More than 100 baby squid and 5,000 microscopic animals are set to be launched to the International Space Station (ISS) on Thursday.
The creatures, along with other equipment for experiments, will head to the ISS aboard Space X's Falcon 9 rocket.
Its hoped that the experiments will be able to help scientists understand the effects of spaceflight.
The launch at 13:29 EDT (17:29 GMT) will be broadcast live by Nasa.
The 128 baby bobtail squid will be used as part of research into the effects of spaceflight on beneficial interactions between microbes and animals.
The squid have an immune system which is similar to that of humans.
Nasa says the experiment could support the development of protective measures to preserve astronaut health during long space missions.
"Animals, including humans, rely on our microbes to maintain a healthy digestive and immune system. We do not fully understand how spaceflight alters these beneficial interactions," Jamie Foster, the experiment's principal investigator said.
She added that the squid will be able to address "these important issues in animal health".
The squid will be frozen before their return to Earth.
They are also joined on the Space X rocket by 5,000 tardigrades, more commonly referred to as water bears. The microscopic animals can tolerate environments more extreme than most life forms can. This makes them perfect for studying how life responds and adapts to extreme environments.
It is hoped that this information can then be used to understand the stress factors affecting humans in space.
"One of the things we are really keen to do is understand how tardigrades are surviving and reproducing in these environments and whether we can learn anything about the tricks that they are using and adapt them to safeguard astronauts," Thomas Boothby, the experiment's principal investigator said.
Other experiments due to be conducted include a look into whether robotic arms can be operated remotely using virtual reality along with a study into the production of tougher cotton.