STS-105
STS-105 was the 106th Space Shuttle mission and the 11th dedicated to International Space Station (ISS) assembly and resupply, launched on August 10, 2001, at 5:10 p.m. EDT from Launch Pad 39A at NASA's Kennedy Space Center in Florida aboard the orbiter Discovery.[1] The mission's primary goals included rotating the ISS resident crews by delivering Expedition 3 and returning Expedition 2, as well as delivering over 7,000 pounds of supplies, research equipment, and logistics via the Italian-built Multi-Purpose Logistics Module (MPLM) Leonardo, marking the first time this module carried EXPRESS Racks for scientific experiments.[2] The shuttle crew consisted of Commander Scott J. Horowitz, Pilot Frederick W. "Rick" Sturckow, and Mission Specialists Daniel T. Barry and Patrick G. Forrester, who were responsible for docking with the ISS, transferring cargo, and conducting two extravehicular activities (EVAs).[1] Expedition 3 crew members—Commander Frank L. Culbertson Jr., Flight Engineer Vladimir N. Dezhurov, and Flight Engineer Mikhail Tyurin—launched with the shuttle to begin their four-month stay aboard the station, while the outgoing Expedition 2 crew—Commander James S. Voss, Flight Engineer Yury V. Usachev, and Flight Engineer Susan J. Helms—returned to Earth after nearly five months in orbit.[1] This rotation ensured continuous human presence on the ISS, which at the time marked its 1,000th day of operation since the launch of the Zarya module.[2] During the 11-day mission, which lasted 11 days, 19 hours, and 38 minutes with 186 orbits covering 4.3 million statute miles, the crew performed key tasks including the attachment and outfitting of Leonardo to the Unity module's nadir port and the deployment of the Simplesat microsatellite for Earth observation experiments.[1] The two EVAs, totaling 11 hours and 45 minutes—the 26th for ISS assembly and the 68th overall in the shuttle program—focused on installing the Early Ammonia Servicer (EAS) to replenish the station's cooling system and attaching the Materials International Space Station Experiment (MISSE), a passive experiment exposing over 800 samples to the space environment to study material degradation.[1] Additional research included the H-Reflex experiment to study neuromuscular responses in microgravity, contributing to understanding human adaptation in space.[2] Discovery undocked from the ISS on August 20, 2001, after transferring more than 3,000 pounds of unused equipment and waste back into Leonardo for return, and landed successfully on August 22, 2001, at 2:23 p.m. EDT on Runway 15 at Kennedy Space Center, completing a mission that advanced ISS habitability and scientific capabilities without any major anomalies.[1]Crew
Shuttle Crew
The STS-105 mission was commanded by a four-member crew aboard Space Shuttle Discovery, consisting of experienced NASA astronauts who managed shuttle operations, crew exchanges with the International Space Station (ISS), and support for extravehicular activities (EVAs). This core team delivered the Expedition 3 crew to the ISS as passengers and returned the Expedition 2 crew upon undocking.[1] Commander Scott J. Horowitz, an Air Force colonel, led his fourth spaceflight on STS-105, where he was responsible for overall mission command and shuttle operations, including oversight of docking and undocking procedures. Selected as an astronaut in 1992, Horowitz had previously served as pilot on STS-75 in 1996 (a tethered satellite system deployment mission), STS-82 in 1997 (Hubble Space Telescope servicing), and STS-101 in 2000 (an ISS logistics flight). He was assigned to the forward left seat in the shuttle cockpit.[3][4] Pilot Frederick W. (Rick) Sturckow, a Marine Corps lieutenant colonel, flew his second spaceflight on STS-105, handling primary shuttle piloting duties, rendezvous with the ISS, and landing operations upon return. Selected in 1990, Sturckow's prior mission was STS-88 in 1998, the first ISS assembly flight where he also served as pilot. He occupied the forward right seat.[5][4] Mission Specialist 1 Patrick G. Forrester, an Army lieutenant colonel on his first spaceflight, acted as lead for EVAs and shuttle robotics operations, including manipulation of the Canadarm for payload handling. Selected as an astronaut in 1993, Forrester brought expertise in mechanical engineering and military service prior to joining NASA. He was positioned in the aft flight deck left seat.[6][4][1] Mission Specialist 2 Daniel T. Barry, a physician and engineer, completed his third spaceflight on STS-105, providing support for payload integration and EVA preparations. Selected in 1992, Barry had flown on STS-72 in 1996 (a satellite retrieval mission) and STS-90 in 1998 (a Neurolab life sciences flight). He sat in the aft flight deck right seat.[7][4]ISS Crew Exchange
