Expedition 1 and the early International Space Station

The configuration of the International Space Station at the beginning of the Expedition 1 crew rotation. Credit: NASA

Two decades ago, Expedition 1 arrived at the International Space Station to begin an unbroken chain of expeditions to inhabit this outpost.

Over those 20 years, 64 expeditions have called the ISS their home. Today’s outpost is a sprawling complex the size of a football field with over a dozen habitable modules and hundreds of science experiments ongoing at any given time.

When the crew of Expedition 1 arrived in November 2000, it was much smaller and their mission was very different — activating this new international outpost.

The Expedition 1 crew: Sergei Krikalev, left, Bill Shepherd, center, and Yuri Gidzenko. Credit: NASA

Consisting of NASA astronaut Bill Shepherd and Russian cosmonauts Yuri Gidzenko and Sergei Krikalev, Expedition 1 launched in their Soyuz TM-31 spacecraft atop a Soyuz-U rocket at 7:52 UTC Oct. 31, 2000, from Baikonur Cosmodrome in Kazakhstan.

It took them two days to reach the outpost, docking at 9:21 UTC Nov. 2.

In a NASA-conducted online conversation with the Expedition 1 crew on Oct. 29, 2020, the trio recounted many of their experiences during their first days aboard the outpost 20 years ago.

“When we just got there, we were not able to open the hatch right away,” Gidzenko said, recounting how they struggled to open the hatch.

Gidzenko said their first tasks included activating the toilet, looking for connector cables, activating the hot water dispenser and turing on lights..

“I remember Shepherd said, ‘Now we can live. We have light, we have hot water and we have [a] toilet.’,” Gidzenko said.

Krikalev, who previously spent time aboard the Russian Mir space station, said many of the systems were similar to that outpost, only newer and less lived in.

When Shepherd, Gidzenko and Krikalev arrived at the ISS in November 2000, the fledgling outpost only included three main modules — Zarya, Zvezda and Unity — and a truss segment called Z1.

The ‘dawn’ of the ISS

Zarya was the first module to launch, having reached orbit Nov. 20, 1998 — two years before Expedition 1.

Its name means “dawn” in Russian and was launched by a Proton rocket from Baikonur Cosmodrome. The main body of Zarya measures 4.1 meters wide and 12.6 meters long with a mass of about 19 metric tons.

Sergei Krikalev, left, along with NASA astronaut James Newman float inside the Zarya module in December 1998 during the STS-88 space shuttle mission. Credit: NASA

It has two solar panels to give it a 25-meter wingspan when fully deployed. However, these have been partially retracted since 2007 to make room for other parts of the ISS.

This first piece is also called the Functional Cargo Block and provided early power, storage, guidance and propulsion for the outpost. It has three docking ports, which are now all occupied by other modules.

Inside is a single long corridor that has various panels with compartments for either storage or equipment.

It’s design heritage actually dates back to the TKS spacecraft that were planned for use in the Soviet Salyut space station program, which was originally intended to send crew and cargo to early outposts. However, only four test missions were flown.

The cargo section of TKS, the Functional Cargo Block, was ultimately used to form the basic structure of many of the modules that formed the Mir space station, which orbited Earth between 1986 and 2001.

Zarya was built in Moscow between 1994 and 1998. Much of the funding, however, came through U.S. contracts to the of about $220 million. As such, it’s mainly owned by the United States.

A spare was also built, which is now intended to fly as a science module to the ISS. Called Nauka, it’s launch has been delayed since 2007 for a variety of reasons and is currently expected to launch in 2021.

Unity and the start of orbital assembly

Just two weeks later, the second piece of the ISS, Unity, was launched, officially beginning the assembly of this massive complex — a process that would ultimately take 12 years to complete.

Unity was the first of three node modules. It was launched out of the Kennedy Space Center in Florida on Dec. 4, 1998, in the payload bay of space shuttle Endeavour during its STS-88 mission.

Zarya attached to the Unity module during the STS-88 mission. Credit: NASA

It had six berthing ports, two of which launched with pressurized mating adapters attached to facilitate docking between the space shuttle and attachment to Zarya.

The node itself is 4.3 meters wide and 5.5 meters long with a mass of about 12 metric tons. It was built by Boeing at the Marshall Space Flight Center in Huntsville Alabama between 1994 and 1997 for about $300 million.

During the two days the space shuttle took to catch up to and rendezvous with Zarya, the STS-88 crew used the Canadarm remote manipulator system to move Unity out of the payload bay to attach it to the Orbiter Docking System via Pressurized Mating Adapter 2.

Then, on Dec. 6, Endeavour’s crew rendezvoused with Zarya and used Canadarm to capture the fre-flying module before attaching it to the other end of Unity via Pressurized Mating Adapter 1.

It required a brief pulse of Endeavour’s thrusters to mate the two modules together at 1:07 UTC Dec. 7, 1998.

Once powered up, the ISS was entered for the first time on Dec. 10, 1998, by NASA astronaut Bob Cabana and Russian cosmonaut Sergei Krikalev (who would return two years later as part of Expedition 1). The other four members of the STS-88 crew followed shortly after.

The interior of the Unity module in 2005. Credit: NASA

Inside Unity are spaces for four International Standard Payload Racks, which are a uniform standard for all the modules on the U.S. segment of the ISS.

The early years saw the racks used for life support and communications equipment. However, today they contain stowage racks for food and supplies and a galley where the crew typically gathers for meals.

It was originally planned for the third module, Zvezda, to be launched later in 1999 to form the permanent service module for the outpost. However, financial difficulties within the Russian space program, as well as technical issues, delayed its arrival for more than a year.

