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STS-51-F
Experiments in Challenger's payload bay
NamesSpace Transportation System-19
Spacelab 2
Mission typeAstronomical observations
OperatorNASA
COSPAR ID1985-063A Edit this at Wikidata
SATCAT no.15925Edit this on Wikidata
Mission duration7 days, 22 hours, 45 minutes, 26 seconds
Distance travelled5,284,350 km (3,283,540 mi)
Orbits completed127
Spacecraft properties
SpacecraftSpace Shuttle Challenger
Launch mass114,693 kg (252,855 lb)
Landing mass98,309 kg (216,734 lb)
Payload mass16,309 kg (35,955 lb)
Crew
Crew size7
Members
Start of mission
Launch date21:00, July 29, 1985 (UTC) (1985-07-29T21:00:00Z) (5:00 pm EDT)
Launch siteKennedy, LC-39A
ContractorRockwell International
End of mission
Landing dateAugust 6, 1985, 19:45:26 (1985-08-06UTC19:45:27Z) UTC (12:45:26 pm PDT)
Landing siteEdwards, Runway 23
Orbital parameters
Reference systemGeocentric orbit
RegimeLow Earth orbit
Perigee altitude312 km (194 mi)
Apogee altitude320 km (200 mi)
Inclination49.49°
Period90.90 minutes
Instruments
  • Carbonated Beverage Dispenser Evaluation
  • Infrared telescope (IRT)
  • Instrument Pointing System (IPS)
  • Plasma Diagnostics Package (PDP)
  • Shuttle Amateur Radio Experiment

STS-51-F mission patch

Front row (seated): C. Gordon Fullerton, Roy D. Bridges Jr.
Back row (standing): Anthony W. England, Karl G. Henize, F. Story Musgrave, Loren W. Acton, John-David F. Bartoe
← STS-51-G (18)
STS-51-I (20) →

STS-51-F (also known as Spacelab 2) was the 19th flight of NASA's Space Shuttle program and the eighth flight of Space Shuttle Challenger. It launched from Kennedy Space Center, Florida, on July 29, 1985, and landed eight days later on August 6, 1985.

While STS-51-F's primary payload was the Spacelab 2 laboratory module, the payload that received the most publicity was the Carbonated Beverage Dispenser Evaluation, which was an experiment in which both Coca-Cola and Pepsi tried to make their carbonated drinks available to astronauts.[1] A helium-cooled infrared telescope (IRT) was also flown on this mission, and while it did have some problems, it observed 60% of the galactic plane in infrared light.[2][3]

During launch, Challenger experienced multiple sensor failures in its Engine 1 Center SSME engine, which led to it shutting down and the shuttle had to perform an "Abort to Orbit" (ATO) emergency procedure. It is the only Shuttle mission to have carried out an abort after launching. As a result of the ATO, the mission was carried out at a slightly lower orbital altitude.

Crew

[edit]
Position Astronaut
Commander C. Gordon Fullerton Member of Red Team Member of Blue Team
Second and last spaceflight
Pilot Roy D. Bridges Jr. Member of Red Team
Only spaceflight
Mission Specialist 1 Karl G. Henize Member of Red Team
Only spaceflight
Mission Specialist 2
Flight Engineer 		F. Story Musgrave Member of Blue Team
Second spaceflight
Mission Specialist 3 Anthony W. England Member of Blue Team
Only spaceflight
Payload Specialist 1 Loren W. Acton Member of Red Team
Only spaceflight
Lockheed
Payload Specialist 2 John-David F. Bartoe Member of Blue Team
Only spaceflight
United States Navy
Member of Blue Team Member of Blue Team
Member of Red Team Member of Red Team

As with previous Spacelab missions, the crew was divided between two 12-hour shifts. Acton, Bridges and Henize made up the "Red Team" while Bartoe, England and Musgrave comprised the "Blue Team"; commander Fullerton could take either shift when needed.[4] Challenger carried two Extravehicular Mobility Units (EMU) in the event of an emergency spacewalk, which would have been performed by England and Musgrave.[4]

Backup crew
Position Astronaut
Payload Specialist 1 George W. Simon Member of Red Team
Lockheed
Payload Specialist 2 Dianne K. Prinz Member of Blue Team
United States Navy

Crew seat assignments

[edit]
Seat[5] Launch Landing
Seats 1–4 are on the flight deck.
Seats 5–7 are on the mid-deck.
1 Fullerton
2 Bridges
3 Henize
4 Musgrave
5 England
6 Acton
7 Bartoe

Launch

[edit]
Aborted launch attempt at T−3 seconds on July 12, 1985
The control panel of the Shuttle on the STS-51-F mission, showing the selection of the Abort-to-Orbit (ATO) option

STS-51-F's first launch attempt on July 12, 1985, was halted with the countdown at T−3 seconds after main engine ignition, when a malfunction of the number two RS-25 coolant valve caused an automatic launch abort. Challenger launched successfully on its second attempt on July 29, 1985, at 17:00 p.m. EDT, after a delay of 1 hour 37 minutes due to a problem with the table maintenance block update uplink.

At 3 minutes 31 seconds into the ascent, one of the center engine's two high-pressure fuel turbopump turbine discharge temperature sensors failed. Two minutes and twelve seconds later, the second sensor failed, causing the shutdown of the center engine. This was the only in-flight RS-25 failure of the Space Shuttle program. Approximately 8 minutes into the flight, one of the same temperature sensors in the right engine failed, and the remaining right-engine temperature sensor displayed readings near the redline for engine shutdown. Booster Systems Engineer Jenny M. Howard acted quickly to recommend that the crew inhibit any further automatic RS-25 shutdowns based on readings from the remaining sensors,[6] preventing the potential shutdown of a second engine and a possible abort mode that may have resulted in the loss of crew and vehicle (LOCV).[7]

The failed RS-25 resulted in an Abort to Orbit (ATO) trajectory, whereby the shuttle achieved a lower-than-planned orbital altitude. The plan had been for a 385 km (239 mi) by 382 km (237 mi) orbit,[4] but the mission was carried out at 265 km (165 mi) by 262 km (163 mi).[8]

Attempt Planned Result Turnaround Reason Decision point Weather go (%) Notes
1 12 Jul 1985, 3:30:00 pm Scrubbed — Technical 12 Jul 1985, 3:29 pm ​(T−00:00:03) Pad abort: malfunction in SSME #2 coolant valve shutdown of all three main engines.[9][10]
2 29 Jul 1985, 5:00:00 pm Success 17 days 1 hour 30 minutes Launched after 1 hour 37 minute delay to resolve issue with table maintenance block update uplink. At T+343 seconds, SSME #1 shut down leading to ATO (Abort to Orbit).[8]

Mission summary

[edit]
The Plasma Diagnostics Package (PDP) grappled by the Canadarm
Space art for the Spacelab 2 mission, showing some of the various experiments in the payload bay
Tony England drinks soda in space
A view of the Sierra Nevada mountains and surroundings from Earth orbit, taken on the STS-51-F mission

STS-51-F's primary payload was the laboratory module Spacelab 2. A special part of the modular Spacelab system, the "igloo", which was located at the head of a three-pallet train, provided on-site support to instruments mounted on pallets. The main mission objective was to verify performance of Spacelab systems, determine the interface capability of the orbiter, and measure the environment created by the spacecraft. Experiments covered life sciences, plasma physics, astronomy, high-energy astrophysics, solar physics, atmospheric physics and technology research. Despite mission replanning necessitated by Challenger's abort to orbit trajectory, the Spacelab mission was declared a success.

