The experiment on board the orbital station,,MIR'' showed that normal
development of quail embryos is possible and viable progeny can be obt
ained although at a considerably smaller hatching rate and a higher fr
equency of anomalies in the development of eyes, brain and beak. The m
orphological indices of embryos and hatchlings did not show any notice
able deviations in mass, and body size. An assumption was put forward
concerning the possible secondary mechanism for development of these d
eviations and a decreased hatching rate. Numerous authors have success
fully studied different phases of embryogenesis of amphibians, fish, i
nsects, birds and mammals in the course of several spaceflights. The f
ull cycle of embryogenesis in weightlessness has not been studied as y
et except for experiments with Drosophylla carried out by G. P. Parfen
ov focused on genetics of gene rations of flies grown in space (Parfen
ov 1988). Unfortunately, these experiments have not been recognized in
literature as the first embryological experiments using insects and c
overing the whole embryogenesis beginning with the moment of fertiliza
tion in weightlessness. The study of embryonic development of birds du
ring space flight is especially important as this model enables invest
igation of the biological role of gravity as a general biology problem
with its practical aspects, taking into consideration the fact that t
he quail is a potential component of a life-support system of man in l
ong-time space flights. The first, though not full, realization of thi
s idea took place in 1979 on board the Soviet satellite ''Cosmos-1129'
'. The work was carried out together with specialists from CSFR. A 12-
days-long experiment yielded results on quail egg incubation under the
conditions of weightlessness and showed that normal development of ab
out 33 % embryos during 2/3 of their embryogenesis is possible, which
was determined by the period of existence of the biosputnik. It was po
ssible to work out technology for an experiment embracing the whole em
bryogenesis and initial phases of post-embryonic development. The expe
riment was carried out in 1991 on board the orbital station ''MIR''.