Author Topic: Discovery STS-41 – Tales of Brave Ulysses  (Read 10095 times)

Offline Ares67

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Re: Discovery STS-41 – Tales of Brave Ulysses
« Reply #360 on: 10/09/2016 09:44 PM »
November 2, 1990: BUDGET PLAN QUELLS FURLOUGH TALK
After a month of continuing resolutions, Congress approved a budget plan for the 1991 fiscal year, putting discussion of federal employee furloughs almost to rest. The budget plan must be approved by President George Bush before becoming final, but indications are that the President will sign the measure before the November 5 deadline. Once signed, the danger of furlough will be past.

Earlier this year, when FY90 was coming to a close with no FY91 budget agreement in sight, all federal employees were informed of a possible sequestration of funds caused by the Gramm-Rudman-Hollings deficit reduction act. The result of the situation was the possible furlough of all federal employees.

As members of Congress ironed out the budget wrinkles, they passed a series of continuing resolutions to keep the government operating. Meanwhile, civil servants waited for a definitive word on the furlough planning. However, passage of the projected $1.236 trillion federal budget plan resolved the issue late Saturday night. There will be no budget-related employee furlough in FY91 if Bush signs the plan.

NASA’s portion of the federal budget totals about $13.9 billion for the next year and includes $1.9 billion for the Space Station Freedom program. The Space Station line item is a slight increase from last year’s $1.8 billion, but is significantly lower than the $2.4 billion requested by President George Bush. The $1.9 billion is midway between the House and Senate version of the money bill. (JSC Space News Roundup, Nov. 2, 1990)


Offline Ares67

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Re: Discovery STS-41 – Tales of Brave Ulysses
« Reply #361 on: 10/09/2016 09:46 PM »
The Best Orbital Complex … or just too complex?

*** The state of Freedom Station 1990 ***


“America has always been greatest when we dared to be great. We can reach for greatness again. We can follow our dreams to distant stars, living and working in space for peaceful, economic, and scientific gain. Tonight, I am directing NASA to develop a permanently manned space station and to do it within a decade.

A space station will permit quantum leaps in our research in science, communications, in metals, and in lifesaving medicines which could be manufactured only in space. We want our friends to help us meet these challenges and share in their benefits. NASA will invite other countries to participate so we can strengthen peace, build prosperity, and expand freedom for all who share our goals.”


- U.S. President Ronald W. Reagan, State of the Union Address, January 25, 1984


(By Dixon P. Otto)


Offline Ares67

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Re: Discovery STS-41 – Tales of Brave Ulysses
« Reply #362 on: 10/09/2016 09:47 PM »
The framework of Freedom – the 508-foot-long transverse truss – moves like the double-helix structure of DNA across computer animation screens. Tubular rungs of aluminum-alloy provide the pathways through Freedom Station, as opposed to the hydrogen and carbon bonds of DNA. Instead of the codeword for life of DNA, Freedom Station carries the codeword for our permanent future in space.

Like cracking the DNA code, the concept of Freedom Station has evolved slowly, painstakingly since the project was initiated by President Reagan in 1984. During the past year, progress has been made, moving Freedom toward actual hardware construction. Yet new questions and concerns have been raised, mainly focusing on the amount of Extravehicular Activity (EVA) needed to build and maintain the complex structure.

Recently, the questions over the lack of final-assembly testing of the Hubble mirrors and the complexity of the shuttle system have splashed over into new criticism of the intricate station. About twenty assembly flights and another ten supply flights will be needed to carry the program through the end of the decade. In the shadow of the recent grounding of the orbiter fleet, critics question the ability of the shuttle to support a regular, tight schedule of Station missions.

Freedom cannot be tested as a whole on the ground and that will create large problems, critics say, pointing to the Hubble’s present troubles as warning about the Station’s future. A new wave of calls to cancel the entire project has washed over Freedom.