The flight marked the first time the European Space Agency (ESA) Instrument Pointing System (IPS) was tested in orbit. This unique pointing instrument was designed with an accuracy of one arcsecond. Initially, some problems were experienced when it was commanded to track the Sun, but a series of software fixes were made and the problem was corrected. In addition, Anthony W. England became the second amateur radio operator to transmit from space during the mission.

Spacelab Infrared Telescope

[edit]

The Spacelab Infrared Telescope (IRT) was also flown on the mission.[3] The IRT was a 15.2 cm (6.0 in) aperture helium-cooled infrared telescope, observing light between wavelengths of 1.7 to 118 μm.[3] It was thought heat emissions from the Shuttle would corrupt long-wavelength data, however it still returned useful astronomical data.[3] Another problem was that a piece of mylar insulation broke loose and floated in the line-of-sight of the telescope.[3] IRT collected infrared data on 60% of the galactic plane.[2] (see also List of largest infrared telescopes) A later space mission that experienced a stray light problem from debris was Gaia astrometry spacecraft launch in 2013 by the ESA - the source of the stray light was later identified as the fibers of the sunshield, protruding beyond the edges of the shield.[11]

Carbonated Beverage Dispenser Evaluation

[edit]
Further information: Space Cola Wars

In a heavily publicized marketing experiment, astronauts aboard STS-51-F drank carbonated beverages from specially designed cans from Cola Wars competitors Coca-Cola and Pepsi.[12] According to Acton, after Coke developed its experimental dispenser for an earlier shuttle flight, Pepsi insisted to American president Ronald Reagan that Coke should not be the first cola in space. The experiment was delayed until Pepsi could develop its own system, and the two companies' products were assigned to STS-51-F.[13]

Blue Team tested Coke, and Red Team tested Pepsi. As part of the experiment, each team was photographed with the cola logo. Acton said that while the sophisticated Coke system "dispensed soda kind of like what we're used to drinking on Earth", the Pepsi can was a shaving cream can with the Pepsi logo on a paper wrapper, which "dispensed soda filled with bubbles" that was "not very drinkable".[13] Acton said that when he gives speeches in schools, audiences are much more interested in hearing about the cola experiment than in solar physics.[13] Post-flight, the astronauts revealed that they preferred Tang, in part because it could be mixed on-orbit with existing chilled-water supplies, whereas there was no dedicated refrigeration equipment on board to chill the cans, which also fizzed excessively in microgravity.

Other payloads

[edit]

The Plasma Diagnostics Package (PDP), which had been previously flown on STS-3, made its return on the mission, and was part of a set of plasma physics experiments designed to study the Earth's ionosphere. During the third day of the mission, it was grappled out of the payload bay by the Remote Manipulator System (Canadarm) and released for six hours.[14] During this time, Challenger maneuvered around the PDP as part of a targeted proximity operations exercise. The PDP was successfully grappled by the Canadarm and returned to the payload bay at the beginning of the fourth day of the mission.[14]

In an experiment during the mission, thruster rockets were fired at a point over Tasmania and also above Boston to create two "holes" – plasma depletion regions – in the ionosphere. A worldwide group of geophysicists collaborated with the observations made from Spacelab 2.[15]

An eggshell and the bone of a baby Maiasaura (a hadrosaurid dinosaur from Cretaceous North America), were brought along on the mission by Acton. They became the first dinosaur fossils to have ever been brought into space.[16]

Landing

[edit]

Challenger landed at Edwards Air Force Base, California, on August 6, 1985, at 12:45:26 p.m. PDT. Its rollout distance was 2,612 m (8,570 ft). The mission had been extended by 17 orbits for additional payload activities due to the Abort to Orbit. The orbiter arrived back at Kennedy Space Center on August 11, 1985.

Mission insignia

[edit]

The mission insignia was designed by Houston, Texas, artist Skip Bradley. Space Shuttle Challenger is depicted ascending toward the heavens in search of new knowledge in the field of solar and stellar astronomy, with its Spacelab 2 payload. The constellations Leo and Orion are shown in the positions they were in relative to the Sun during the flight. The nineteen stars indicate that the mission is the 19th shuttle flight.

Legacy

[edit]

One of the purposes of the mission was to test how suitable the Shuttle was for conducting infrared observations, and the IRT was operated on this mission.[17] However, the orbiter was found to have some drawbacks for infrared astronomy, and this led to later infrared telescopes being free-flying from the Shuttle orbiter.[17]

See also

[edit]

References

[edit]
[edit]
Revisions and contributorsEdit on WikipediaRead on Wikipedia

STS-51-F

View on Grokipedia
from Grokipedia
STS-51-F, also known as , was the nineteenth flight of NASA's and the eighth mission for the orbiter Challenger. Launched on July 29, 1985, at 5:00 p.m. EDT from Launch Pad 39A at in , the mission carried a crew of seven astronauts to deploy the European-built module in the payload bay for a series of multidisciplinary scientific experiments focused on astronomy, astrophysics, plasma physics, atmospheric science, solar physics, and life sciences. It is historically notable as the only Space Shuttle mission to execute an abort-to-orbit (ATO) procedure following a premature shutdown of one main engine during ascent, yet the crew successfully adapted and accomplished most primary objectives during the 7-day, 22-hour, 45-minute, and 26-second flight, which concluded with a landing at in California on August 6, 1985, at 12:45 p.m. PDT. The crew was commanded by veteran astronaut C. Gordon Fullerton, with Roy D. Bridges Jr. serving as pilot; mission specialists included F. Story Musgrave, Karl G. Henize, and Anthony W. England, while payload specialists Loren W. Acton (from Lockheed Palo Alto Research Laboratories) and John-David F. Bartoe (from the U.S. Air Force) oversaw the operations. This was a dedicated mission and the first to operate on a two-shift, around-the-clock schedule, utilizing three instrument-pointing pallets configured for observations outside the Earth's atmosphere, including and of celestial objects. Key experiments verified systems performance, measured the spacecraft environment, and advanced understanding of solar magnetic fields, plasma behaviors, and biological adaptations in microgravity, despite challenges like the need for in-flight software adjustments to the Instrument Pointing System. The mission's defining incident occurred approximately 5 minutes and 43 seconds after liftoff, when a faulty temperature sensor on the number-one main triggered its shutdown, reducing and necessitating the ATO to achieve a lower-than-planned initial of 108 by 143 nautical miles using the remaining two engines and an additional burn of approximately 4,400 pounds of propellant from the (OMS). Ground teams rapidly replanned the timeline to accommodate the lower , enabling the crew to conduct 13 major experiments that yielded valuable data on , atmospheric plasma, and even a lighthearted comparison of carbonated beverages in space (the "" test). Overall, STS-51-F demonstrated the Shuttle program's resilience and advanced international collaboration in space-based research, paving the way for future astronomical observations from .