The STS-105 mission facilitated the rotation of the International Space Station's resident crew by delivering Expedition 3 and returning Expedition 2 to Earth.[2] Expedition 3 consisted of Commander Frank L. Culbertson Jr. from NASA, Flight Engineer Mikhail Tyurin from Roscosmos, and Flight Engineer Vladimir N. Dezhurov from Roscosmos.[1] Culbertson, on his third spaceflight following prior missions as pilot on STS-38 in 1990 and commander on STS-51 in 1993, took command of the station.[8] Tyurin was on his first spaceflight, bringing expertise as an engineer from RSC Energia specializing in flight software and systems testing. Dezhurov, on his second spaceflight after commanding Soyuz TM-21 to Mir in 1995, contributed his experience in station operations and spacewalks. The crew was planned for a 128-day stay, focusing on scientific research, maintenance, and preparation for future assembly tasks aboard the growing orbital laboratory.[9] The returning Expedition 2 crew included Commander Yury V. Usachev from Roscosmos, with NASA flight engineers James S. Voss and Susan J. Helms.[1] Usachev, on his third spaceflight after Soyuz TM-18 to Mir in 1994 and STS-101 in 2000, had led the station through key assembly phases including the arrival of major modules. Voss, on his fifth spaceflight following STS-44, STS-57, STS-69, and STS-101, handled engineering and payload operations during their tenure.[10] Helms, also on her fifth flight after STS-54, STS-64, STS-78, and STS-101, supported life support systems and microgravity experiments.[11] The crew completed a 167-day mission, extended slightly from the original plan due to scheduling adjustments, during which they oversaw the station's expansion and conducted over 100 experiments.[2] This rotation highlighted the multinational collaboration between NASA and Roscosmos, with American and Russian members sharing command and engineering roles to ensure seamless operations on the binational outpost.[2] The STS-105 shuttle crew assisted in the transfer by providing logistical support during docking and joint activities.[1]Mission Objectives
Primary Goals
STS-105, designated as International Space Station (ISS) Assembly Flight 7A.1, marked the 11th shuttle mission dedicated to ISS assembly and the 30th flight for Space Shuttle Discovery.[1][12] The mission's core objectives centered on enhancing station operations through crew rotation and logistical support, without introducing new structural elements.[13] A primary goal was the rotation of long-duration crews, delivering the three-member Expedition 3 team—commander Frank L. Culbertson Jr., flight engineer Vladimir N. Dezhurov, and flight engineer Mikhail Tyurin—to the ISS while returning the Expedition 2 crew of commander Yury V. Usachev, flight engineer James S. Voss, and flight engineer Susan J. Helms to Earth.[2] This exchange included a command handover from Usachev to Culbertson, ensuring continuity in station management.[2] Another key objective involved resupplying the ISS with approximately 7,000 pounds of equipment, provisions, and scientific payloads transported in the Multi-Purpose Logistics Module (MPLM) Leonardo, which facilitated the delivery of food, clothing, and research hardware to sustain expanded crew operations.[1][2] The mission also aimed to restore critical thermal control by installing the Early Ammonia Servicer (EAS) on the P6 truss, replenishing ammonia in the station's cooling loops to maintain system functionality.[2] Additionally, crews performed a software transition in the Zvezda service module, uploading updated command software to improve attitude control and overall station performance.[1] Secondary objectives included deploying the Simplesat micro-satellite from the shuttle's payload bay to demonstrate low-cost imaging technology and conducting shuttle-based experiments, such as the Microgravity Smoldering Combustion experiment, to advance microgravity research.[1][14][15]Payload and Logistics
