Home / Space/ Special reports A day on board the International Space Station A day in space Every day, on board the ISS (International Space Station), the one and only human outpost in Space, three to seven astronauts of different nationalities, work actively together. Days are filled with activity and work becomes even more intense due to the constant condition of absence of weight. In fact, the astronauts experience the condition of fluctuating in Space. How do they spend their time on the ISS? To understand this, we shall follow the day of a hypothetical astronaut who, to make things more simple, we shall call Luca, after Luca Parmitano the last Italian astronaut, in time, to visit the International Space Station. Fig. 1 Image of the members of mission Expedition 36. Font row: Russian cosmonauts Pavel Vinogradov (left), Commander and Fyodor Yurchikhin, flight engineer. Second row, from left to right: Russian cosmonaut Alexander Misurkin, NASA astronaut Chris Cassidy, Italian ESA astronaut Luca Parmitano and NASA astronaut Karen Nyberg, all flight engineers. Credits: NASA/ESA The alarm rings, a new day begins Luca’s day begins very early. He wakes up at 5.50 a.m. And to speak of a precise hour of the day is rather strange, as the ISS completes an orbit around the Earth every 90 minutes, crossing all the time-zones. And so, theoretically, every 90 minutes a day passes, because the ISS completes an orbit around the Earth. In order to solve this problem of time, it has been established that the time indicated on the watches is Greenwich Mean Time. Now let us get back to Luca. He wakes up at 5.50 a.m. GMT. After a short time to realize where he is and shed any sleepiness, he immediately starts to work, and switches on the computer to read the Daily Summary Report, a daily summary sent by Houston at night time, where all the operations to be carried out during the day are indicated. A healthy breakfast to start the day While he reads the Daily Summary Report, Luca loves to drink some tea. This is a simple and relaxing action which however is somewhat more complex on the ISS: First of all the tea needs to be re-hydrated by positioning a small box near to a unit which fills in water and also heats the tea. Now all he has to do is drink. Not so easy, because everything, also the liquids, float in Space, not only the astronauts. If Luca were to take a cup and bring it to his mouth to drink, and if he were to tilt it, he would realize that the tea remains in the cup and does not even hint at sliding towards his mouth. In order to drink the tea, Luca must create a force that compels the liquid to move towards his mouth. The most simple thing to do is to use a straw . Home / Space/ Special reports All the containers used for liquids are closed with a cap that can be broken with a straw. Once the liquid is in Luca’s mouth he will swallow it so that it moves down to his stomach, also helped by the peristaltic movements of his oesophagus. All drinks, even water, containing bubbles are prohibited because they remain in the mouth. In fact they are impossible to swallow. Fig. 2 The Russian cosmonaut, Mikhail Tyurin and the American astronaut Sunita Williams pose for a photograph while drinking. Credits: NASA Work activities It is 8:00 a.m. GMT. Luca starts his working day with the first of the two DPCs (Daily Planning Conferences), i.e. the conferences with the various organisms on the Earth which tell the astronauts how the day on board the ISS will be organized. Luca communicates with the Earth: “Houston, Huntsville, Munich, Tsukuba and Moscow: Good morning from Luca. We are ready for the DPC”. Obviously he speaks English, the official language in Space! After this connection, the astronauts, and therefore also Luca, dedicate their time to specific work: scientific experiments on board the European laboratory Columbus, the real scientific heart of the ISS. Fig. 3 The Columbus module on the ISS. Credits: ESA Home / Space/ Special reports Luca can make use of a number of racks with materials for experiments. In the Columbus laboratory also physiological studies on the astronauts are carried out : variations in weight, blood sampling and all types of echographic examinations (spine, heart, eyes). Now Luca concentrates on carrying out an experiment to assess the effect of microgravity on the human cardiovascular system. He ties two straps around his thighs, once these are inflated, the flow of blood from the upper part to the lower part of his body decreases remarkably, The experiment lasts about three minutes, after which the straps are rapidly deflated. From this moment two pressure indicators monitor the response of the cardiovascular system to the demand for blood