Mission Background

Designation and Objectives

STS-51-F was the 19th flight of NASA's and the eighth flight for the orbiter Challenger, designated as part of the long-duration mission series to support multidisciplinary scientific research in . The mission, also known as 2, utilized a pallet-only configuration of the 's facility to accommodate experiments requiring precise pointing and space exposure. The primary objectives centered on verifying the performance of Spacelab systems integrated with the orbiter, measuring the induced space environment, and conducting experiments across astronomy, plasma physics, life sciences, high-energy astrophysics, solar physics, and atmospheric physics. Key goals included the inaugural flight test of the Instrument Pointing System (IPS), a three-axis stabilized platform developed by the European Space Agency for sub-arcsecond pointing accuracy to support astronomical observations. Another critical element was the deployment and retrieval of the Plasma Diagnostics Package (PDP), which investigated plasma interactions with the orbiter and shuttle bay environment during free-flight operations. The mission was planned for 7 days to allow comprehensive data collection from these unique experiments. Secondary objectives encompassed middeck experiments to explore microgravity effects, such as the Carbonated Beverage Dispenser Evaluation (CBDE), which tested the packaging and dispensing of carbonated beverages to assess fluid behavior and crew consumption in weightlessness. Despite an in-flight abort-to-orbit that reduced the achievable altitude, most primary and secondary objectives were successfully met, though some astronomical experiments were impacted by the lower orbit, with the mission concluding after 7 days, 22 hours, 45 minutes, and 26 seconds.

Historical Context

STS-51-F, designated as the Spacelab 2 mission, marked the third dedicated flight of the Spacelab laboratory chronologically, following STS-9 in 1983 and STS-51-B earlier in 1985, underscoring NASA's commitment to advancing microgravity research through international partnerships with the European Space Agency (ESA), which developed the reusable Spacelab components. This mission built on the foundational Spacelab operations established during STS-9 in 1983 and the life sciences focus of STS-51-B, emphasizing astrophysics, plasma physics, and technology demonstrations to expand the shuttle's role as a versatile orbital platform. The mission's astronomical experiments also served as a precursor to Hubble Space Telescope operations, testing key observation techniques from orbit. Originally targeted for launch on July 12, 1985, STS-51-F faced delays due to technical challenges with the Instrument Pointing System required for the unpressurized pallet configuration, which necessitated extensive ground testing and integration adjustments. These issues, combined with scheduling constraints in the shuttle , pushed the mission to July, occurring approximately 84 days after Challenger's return from on May 6, 1985—a relatively rapid turnaround that highlighted the orbiter's increasing operational reliability. The program had matured significantly since in April 1984, when Challenger successfully performed the first in-orbit satellite repair, boosting confidence in extended shuttle capabilities for complex payloads like . A distinctive feature of STS-51-F was its implementation of dual crew shifts—Red and Blue teams—enabling around-the-clock science operations for the first time, which addressed the operational constraints of shorter prior missions and maximized the seven-day flight's productivity despite an in-flight Abort to Orbit. Pre-launch preparations were further impacted by external factors, including weather considerations that influenced the final selection on July 29, 1985, after a July 12 pad abort due to a coolant valve malfunction.

Crew

Composition and Roles

The STS-51-F crew consisted of seven members, including a commander, pilot, three mission specialists, and two payload specialists, selected for their expertise in piloting, engineering, science, and astrophysics to support the Spacelab 2 mission objectives. Commander C. Gordon Fullerton, aged 48 and a Colonel in the U.S. Air Force, was a veteran NASA astronaut since 1969 with a background in mechanical engineering from the California Institute of Technology and extensive experience as an Air Force test pilot. He had previously served as pilot on STS-3, accumulating 192 hours in space, and was responsible for overall mission command and flight operations. Pilot Roy D. Bridges Jr., aged 42 and also a in the U.S. , was on his first ; he held degrees from the U.S. Academy and , with a career as a fighter and since joining in 1980. Bridges assisted Fullerton in spacecraft piloting, navigation, and rendezvous operations. Mission Specialist Karl G. Henize, aged 58 and holding a Ph.D. in astronomy from the , was a scientist-astronaut selected in 1967 with prior support roles on Apollo and missions; he had over 1,900 hours of flying time. Henize, an astronomer, managed systems and conducted astronomical observations. Mission Specialist F. Story Musgrave, aged 49 and an M.D. with degrees in and chemistry, was a veteran of STS-6 with more than 13,200 hours of flying experience; he served as , overseeing systems and supporting experiment operations. Mission Specialist Anthony W. England, aged 43 and holding a Ph.D. in from MIT, specialized in Earth and planetary sciences with over 2,000 hours of flying time; he focused on conducting experiments such as the Infrared Imaging System (IRT) and other geophysical payloads. Payload Specialist Loren W. Acton, aged 49 and a Ph.D. in from the , from Lockheed Palo Alto Research Laboratories, as a for the 2 mission; as a and co-investigator for the Solar Optical Universal Polarimeter (), he was responsible for solar observation experiments aboard 2. Payload Specialist John-David F. Bartoe, aged 40 and holding a Ph.D. in physics from , was an astrophysicist from the Naval Research Laboratory and co-investigator for the High-Resolution Telescope/Spectrograph (HRTS) and Solar Ultraviolet Spectral Irradiance Monitor (SUSIM); he handled astrophysics experiments and payload operations. Fullerton and Bridges primarily managed flight operations from the forward flight deck, while Henize and Musgrave oversaw module systems and integration. , Bartoe, and Acton concentrated on executing scientific experiments, including the IRT for infrared mapping and IPS (Instrument Pointing System) for precise observations. Crew seating assignments for launch and entry positioned Fullerton in seat 1 (commander, forward left), Bridges in seat 2 (pilot, forward right), Henize in seat 3 (mission specialist, aft left), Musgrave in seat 4 (mission specialist, aft right), England in seat 5 (middeck forward left), Acton in seat 6 (middeck forward right), and Bartoe in seat 7 (middeck aft).
SeatPositionCrew MemberRole
1Forward Left (Commander)C. Gordon FullertonCommander
2Forward Right (Pilot)Roy D. Bridges Jr.Pilot
3Aft Left (MS)Karl G. HenizeMission Specialist
4Aft Right (MS)F. Story MusgraveMission Specialist
5Middeck Forward LeftAnthony W. EnglandMission Specialist
6Middeck Forward RightLoren W. ActonPayload Specialist
7Middeck AftJohn-David F. BartoePayload Specialist