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Re: Discovery STS-41 – Tales of Brave Ulysses
« Reply #363 on: 10/09/2016 09:51 PM »
MAINTAINING THE GOAL

“In one year, I want to be able to say that we are one year closer to first element launch,” said Station Director Richard Kohrs in early 1990. That would seem a given, except for the Station’s history. When first proposed in 1984, it was envisioned a being built in 1992, but the schedule has slipped about a year for every year of its history. “I want to maintain the preliminary design review schedule and the first element launch – that’s my goal,” Kohrs said. So far, he is maintaining his goal.

However, even though the first element launch remains set for March 1995, the rest of the construction schedule has slipped due to budget squeezes. The “man-tended” capability, during which science experiments can begin, has slipped six months from its previous goal of the end of 1995. Permanent occupation of the Station similarly has slipped a half-year from the end of 1996. Final completion, which had been slated for the first quarter of 1998, has been pushed back until July 1999.

The fiscal year 1991 budget requested by President Bush included $2.4 billion for Freedom, but it is facing a cut of approximately $500 million by Congress. For the FY 1992 budget, Bush announced he will ask for about $2.9 billion for the Station.

Kohrs’ goal for the preliminary design review, a technical review of the overall design, barely kept on track, slipping slightly from the third quarter of this year to December. The entire design will be subjected to a rigorous review, where problems and concerns will be thrashed out. In April 1992, the overall design will again be analyzed in its “critical design review” which will verify and freeze the design and open the way for manufacture of flight hardware.


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Re: Discovery STS-41 – Tales of Brave Ulysses
« Reply #364 on: 10/09/2016 09:55 PM »
BENDING METAL

The project presently is switching from the drawing board to “bending metal” for prototype equipment. Nine shuttle flights in the next three years will test Station equipment, beginning with the EVA demonstration of spacewalk equipment set for STS-37. “It’s no longer a paper program,” said William Lenoir, NASA Associate Administrator for Spaceflight. “It’s a hardware program with real hardware.”

Ground breaking as well as metal bending is underway. Several new facilities are being constructed at Johnson Space Center in Houston for Station design, testing, and construction. These include a Neutral Buoyancy Lab, planned for completion in 1991, equipped with a 60-feet deep pool measuring 235 feet long and 135 feet wide. The pool will be used to test seals in many of the components, as well as to train astronauts for EVAs.

An extra five-story building, called the Space Station Control Center, is being added to the control center which handles shuttle missions. Also at JSC, construction is continuing on the Space Systems and Automation Integration and Assembly Facility, designed to test assembly procedures. The building was started in April 1990 and completion is scheduled for March 1991.

JSC will gain the Mission Simulation and Training Facility to house support crew persons as well as computer support facilities. Additions to facilities are also underway at the Marshall Space Flight Center in Huntsville, Alabama, the Kennedy Space Center, and other centers.



POWER STRUGGLE

“The international Space Station Freedom team is working toward its preliminary design review, an exercise when the plans developed now will be tested,” said NASA Administrator Richard Truly. The overall design of Freedom, which will be stationed in a 250-mile-high orbit inclined 28.5 degrees to the equator, has remained unchanged in the past year.

The simplicity of the truss backbone, like that of a strand of DNA, belies its core role. The 41,801-pound girder assembly, composed of graphite epoxy tipped with aluminum, provides a rigid structure supporting pressurized modules, power systems, and attached experiments. It also will provide a pathway for robotic systems designed to ride along its tubular tracks for access to nearly the entire complex.

The truss will be tipped by sets of thin-blanket solar arrays, measuring 34-feet wide by 108-feet long. Four solar panels will erected at first. By 1998, eight panels, containing half an acre of solar cells, will be producing 75 kw of power. Previously, the eight array/75 kw capacity was planned to be completed earlier in the Station’s construction. Budget bickering led to a one-half cut to four arrays/37.5 kw, with about 18 kw allotted to experiments and the rest going to maintaining the Station. That electrical allotment will not pull enough for full science activities, critics charge.

