MANNED SPACE PROGRAM

 

    The United States manned space program has been conducted in three major phases-Mercury, Gemini, and Apollo. Each manned flight has led to increased knowledge of the systems and techniques needed to operate successfully in space, and each phase represents a significant advancement over the previous one.

    The first man in space was the Russian Yuri Gagarin, who made one orbit of the earth in his Vostok 1 spacecraft on April 12, 1961. The first American spaceman was Alan B. Shepard, Jr., who rode his Mercury spacecraft into space atop a Redstone booster on May 5, 1961. The first American to orbit the earth was John H. Glenn, Jr., who made three orbits in a Mercury spacecraft on Feb.20,1962.

    To date (August 1, 1968), 19 Americans have been in space, and seven of these have made two space flights. There were six manned flights during the Mercury program and 10 manned flights in the Gemini program.

    Eleven Russians have been in space in their nine launch program. The Russian manned program also has involved three spacecraft, with six flights aboard the one-man Vostok, two flights with the Voskhod (one a three-man and the other a two-man craft), and a single flight with the Soyuz spacecraft.

    There have been no fatalities in space, but accidents have marred the advanced programs of both the United States and Russia. Three American astronauts-Virgil 1. Grissom, Edward H. White, 11, and Roger B. Chaffee-died in a fire aboard an Apollo spacecraft on the pad at Kennedy Space Center. Grissom, a veteran of two space flights, was pilot of the second Mercury spacecraft and commander of the first Gemini to go into space. White was aboard the second manned Gemini spacecraft in orbit, and made the historic 21minute "walk in space." The accident occurred on Jan. 27, 1967, as the three men were rehearsing countdown procedures for what was to have been the first Apollo manned launch.

    The Russian tragedy occurred during a space mission, but not in space. Cosmonaut Vladimir Komarov died in the Soyuz 1 spacecraft on April 24, 1967, when it crashed during landing. The Soyuz flight, which lasted about 25 hours, had been characterized as successful by the USSR. It had entered the atmosphere and was at an altitude of about 4.3 miles when its parachutes became fouled and it plunged to earth. Komarov was the first Russian to go into space twice: he was one of the three cosmonauts aboard the Voskhod 1.

 

MERCURY

    Project Mercury was America's first step into space. The one man Mercury capsules were designed to answer the basic questions about man in space; how he was affected by weightlessness, how he withstood the gravitational forces of boost and entry, how well he could perform. A milestone in applied science and engineering, the Mercury flights proved that man not only could survive, he could greatly increase the knowledge of space.

Mercury Spacecraft.

(P-42) Mercury Spacecraft

 

Table 6, Mercury Flights

 Date

 Vehicle

 Astronaut

 Revolutions

 Hours

 

 May 5, 1961

 Mercury - Redstone 3

 Alan B. Shepard, Jr

*

00:15:22

 First American in space: Freedom 7

 July 21, 1961

 Mercury - Redstone 4

 Virgil 1. Grissom

*

00:15:37

 Capsule sank: Liberty Bell 7

 Feb.20,1962

 Mercury - Atlas 6

 John H. Glenn, Jr.

3

04:55:23

 First American in orbit: Friendship 7

 May 24, 1962

 Mercury - Atlas 7

 M. Scott Carpenter

3

04:56:05

 Landed 250 miles from target: Aurora 7

 Oct. 3, 1962

 Mercury - Atlas 8

 Walter M. Schirra, Jr.

6

09:13:11

 Landed 5 miles from target: Sigma 7

 May 15-16, 1963

 Mercury - Atlas 9

 L. Gordon Cooper, Jr.

22

34:19:49

 First long flight: Faith 7

    * Sub-orbital

 

GEMINI

    Gemini was the next step in NASA's program. The goal of these two-man flights was to find out how man could maneuver himself and his craft, and to increase our knowledge about such things as celestial mechanics and space navigation. Gemini has a record of 10 successful manned flights and set many records, including the longest duration (almost 14 days), the first rendezvous by two maneuverable spacecraft, and the first docking.

Gemini Spacecraft.