Following the STS-88 mission, Unity and Zarya were left in a safe configuration, only being occupied periodically by space shuttle crews working to outfit the early outpost.

In the meantime, two space shuttle missions — STS-96 and STS-101 — would visit the outpost to install various equipment to ready the early ISS for its first permanent crews.

Zvezda: the ISS service module

Finally, on July 12, 2000, Zvezda was launched atop a Proton rocket from Baikonur Cosmodrome, and autonomously rendezvoused with the Unity and Zarya modules two weeks later.

Once near the ISS, Zvezda played the passive role during its attachment as the Zarya module with Unity attached maneuvered itself to the service module’s forward docking port, officially becoming part of the outpost on July 26, 2000.

The Zvezda module (the large module on the left) as seen in September 2000. Credit: NASA

Zvezda means “star” in Russian. It was the first fully-Russian contribution to the outpost. It was built in Moscow for a cost of about $320 million.

The module, which serves to this day as the service module for the ISS, is 4.35 meters wide and 13.1 meters long with a mass of about 20 metric tons. It has two solar panels that stretch out a total of 29.7 meters.

Also known as DOS-8, the module’s design is based on the early Salyut outposts in the 1970s and 1980s, including history’s first space station, Salyut 1.

In fact, the main structure was originally a backup to the Mir space station’s service module and was to be used as the core for the then-planned Mir-2 space station.

However, when the Soviet Union collapsed and the Cold War ended in the early 1990s, the United States and the newly-formed Russian Federation agreed to combine their respective Freedom station and Mir-2 designs to form the International Space Station.

The interior of the Zvezda module in 2008. Credit: NASA

Zvezda has four docking ports, three of which now have other space station modules attached. The fourth, aft port serves as an arrival point for visiting spacecraft.

The module includes two sleeping quarters, a treadmill and bicycle for exercise, a toilet and a galley. It also included some of the early life support and communications equipment. Today, many of these systems are augmented by other areas of the outpost.

Zvezda still remains the functional center of the ISS, however, and is typically the assembly area for the crew during emergencies.

Also inside the module is a control unit called TORU, which is used to manually dock Soyuz and Progress spacecraft from inside the ISS, should it be necessary.

Preparing ISS for habitation

Once in orbit, the crew of space shuttle mission STS-106 visited the outpost in September 2000 to finish outfitting Zvezda in advance of Expedition 1.

A month later, the crew of STS-92 would add the Z1 truss, which included control moment gyroscopes and communications equipment. It would also serve as a temporary location for the first large truss segment, P6, which would be launched via STS-97 about a month into the Expedition 1 mission. Also added to the outpost was a third pressurized mating adapter.

Sergei Krikalev in front of a Zvezda module window while space shuttle Atlantis departs in February 2001. Credit: NASA

Meanwhile, the uncrewed Progress M1-3 cargo spacecraft brought additional supplies to the ISS. It docked to the aft port of Zvezda and was unloaded by space shuttle crews during their logistics flights.

Progress M1-3 undocked a day before the arrival of Expedition 1 to allow for their Soyuz TM-31 spacecraft to dock at the same port.

Expedition 1

While the Expedition 1 crew was aboard the outpost, the trio worked to activate many of the systems and get it ready for utilization.

During their first month, only Zvezda and Zarya were occupied as there wasn’t enough power to heat Unity until the P6 truss arrived with massive solar arrays and radiators.

The first spacecraft to arrive was actually the uncrewed Progress M1-4. It docked to the Earth-facing port of the Zarya module on Nov. 16, 2000. It was supposed to dock autonomously, but it's automatic docking system had an issue prompting Krikalev to manually dock the spacecraft from inside the Zvezda module.

The Progress was undocked several weeks later on Dec. 1 to make room for the STS-97 space shuttle mission to arrive and add the P6 truss.

Progress M1-4 was re-docked on Dec. 26 before leaving for good on Feb. 8, 2001.

The configuration of the International Space Station at the end of Expedition 1 in March 2001. Credit: NASA

Following the STS-97 mission in December 2000, the STS-98 mission launched in February, bringing the first science module to the outpost — the U.S. Destiny laboratory.

Progress M-44 was another uncrewed cargo resupply spacecraft to arrive at the ISS. It docked to the aft port of the Zvezda module on Feb. 28 and would remain there for the remainder of Expedition 1.

To clear the aft port, the Expedition 1 crew relocated their Soyuz TM-31 spacecraft to the Earth-facing port of Zarya.

Expedition 1 ultimately lasted for 140 days, concluding on March 19, 2001. They were replaced by Expedition 2, which included Russcian cosmonaut Yury Usachev and NASA astronauts James Voss and Susan Helms.

Expedition 2 was launched with the crew of STS-102 in space shuttle Discovery. Expedition 1 returned in their place. The Soyuz TM-31 spacecraft would remain at the ISS to serve as a “lifeboat” if needed.

A lasting legacy

Over the next two decades, more than 240 people from 19 countries would visit the ISS with many traveling there multiple times.

While the first decade was mainly focused on assembly, its second decade was about utilization.

Overall, an unbroken string of expeditions with crews ranging from two to six people have supported this international research outpost and the 2,500 science investigations conducted aboard it.

While the ISS is currently expected to remain funded through 2024, it's likely to continue operations well into the 2020s to not only continue scientific research, but also to help with the commercialization of low Earth orbit research and to help support human journeys into deep space.

Aboard the International Space Station, Expedition 64 Commander Sergey Ryzhikov of Roscosmos and Flight Engineers Kate Rubins of NASA and Sergey Kud-Sverchkov of Roscosmos discussed the upcoming 20th anniversary of a permanent human presence on the orbital laboratory and other elements of life and work in orbit during an in-flight news conference Oct. 30.