To answer the need for more power, Lewis Research Center in Cleveland, Ohio, in charge of designing solar power systems, is developing and entirely different means of solar power. Instead of adding more solar wings, which would increase the atmospheric drag on the Station, a solar dynamic system will be incorporated into an expanded “phase two” of the Station early in the next decade.

The system uses a large umbrella dsih to focus the Sun’s heat onto a turbine which drives an alternator. While on the dark side of the orbit, the new system does not require the 20 nickel-hydrogen batteries used by the solar-array system to store power. Instead, the Sun’s energy is “stored” in a salt-fluid during the sunny side of the orbit. During darkness, the salt solidifies, giving off heat to drive the power turbines.

During the last year, NASA considered using the solar dynamic system earlier in the Station’s life. That idea was dropped due to the design complexities and increased costs. The power shortfall of the present phase one of the Station remains a concern.


LIVING SPACE

Below the truss and attached just right of its center, the 70,390-pound U.S. laboratory module will be positioned, with launch scheduled in mid-1996. The lab, measuring 44 feet long and 14 feet in diameter, will give Freedom a “man-tended” capability. Experiments will be run autonomously in the lab, with periodic attention and adjustment by astronauts during its first year in space. The module will be able to accommodate up to 46 cubic meters of research equipment in 28 double racks on its port and starboard walls. Materials processing and life sciences experiments concerning adaptation to long exposure to microgravity will be conducted.

The habitat module, weighing 55,826 pounds with the same outward dimensions as the lab, will provide the living space to allow permanent occupation of the Station to begin in mid-1997. The “hab” is broken into three sections: a quiet zone for sleeping, an activity area for dining and recreation, and a health facility.

The sleeping area will provide each crewmember with personal living space about the size of a train berth. Each compact cabin will come with a telephone, television, stereo, and a personal computer. The active area will contain a galley equipped with a microwave and a refrigerator, as well as an exercise area fitted with a stationary bicycle and a treadmill. The health maintenance facility will hold equipment for blood analysis, dental work, and minor surgery.

Four “nodes,” each weighing 17,000 pounds, will cap the end of the main modules, providing connection points to each other and additional modules. The nodes, about 17 feet long and 14 feet in diameter, contain windowed “cupolas” so astronauts can visually oversee and control outside work conducted via robot manipulators. The nodes also hold control equipment and the Station’s airlock.

Like DNA, the Station will be designed to replicate itself. To allow for future additions and provide greater flexibility, designers have made it possible for expanded computer circuitry and software to be simply plugged into the Station’s loop. Such open-ended circuitry is known as “hooks,” a slang word for a modular design allowing computer equipment to be easily added and upgraded – sizing power cables for growth, providing connectors for additional units, allowing extra margins in computer memory capacity.

Following the same sort of NASAese, “scars” are the mechanical equivalents of hooks. They refer to designing structures for plug-in growth – modules can be added easily, radiators and cooling systems can be added as needed, power and fluid systems are sized for expansion and additional feed offs.


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Re: Discovery STS-41 – Tales of Brave Ulysses
« Reply #365 on: 10/09/2016 09:57 PM »
SPACE FOR PARTNERS

“International cooperation… has long been a guiding principle of the United States space program. The tricentennial of the first German immigration to America was celebrated last year with a joined space effort. Just as our friends were asked to join us in the shuttle program, our friends and allies will be invited to join with us in the Space Station project.”

- U.S. President Ronald W. Reagan, January 28, 1984


The international nature of the Station shows vividly in the major contributions planned by the European Space Agency, Japan, and Canada. The Europeans and the Japanese will attach modules, and the Canadians will provide robotic systems.

The ESA module, known as Columbus, measuring 14 feet in diameter and 41 feet long, will be used for an array of life sciences, materials sciences and fluid physics experiments. In addition, the Europeans are planning a free-flying Columbus platform to be launched by their Ariane 5 booster.