(P-43) Gemini Spacecraft

 

Table 7, Gemini Flights

Date

 Vehicle

 Astronauts

 Revolutions

 Hours

 

 Mar. 23, 1965

 Gemini 3

 Virgil Grissom
 John Young

 3

4.9

 First manned orbital maneuvers

 June 3-7, 1965

 Gemini 4

 James McDivitt
 Edward White

 62

97.9

 21 -minute "space walk" by White

 Aug. 21-29, 1965

 Gemini 5

 Gordon Cooper
 Charles Conrad

 120

190.9

 First extended manned flight

 Dec. 4-18, 1965

 Gemini 6

 Frank Borman
 James Lovell

 206

330.6

 Longest space flight; served as Gemini VI-A target vehicle

 Dec. 15-16, 1965

 Gemini 7A

 Walter Schirra
 Tom Stafford

 16

25.9

 Rendezvous within 1 foot of Gemini 7

 Mar. 16-17, 1966

 Gemini 8

 Neil Armstrong
 David Scott

 6.5

10.7

 First docking, to Agena target; short circuit cut flight short

 June 3-6, 1966

 Gemini 9A

 Tom Stafford
 Eugene Cernan

 45

72.3

 Rendezvous, extra vehicular activity, precision landing

 July 18-21, 1966

 Gemini 10

 John Young
 Michael Collins

 43

70.8

 Rendezvous with 2 targets; retrieved package from Agena in space walk

 Sept. 12-15, 1966

 Gemini 11

 Charles Conrad
 Richard Gordon

 44

71.3

 Rendezvous and docking, 161-minute extravehicular activity

 Nov. 11-15, 1966

 Gemini 12

 James Lovell
 Edwin E. Aldrin

 59

94.6

 3 successful extravehicular trips, rendezvous and docking, rendezvous with solar eclipse

 

 


RUSSIAN MANNED PROGRAM

    The Soviet Union opened the space age when it put the first man, Yuri Gagarin, into space in April of 1961. They followed four months later with the 25-hour flight of Gherman Titov.

    The Russians waited a year after the Gagarin flight before their next, but that was the first group flight; two spacecraft on successive days. A 10-month lull followed before the second group flight, this time including a woman, Valentina Tereshkova, as one of the cosmonauts.

    These six flights were with the Soviet Union's first manned spacecraft, the Vostok. Their second generation spacecraft, the Voskhod, made only two flights about six months apart. The first Voskhod mission, 16 months after the last Vostok flight, carried a crew of three and was the first spacecraft with more than one passenger. The second Voskhod flight carried only two men but featured the first man to leave his spacecraft and "walk" in space.

    The Soviet Union's third-generation spacecraft, Soyuz, made its only flight in April of 1967, when Komarov was killed.

Table 8,Russian Manned Flights

Date

 Spacecraft

 Cosmonaut

 Revolutions

 Hours

 

 Apr. 12, 1961.

 Vostok 1.

 Yuri Gagarin.

1

1.8

First manned flight

 Aug. 6, 1961

 Vostok 2.

 Gherman Titov.

17

25.3

 More than 24 hours in space

 Aug. 11,1962.

 Vostok 3.

 Andrian Nikolayev.

64

94.4

 First group flight

 Aug.12,1962.

 Vostok 4.

 Pavel Popovich

48

71.0

 Came within 3.1 miles of Vostok 3 on first orbit

 June 14, 1963.

 Vostok 5.

 Valery Bykovsky.

81

119.1

 Second group flight

 June 16, 1963.

 Vostok 6.

 Valentina Tereshkova.

48

70.8

 Passed within 3 miles of Vostok 5; only woman in space

 Oct. 12, 1964.

 Voskhod 1

 V. Komarov.
 K. Feoktistov
 B. Yegorov

16

24.3

 First 3-man craft

 Mar. 18, 1965

 Voskhod 2

 A. Leonov
 P. Belyayev

17

26.0

Leonov was first man outside spacecraft in 10-minute "walk"

 Apr. 23, 1967

 Soyuz 1

 Vladimir Komarov

17

25.2

Heaviest manned craft; crashed killing Komarov

 

 

SPACECRAFT DIFFERENCES

    Many differences in the three manned U.S. spacecraft are readily apparent, such as size and weight. The major differences are in the complexity and refinement of subsystems. Apollo's requirement for hardware "maturity" is significantly higher than for earlier spacecraft programs. Each subsystem has become progressively more complex, with many more demands made upon it and a correspondingly greater capability. Only Apollo has its own guidance and navigation system.

