Spaceflight History

Since the beginning of aeronautics and space exploration, animals have accompanied and sometimes preceded humans as space travelers. Historically, extensive animal experimentation was used in both the United States and Soviet/Russian space programs to collect the medical knowledge and test the engineering design concepts that would be required to support human spaceflight. A variety of animal models were used as substitutes to test the suitability of the space environment for human presence, including launch systems, radiation and microgravity exposure, life support systems, and recovery procedures (Borkowski et al. 1996). At first, small organisms, such as insects and plant seeds, were sent in space, primarily to evaluate the effects of cosmic radiation. Later, test flights involved mammals and primates for investigating the physiological effects of acceleration and microgravity. These early animal flights evaluated the basic medical risks of short-duration spaceflights, paving the way for human missions. Once it was determined that complex biological organisms could survive in orbit, humans ventured into space, and took animals along as experimental subjects. With humans spending longer and longer periods in space, biological specimens continue to be flown during manned or unmanned missions to better understand the long-term physiological effects of the space environment, including microgravity and cosmic radiation (Balard and Souza 1991).

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Figure 2-02. Photograph of Laika in her space capsule. Image courtesy of Alexander Chernov and the Virtual Space Museum in Russia. Source: http://www. nasa.gov

1.1 Preparation for Human Spaceflights

1.1.1 Suborbital Flights

Non-human organisms have played a leading role throughout the history of technological flight. In 1783, a duck, a rooster, and a sheep became the first passengers in a hot air balloon, since no one knew whether a human could survive the flight. All three animals survived the flight, although the duck was found with a broken leg, presumably due to a kick from the sheep after landing. Humans followed soon after and experienced for the first time the symptoms of hypoxia.

In the 1950s, when the decision was made to explore space, some people were skeptical. Could human beings live in a world virtually without gravity? Did the space environment harbor dangerous organisms? Just like for balloon flights, animals were sent up in rockets before humans to ascertain whether a living being could withstand and survive a journey into space. Instruments monitored various physiological responses as the animals experienced the stresses of launch, reentry, and the weightless environment.

The first animals intentionally sent into space were fruit flies that were sent with corn seeds inside the nose cone of a captured German V-2 rocket in July 1946. These were the same models as those used during World War II. The purpose of the experiment was to explore the effects of radiation exposure at high altitudes. Some further V-2 missions carried biological samples including moss. During subsequent tests, vertebrate animals flew (Table 2-01). The first was a 4-kg anaesthetized rhesus monkey (Macaca mulatto) named Albert. Unfortunately, Albert died as a result of breathing difficulties in the cramped capsule before his rocket left the ground. In the second flight, in 1949, the capsule was redesigned to allow the subject (Albert II) assume a less cramped position. Albert II died at impact, however, but respiratory and cardiological data were successfully recorded up to that moment. Thus, it was established that a monkey had lived during an entire flight which reached an altitude approximately 133 km above the surface of the Earth, following accelerations of 5.5 g at lift off and 13 g at the opening shock of the parachute recovery system. The evolution of engineering techniques was making possible greater success in the scientific exploration of physiological factors related to spaceflight.

One of the following V-2 experiments used a mouse as the subject and no attempt was made to record heart action or breathing. Unlike the monkeys, the mouse was not even anesthetized because the purpose of the experiment was to record the conscious reactions of an animal to changing gravity conditions. For this purpose, the mouse capsule was equipped with a camera system to photograph the mouse at fixed intervals. Again, the recovery system failed and the mouse did not survive the impact. But the photographs came through successfully and showed that the mouse retained "normal muscular coordination" throughout the very brief period of microgravity, even though "he no longer had a preference for any particular direction, and was as much at ease when inverted as when upright relative to the control starting position" (Dempsey 1985).