The Japanese Experiment Module (JEM) will consist of a pressurized module, an exposed facility and an experiment logistics module. The module, 14 feet wide and 35 feet long, will also house experiments into materials processing and life sciences. JEM will have nearly 5,000 cubic feet of area, holding 23 experimental racks. The exposed facility will serve as a “back porch,” providing room for experiments which need to be exposed to open space and coming complete with a manipulator arm to move experiments.

Delays in the Station schedule have affected the international partners. The Japanese module, previously scheduled for launch in the second quarter of 1997, has been delayed nine months. The ESA module, planned for launch in the third quarter of 1997, has also been delayed by about nine months.

NASA considered moving launch of the international modules forward in the schedule, but recently rejected such a shift. International voices now have joined with domestic ones questioning the current Station plan and prognosis.


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Re: Discovery STS-41 – Tales of Brave Ulysses
« Reply #366 on: 10/09/2016 09:58 PM »
« Last Edit: 10/10/2016 06:17 AM by Ares67 »

Offline Ares67

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Re: Discovery STS-41 – Tales of Brave Ulysses
« Reply #367 on: 10/09/2016 10:00 PM »
CAUTION – CONSTRUCTION AREA

Launch of the first Station element in March 1995 will begin a “hardhat” construction era lasting until the end of the century and involve about 30 shuttle flights. The first flight will loft a section of the truss, a pair of solar arrays, and the starboard node. Currently, the first major milestone, attaining man-tended capability, will be achieved in June 1996, after the fourth construction flight, which will loft the U.S. lab module. While “man-tended,” the first experiments can be run tended by visiting astronauts.

Freedom will be permanently manned in July of 1997. Crew size has been reduced from eight to four or six and their stay time has been increased from three to four months in effort to save money and reduce the number of shuttle flights.

Automated robots will assist in every phase of Station construction and will enable Freedom to carry out its daily duties. Skimming along the 500-foot main truss, Canada’s Mobile Servicing Center (MSC) will aid with Station construction, assist spacewalkers and move supplies and hardware along the Station. Other duties include servicing attached payloads, docking the shuttle and the loading and removal of cargo from the shuttle.

MSC will weigh 10,584 pounds and measure 16.4 feet by 16,4 feet at its base. It will house a robot manipulator arm 57.7 feet long with the strength to lift 110 tons, three times as strong as the shuttle arm. The MSC will glide along the lattice like an amusement ride on a track, moving on a mobile platform NASA will provide. The combined package is called Mobile Servicing System (MSS).

To perform delicate jobs, the MSS will employ the Special Purpose Dexterous Manipulator (SPDM) – two sensitive arms, each measuring 6.56 feet long – which can be attached to the end of the long MSC arm. The SPDM, which can also work independently on the MSS, can repair fuel lines, work on cooling systems, and even repair electrical connections.

NASA is designing its own mechanical repairman, known as the Flight Telerobotic Servicer (FTS) for use from the earliest moments of Station construction and maintenance, allowing for less hours of manned EVA. This $297 million robot, built by Martin Marietta, will perform many of the routine jobs of Freedom assembly, and can later be incorporated into the MSS.

The FTS, weighing 1,983 pounds, will be mounted on the end of a mechanical arm the size of the Space Shuttle RMS. It has three arms to guide its way along the truss, appearing like a spider creeping along its web. Two of the arms are arranged like those of a human and perform the work. The third arm, attached to its bottom, acts as an anchor to the Station, providing stability. Fingers at the end of the arms come complete with force sensors which allow it to pick up delicate pieces of equipment.


THE POINT OF IT ALL

“Scientists from NASA, universities, and private industry will do research in and around the Space Station – research that’s only possible in the zero-gravity and vacuum of space. As needed, private industry will fund expansions of the NASA facility where companies can manufacture new products and provide new services.

But most importantly, like every step forward, a Space Station will not be an end in itself, but a doorway to even greater progress in the future. In this case, a Space Station will open up new opportunities for expanding human commerce and learning and provide a base for further exploration of that magnificent and endless frontier of space.”


