funding Requirement for Viking & JPL Funding Requirement for Viking

The graphs illustrate the major milestones for the Viking lander and orbiter and the amount of money required for each phase of the project. From Langley Research Center, Viking Proj. Off., "Viking 75 Project, Resource Planning Report, July 1970,''30 July 1970. PDR = preliminary design review. CDR = critical design review. PTO = proof-test orbiter.

 

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