Fwd: The 11 Barking Days of STS-69

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From: "Gary Johnson" <gjohnson144@comcast.net>
Date: September 21, 2014 3:49:07 PM CDT
To: "Gary Johnson" <gjohnson144@comcast.net>
Subject: FW: The 11 Barking Days of STS-69

 

 

AmericaSpace

For a nation that explores
September 20th, 2014

Dog Names, Dog Tags, Dog Bowls: The 11 Barking Days of STS-69 (Part 1)

By Ben Evans

 

Mike Gernhardt, pictured during his EVA on STS-69. Photo Credit: NASA

Nineteen years ago, last week, the "Dogs of War" barked, woofed, and yelped their way through a remarkable mission which put virtually all of the space shuttle capabilities—satellite deployment and retrieval, rendezvous and proximity operations, spacewalking, and science—to the test. During STS-69 in September 1995, Commander Dave Walker, Pilot Ken Cockrell, Payload Commander Jim Voss, and Mission Specialists Jim Newman and Mike Gernhardt put a series of lengthy delays behind them and successfully completed one of the most impressive and multi-faceted flights in the shuttle program's 30-year history. Yet, less than a decade since the calamitous loss of Challenger, STS-69 illustrated that the long shadow of tragedy was never far away and vigilance in shuttle operations could never be taken for granted.

The mission was planned for launch at the end of July 1995, kicking off a complex, 11-day flight to deploy and recover a pair of satellites and perform an EVA to evaluate techniques and tools for International Space Station (ISS) construction and maintenance. However, in the days after the landing of the previous shuttle mission—STS-70 on 22 July—disassembly of its Solid Rocket Boosters (SRBs) revealed a tiny air pocket, known as a "gas path," in the nozzle internal joint No. 3, at the base of the right-hand booster.

It extended from the motor chamber, through the Room Temperature Vulcanizing material, and up to the primary O-ring, the latter of which provided a critical sealing mechanism to prevent gas at a temperature of 2,760 degrees Celsius (5,000 degrees Fahrenheit) leaking through the booster casing. Although the primary O-ring was unbreached on STS-70, it did exhibit a "slight heat effect," a trio of singe marks and small amounts of soot. Also observed were heat-affected insulation and eroded adhesive. As well as having been a key player in the loss of Challenger, a similar gas-path issue was noted after the STS-71 mission in June 1995. "Gas paths or small air pockets are the result of nozzle fabrication involving backfilling of the joint with insulation material," explained NASA's anomaly report. "Similar paths had been expected or observed following previous flights, but missions STS-71 and STS-70 marked the first time slight heat effect was noted on the primary O-ring."

The crew patch for the STS-69 mission, emblazoned with the surnames of Endeavour's five-man crew: Commander Dave Walker, Pilot Ken Cockrell, Payload Commander Jim Voss, and Mission Specialists Jim Newman and Mike Gernhardt. Image Credit: NASA

As investigators set to work on the problem, the STS-69 launch met with delay. Originally targeted for launch on 30 July, Endeavour and her crew first fell foul to the ravages of Hurricane Erin, which was threatening the coast of Central Florida. Having been initially rolled out to Pad 39A on 5 July, the shuttle stack was rolled back to the Vehicle Assembly Building (VAB) on 1 August as a protective measure and returned to the pad on the 8th. However, by this stage, as the SRB anomaly became more clear, the launch was postponed until no earlier than the end of August.

Although the primary O-ring was not breached and the secondary O-ring was untouched in the STS-71 and STS-70 ascents, it became clear that similar instances of exhaust burning through to reach the seals had occurred on 11 previous shuttle flights. Quoted by Flight International a few days later, NASA noted that there were "no design issues" with the SRBs and that the STS-71 and STS-70 crews were in "no added danger," the investigation team was studying a procedure which could allow for ultrasound inspections and minor adjustments to the injection of an insulating putty. It was hoped that this "may reduce" the possibility of gas paths reaching the primary O-ring on future missions.

"Working inside the nozzle of the boosters," explained Flight International on 30 August, "technicians are replacing the insulating material protecting the nozzle O-ring joints with a new material. Seven sets of [SRBs] will undergo this work and the new material will be introduced on future production." Although it was considered unlikely that STS-69 would fly until at least mid-September 1995, engineers and managers ultimately concluded at the Flight Readiness Review (FRR) that the issue did not pose a significant safety-of-flight concern and the mission was rescheduled for launch on 31 August.