Flights of more advanced Aerobee rockets in late 1951 and 1952 carried an ark full of animals to space and brought them all back alive. Included in the menagerie were a monkey instrumented to record heart beat, respiration and blood pressure; nine mice who went along simply to be exposed to cosmic radiation; and two other mice in a rotating drum for the photographic observation of their reactions to short-term microgravity. One of the two mice had undergone a prior operation removing the vestibular apparatus, and was already accustomed to orient itself by vision and touch exclusively. Interestingly enough, she did not seem affected by loss of gravity during the flight. The other mouse, which was normal, clawed at the air and appeared definitely disturbed during the microgravity phase of the trajectory (Dempsey 1985).

On December 13, 1958, a Jupiter ballistic missile was launched from Cape Canaveral, Florida with a U.S. Navy trained South American squirrel monkey named Gordo onboard. The nose cone recovery parachute failed to operate and Gordo did not survive the flight. Telemetry data sent back during the flight showed that the monkey survived the 10 g of launch, 8 minutes of weightlessness and 40 g of reentry at 16,000 km/h. The nosecone sank and was not recovered. A rhesus and a squirrel (SaimirĂ­ sciureus) monkey, named Able and Baker, respectively, became the first monkeys to survive spaceflight after their 1959 flight on board a Jupiter missile. They withstood forces 38 times the normal pull of gravity and were weightless for about 9 minutes. A top speed of 14,000 km/h was reached during their 16-min flight. The monkeys survived the flight in good condition.

The Soviet Union, which began the space race with Sputnik in 1957, also launched dogs during suborbital flights. In other countries, France flew rats into space in 1961 and 1962, and two cats in 1963. The cats had electrodes implanted into the head to measure neural impulses. The first cat was recovered alive but the next cat in space was not. The final French animal launches were of two monkeys (Martine and Pierrette) in March of 1967. China launched mice and rats in 1964 and 1965 and two dogs in 1966 (Table 2-01).

Spacecraft

Date

Animals (number) Apogee (km)

V-2 No 37

1948 Jun 11

Rhesus monkey

63

V-2 No 47

1949 Jun 14

Rhesus monkey

133

V-2 No 32

1949 Sep 16

Rhesus monkey

1?

V-2 No 31

1949 Dec 08

Rhesus monkey

127

V-2 No 51

1950 Aug 31

Mouse

?

Aerobee -12

1951 Apr 18

Rhesus monkey

61

R-1V

1951 Jul 22

Dog (2)

100

R-1B

1951 Jul 29

Dog (2)

100

R-1B

1951 Aug 15

Dog (2)

100

R-1V

1951 Aug 19

Dog (2)

100

R-1B

1951 Aug 28

Dog (2)

100

R-1B

1951 Sep 2

Dog (2)

100

Aerobee-19

1951 Sep 20

Rhesus monkey; Mice (11)

71

Aerobee-26

1952 May 22

Phillipine monkeys (2)

Mice (11)

26

R-1D

1954 Jul 2

Dog (2)

100

R-1D

1954 Jul 7

Dog

100

R-1D

1954 Jul 26

Dog

100

R-1E

1955 Jan 25

Dog

100

R-1E

1955 Feb 5

Dog

100

R-1E

1955 Nov 4

Dog

100

R-1E

1956 May 14

Dog

100

R-1E

1956 May 31

Dog

100

R-1E

1956 Jun 7

Dog

100

V-2A (R-2)

1957 May 16

Dog (2)

220

V-2A

1957?

Dog

220

V-2A

1957?

Dog

220

V-2A

1957?

Dog

220

V-2A

1957 Aug 31

Dog

220

Thor A ble

1958 Apr 23

Mouse

0?

Thor A ble

1958 Jul 10

Mouse

(45 min)

Thor Able

1958 Jul 24

Mouse

?

V-5A (R-5)

1958 Aug 27

Dog (2)

450

V-5A (R-5)

1958 Sep 17

Dog (2)

450

V-5A (R-5)

1958 Oct 31

Dog (2)

450

AM-13 Bio-1

1958 Dec 13

Squirrel monkey

?

AM-18 Bio-2

1959 May 28

Rhesus & Squirrel monkeys 600

V-2A

1959 Jul 2

Dog (2),

220

V-2A

1959 Jul 10

Dog

220

AM-23 Bio-3

1959 Sep 15

Mice (12)

0?