The Multi-Purpose Logistics Module (MPLM) Leonardo, an Italian-built pressurized cargo carrier, served as the primary logistics vehicle for STS-105, transporting approximately 3,175 kg (7,000 lb) of upmass to the International Space Station, including science experiment racks, crew provisions such as food and clothing, and logistical support equipment.[2] Upon its return to Earth, Leonardo carried back over 1,360 kg (3,000 lb) of downmass, comprising station-generated trash, completed scientific experiments, and other refuse for disposal or analysis on the ground.[2] This module, measuring 6.4 meters in length and 4.6 meters in diameter, was designed for efficient transfer of resupply items and waste between low Earth orbit and the surface. A key external payload was the Early Ammonia Servicer (EAS), a 635 kg (1,400 lb) assembly consisting of a nitrogen-purged ammonia tank and servicing hoses, intended to replenish the cooling loops on the P6 integrated truss segment and mitigate potential leaks in the station's external thermal control system.[1] The EAS was stowed in an Integrated Cargo Carrier in the shuttle's payload bay for delivery. Among the return cargo in Leonardo were personal effects and clothing from the outgoing Expedition 2 crew, along with results from station-based research, including plant growth samples from the Advanced Astroculture experiment and microbial water analysis specimens collected during their tenure. Additional shuttle-hosted experiments included the Commercial Protein Crystal Growth-High Density setup, which utilized vapor diffusion techniques to cultivate protein crystals for pharmaceutical applications in microgravity. These experiments leveraged the reduced sedimentation in orbit to improve crystal quality compared to ground-based growth.[16][17] Post-undocking, the crew deployed Simplesat, a compact 52 kg (115 lb) microsatellite from a Hitchhiker carrier in the payload bay, to conduct Earth observation and demonstrate low-cost satellite technologies using commercial off-the-shelf components.[1][18] For integration, Leonardo was grappled by the shuttle's Canadarm2 robotic arm, maneuvered to the nadir port of the Unity node, and securely berthed to enable crew access and cargo transfer between vehicles. This logistical framework directly supported the crew rotation by ensuring sustained station habitability and research continuity for Expedition 3.[2]Flight Phases
Launch and Ascent
The STS-105 mission lifted off from Launch Complex 39A at NASA's Kennedy Space Center in Florida at 5:10:14 p.m. EDT (21:10:14 UTC) on August 10, 2001.[1] The Space Shuttle Discovery (OV-103), configured as the 106th flight in the Space Shuttle Program, was mated to External Tank ET-110—the 13th flight-proven Super Light Weight Tank—and the BI-109 Solid Rocket Booster pair, which had previously supported STS-104.[17] The countdown, initiated at T-minus 6 hours with crew ingress into the orbiter, proceeded without holds or unplanned pauses, culminating in solid rocket booster ignition and nominal main engine start at T-minus zero.[17] During ascent, Discovery followed a standard profile for International Space Station missions, with the solid rocket boosters performing as planned before separation approximately two minutes after liftoff.[17] External Tank ET-110 separated cleanly at T-plus 8 minutes 48 seconds, after the three space shuttle main engines throttled down following main engine cutoff.[17] The Orbital Maneuvering System engines then fired for the first time shortly thereafter, achieving initial orbital insertion at an altitude of 185 nautical miles.[17] Post-launch systems checks confirmed successful activation of all onboard subsystems, including the auxiliary power units, reaction control system jets, and orbital maneuvering system pods, with no anomalies reported during the ascent phase.[17] The crew, led by Commander Scott J. Horowitz who monitored vehicle performance from the flight deck, reported nominal conditions throughout the initial orbit.[1]Rendezvous and Docking
