Pressurised Mating Adaptor (PMA1)

Unity with PMA1 in the background. Credits: NASA

Unity with PMA1 in the background.
Credits: NASA

From the FGB, moving toward the bow, we pass through a corridor that looks rather strange. The corridor is an asymmetrical truncated cone. Starting from the round hatch, it transforms into a square that is Node-1. This transitional area is called PMA1, and in addition to connecting the two main segments, it is also a convenient place to store things: its walls are covered with the typical white bags we call CTBs that contain equipment on the Station. When you float through the PMA1 it feels as though you are going down because of its asymmetrical shape .

Node-1 (Unity)

Mealtime in Unity Credits: NASA

Mealtime in Unity
Credits: NASA

This is the oldest module of the American segment and you can tell by the state of the of the walls that have suffered from dozens of inexperienced astronauts eating meals here. Node-1 is still the main meeting point for the crew, and the only passage from one segment to another . The table here is the missing half of the Russian table mentioned in my previous post. The table was disassembled several expeditions ago and reassembled here with wit and some space do-it-yourself. The four walls around the table are used as stowage. The deck , in particular, contains the Station’s toolbox , so it is normal to see an astronaut selecting tools for a job or storing them here when finished. The walls are made of a white, plastic material except for the structures on the four sides of the hatches which are pink to distinguish them from the blue-coloured Destiny Lab and the grey Node-2. Node-1’s second bay has four access hatches to the modules but only three are related to other areas. The fourth, at the very top, is used for storage and currently it holds categorised food containers.

Permanent Multipurpose Module (Leonardo)

The interior of Leonardo. Credits: NASA

The interior of Leonardo.
Credits: NASA

Crossing the Unity hatch at the nadir you access the Permanent Multipurpose Module, or PMM. Also called Leonardo, the name of this module has an interesting history. Built by the Italian Space Agency, the module began life in space as one of three logistic modules carried by the Space Shuttle to resupply the Station. The Italian Space Agency then converted MPLM to a permanent storage module. Here the feeling of going down is very strong, and we all play at ‘falling’ into the PMM and then bouncing back by pushing off from the bottom. The walls of Leonardo are stowed with CTBs, spare parts and food. One of the racks is allocated to the astronauts, we use it as a personal locker: our clothes, personal hygiene material and other belongings are here.

Airlock (Quest)

Quest airlock. Credits: NASA

Quest airlock.
Credits: NASA

If you move to the right from Node-1 , looking in the flight direction, you enter the Airlock. I have described this module many times, because during my first spacewalk I spent lots of time preparing the spacesuits which are installed in the two walls of the Equipment Lock. The two suits are waiting patiently for the next astronaut to bring them to life. A smaller cylinder – the Crew Lock – is used as storage for spacewalk material when not used for a spacewalk itself. Our reserve suits, the SAFER and tethers are attached to its walls . The rest of the material is behind the four walls of the Equipment Lock: batteries for the suit , CO2 filters, drinking-water containers and maintenance tools. The Airlock will always have a special aura for me: it is particularly quiet and cosy because it is smaller than the other modules and I always love working here .

Node-3 (Tranquility)

Inside Tranquility Credits: NASA

Inside Tranquility
Credits: NASA

Directly in front of the Airlock is Node-3 . Without doubt this module has the highest number of astronauts pass by each day, for a variety of reasons. Perhaps this module is the less noble one but certainly one of the most useful and very essential as it holds the toilet. It is identical to the Russian toilet, the liquid recycling system is fully integrated and astronauts intervention is minimal. The cabin dimensions are more comfortable than the toilet at the other end of the Station , and Fyodor likes to joke that our toilet is the “first class” toilet.

The second reason why this module is particularly busy is that two of our sports equipment are installed here. The first one – T2, or better known as our treadmill – is on the right wall as you enter from Node-1. We run on the wall that looks towards our flight direction meaning that our body is parallel to Earth. I wrote about T2 in a previous blog. The second sports equipment is called the Advanced Resistive Exercise Device – ARED – and it works on the principle of vacuum pumps : two sealed and calibrated pistons allow us to exercise weight lifting. The detail I want to point out here is that the three elements of Node-3 described so far lie on three different levels: if an astronaut in Node-1 looks inside Tranquility, they could see an astronaut running parallel to the deck, another using the toilet in normal orientation (i.e. with their head towards the zenith) and another astronaut training on ARED head down. Because each of us trains on ARED at least 90 minutes a day, and at least two people, if not three , train daily on T2, it is very likely that someone, at any given time is training .


Cupola and the robotics workstation. Credits: NASA

Cupola and the robotics workstation.
Credits: NASA

The third reason why there is always someone in Node-3 is because of Cupola which is installed on the nadir port. As you cross Node-3 while doing a 180-degree somersault you will enter Cupola. Often our feet remain hooked to the hatch so Earth flows towards us, our view looking in the direction of flight, with North on the right and South on the left. This window on the world has fascinated and charmed all astronauts and cosmonauts who have had the privilege of looking at our planet from up here. Its seven windows allow a view of 360 degrees of the horizon and offers a spectacle of unparalleled beauty that nourishes the soul and fills the eyes without ever being indulging.

I could go on trying in vain to find the right words, but this is not the right moment. So we move back, through Node-3 and through Node-1 to continue past the hatch in the flight direction.