Training and Shift Teams

The crew of STS-51-F underwent a comprehensive training regimen that encompassed both mission-dependent and mission-independent components to prepare for the complex operations of Spacelab 2. Mission-dependent training focused on payload-specific procedures, including hands-on sessions with principal investigators in their laboratories for experiment operations, as well as simulations using high-fidelity mockups of the Spacelab module and aft flight deck at the Johnson Space Center (JSC). This preparation emphasized integration testing at the Kennedy Space Center and familiarization with flight hardware to ensure seamless execution of astronomical and plasma physics experiments. Mission-independent training covered essential skills such as living conditions in orbit, medical procedures, emergency response, and survival training, conducted primarily at JSC and the Kennedy Space Center. Payload specialists received specialized instruction tailored to their roles; for instance, Loren Acton, as PS1, participated in sessions on solar and instrument operations provided by relevant principal investigators. All four payload specialist candidates, including Acton and John-David Bartoe, completed these dual training types to build proficiency in handling unique mission elements like the Infrared Telescope (IRT) cooldown procedures, which required precise gravity-gradient attitudes for superfluid helium management. Rehearsals for the Plasma Diagnostics Package (PDP) deployment using the Remote Manipulator System were also integral, simulating the satellite's release on flight day 3 for and subsequent retrieval. across the crew addressed potential abort scenarios, ensuring versatility in high-stress situations through integrated simulations that verified experiment compatibility and from the Payload Operations Control Center. To support the mission's extended science operations, the crew adopted an innovative dual-shift system with Red and Blue teams alternating 12-hour schedules, enabling 24-hour monitoring and maximizing experiment uptime. The Red Team consisted of Pilot Roy D. Bridges Jr., Mission Specialist 1 Karl G. Henize, and Payload Specialist 1 Loren W. Acton, while the Blue Team included Mission Specialist 2 F. Story Musgrave, Mission Specialist 3 Anthony W. England, and Payload Specialist 2 John-David F. Bartoe; Commander C. Gordon Fullerton worked across both shifts as needed to coordinate activities. This structure facilitated continuous payload oversight, with built-in overlap periods for detailed handovers to maintain operational continuity and address any real-time issues during the 126-orbit mission. The shift teams' design drew from prior Spacelab missions, adapting to the pallet-only configuration's demands for round-the-clock data collection in X-ray, ultraviolet, and infrared spectra.

Spacecraft and Payloads

Orbiter Configuration

The (OV-099) served as the orbiter for STS-51-F, marking its eighth flight following refurbishment after the previous mission, . The refurbishment process included standard inspections, tile repairs, and system upgrades to prepare for the 2 payload integration. The vehicle's external tank was ET-19, a lightweight configuration (LWT-12) designed for improved performance during ascent, which functioned nominally without any launch commit criteria violations. The solid rocket boosters were designated BI-017, refurbished units that provided the initial thrust, with separation occurring within one second of predictions despite a pre-launch yaw gyro failure on the left SRB. Key propulsion and control systems included three Space Shuttle Main Engines (SSMEs): serial number 2023 in the number 1 position (its third flight), 2020 in the number 2 position (fourth flight), and 2021 in the number 3 position (fourth flight). The (OMS) pods—left pod 01 on its seventh flight and right pod 04 on its second—enabled seven orbital insertion burns to achieve a nominal 207 circular orbit, adjusted for the mission's abort-to-orbit profile. The (RCS) thrusters supported attitude control throughout the flight, with forward RCS pod FRC 9 on its eighth use, ensuring precise orientation for payload operations. Integration of the tunnel adapter allowed access from the orbiter's aft flight deck to the payload bay's pallet-only configuration. To accommodate the long-duration science mission, the orbiter underwent modifications for enhanced power distribution and thermal management, including a dedicated cooling loop to handle the increased heat loads from experiments. Electrical power systems were upgraded to verify interface compatibility with the module, supporting continuous operations over the eight-day flight. The middeck was configured with additional berthing facilities and storage to support the two-shift rotation, facilitating 24-hour experiment monitoring without compromising comfort or safety. Safety enhancements focused on abort modes, with pre-flight testing validating the Abort-to-Orbit (ATO) capability, which was successfully executed during ascent when SSME number 1 shut down at T+343 seconds due to a anomaly. This demonstrated the orbiter's redundant systems, allowing the mission to proceed at a slightly lower altitude while maintaining full operational integrity.

Spacelab 2 Module

The Spacelab 2 payload for STS-51-F featured an unpressurized configuration comprising the support module and three pallets integrated into the orbiter's payload bay, marking a departure from the pressurized long module used in prior missions. Built by the (ESA), the Igloo served as an unpressurized cylindrical enclosure housing control electronics, power distribution, and support subsystems for the pallet-mounted experiments, with dimensions of approximately 3 m in height and 1.5 m in diameter. Each pallet measured approximately 3.05 m (10 ft) in length by 3.96 m (13 ft) in width, allowing direct exposure of instruments to the . This setup represented the first operational use of the Instrument Pointing System (IPS), a gyro-stabilized platform mounted on the second pallet that provided arcsecond-level pointing accuracy for celestial observations, independent of orbiter attitude maneuvers. Among the core astronomical instruments was the Infrared Telescope (IRT), a 15-cm aperture Ritchey-Chrétien telescope cooled to about 4 via a superfluid , enabling background-limited observations of diffuse and point sources across the 2 to 120 μm spectral range. The High Resolution Shuttle Glow Spectrograph (HRSGS) complemented this by capturing high-resolution spectra (down to 0.2 nm) of the orbiter-induced atmospheric glow in the 180-400 nm band, investigating chemical reactions between the spacecraft surface and residual atmosphere. The Solar UV Visibility Experiment (SUVE) utilized a spectrometer to assess solar irradiance transmission through Earth's upper atmosphere, focusing on wavelengths critical for studies. Additional payloads encompassed the Plasma Diagnostics Package (PDP), a free-flying instrument suite equipped with Langmuir probes, retarding potential analyzers, and mass spectrometers for in-situ plasma diagnostics and wave-particle interactions in the . The Carbonated Beverage Dispenser Experiment (CBDE) evaluated microgravity effects on carbonated drink containment and dispensing using a modified zero-gravity . Several Get Away Special (GAS) canisters carried student and small experiments. Integration of the 2 payload with the Challenger orbiter involved allocating up to 7.5 kW of electrical power from the orbiter's system to support instrument operations and cryocoolers, while and command interfaces connected directly to the orbiter's general-purpose computers via the payload interrogator for real-time and ground communication. The overall payload mass totaled approximately 14,500 kg, optimized for the mission's 7-day duration and diverse scientific objectives.

