 Frogs have been used
in space research a
number of times in the
past.
 We will look at two
different experiments
 In November 1970 NASA launched the Orbiting Frog
Otolith spacecraft.
 This spacecraft carried two bullfrogs into orbit to
study the effect of microgravity on the frog’s
vestibular system.
The orbiting frog otolith experimental package
 Bullfrogs were used
because their inner ear
otolith organs and
labyrinths are very
similar to humans.
 Also, because the frogs
are amphibians they
could survive in air for
prelaunch preparation
and then in water
during the flight.
 Electrodes implanted in the frog’s vestibular nerves
measured the reaction of the vestibular system to
microgravity.
 Through the use of a centrifuge the frogs were
subjected to 1 ‘g’ and the difference measured.
 This experiment provided vital information for our
understanding of space motion sickness and
disorientation.
 We will be focusing on the Frogs
in Space (FRIS) experiment
performed by Japanese
scientists aboard the Mir Space
Station.
 In December 1990 six adult
Japanese tree frogs (an aboreal
species) were sent to the Mir
Space Station for 8 days to
observe and record their
behaviour in microgravity.
 One of the Japanese scientists involved in the FRIS
experiment, Assoc. Prof. Izumi-Kurotani, has kindly
shared her results and pictures with you.
 Frogs and other amphibians are interesting specimens
to study in microgravity because they were the first
creatures to leave the water and live on land
supporting their weight on their legs.
 Frogs begin life as tadpoles in water and become
terrestrial after a metamorphosis.
 Because air is about 1000 times lighter than water
amphibians must make many physiological changes as
they emerge from water.
 Frogs have many modes of locomotive behaviours
walking, climbing, jumping and swimming.
 In microgravity, which mode of behaviour does a frog
show?
 Some species of frogs and toads can experience
microgravity environment on Earth because arboreal
species may fall. It is interesting to compare the
behaviours of arboreal and non arboreal species.
 The six frogs were housed
separately in small
compartments within a
specially designed Life
Support Box (LSB).
 The LSB provides air and
room to move but also
moisture which is
important for a frog
habitat.
 To decrease the effects of
vibration and impact on
the frogs during launch
the LSB provided no
room to move
 When on board the Space Station the frogs were released
into a 2o litre clear glove box the inside moistened with a
wet sponge.
 The frogs were observed
through the window of
the glove box everyday
and were stimulated with
food (meal worms) and
their behaviour videoed.
 A group of control frogs
on Earth were subjected
to the same set of stimuli
as those in orbit.
First Japanese cosmonaut, Toyohiro Akiyama,
observes the frogs
 How do you think frogs would react in microgravity?
 What do you think they would try and do when
floating?
 Is it similar to anything they would experience on
Earth?
In space
On Earth
 It was found that when the
frogs floated in microgravity
they took the same spread
limbed pose as when they
freefall from trees on Earth,
very similar to a skydiver.
 This was thought to be a frogs
natural reaction to a decrease
in gravity felt during freefall
and in space that was exactly
what was happening to them!
 While the tree frog is an
aboreal species and can
experience freefall on Earth,
non aboreal frogs do not
experience freefall.
 How do you think a non
aboreal species of frog would
react in microgravity?
 The frogs also moved their legs in
a motion similar to swimming
though much bigger.
 It was discovered that these were
the motions frogs used on Earth
when upside down to turn their
bodies the correct way up.
 The frogs also moved their limbs
asymmetrically in an attempt to
stabilise rotation.
 In microgravity, it was
discovered that a species of
non aboreal frog (Xenopus
laevis) showed the same
motions frogs use on Earth
when upside down to turn
their bodies the correct way
up.
 The frogs moved their limbs
asymmetrically in an attempt
to stabilise rotation.
 Over 8 days in orbit the frogs
slowly declined their attempts to
jump within the box suggesting
they were adapting to the
microgravity environment.
 Frogs have extensive experience
with microgravity when they
jump from trees on Earth
perhaps this helped them adjust
to space conditions.
In Space
On Earth
 If the frogs stayed in orbit for a
longer period, maybe several
months or years, do you think
they would continue the same
behaviour?
In Space
On Earth
 One strange behaviour noted was that the frogs would
bend their heads backward strongly when sitting on
surfaces.
 This posture is only displayed on Earth when the frogs
are retching or vomiting.
 This raised the possibility that perhaps the frogs were
experiencing Space Motion Sickness!
 All six frogs returned alive to Earth and were observed
directly after landing and over the next 12 hours to
observe their readaption to the 1 ‘g’ environment.
 The flight frogs displayed different posture and
movement to the Earth control frogs.
 The differences in behaviour began to fade and within
12 hours the space frogs displayed completely normal
behaviour showing their readaption to the 1 ‘g’
environment.
 The Japanese Experimental
Module, Kibo, has just been
docked with the ISS.
 Using what you have learned
about frogs, animal habitats
in space and ethics, imagine
you have been asked to
propose an experiment to
determine whether we can
use frogs as an indicator of a
healthy environment in
space.