Destiny Laboratory (Lab)

Robonaut working in the Destiny Lab Credits: NASA

Robonaut working in the Destiny lab.
Credits: NASA

Entering the American laboratory the size of the module is surprising, it is at least twice as large as the modules described so far. The two cone-shaped areas to the front and rear are blue, but the rest of the walls are white (or rather, what we can see of them!). The Lab is the core of the US segment , not only because it contains most of the systems that support life on the Station but also for the scientific racks distributed along the surfaces: we carry out many experiments here. As you enter, on the right, you will find many lenses and cameras that are always available for us to take pictures of our activities. To the left is a workplace used for the Daily Planning Conferences where the logbook can be found (in fact it is a completely unofficial note book), along with pens, markers and pencils, all attached with Velcro. Immediately after that, on both sides, are control joysticks for Canadarm2. The Lab is the support location for the robotic operations when the one in Cupola is not used. Only the robotic work station to the left is operational, the one to the right is connected to the training system called ROBOT, a Canadarm2 simulator.

Further on, we will see the drinking water dispenser overhead, then, to the left, CEVIS, our space exercise bike . It takes little time to adapt to cycling in orbit but it is always strange to think that CEVIS has no saddle or handlebar: they are useless at 0g. The other four bays on the right-hand side are occupied by science racks including the easily recognisable Microgravity Science Glovebox with its large glass window now running the InSpace3 experiment.

Node-2 (Harmony)

Crew quarters in Harmony. Credits NASA

Crew quarters in Harmony. Credits NASA

Identical in shape to Node-3 (they are both built in Italy) , Node-2 contains four sleeping berths where astronauts (and a cosmonaut!) rest. To ensure a bit of space, the berths are placed away from the walls. Slightly smaller than a phone booth (for those old enough to remember them) these ‘phone boxes’ are a luxury in orbit because they allow a little privacy. Inside each, bound to the interior wall, we have our light-green sleeping bags and two computers (one for the onboard network and one to connect to the internet). On the walls, each astronaut arranges photos of their family and personal belongings the best they can – all this helps to create a welcoming and comfortable environment.

The second bay is a working area, and the walls are fitted with two blue, metal benches for tools, equipment and experiments. This is where Karen and Mike are working on the CFE experiment. The docking port at the nadir is now empty but has hosted HTV-4 and Cygnus -D over the course of my mission. This is also where Dragon docks. The upper door is empty, while the front is used for stowage. Behind that door is PMA2 , the Space Shuttle docking port: every time I think about PMA2 I see myself installing the insulating cover on the outside during my first spacewalk… but that is another story .

Japanese Experiment Module (Kibo)

Expedition 37 crew members pose for a photo in Kibo. Credits: NASA

Expedition 37 crew members pose for a photo in Kibo.
Credits: NASA

A small, Japanese-style curtain welcomes us when we turn to the left to enter Kibo . If the Destiny Lab is large, Kibo is huge , as the inscription at the entrance confirms: “Welcome to Kibo – please enjoy and relax in this brand new , spacious and the most quietest room in the ISS ” (sic). Always immaculate , spacious and well lit, Kibo is a favourite place for filming videos. Here, too, the walls offer stowage and experiment areas but four features make Kibo even more extraordinary : first, the last bay on the left has a robotic station (with integrated joystick and screens) to control the Japanese robotic arm on the Exposed Facility outside (the so-called veranda). Second is an integrated sealed chamber to move experiments to outside the Station and vice-versa . The third feature are the two windows just above the sealed chamber that look to the right of the Station. To discover the fourth feature we have to cross the entire module to the wall at the very end. Here the module widens and you will find another pressurised module when you look up.

Experiment Logistics Module- Pressurized Section (JLP)

A view of JLP from the outside. Credits: NASA

A view of JLP from the outside.
Credits: NASA

The JLP is a (relatively) small pressurised logistics module on top of Kibo. It is much loved by astronauts to film scenes where we fly upward to demonstrate microgravity. The words “Welcome to the highest place of Japan over Mt Fuji” are written at the entrance which always puts a smile on our faces. The module is the same size as an HTV and is full of materials stowed like in an HTV spacecraft.

Columbus Laboratory

Fisheye view of Columbus Laboratory. Credits: NASA

Fisheye view of Columbus Laboratory.
Credits: NASA

Crossing Kibo in the opposite direction to return to Node-2 and moving across, we find ourselves in the Columbus laboratory , the European contribution to the International Space Station. When you get inside, you immediately realise the scientific nature of this module: all the bays to the right are occupied by experiment racks as well as the first bay above us and three to our left. The deck is dedicated to onboard systems and is covered by metal panels. Besides containing systems including two monitors, the cone in front of us is used for stowage. In addition to being used for European experiments, Columbus is also the most used module for physiology studies and checks are performed on weight changes, blood samples are taken and all types of ultrasounds are performed (spinal , cardiac and optical) .

Since our journey on the Station began we have crossed many tens of metres and visited a volume of about 840 cubic meters – equivalent to that of a large transport aircraft. This extraordinary ship , built and operated by five space agencies (the best example of international cooperation in the world) travels at an altitude of 400km and 28 000km per hour. A student asked me “What is the thing that most impressed you the Space Station?”. Now you can understand my answer. And you, what would you have answered?