Launch Preparations

Vehicle Integration

The vehicle integration for STS-51-F commenced in the (OPF) at , where the orbiter Challenger, landed from its previous mission on May 6, 1985, underwent post-flight maintenance, inspections, and reconfiguration for the upcoming flight. The primary focus during this phase was the installation of the payload, a pallet-only configuration consisting of three pallets and an igloo module housing support equipment. On June 8, 1985, the integrated payload was transferred to the OPF and installed in Challenger's payload bay, marking a key step in preparing the spacecraft for the mission's scientific objectives. This process highlighted the collaborative efforts between and the (ESA), as was an ESA-developed system requiring joint verification to ensure seamless interface with the U.S. orbiter. Following installation, a series of rigorous testing phases verified the payload's compatibility and the overall vehicle's readiness. On June 12, 1985, Spacelab-orbiter interface tests were conducted in the OPF to confirm electrical, data, and mechanical connections. The next day, June 13, 1985, end-to-end testing linked the payload with ground control systems at the Payload Operations Control Center in , simulating mission operations. Standard ground verification activities included vibration testing to simulate launch acoustics, leak checks on propulsion and payload systems, and fit verifications to ensure all components aligned without interference. Notably, the Infrared Telescope (IRT) experiment's helium cryocooler underwent dedicated ground thermal performance evaluation tests to assess its cooling efficiency for infrared observations, confirming operational readiness prior to flight. These tests prioritized structural integrity and environmental resilience, drawing on established protocols for shuttle payloads. Challenger was then transferred to the (VAB) in late June 1985 for mating with the External Tank (ET) and Solid Rocket Boosters (SRBs). The stacking process involved hoisting the orbiter atop the ET, followed by attachment of the SRBs, with additional leak checks and alignment verifications to secure the stack. This phase addressed minor ongoing refinements to SRB field joint seals, informed by certification reviews from prior missions, including an updated SRB Board meeting on June 21, 1985, as part of the Flight Readiness Review process. No major delays arose from these activities for STS-51-F, though the international coordination for components occasionally required iterative adjustments to timelines and interfaces. The completed shuttle stack was rolled out to Launch Complex 39A on June 29, 1985, positioning the vehicle for final preparations. Post-rollout activities included pad interface tests and system checks, interrupted by holds for inclement weather and technical evaluations, which contributed to the overall schedule compression leading into the .

Countdown Timeline

The for STS-51-F's initial launch attempt targeted liftoff on July 12, 1985, at 19:30 UTC from Launch Complex 39A. The final phases advanced nominally through early holds, including propellant loading and systems checks following vehicle integration. During the planned T-3 hour hold, the seven-member crew ingressed the orbiter Challenger, completing suiting and boarding without incident. Post-hold activities included chilldown of the three Space Shuttle Main Engines (SSMEs) using to maintain thermal conditioning and loading of hypergolic propellants into the and tanks, with all parameters within limits. At T-5 minutes, the auxiliary power units were activated to power hydraulic systems, and the proceeded to T-31 seconds, when control transferred from ground launch sequencer to onboard computers. Main engine ignition began at T-6.6 seconds, but at T-3 seconds, a malfunction in the high-pressure fuel-side of the number two SSME—failing to transition from 100% to 70% open—triggered a Redundant Set Launch Sequencer abort, shutting down all three engines and halting the launch. Following the abort, the vehicle underwent safing procedures, including detanking of propellants, and Challenger was rolled back to the Orbiter Processing Facility on July 13 for diagnostics and replacement of the faulty coolant valve. Processing and verification tests were completed by July 22, when the orbiter was remated to the External Tank and Solid Rocket Boosters in the Vehicle Assembly Building and rolled out to the pad. The countdown for the second launch attempt began at T-43 hours on July 27, 1985, targeting July 29 at 19:23 UTC (3:23 p.m. EDT). The sequence progressed smoothly through the T-3 hour hold for crew ingress and meteorological evaluations, with the astronauts boarding Challenger amid clear weather conditions. Subsequent pre-liftoff preparations, encompassing SSME chilldown and hypergolic propellant loading, reported no significant anomalies, and systems remained green through T-5 minutes. A 1 hour 37 minute hold was imposed at T-3 minutes to address an erroneous command during the table maintenance block update to the backup flight system computers; the issue was resolved by verifying and retransmitting the uplink data. The countdown then resumed without further delays, confirming all go parameters prior to engine start.

Launch Sequence

Scrub and Delays

The first launch attempt for STS-51-F occurred on July 12, 1985, at 3:30 p.m. EDT from Launch Complex 39A, but the countdown was halted at T-3 seconds after main engine ignition. The abort was triggered by a malfunction in the chamber coolant valve of Space Shuttle Main Engine No. 2, which failed to close properly from 100 percent open to the required 70 percent position for startup. This violation of flight rules, detected by the redundant set launch sequencer, risked inadequate cooling of the engine chamber and potential overheating during ascent. Ground crews immediately initiated safing procedures, including shutdown of the main engines and detanking of the external tank, completing the process without damage to the orbiter, external tank, or solid rocket boosters. The crew was demated from Challenger approximately 90 minutes after the abort and returned to crew quarters before resuming training simulations. The faulty main engine was replaced with a spare unit, requiring extensive inspections and verification to ensure system integrity. The scrub resulted in a 17-day delay to the next attempt, allowing time for engine replacement and additional payload verifications on , including checks on experiment pallets and instrument alignments. This incident underscored ongoing challenges with main reliability in the early Shuttle program, though no broader vehicle damage occurred. The mission timeline had already been affected by cumulative delays stemming from external tank and production and integration issues earlier in 1985, which compressed the overall Shuttle manifest following . These factors contributed to the initial targeting of rather than an earlier slot. The final countdown resumed on July 29, 1985, following a 1 hour, 37 minute hold to resolve a table maintenance block update uplink problem.

Liftoff and Abort Event

The Space Shuttle Challenger lifted off from Launch Pad 39A at Kennedy Space Center on July 29, 1985, at 21:00:00 UTC, marking the start of the STS-51-F mission. The ascent proceeded nominally in the initial phases, with solid rocket booster (SRB) ignition occurring at T+0 seconds and SRB separation at approximately T+2:05, consistent with pre-flight predictions. External tank (ET) systems performed as expected during this period, with no anomalies reported in propellant flow or structural integrity up to that point. At T+5:43 (343 seconds), an anomaly occurred when Space Shuttle Main Engine (SSME) #1—the center engine—shut down prematurely due to erroneous high readings from its high-pressure fuel (HPFTP) discharge temperature s. Specifically, one failed at T+3:41, followed by the second at T+5:43, triggering the redundant shutdown logic despite the actual temperatures remaining within safe limits. This sensor malfunction led to an automatic Abort-to-Orbit (ATO) mode being initiated, the only in-flight abort in the history of the . The ATO sequence allowed Challenger to continue ascent using the remaining two SSMEs, achieving an initial orbit of approximately 265 by 200 kilometers (143.1 by 108.0 nautical miles) at a 49.57-degree inclination. Main engine cutoff (MECO) occurred at T+8:22, followed by ET separation, and the crew then performed an Orbital Maneuvering System (OMS) burn lasting 106 seconds to circularize the orbit at around 330 kilometers altitude. No risks to crew safety arose from the event, as the abort profile ensured a stable orbital insertion. Commander C. Gordon Fullerton and Pilot Roy D. Bridges Jr. responded effectively by manually confirming the ATO via the cockpit selector and button activation, overriding any potential automated hesitations to execute the procedure seamlessly. Their actions, combined with ground control guidance, enabled rapid transition to orbital operations without further complications.