However, this attempt was scrubbed by the Mission Management Team at 3:30 a.m. EDT on the 31st, just prior to the loading of liquid oxygen and hydrogen aboard the External Tank (ET), when a temperature "spike" was recorded in Endeavour's No. 2 fuel cell. Since mission rules dictated that all three of the orbiter's electricity-generating cells had to be fully operational for a launch to go ahead, it was elected to replace the unit and the countdown resumed on the afternoon of 4 September, tracking a liftoff on the 7th. Early that morning, the STS-69 crew departed their quarters and arrived at Pad 39A at 8:10 a.m., with Newman taking a moment on the gantry to snap a photograph of his four crewmates. They took their seats aboard the shuttle, but after closing and sealing the middeck side hatch it failed to pass a standard leak check. The hatch was reopened, its seals checked, and it was closed and retested without incident. Later in the countdown, a pressure issue cropped up with a water spray boiler, but was cleared, since it did not violate any Launch Commit Criteria and posed no constraints. In the final minutes, Walker stretched out his gloved hand to his three comrades on the flight deck—Cockrell, Voss, and Newman—to express how much he had enjoyed training with them. Endeavour thundered safely into orbit at 11:09 a.m. EDT.

For the first time in the shuttle program, two satellites would be deployed and retrieved, using the Canadian-built Remote Manipulator System (RMS) mechanical arm on STS-69. The first was the Wake Shield Facility (WSF), flying its second mission, and the other was the Shuttle-Pointed Autonomous Research Tool for Astronomy (SPARTAN)-201. Yet when veteran NASA astronaut Jim Voss was assigned as Payload Commander of STS-69 in August 1993, the cargo was quite different, consisting instead of the fourth Spacehab laboratory and the Shuttle Pallet Satellite (SPAS)-III.

Jim Voss (center, in teal-colored shirt) was STS-69 Payload Commander and carried responsibility for orchestrating the success of its multiple mission objectives. He is pictured during training on the flight deck simulator with Ken Cockrell (left) and Jim Newman. Photo Credit: NASA

"Spacehab is a complement of commercial experiments flown in a pressurized module in the shuttle's cargo bay as a supplement to the middeck of the orbiter," a NASA press release announced, "and SPAS-III is a group of instruments which will measure the atmosphere around the orbiter and the background clutter in the Earth's atmosphere, calling for a complex flight plan." One of the key instruments aboard SPAS-III was the Infrared Background Signature Survey (IBSS), developed by the Strategic Defense Initiative (SDI). Distinguished by its large, barrel-shaped cryostat, IBSS had previously flown on the STS-39 mission in April 1991 and sought to obtain scientific data in support of missile defence applications. Flying freely from the shuttle aboard SPAS-III at various ranges, IBSS would make spectral, spatial, and temporal radiometric observations of the orbiter's exhaust plumes and replications of booster firings. Interactions of these plumes with the ionosphere would be analysed, as would the region around the engine nozzles.

In September 1991, Flight International reported that Fairchild Space had been awarded a $14 million systems integration contract for SPAS-III by the SDI's Sensor Technology Directorate. However, SPAS-III and IBSS met with delay and eventually cancellation, and by the time the remainder of the STS-69 crew was named in July 1994 it had vanished from the payload complement entirely. So too had the Spacehab module, which was remanifested onto a later mission. In their place was WSF-2 and SPARTAN, the latter equipped with a battery of experiments for NASA's Office of Aeronautics and Space Technology, and known as "OAST-Flyer." As the months wore on, OAST-Flyer was itself shifted onto a subsequent flight and replaced with the SPARTAN-201 payload, equipped with two instruments for solar science research. As payload commander, it was Voss' responsibility to develop and co-ordinate the crew's training plan, liaise with the mission's payload sponsors and principal investigators, attend relevant meetings, and oversee pertinent hardware and software changes, ahead of the announcement of the other crew members.

Voss and Dave Walker had previously flown together on STS-53. During preparations for that mission, their training instructors nicknamed them "The Dogs of War" and the entire team received individual "dog names" and "dog tags." In recognition of his hair, Walker became "Red Dog" and Voss assumed the moniker of "Dog Face"; for STS-69, they continued the tradition and their fellow crewmates acquired their own alter-egos: Ken Cockrell became "Cujo," Jim Newman became "Pluto," and Mike Gernhardt—the only rookie astronaut—became "Underdog." On launch morning, 7 September 1995, Walker and his men presided not over plates and mugs and cutlery at the breakfast table, but over a quintet of dog bowls, each emblazoned with their respective dog names. As they departed crew quarters, they were greeted by a chorus of tongue-in-cheek barks and woofs from the assembled journalists, family members, and friends. Even in orbit, the astronauts could not escape: on the morning of 10 September, three days into the mission, they were awakened to the sound of "Bingo Was His Name," sung by Cockrell's five-year-old daughter, Madeline. …