LJ-2

1959 Dec 4

Rhesus monkey

85

LJ-1B

1960 Jan 21

Rhesus monkey

15

V-2A

1960 Jun 15

Dog (2)

220

V-2A

1960 Jun 24

Dog (2)

220

V-2A

1960 Sep 16

Dog (2)

220

V-2A

1960 Sep 22

Dog (2),

220

Atlas 7ID

1960 Oct 13

Mice (3)

(20 min)

MR-2

1961 Jan 31

Rhesus monkey

253

Veronique-24

1961 Feb 22

Rat

110

SP Pod 13

1961 Nov 10

Squirrel monkey

1

SP Pod 6

1961 Dec 10

Rhesus monkey

500?

Veronique-37

1962 Oct 15

Rat

?

Veronique-36

1962 Oct 18

Rat

?

Veronique-47

1963 Oct 18

Cat

?

Veronique-50

1963 Oct 24

Cat

?

T-7A-S

1964 Jul 19

Rats and mice

?

T-7A-S

1965 Jun 1

Rats and mice

?

T-7A-S

1965 Jun 5

Rats and mice

?

T-7A-S2

1966 Jul 14

Dog (m.)

100

T-7A-S2

1966 Jul 28

Dog (f.)

?

Vesta 4

1967 Mar 7

Pigtailed macaque

233

Vesta 5

1967 Mar 13

Pigtailed macaque

240?

Table 2-01. List of vertebrate animals flown during suborbital flights between 1948 and 1967. Source: http://planet4589.org/space/book/astronauts/astronaut/bio.html

Table 2-01. List of vertebrate animals flown during suborbital flights between 1948 and 1967. Source: http://planet4589.org/space/book/astronauts/astronaut/bio.html

1.1.2 Orbital Flights

In 1957, a dog named Laika the first organism to orbit the Earth (Figure 2-02). Dogs were used because scientists believed they could endure long periods of inactivity better than other animals and because the Soviets had a long history of research with canines. The dogs were trained using centrifuges to simulate the extreme g forces of take off. Laika had been equipped with a comprehensive array of telemetry sensors, which gave continuous physiological information to tracking stations. The cabin conditioning system maintained sea-level atmospheric pressure within the cabin, and Laika survived six days before depletion of the oxygen stores caused asphyxiation. Laika's flight demonstrated that spaceflight was tolerable to animals. The Soviet Union launched mice and for the first time, guinea pigs and frogs in the Vostok-3A flights of March 1961, just preceding the historical flight of Yuri Gagarin in April 1961.

Twelve other dogs, as well as mice, rats and a variety of plants were then sent into space for longer and longer duration between 1960 and 1966 (Table 2-02). In 1966, a Soviet biosatellite Cosmos mission carried two dogs in orbit for 23 days. The dogs were observed via video transmission and biomedical telemetry. Their spacecraft landed safely. The first tortoise in space and the first animal of any kind in deep space was launched in 1968 by the Soviet Union. The Horsfield's tortoise was sent on a circumlunar voyage along with flies, worms, and other biological specimens, and the capsule was recovered at sea.

Figure 2-03. This photograph shows the biosensors used for monitoring the physiological parameters of monkeys during spaceflight. Photo courtesv of NASA.

During this period, in the U.S., in preparation for the human flights, Sam, a rhesus monkey, was launched in a Mercury capsule in the late 1959. He returned safely to Earth after a suborbital flight (Table 2-01). He flew again later, becoming the first animal to fly in space twice. Ham preceded Alan Shepard into space, in January of 1961 (Figure 2-01). He enjoyed a ballistic flight of about 16 minutes and landed in the Atlantic Ocean, again with no untoward effects. He was trained to pull levers to receive rewards. His flight demonstrated the ability to perform tasks during spaceflight. The chimpanzee Enos flew in Mercury Atlas-5 immediately preceding John Glenn's orbital flight. He was the first primate to orbit the Earth, during which he was carefully monitored (Figure 2.03), with no change in his physiology. He performed tasks as he would have on Earth, which indicated that humans would not be incapacitated by the environment of space.

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