Orbital Operations

Flight Adjustments

Following the Abort to Orbit (ATO) maneuver, Challenger achieved an initial elliptical with an apogee of 265 km and a perigee of 200 km at an inclination of 49.5°. This lower-than-planned trajectory resulted from the premature shutdown of the orbiter's center main engine during ascent, necessitating immediate orbital adjustments to ensure mission viability. The crew executed the first (OMS) burn approximately 2 minutes after main engine cutoff, lasting 106 seconds and consuming 4,134 pounds of propellant, to establish the preliminary orbit. Subsequent OMS burns, including three additional maneuvers over the next few hours, raised the perigee progressively. These adjustments stabilized the vehicle dynamics, with (RCS) thrusters used for fine attitude tuning to support module activation on the mission's second day. Mission planners adjusted the planned 7-day timeline, extending it by 24 hours to accommodate the abort while conserving resources impacted by the abort; for instance, Infrared Telescope (IRT) observation windows were reduced to account for the altered orbital parameters and delayed cryocooler power-up due to thermal stabilization concerns in the lower initial orbit. The final operational orbit was established at 312 km by 321 km, enabling the full range of astronomical and plasma physics experiments aboard Spacelab 2.

Experiment Execution

Following the abort-to-orbit event, the crew initiated activation approximately 15 hours after launch on Flight Day 1, opening the payload bay doors and deploying the Instrument Pointing System (IPS) for initial checkout and solar observations. The Plasma Diagnostics Package (PDP) was deployed on Flight Day 3 for about seven hours of free-flyer operations before retrieval later that day, with additional proximity operations extending into Flight Day 4 to study interactions with the orbiter's plasma environment. From Flight Days 2 through 5, the Telescope (IRT) conducted observations of planets and stars, including , , and galactic sources, while IPS pointing accuracy tests verified stability for and instruments, achieving sub-arcsecond precision in most cases. Operations proceeded on a 24-hour schedule with alternating Red and Blue teams, each working 12-hour shifts and conducting handovers to ensure continuous experiment monitoring; the Blue team, including mission specialists and Musgrave along with Bartoe, primarily handled life sciences tasks such as the Continuous Blood Draw Experiment (CBDE) for monitoring crew physiological responses. Musgrave and oversaw sample collections and data logging for experiments like the absorption study and plant growth unit, integrating these with broader payload activities during their shifts. Key highlights included the inaugural use of the IPS for ultraviolet astronomy, enabling high-resolution observations with the University of Wisconsin's Ultraviolet Spectrometer and Polarimeter, which captured data on solar chromospheric structures. On Flight Day 4, the crew released grid spheres from a Get Away Special canister as part of a student-designed experiment to study reentry aerodynamics and atmospheric density, with the spheres tracked via ground radar for several days. Overall, the experiments accumulated approximately 120 hours of runtime across the 127 orbits, supporting multidisciplinary investigations in astronomy, plasma physics, and life sciences. Despite the mission's adjustments due to the ascent abort, challenges arose, including intermittent IRT door mechanism issues that delayed some observations by up to two hours per session, and cooldown delays for the superfluid helium experiment caused by the unexpected orbital insertion altitude. These factors contributed to objectives being met at a rate of at least 50%, with many experiments achieving 90-100% success, all primary verification goals met but some secondary astronomical targets partially deferred.

Landing Sequence

Deorbit Preparation

On flight day 8, the crew of STS-51-F initiated payload safing procedures to prepare the Spacelab module and attached experiments for re-entry, including power-down sequences for non-essential systems. The remaining Spacelab experiments were fully powered down to prevent any thermal or electrical issues during atmospheric descent. The Plasma Diagnostics Package (PDP), which had been deployed and retrieved earlier in the mission, was securely stowed in the payload bay. These configurations ensured the integrity of the scientific payload after completing observations in astronomy, plasma physics, and atmospheric science. The crew also reconfigured the orbiter for deorbit and entry, stowing loose items and conducting pre-burn systems checks. Payload specialists, such as Loren Acton, transitioned from the working area to flight seats on the middeck to assume entry positions alongside the core flight crew. The vehicle was in a near-circular at approximately 320 km (170 nmi) altitude, achieved after several orbital adjustment burns necessitated by the earlier Abort-To-Orbit during ascent. The ATO had placed Challenger in a lower-than-planned initial , requiring additional maneuvering and ultimately extending the mission duration by about one day to maximize science return; this adjustment compressed the timeline for final experiments, including limited operations with the High Resolution Gamma Ray and Spallation Spectrometer (HRGSS). Weather conditions at the primary landing site, , were closely monitored, with crosswinds assessed to remain within acceptable limits for runway 23. Contingency planning included a potential divert to if winds exceeded thresholds, but conditions supported the nominal Edwards landing. The deorbit burn, using the (OMS) engines, was executed on August 6, 1985, from the 320 km orbit, lasting 172 seconds and targeting Edwards AFB for touchdown later that day.

Re-entry and Touchdown

The Space Shuttle Challenger initiated atmospheric re-entry following the deorbit burn, crossing entry interface at an altitude of approximately 400,000 feet (122 kilometers) about 30 minutes prior to touchdown. Peak heating occurred during this phase as the orbiter descended at speeds reaching Mach 25, subjecting the thermal protection system to extreme temperatures exceeding 3,000 degrees (1,650 degrees ). The flight transitioned to the Terminal Area Energy Management (TAEM) phase at around 83,000 feet (25 kilometers), where the crew monitored the automated systems for the approach to . The approach and landing were manually conducted by C. Gordon Fullerton, aligning for Runway 23 at under clear skies and light winds. Touchdown occurred at 19:45:26 UTC on August 6, 1985, with a landing speed of 215 (346 kilometers per hour) after a mission duration of 7 days, 22 hours, 45 minutes, and 26 seconds. The main landing gear touched down first, followed by the nose gear 9 seconds later, initiating deceleration via wheel brakes and the deployment of the nose skid to manage rollout. Post-touchdown, the orbiter decelerated to a after a rollout of 8,569 feet (2,612 meters) in 55 seconds. T-38 chase aircraft confirmed the parameters and orbiter condition, marking the successful conclusion of the mission without significant anomalies during re-entry or touchdown.