STS-69 rockets into orbit on the morning of 7 September 1995. Photo Credit: NASA

When STS-69 launched, Newman was the only member of the crew to boast a spacewalk to his credit. That was expected to change, for NASA had implemented a series of EVA Development Flight Tests (EDFT) to evaluate tools and techniques for the construction of the ISS. Already, on STS-64 in September 1994 and on STS-63 in February 1995, shuttle spacewalkers had evaluated a variety of new systems, and on STS-69 Voss and Gernhardt would perform a 6.5-hour spacewalk to press the envelope still further. Planned for late in the 11-day mission, the excursion would support four Detailed Test Objectives (DTOs): to evaluate space suit design modifications to guard against extremely cold temperatures, to perform specific assembly and maintenance tasks, to evaluate an Electronic Cuff Checklist, and to support ground crews in making improvements to EVA operations. Specifically, it was intended that Voss and Gernhardt would perform an hour apiece at a "task board" on the starboard side of Endeavour's payload bay, working with hand rails, mechanical fasteners, electrical and fluid connectors, and mock-up Orbital Replacement Units (ORUs). The men would also install a pair of "thermal cubes" in the payload bay—one at the end of the RMS mechanical arm, the other at the task board work site—to gather temperature data. Additional measurements would be taken from sensors inside their space suits throughout the EVA. To differentiate between the two men, Voss was designated "EV1" and wore red stripes on the legs of his suit, whilst Gernhardt ("EV2") wore a pure-white suit.

Near the end of STS-69, on 16 September 1995, Voss and Gernhardt prepared for the first spacewalk of their respective careers. At length, a go-ahead came from Mission Control and Voss commenced the final depressurization of the airlock and pushed open the outer hatch into the payload bay. Sunlight flooded into both of their faces and, beyond, the enormous expanse of the bay. The EVA officially started at 4:20 a.m. EDT, and the spacewalkers' first task was to install the thermal cubes at the end of the RMS and at the task board on the starboard wall of the bay. They then removed a debris shield from the work site, manipulated a duplicate of a computer control box for ISS hardware, and tested new helmet lights and suit heaters. Taking turns at the end of the RMS, they were maneuvered by Newman away from the radiated warmth of the payload bay, exposed to temperatures as low as -84 degrees Celsius (-119 degrees Fahrenheit).

Earlier in 1995, STS-63 spacewalkers Mike Foale and Bernard Harris had ended their EVA early when suit modifications to counter cold temperatures proved ineffective. However, on STS-69, Voss and Gernhardt benefited from battery-powered fingertip heaters in their gloves and a system which enabled them to totally shut down their suits' liquid-cooling system and rely upon body heat for warmth. The men continually provided subjective ratings on their comfort levels to flight controllers and experienced no difficulties during their "cold soak" evaluations. They returned inside Endeavour after an EVA lasting six hours and 46 minutes. Yet Voss and Gernhardt's spacewalk was but a relatively minor component of STS-69, which became the first shuttle flight to launch and retrieve two satellites during the same mission.

 

Copyright © 2014 AmericaSpace - All Rights Reserved

 

 

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AmericaSpace

For a nation that explores
September 21st, 2014

Dog Names, Dog Tags, Dog Bowls: The 11 Barking Days of STS-69 (Part 2)

By Ben Evans

 

The SPARTAN-201 science satellite, pictured during its period of free flight on STS-69. Photo Credit: NASA

Nineteen years ago, last week, the "Dogs of War" barked, woofed, and yelped their way through a remarkable mission which put virtually all of the space shuttle's capabilities—satellite deployment and retrieval, rendezvous and proximity operations, spacewalking, and science—to the test. During STS-69 in September 1995, Commander Dave Walker, Pilot Ken Cockrell, Payload Commander Jim Voss, and Mission Specialists Jim Newman and Mike Gernhardt put a series of lengthy delays behind them and successfully completed one of the most impressive and multi-faceted flights in the shuttle program's 30-year history. One of its most visible goals, as described in yesterday's AmericaSpace history article, was a complex EVA by Voss and Gernhardt, but STS-69 also made history by becoming the first shuttle mission to deploy and retrieve two satellite during the same flight.

In fact, by the time of the spacewalk, the mission's two primary payloads had already been successfully deployed and recovered. The first satellite—the Shuttle-Pointed Autonomous Research Tool for Astronomy (SPARTAN)-201—was a 2,200-pound (1,000-kg), cube-shaped spacecraft, designed to accommodate instrumentation for astrophysics or solar physics research. Once deployed from the shuttle, it undertook a pre-programmed mission and was retrieved by the shuttle after two days and returned to Earth for the recovery of data and refurbishment in readiness for its next flight.