The STS-105 mission, aboard Space Shuttle Discovery, followed a two-day rendezvous profile with the International Space Station (ISS) after launch on August 10, 2001, at 5:10 p.m. EDT from Kennedy Space Center's Launch Pad 39A.[2] Rendezvous operations commenced on August 11 with a series of ground-targeted midcourse burns using Discovery's Orbital Maneuvering System (OMS) engines and Reaction Control System (RCS) thrusters to adjust the shuttle's trajectory and phase angle relative to the ISS.[19] These maneuvers positioned Discovery approximately 50,000 feet behind the station by early August 12, initiating the R-Bar (Earth-radius vector) approach corridor, which minimized relative velocity and propellant use while allowing for precise alignment.[20] Proximity operations began with the Terminal Intercept (TI) burn, firing Discovery's RCS jets to close the distance to the ISS at a controlled rate of about 0.1 mph.[13] Commander Scott J. Horowitz then transitioned to manual control, executing up to four course corrections and a yaw-pitch-yaw attitude maneuver to orient the shuttle's docking port toward the ISS.[20] At around 600 feet, the crew used the Rendezvous Performance Monitor (RPM) display and video feeds for relative navigation, pausing at station-keeping holds—such as 400 feet and 30 feet—for Mission Control verification and final alignment adjustments via RCS thruster firings.[4] During this phase, the crew conducted visual inspections of the ISS exterior through the orbiter's windows to assess any potential damage or anomalies on the station's structure.[21] Discovery completed a Twice-Orbital-Rate (+R-Bar to +V-Bar) approach maneuver before docking softly to the Pressurized Mating Adapter-2 (PMA-2) on the forward port of the Destiny laboratory module at 2:42 p.m. EDT on August 12, 2001, at an altitude of 240 miles over northwestern Australia.[20] The contact occurred at a closing rate of 0.1 foot per second, with the docking mechanism capturing within 3 inches of perfect alignment; preliminary latches engaged immediately, followed by structural latches and equalization of cabin pressures.[4] Hatch opening ensued at 3:47 p.m. EDT after leak checks confirmed a secure seal, enabling the transition to joint operations.[20]Undocking and Reentry
On August 20, 2001, Space Shuttle Discovery undocked from the Pressurized Mating Adapter 2 (PMA-2) on the International Space Station at 14:51 UTC (10:51 a.m. EDT), initiating the separation with a spring-loaded mechanism that provided an initial gentle push away from the station.[4] Pilot Frederick W. Sturckow then maneuvered Discovery for a traditional flyaround, allowing the crew to capture high-resolution photographs of the expanding station configuration, including the newly installed Quest airlock and other assembly elements.[1] This post-undocking activity lasted approximately 30 minutes and ensured clear visual documentation of the station's exterior prior to the shuttle's departure.[21] Following the flyaround, the crew conducted a survey of the payload bay using onboard cameras to inspect the shuttle's thermal protection system and cargo bay hardware for any debris or damage incurred during the mission.[1] At 18:30 UTC (2:30 p.m. EDT), they deployed the Simplesat-2 secondary payload—a small, low-cost ultraviolet telescope satellite—from a Get Away Special (GAS) canister in the payload bay via a spring ejection system, demonstrating affordable access to space for university-led science experiments.[22] Simplesat-2 operated briefly in low Earth orbit to collect stellar spectra data before reentering the atmosphere.[1] These activities marked the completion of shuttle-specific tasks after the station stay, with the crew focusing on orbital housekeeping and reentry preparations over the next two days.[23] Reentry preparations culminated on August 22, 2001, when Commander Scott J. Horowitz and Pilot Sturckow ignited the Orbital Maneuvering System engines for the deorbit burn at approximately 17:15 UTC (1:15 p.m. EDT), lasting about three minutes and reducing Discovery's velocity to initiate atmospheric interface.[21] The burn targeted a ground track for Kennedy Space Center, with peak heating during reentry reaching around 3,000°F on the orbiter's reinforced carbon-carbon nose cap and tiles as it descended through the sensible atmosphere.[1] Clear skies and favorable weather conditions at the landing site permitted no delays, allowing the second opportunity of the day to proceed without wave-offs.[23] Discovery touched down smoothly on Runway 15 at Kennedy Space Center at 18:23 UTC (2:23 p.m. EDT), completing the mission after 11 days, 19 hours, and 38 minutes in space.[1] The rollout covered 10,036 feet in 68 seconds, during which Sturckow adeptly managed moderate crosswinds that fell below the threshold for a planned crosswind landing test objective (DTO 805) but required precise control inputs to maintain alignment.[23][21] Post-landing inspections confirmed the orbiter's thermal protection system integrity, paving the way for safe crew egress and vehicle turnaround.[1]Station Operations