Post-Mission Analysis

Technical Review

Following the successful landing of STS-51-F on August 6, 1985, at , NASA's technical review centered on the in-flight Abort to Orbit (ATO) event and the overall condition of the flight hardware. The investigation into the ATO, which occurred at T+345.3 seconds after liftoff, determined that Space Shuttle Main Engine (SSME) number 1 shut down prematurely due to a false high-temperature reading from its Channel A high-pressure fuel (HPFTP) discharge . This erroneous signal, caused by a failure rather than any actual hardware anomaly such as a crack, triggered the automatic shutdown to protect the engine, while SSMEs 2 and 3 continued nominal operation. Post-flight disassembly and analysis of SSME-1 confirmed no physical damage to the blades or other components, validating the as the sole point of failure. No anomalies were identified in the External Tank (ET) insulation, structure, or separation systems, nor in the Solid Rocket Boosters (SRBs), which performed within specifications throughout ascent and separation. A comprehensive failure tree analysis traced the root cause to a calibration drift in the resistance temperature detector (RTD) sensors monitoring HPFTP discharge temperature, with the critical error manifesting at approximately T+345 seconds during mainstage burn. This event highlighted vulnerabilities in sensor redundancy, as a secondary Channel B sensor had already failed earlier at T+221 seconds, leaving the system reliant on the faulty primary channel. In response, implemented upgrades to the SSME temperature , including improved materials and protocols for enhanced reliability and to prevent false exceedances in future missions. These modifications were incorporated into subsequent Block I SSME configurations, ensuring dual-channel validation before shutdown commands. The review also confirmed that the ATO maneuver itself was executed flawlessly, with the crew and ground control adhering to procedures that stabilized the vehicle in a stable 49.6-degree inclination at approximately 170 nautical miles altitude. Assessment of the Orbiter Challenger post-landing revealed minimal impact damage to its thermal protection system (TPS), with a total of 553 sites documented during the detailed inspection—226 of which were 1 inch or larger in diameter—but no tiles were missing or required replacement prior to re-entry. The reinforced carbon-carbon leading edges and high-temperature reusable surface insulation tiles sustained only superficial impacts, primarily from ascent , allowing for a nominal without concerns. The Spacelab-2 module emerged intact, with its igloo-pallet structure and all scientific instruments operational except for the initial inoperability of the Solar Optical Universal Polarimeter (), which was resolved mid-mission through crew intervention. Additionally, the Plasma Diagnostics Package (PDP), deployed on flight day 2 to study plasma interactions in low-Earth , was retrieved successfully on flight day 3 after nominal operations, with no degradation to its instrumentation. Debriefing sessions at involving the crew, engineers, and mission managers evaluated the ATO performance and overall vehicle dynamics, affirming that Challenger's subsystems— including , , and —demonstrated excellent reliability throughout the 7-day, 22-hour mission. The review concluded that the orbiter was in high readiness for turnaround and the subsequent flight (STS-51-I), with only routine maintenance needed and no major refurbishments impacting the manifest. This assessment underscored the robustness of the system's design margins, even under anomalous conditions, while the sensor upgrades addressed the identified gap in SSME health monitoring to bolster future operational safety.

Scientific Outcomes

The Infrared Telescope (IRT), mounted on the Instrument Pointing System, conducted observations of the at 2 and 7 microns, revealing a broader structural extent than detected at longer wavelengths, and identified new sources within the . These results provided valuable insights into diffuse celestial emissions, though elevated background noise from shuttle exhaust gases exceeded expectations, complicating low-surface-brightness detections. Cooldown issues with the helium-cooled system resulted in approximately 20% operational downtime, limiting extended observations of select stellar and planetary targets such as and . The Plasma Diagnostics Package (PDP) yielded extensive data on shuttle-induced plasma perturbations, measuring ion and electron densities in the orbiter's wake that were up to two orders of magnitude lower than theoretical predictions from the International Reference model, thereby validating and refining computational models of spacecraft-ionosphere interactions. Key findings included the detection of a cloud with densities around 10⁹ H₂O molecules/cm³ at 50 meters from the shuttle, alongside dominant H₂O⁺ ions forming ring distributions via charge exchange, and O⁺ streaming from the ram direction up to 400 meters upstream. These measurements, taken during free-flyer deployments and wake transits, also captured electrostatic noise (1-5 mV/m) correlated with thruster firings and neutral gas rates of about 2.5 × 10²² s⁻¹. Other experiments contributed notable results despite the mission's abbreviated duration following the ascent abort. The in Bubbles and Drops Experiment (CBDE) observed unexpected anomalies in bubble formation and dynamics under microgravity, where bubbles exhibited irregular coalescence and migration patterns deviating from pre-flight simulations, informing fluid behavior in low-gravity environments. The Instrument Pointing System (IPS) demonstrated pointing accuracy and stability within design specifications of approximately 1-2 arcseconds, supporting successful solar and astrophysical observations after initial alignment challenges were resolved. Additionally, solar physicist Loren Acton's oversight of the Spectrometer/ (UVSP) and Solar Irradiance Monitor (SUSIM) produced high-resolution UV spectra (120-400 nm) that advanced understanding of solar atmospheric variability and its influence on Earth's upper atmosphere . The collective scientific outcomes from STS-51-F spurred over 50 peer-reviewed publications in , , and space plasma domains, with broader contributions exceeding 2,400 refereed papers that enhanced models of galactic emissions, plasma wake phenomena, and solar-terrestrial interactions. Although the abort-to-orbit maneuver shortened the mission by one day, reducing opportunities for deep-space targets, the acquired datasets addressed key gaps in astronomy and ionospheric perturbation studies, laying groundwork for subsequent shuttle-based observations.

Legacy

Engineering Lessons

The Abort to Orbit (ATO) mode was successfully validated during STS-51-F when the center Space Shuttle Main Engine (SSME) prematurely shut down 5 minutes and 43 seconds after launch due to erroneous readings from two redundant temperature sensors on the high-pressure fuel turbopump's turbine discharge. This failure, the only in-flight SSME shutdown in the shuttle program, allowed the vehicle to reach a stable lower-than-planned of approximately 108 by 143 nautical miles at 49.5-degree inclination using the remaining two engines, later raised to 170 nautical miles, confirming the ATO's effectiveness for contingency operations while exposing critical vulnerabilities in sensor design and single-point failure modes. Although the mission proceeded with adjusted objectives, the incident underscored the risks of fragile Resistance Temperature Detectors (RTDs) in harsh environments, prompting immediate post-flight reviews that influenced subsequent hardware enhancements. In response to the sensor malfunction, implemented software modifications to SSME controllers for improved fault detection, including logic requiring cross-verification of sensor data before shutdown initiation, which was incorporated in subsequent missions to enhance without full hardware replacement. Longer-term, these lessons contributed to the Block I SSME upgrade in 1995, replacing RTDs with more robust thermocouples to prevent similar cascading failures, thereby increasing overall engine reliability for high-thrust operations. System-level improvements from the mission included refined protocols for thermal management, as the pallet-only configuration tested superfluid helium cryocoolers that maintained instrument temperatures near despite orbital perturbations, leading to enhanced cooling guidelines for subsequent payloads. These tests validated low-temperature operations for sensitive detectors, directly informing the thermal isolation designs in the Hubble Space Telescope's instruments. Additionally, the European Space Agency's Instrument Pointing System (IPS), flown for the first time on STS-51-F, underwent in-orbit refinements to its three-axis stabilization algorithms, achieving sub-arcsecond pointing accuracy that served as a precursor for Hubble's fine guidance systems by demonstrating stable platform control in microgravity. At the program level, the mission's use of a seven-person divided into red and blue shift teams for 24-hour operations reinforced the efficacy of rotating schedules in sustaining productivity during multi-week flights, providing operational templates for assembly missions that required similar crew endurance strategies.