STS-69's first night in space was a disturbed one for Dave Walker, who was awakened twice by a pair of alarms, which indicated a problem in the data path between Endeavour's General Purpose Computers (GPCs) and the Ku-band communications system. Walker reset the system, and Newman later rebooted it. Next morning, 8 September, the deployment of SPARTAN-201 got underway when Gernhardt released it at 11:42 am EDT. Within minutes of departing the Canadian-built Remote Manipulator System (RMS) mechanical arm, the satellite executed a planned 45-degree pirouette to verify that its internal attitude control system was functioning correctly. Walker and Cockrell then performed two separation burns to maneuver Endeavour away from the payload, creating a mean distance of about 40 miles (64 km) and leaving SPARTAN-201 alone for two days of dedicated solar science operations.

Dave Walker (right) and Mike Gernhardt occupy themselves with their rendezvous responsibilities during STS-69. This mission marked the first shuttle flight to deploy and retrieve as many as two free-flying spacecraft. Photo Credit: NASA

With the retrieval planned for early on 10 September, Walker and Cockrell performed a thruster firing on the 9th to refine Endeavour's rate of closure and prepare for the rendezvous. By the morning of the 10th, they had maneuvered the shuttle to a distance of just 330 feet (100 meters) from the payload. Gernhardt was scheduled to capture SPARTAN-201 at 10:24 a.m. EDT, but this opportunity was missed due to the payload entering an unexpected attitude during proximity operations. "Concern about whether the SPARTAN had operated correctly was raised when the spacecraft was to be retrieved," noted NASA in a 29 September news release. "At that time, the crew reported that SPARTAN was rotating slowly and its batteries seemed to have been drained." Preliminary indications suggested that the payload placed itself into a "safe mode" and shut down its power systems, which prevented it from achieving its intended rendezvous attitude. Consequently, Walker and Cockrell manually flew a 180-degree maneuver "around" their quarry to line up the RMS grapple fixture with the end effector and Gernhardt successfully captured SPARTAN-201 at 11:02 a.m. Approximately 19 minutes later, he had lowered the satellite onto its berth in the payload bay.

At the close of its third mission, SPARTAN-201 was hailed as a huge success by NASA. In late September, after STS-69 had landed, Project Scientist Dick Fisher of the Goddard Space Flight Center in Greenbelt, Md., reported that its data tapes indicated that the payload operated as planned throughout its flight. The attitude issue during the final rendezvous and proximity operations could not be properly investigated until the payload was back on Earth. Nor could a full assessment of its scientific data be made until it was back in the hands of principal investigators. One of the key mission objectives had been to observe the Sun's north pole, since the mission coincided with the passage of the Ulysses spacecraft over this region. As Ulysses performed in-situ measurements of the physical properties of electrons, protons, and ions in the solar wind, SPARTAN-201 complemented it by completing observations from low-Earth orbit. Specifically, researchers were interested in making collaborative observations of the source of the solar wind and developing a clearer understanding of physical circumstances of the Sun's outer corona.

With the SPARTAN-201 operations thus behind them, the STS-69 crew focused attention on the second satellite, the Wake Shield Facility (WSF-2), whose RMS-assisted deployment and retrieval was to be undertaken by Newman. The payload was developed by the University of Houston, in conjunction with Dr. Alex Ignatiev, head of the Space Vacuum Epitaxy Center (SVEC). Today known as the Texas Center for Superconductivity at the University of Houston (TcSUH), this institution has for more than two decades explored thin-film deposition, processing and characterization of semiconducting, high-temperature superconducting, and ferroelectric oxide material systems.

The Wake Shield Facility is pictured on the end of Endeavour's mechanical arm. Photo Credit: NASA

As long ago as the 1970s, NASA engineers published papers arguing that a satellite sailing through space would leave an "ultra-vacuum" in its wake, but the absence of practical applications at the time meant that the idea was left unexplored until Ignatiev and his team revived it. In 1986, they joined forces with nine other companies to form a Center for the Commercial Development of Space, with the plan to build a free-flying Wake Shield Facility. It was conceived as an 11.8-foot (3.6-meter) stainless steel disk for the purposes of generating an "ultra-vacuum" within which to grow thin films for future advanced electronics applications. The purely functional shape of the WSF made it appear like a factory cast-off: of dull, silver-grey color, it was a clumsy arrangement of boxes, rods, tubing, and angular shapes. First flown on STS-60 in February 1994, technical difficulties prevented its deployment, and it was "hung" at the end of the RMS to validate its basic concept by growing five thin semiconducting films and gathering associated data. In the aftermath of STS-60, an advisory committee analyzed the anomalies and a NASA independent review board evaluated the satellite's systems and unanimously agreed that WSF-2 was ready to fly.