Crew Transfer
Following docking on August 12, 2001, the hatches between Space Shuttle Discovery and the International Space Station (ISS) were opened, allowing the STS-105 crew to greet Expedition 2 members Yury V. Usachev, James S. Voss, and Susan J. Helms.[2] The combined crews shared a joint meal in the Zvezda Service Module and conducted initial briefings on station layout and procedures.[2] On August 17, 2001, a formal handover ceremony took place in which Expedition 2 Commander Usachev transferred command of the ISS to incoming Expedition 3 Commander Frank L. Culbertson.[1] This was followed by detailed briefings from Expedition 2 to Expedition 3 on critical systems, including life support operations and procedures for the Russian segment.[1] During the docked phase, the crews transferred approximately 7,000 pounds of supplies, equipment, and scientific payloads from the Leonardo Multi-Purpose Logistics Module (MPLM) to the ISS, utilizing the shuttle's remote manipulator system and crew-assisted methods.[2] Over 3,000 pounds of return hardware and expended materials were loaded into Leonardo for the trip back to Earth, with all items inventoried to ensure accountability.[2] Joint operations included the successful upload of upgraded software to the Zvezda module's computers on August 16, 2001, performed by Russian flight controllers with crew support to enhance station attitude control.[1] A crew farewell ceremony marked the conclusion of joint activities on August 19, 2001, prior to final preparations for undocking.[2] The STS-105 crews overlapped with both Expedition 2 and Expedition 3 for eight days during the station visit, from August 12 to August 20, 2001, facilitating seamless crew rotation and logistics handover.[2]Extravehicular Activities
The STS-105 mission featured two extravehicular activities (EVAs) conducted by mission specialists Daniel T. Barry and Patrick G. Forrester to support International Space Station (ISS) assembly and maintenance. These spacewalks, staged from the Quest Joint Airlock, totaled 11 hours and 45 minutes and advanced preparations for future truss installations while contributing to the station's ammonia cooling system replenishment.[2][24] The first EVA began on August 16, 2001, at 13:58 UTC and lasted 6 hours and 16 minutes. Barry and Forrester, both wearing the Extravehicular Mobility Unit (EMU) spacesuits equipped with the newly flight-tested Simplified Aid for EVA Rescue (SAFER) jetpacks, exited the Quest airlock to install the Early Ammonia Servicer (EAS) on the P6 integrated truss structure. The primary tasks included securing the EAS unit, connecting nitrogen hoses to the truss's cooling lines, and removing protective caps from ammonia quick-disconnect fittings to enable future replenishment of the station's thermal control system. They also deployed the Materials International Space Station Experiment (MISSE)-1 and MISSE-2 passive experiment carriers on the exterior of the Quest airlock for long-term exposure to the space environment. All objectives were achieved ahead of the timeline with no anomalies reported, marking Barry's third career spacewalk and Forrester's first.[2][24][7] The second EVA commenced on August 18, 2001, at 13:42 UTC and concluded after 5 hours and 29 minutes. Barry, serving as the lead spacewalker, and Forrester focused on outfitting the S0 truss area in preparation for its upcoming delivery and installation. Key procedures involved routing and securing heater control cables along the S0 truss to maintain thermal protection, installing additional handrails on the Destiny laboratory module to facilitate mobility during future EVAs, and conducting tests of various EVA tools, including torque wrenches and tethers, to verify their performance in microgravity. The activities proceeded smoothly, completing all tasks without issues and further enhancing station infrastructure accessibility. This spacewalk brought Barry's cumulative extravehicular time to over 25 hours across four career EVAs.[2][24][7] Both EVAs utilized the shuttle's payload bay as a worksite and demonstrated the effectiveness of the Quest airlock for ISS operations, with the SAFER jetpacks providing enhanced safety for untethered maneuvering if needed. The absence of any technical or procedural anomalies underscored the maturity of shuttle-ISS EVA protocols at this stage of assembly.[24][1]Post-Mission
Statistics and Achievements