in the lower limbs. One of Luca’s colleagues Fryod, is carrying out a study (GEOFLOW) which regards the physics of fluids. In other words, the dynamics of liquids that are normally inhibited by the presence of gravity, are studied. For example, Fryod has successfully created a round boiler in which hot water rises from the centre towards the external surface. On the Earth this does not happen because the force of gravity prevents it. In space, because of the absence of gravity it is possible to study the effects of fluid dynamics that are normally hidden by the force of gravity. Other experiments are dedicated to the study of radiations in space. In fact, the astronauts are subjected to enormous amounts of radiations that are much greater than those affecting pilots of transoceanic airlines. During the studies also the effects of these radiations on the human body are evaluated. Physical activity to keep fit After a couple of hours at work, at around 10 a.m. GMT, Luca begins his session of about one and an half hours of physical exercise. The exercises have been scheduled to prevent the heart from becoming weak and the muscles from becoming atrophic, because due to the absence of weight, there is no contrasting gravity to pump blood in the body or to move a muscle. Furthermore, a great effort is made to avoid any decrease of calcium in the bones. Even though this unfortunately is inevitable. For astronauts like Luca, who must face missions lasting a long time, there is a rehabilitation period, when they return to the Earth, before they can walk again. In fact, once they land on the Earth, they are taken from the spaceship that brings them back to Earth and carried on special stretchers in order to prevent any bones from breaking . Fig. 4 The Russian astronaut Fyodor Yurchikhin carried on a seat, by the ground staff. Credits: NASA There are numerous exercises - from riding a classic cyclette exercise bike, to running on the T2 , a treadmill that simulates walking and running in normal gravity conditions. In fact there are elastic straps that keep the astronaut on the treadmill, preventing the astronaut from shooting off to the ceiling with the first step. Home / Space/ Special reports Fig. 5 ESA astronaut, Frank De Winne, Commander of mission Expedition 21, during the Tip training session. Credits NASA Then there is a cyclette to exercise arms and legs, and this too has straps to keep the astronaut in a seated position. Fig. 6 Paolo Nespoli during a session on the cyclette exercising bicycle, which is necessary in order to maintain the astronauts’ muscle tone and to keep the blood circulation active. Credits: ESA/NASA The astronauts can also carry out bodybuilding routines with ARED (Advanced Resistive Exercise Device) an exercising machine that uses the principle of vacuum pumps and in fact has two air-tight calibrated pistons, which enable weight lifting exercises. The physical fitness of each astronaut is constantly monitored by a team of doctors on the Earth, who record any changes in the physical parameters, and, if necessary, they prescribe changes in the astronauts’ exercise routines. Home / Space/ Special reports Fig. 7 The ARED device uses resistance cylinders in which the resistance can be varied by regulating the vacuum pistons. In this way it is possible to reproduce weight lifting exercises as in normal gravity conditions. Some studies have shown that without exercises like these made possible with ARED, the astronauts could lose up to 15% of their muscle volume, which is difficult or even impossible to regain when back on the Earth. Credits: NASA It is time to eat Three food-breaks are programmed: breakfast, lunch and dinner. However, drinks and snacks are always available. Over the years, food for astronauts has changed even in terms of quality. In the beginning it consisted mainly of lyophilized food, to be rehydrated with equipment to heat water. Fresh vegetables were practically inexistent. Today the situation is decidedly different. Specialized companies prepare the astronauts’ meals. For example Luca likes to eat light food, for lunch he is quite happy with two small tortillas rolled around some tuna fish, salmon and some vegetables. No bread can be eaten, nor any foods that produce crumbs, because these would scatter around the cabin, also creating problems for the instruments. Every astronaut is allowed a special food, Franco Malerba, the first Italian astronaut on board a Space Shuttle in 1992, took some parmigiano reggiano cheese cut in cubes along with him. The astronaut Samantha Cristoforetti, the first Italian woman astronaut, has already defined the menu for her long term mission in space which will begin in November 2014.