Mission plans called for it to grappled by the RMS, under Newman's control, on 10 September. He would leave it in that position, still latched to its carrier platform, overnight, ahead of the scheduled unberthing and deployment on the 11th. In readiness for WSF-2 operations, Walker and Cockrell had executed a pair of engine firings to slightly raise the shuttle's orbit. Already, Gernhardt and Newman had begun to slightly shift their sleep schedules, to ensure that one or both of them was awake during all critical mission events. Newman successfully unberthed the payload and maneuvered it into its so-called "ram-cleaning" position for three hours, which was essential for the atomic oxygen of low-Earth orbit to "scour" its ram side and atomically clean it in readiness for two days of semiconductor processing.

As Jim Newman (left) eyeballs one of STS-69's two satellite payloads through the flight deck windows, Ken Cockrell takes a moment to grin for the camera. Photo Credit: NASA

The actual deployment was postponed by almost two hours, as flight controllers wrestled with communications dropouts between WSF-2 and the data relay and telemetry equipment aboard its carrier platform in the payload bay. Eventually, Newman released the satellite over the starboard side of the bay at 7:25 a.m. EDT, as Endeavour flew high above West Africa, and WSF-2 executed a perfect firing of its own cold-gas thruster to maneuver away from the orbiter and avoid contamination by waste water dumps, fuel cell purges, and thruster firings. This was the first occasion that a payload had maneuvered itself away from the shuttle; previously, the orbiter had taken the "active" role in such operations.

Nine hours later, at 4:30 p.m., WSF-2 began its first thin-film semiconductor processing run. Described by investigators as a "dirty" run, it lasted about three hours and served to remove any residual contaminants from the containers housing the GaAs sample growth materials. Earlier in the afternoon, Walker and Cockrell had fired the shuttle's thrusters toward the satellite to slow their relative separation rate, with the intention that by the time of rendezvous and retrieval on 13 September the two spacecraft would be about 30 miles (45 km) apart. By the morning of its second day of operations, WSF-2 had grown three thin films, with seven anticipated before the end of the mission. However, just before the fourth film run commenced, the satellite pitched forward slightly, after sensing a temperature increase, and placed itself into safe mode as a precautionary measure. Operations resumed about 12 hours later, and it was decided to incorporate cooling periods into the WSF-2 timeline and extend the satellite's phase of free flight by an additional 24 hours. This produced a revised retrieval time of late on the morning of 14 September.

Another delay cropped up when controllers were rendered unable to trigger the flow of arsenic from aluminum source cells on WSF-2 onto a substrate platform. The science instruments were again shut down in the hope that allowing them to cool would permit additional attempts to grow further thin-film samples. It later became clear that the shutter on the source cell had failed to close on command, but investigators doubted that it would negatively affect the quality of the sample. In total, four of the seven planned thin films were satisfactorily grown, with plans for a fifth eventually called off when WSF-2 payload controllers noticed a low reading in one of the satellite's four batteries.

By the morning of the 14th, Endeavour had closed to within 425 feet (130 meters) of WSF-2, whereupon Walker and Cockrell performed a series of 14 thruster firings to assess the impact of thruster plumes on the satellite's structure. Newman successfully grappled WSF-2 with the RMS arm at 9:59 a.m. EDT and berthed it back onto its carrier platform in the payload bay at 11:18 a.m. Endeavour's orbit was subsequently adjusted, ahead of Voss and Gernhardt's EVA, and STS-69's final research experiments consumed the closing days of the mission.

Even as their mission entered its final days, the "Dog Crew" of STS-69 could not escape the daily reminders of their canine camaraderie, with "He's A Tramp," from the cartoon movie "Lady and the Tramp," providing their wake-up music one morning. With weather conditions considered near-perfect at the Shuttle Landing Facility (SLF) at the Kennedy Space Center (KSC), and only scattered clouds, light north-easterly winds, and a slight chance of ground fog, Dave Walker was given the green light for the irreversible de-orbit burn at 6:35 a.m. EDT. A little over an hour later, precisely on time, Endeavour alighted on Runway 33 at 7:38 a.m., concluding a mission of slightly less than 11 full days in orbit. Short of actually docking with a "real" space station—which four of the five STS-69 crewmen would accomplish later in their careers—the mission had trialed many of the shuttle's capabilities and cleared a significant hurdle before the beginning of the ISS era.

 

Copyright © 2014 AmericaSpace - All Rights Reserved

 

 

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