Astronomical Contributions

The Telescope (IRT) experiment aboard STS-51-F represented a pioneering effort in space-based astronomy, as it was the first cryogenically cooled telescope deployed from the . Equipped with a 15.2 cm Herschelian design cooled by superfluid to approximately 8 , the IRT operated across wavelengths from 1.7 to 118 μm, enabling sensitive mapping of low-surface-brightness celestial sources without atmospheric distortion. Despite operational challenges, including thermal interference from the Orbiter that affected some data quality, the instrument successfully surveyed over 60% of the and cataloged observations of numerous celestial objects, including detailed 2.4 μm maps of the galactic center region and extended plane segments from longitude l = -10° to 110°. These results complemented the Astronomical Satellite () all-sky survey by providing deeper, targeted views of galactic structures, advancing understanding of dust distribution and star-forming regions. In addition to infrared advancements, STS-51-F's observations significantly contributed to . Payload specialists Loren Acton and John-David Bartoe operated instruments such as the Solar Optical Universal Polarimeter () and ultraviolet spectrometers, capturing high-resolution imagery and spectra of solar fine structures, including chromospheric networks and coronal features. This data, obtained above Earth's absorbing atmosphere, refined models of solar atmospheric dynamics and ultraviolet irradiance variations, offering insights into magnetic activity and energy transfer processes in the Sun's transition region. Karl G. Henize, a renowned with expertise in galactic studies, supported the astrophysical payload operations, including the IRT, and his involvement helped integrate solar and datasets to enhance broader galactic mapping efforts during post-mission . The scientific output from STS-51-F has endured through extensive publications and archival resources. The mission generated over 100 peer-reviewed papers detailing astronomical findings, with key contributions appearing in journals like Astrophysical Letters and Communications and , covering topics from galactic emission to solar UV . Data from the IRT and UV instruments are preserved in NASA's Technical Reports Server and other archives, facilitating their use in 1990s research on source catalogs and solar modeling, while serving as technological precursors for advanced observatories.

Mission Insignia

Design Elements

The STS-51-F mission patch is a circular emblem featuring the silhouette of the ascending through space, set against a black background representing the . At the center, the design highlights the Challenger's payload bay containing the 2 module, emphasizing the mission's astronomical focus. Key graphical elements include the constellations Leo and Orion, rendered in white to depict their relative positions to the sun during the flight, along with nineteen individual stars symbolizing the program's nineteenth mission. The patch incorporates a classic aesthetic with bold contrasts: the shuttle in white outline, stellar features in white tones, and the dark void of providing depth. Designed by Houston-based artist Skip Bradley in collaboration with crew input, it adheres to the standard style of embroidered cloth . These patches measure approximately 4 inches in diameter and were produced as fully embroidered items with merrowed edges for durability. Crew members wore them on flight suits and personal gear during the mission, while additional units were distributed to NASA personnel, international partners, and mission contributors following the flight's completion.

Symbolism and Usage

The STS-51-F mission patch embodies the scientific ambitions of 2 through its central imagery of the ascending amid celestial elements, symbolizing the pursuit of knowledge in solar and stellar astronomy. The constellations Leo and Orion, positioned relative to the Sun as viewed during the flight, denote the specific astronomical targets, while the nineteen individual stars honor the mission as the 19th flight. The inclusion of the Spacelab module, developed by the European Space Agency (ESA) in collaboration with NASA, highlights the international partnership that made the mission possible. As the official NASA emblem for STS-51-F, the patch appeared prominently in mission press kits, official videos, and documentation to identify and promote the flight's objectives. Crew members wore it on their flight suits throughout the mission, signifying team unity and mission identity in line with longstanding NASA tradition. Post-mission, embroidered replicas were distributed as awards to contributors, recognizing their roles in the successful abort-to-orbit launch and scientific achievements. The patch also played a cultural role in public outreach, featured in NASA publications to showcase advancements in space science and international cooperation. By 2025, high-resolution digital versions have been archived in NASA's online collections, preserving the for educational and historical access.

References

  1. https://www.nasa.gov/mission/sts-51f/
  2. https://appel.nasa.gov/2022/07/12/this-month-in-nasa-history-sts-51-f/
  3. https://www.ibiblio.org/apollo/Shuttle/Reports/Mission%20Reports/STS-51-F%20National%20Space%20Transportation%20System%20Mission%20Report.pdf
  4. https://www.eoportal.org/satellite-missions/ips
  5. https://airandspace.si.edu/collection-objects/coca-cola-can-sts-51-f/nasm_A19850814000
  6. https://ntrs.nasa.gov/api/citations/19870012671/downloads/19870012671.pdf
  7. https://www.spaceline.org/united-states-manned-space-flight/space-shuttle-mission-program-fact-sheets/sts-51f/
  8. https://spacepresskit.wordpress.com/wp-content/uploads/2012/08/sts-51f.pdf
  9. https://www.nasa.gov/wp-content/uploads/2016/01/fullerton_charles.pdf
  10. https://www.nasa.gov/wp-content/uploads/2016/01/acton-lw.pdf
  11. https://www.spacefacts.de/mission/english/sts-51f.htm
  12. https://www.nasa.gov/history/rogersrep/v1ch6.htm
  13. https://nssdc.gsfc.nasa.gov/nmc/spacecraft/display.action?id=1985-063A
  14. https://ntrs.nasa.gov/citations/19900016392
  15. https://ntrs.nasa.gov/citations/19940014701
  16. https://solarscience.msfc.nasa.gov/SpaceLab2.shtml
  17. https://www.nasa.gov/mission/sts-51b/
  18. https://ntrs.nasa.gov/citations/19860030629
  19. https://www.nasa.gov/history/rogersrep/v2apph.htm
  20. https://weebau.com/flights/sts51f.htm
  21. https://www.americaspace.com/2020/07/12/i-didnt-touch-a-thing-remembering-challengers-pad-abort-otd-in-1985/
  22. https://www.americaspace.com/2015/07/25/going-to-spain-30-years-since-the-unlucky-success-of-mission-51f-part-1/
  23. https://www.nasa.gov/history/rogersrep/v2appj.htm
  24. https://ntrs.nasa.gov/api/citations/19920022612/downloads/19920022612.pdf
  25. https://ntrs.nasa.gov/api/citations/20120001539/downloads/20120001539.pdf
  26. https://ntrs.nasa.gov/api/citations/20000021374/downloads/20000021374.pdf
  27. https://ntrs.nasa.gov/api/citations/20000017914/downloads/20000017914.pdf
  28. https://ntrs.nasa.gov/api/citations/19890017351/downloads/19890017351.pdf
  29. https://ntrs.nasa.gov/api/citations/19860003891/downloads/19860003891.pdf
  30. https://ntrs.nasa.gov/api/citations/20110015564/downloads/20110015564.pdf
  31. https://www.esa.int/ESA_Multimedia/Images/2023/11/Instrument_Pointing_System_in_use_on_Spacelab_flight
  32. https://ntrs.nasa.gov/citations/19800033264
  33. https://ui.adsabs.harvard.edu/abs/1987AIPC..155..157M/abstract
  34. https://www.icc.dur.ac.uk/~tt/Lectures/Galaxies/Images/Infrared/Timeline/timeline2.html
  35. https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/JD092iD01p00839
  36. https://adsabs.harvard.edu/full/1994BAAS...26.1604P
  37. https://core.ac.uk/download/pdf/10549293.pdf
  38. https://www.nasa.gov/gallery/sts-51f/
  39. https://www.esa.int/About_Us/50_years_of_ESA/Building_and_flying_Spacelab
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