The STS-105 mission lasted 11 days, 19 hours, and 38 minutes, completing 186 orbits around Earth and traveling approximately 4.3 million statute miles.[1] Key achievements included the successful rotation of the International Space Station (ISS) crew from Expedition 2 to Expedition 3, marking the first such rotation where the incoming crew remained on station during the September 11, 2001, terrorist attacks, with Commander Frank Culbertson witnessing the events from orbit.[2] Additionally, during two extravehicular activities (EVAs) totaling 11 hours and 45 minutes, mission specialists Daniel Barry and Patrick Forrester installed the Early Ammonia Servicer (EAS) on the ISS's P6 truss, providing a reserve of ammonia coolant to ensure full thermal control system redundancy and 100% cooling capacity for the station's electronics.[1] Expedition 3 lasted 128 days, 19 hours, and 18 minutes, with Commander Frank Culbertson accumulating that time in space.[9] In terms of legacy, STS-105 significantly advanced ISS habitability by delivering over 7,000 pounds of supplies, equipment, and scientific payloads via the Leonardo Multi-Purpose Logistics Module (MPLM) on its second flight, enabling expanded research capabilities and crew support without any reported safety incidents throughout the mission.[1] Following landing on August 22, 2001, at Kennedy Space Center, the crew was not subjected to post-mission quarantine, and Space Shuttle Discovery underwent major refurbishment, including updates to its flight systems, in preparation for STS-108 later that year.Wake-up Calls
The NASA tradition of musical wake-up calls originated during the Gemini program, with the first instance occurring on Gemini 7 in December 1965 when "The Green Leaves of Summer" by The Brothers Four was played to boost crew morale and foster camaraderie among the team and ground control.[25] This practice continued through the Apollo era and became a staple of Space Shuttle missions, where songs were selected by family, friends, or mission teams and broadcast from Mission Control in Houston to help maintain high spirits amid the demanding schedules of spaceflight.[26] For STS-105, which flew from August 10 to 22, 2001, the 12 wake-up calls were personalized to honor individual crew members, including dedications to the incoming Expedition 3 astronauts (Frank Culbertson, Vladimir Dezhurov, and Mikhail Tyurin) and outgoing Expedition 2 members (Yuri Usachev, James Voss, and Susan Helms), as well as shuttle pilots and mission specialists.[25] The selections reflected cultural diversity, with traditional Russian music for the cosmonauts, and often tied to personal milestones or family contributions, enhancing the emotional connection between the crew and Earth-based supporters during the mission's focus on International Space Station crew rotation and logistics delivery.[25] These calls played a key role in uplifting the crew's morale throughout the 11-day flight, providing brief moments of levity and normalcy in an otherwise high-stakes environment.[25] The full list of wake-up calls for STS-105 is as follows:| Date | Song Title | Artist/Performer | Dedication/Notes |
|---|---|---|---|
| Aug 11 | "Back in the Saddle Again" | Gene Autry | For Commander Frank Culbertson, marking his third spaceflight. |
| Aug 12 | "The White Eagle" | Traditional Russian folk song | For Expedition 3 Pilot Vladimir Dezhurov. |
| Aug 13 | Overture from "The Barber of Seville" | Gioachino Rossini | Tribute to Expedition 3 Flight Engineer Mikhail Tyurin. |
| Aug 14 | "Arthur's Theme (Best That You Can Do)" | Christopher Cross | Theme song from the film Arthur. |
| Aug 15 | "Big Boy Toys" | Aaron Tippin | For Pilot Rick Sturckow, selected by his wife. |
| Aug 16 | "The Marvelous Toy" | Tom Paxton | For Mission Specialist Daniel Barry, from his wife. |
| Aug 17 | "Time Bomb" | Performed by Patrick and Andrew Forrester | For Mission Specialist Patrick Forrester, performed by his sons. |
| Aug 18 | "Hotel California" | The Eagles | For Expedition 2 Commander Yuri Usachev, requested by his wife. |
| Aug 19 | "Under the Boardwalk" | The Drifters | For Expedition 2 Flight Engineer James Voss, from his wife Suzan. |
| Aug 20 | "Brand New Day" | Sting | For Mission Specialist Susan Helms, requested by family and friends. |
| Aug 21 | "East Bound and Down" | Jerry Reed | Requested by the Houston-based training team. |
| Aug 22 | "Again" | Lenny Kravitz | Final call before landing. |