    Electrical power is a good example of increased system complexity. Electrical power for Mercury was supplied by six batteries; for Gemini, it was supplied by seven batteries and two fuel cell powerplants; for Apollo, it is supplied by five batteries and three fuel cell powerplants. The three systems do not sound too different physically. In operation, however, the differences are considerable.

    The greatest demand on the Mercury system was to supply power to sustain the 4,265-pound spacecraft and its single astronaut for a day and a half (the 34-hour flight of Gordon Cooper). In Gemini, the electrical power system had to provide sufficient power to operate a typical 7,000-pound craft containing two astronauts for as long as two weeks (the 14-day flight of Frank Borman and James Lovell). In Apollo, the system is designed to support a 100,000-pound spacecraft carrying three men for up to two weeks.

Table 9, Basic spacecraft differences.

 

Mercury

Gemini

Apollo

 Height

 26 ft

 19 ft

 82 ft

 Diameter

 6.2 ft

 10 ft

 12 ft 10 in.

 Launch weight

 4265 lb at launch
 2987 lb in orbit
 2422 lb at recovery

 8360 lb

109, 500 lb at launch
100,600 lb injected

 Crew

 1

 2

 3

 Major components

 Manned capsule (6 ft 10 in.)
 Adapter (4 ft 3 in.)
 Launch escape tower (16 ft 11 in.)

 Entry (manned) module (11 ft 4 in.)
 Adapter module (7 ft 6 in.)

Command module (10 ft 7 in.) (top of apex cover)
Service module (24 ft 2 in.) (top of fairing)
Lunar module (22 ft 11 in.) (legs folded)
Launch escape system (33 ft)
Adapter (28 ft)

 Subsystems

 Abort

 Launch escape rocket and tower to carry manned capsule to safety

 Ejection seat for each astronaut up to about 70,000 ft; malfunction detection system

 Launch escape rocket and tower (similar to Mercury but about twice the size); emergency detection system

 Communications

 UHF and HIF for voice; UHF for telemetry; C-band and S-band tracking radar

 UHF primary for voice with HF backup; C-band tracking beacon; rendezvous radar; 300 flight measurements telemetered to ground

 VHF-AM primary for near earth; S-band primary for deep space; rendezvous radar; 700 flight measurements telemetered to ground

 Docking

 None

 Index bar (to fit in notch on target vehicle) and latches

Probe and docking ring on CM, drogue on LM

 Earth Landing

 4 chutes: main, drogue, reserve, pilot

 3 chutes: main, drogue, pilot, and ejection seats

8 chutes: 3 main, 2 drogue, 3 pilot

 Electrical Power

 6 batteries: 3 main auxiliary, 2 standby, and 1 isolated

 2 small fuel cells; 2 cryogenic tanks, 4 entry batteries, 3 pyro batteries

 3 large fuel cells; 4 cryogenic tanks; 3 entry batteries; 2 pyro batteries

 Environmental Control

 Suit cooling and oxygen loop, cabin cooling loop (water coolant); cabin pressurized to 5 psi; no space radiators

 Suit cooling and oxygen loops; redundant cabin cooling loops (silicon ester coolant); cabin pressurized to 5 psi; space radiators, coldplates for operating equipment; shirtsleeve environment

 Four major loops: oxygen, suit circuit, water, and coolant (water-glycol); space radiators and coldplates; cabin pressurized to 5 psi; shirtsleeve operations

 Guidance and Control

 Attitude control equipment (2 attitude gyros, 3 rate gyros, logic and programming circuits); automatic system using 12 small H202 thrusters and manual system using 6 small H202 thrusters; horizon sensors, periscope

 Small computer (4,000-word memory), horizon sensor, no redundancy; 16 orbital attitude maneuvering system thrusters of 25 to 100 lb (No redundancy); 16 entry control thrusters (redundant systems of 8 25-lb engines); inertial platform, rendezvous radar

 Large computer (39,000word memory), telescope and sextant; semiautomatic operation; optical, inertial, and computer systems; attitude control through stabilization and control systems; 16 SM reaction control engines (100-1b) redundant systems, 12 CM reaction control engines in redundant systems; separate guidance and control systems in LM

 Propulsion

 3 posigrade rockets for separation from booster, 3 retrograde rockets for entry from orbit

 4 retrograde rockets for entry (2,500 lb each)

 Restartable service propulsion engine (20,000 lb); liquid propellant rodset propulsion with unlimited restart and thrust vector control (automatic and manual)