- U.S. President Ronald W. Reagan, January 28, 1984


Freedom Station will serve to study how humans react to long spaceflights, opening the way for long voyages to Mars. In addition, a biotechnology facility will observe the effect of weightlessness on biological specimens, conducting research with new medical applications on Earth.

In addition to studying the effect of weightlessness on humans, Freedom will investigate the effect of microgravity on glass, metals, and alloys. NASA’s Microgravity Science and Applications will fly six facilities for materials processing in the U.S. laboratory module. Such experimentation could yield improved computer chips as well as stronger and lighter metal alloys with military and commercial applications.

The largest of these experiment packages is the Space Station Furnace Facility (SSFF). The furnace will heat and cool different materials and make thermophysical measurements. When a liquid changes state and becomes solid, the internal structure formed in space is different than that produced on the ground. These differences could lead to new hybrid materials. Such experiments must be conducted over a long period of time, and can only be done on Freedom. Many new material processing experiments require at least one month, or even two or three months, to produce results.

Vibrations from Freedom, such as crew movement and even from atmospheric drag could cause the sample in a module to bump into the side of its container, resulting in contamination. Also, many highly corrosive gasses used during the process would react with the material of an experiment container.

To overcome this, the Office of Space Science and Applications plans to have several containerless experiments in the laboratory module, part of the Modular Containerless Processing Facility. The device uses electromagnetic, electrostatic or acoustic fields to keep the sample in the center of the container. In 1992 and 1997, two shuttle missions will give input on how to build the containerless facility, and in 1998 the first section will be placed aboard Freedom. In 2001, the facility’s two experiment racks will be completed.

Freedom Station will support increased research into the growth of crystals – many of which, such as proteins, have medical applications. The Station’s Advanced Protein Crystal Growth Facility, to be sent aboard Freedom in 1996, will be able to grow crystals with more precisely controlled concentrations, numbers and growth. Microgravity produces larger and more differentiated crystals – allowing for more detectable X-ray patterns which reveal their minute structure. When the structure of biological crystals is known, new drugs can be tailor made to interact with them.

Another problem faced in protein growth will be solved on the Station. Many of the newly produced proteins are too weak for shipment to Earth. A device that will analyze them while in orbit will be aboard the Station.

The remaining experiments housed in the laboratory module include a combustion experiment to study the effect of combustion while in near zero-gravity to produce new fire control and safety methods. The Fluids/Dynamics Facility will study how fluids function in weightlessness, studying flows and formations.

In addition to experiments inside the pressurized modules, several will be attached to the main truss of Freedom. Fourteen preliminary experiments for studying the Earth, Sun, and the environment of space have been selected for attachment during the assembly period.

Many of the attached payloads will study the environment of space. The Cosmic Dust Collection Facility (CDCF) will study the trajectory and characteristics of dust particles, giving clues on planetary and solar system composition. The Cosmic Dust Orbit and Capture Experiment (CDOCE) will capture particles in space for later analysis on Earth in a search for organic molecules.

The Earth will be viewed with such experiments as the Clouds and the Earth’s Radiant Energy System (CERES), measuring the Sun’s energy striking and reflecting from the Earth, the Stratospheric Aerosol and Gas Experiment (SAGE-III), and the Lightning Imaging Sensor (LIS).

These experiments, both inside the modules and out, are only the beginning of the useful lifespan of Freedom. With phase-two expansion early in the next decade, a large rectangular truss, called the double keel, could be built stretching above and below the present horizontal boom. The double keel would provide a more stable and vibration-free anchor for experiments. In addition, it would house the satellite servicing centers which would transform Freedom into a staging area for expeditions to the Moon and Mars.


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Re: Discovery STS-41 – Tales of Brave Ulysses
« Reply #368 on: 10/09/2016 10:01 PM »
KEEP WALKING

Freedom Station is designed for an unprecedented lifespan of at least 30 years. Grave concerns are being raised about the ability of astronauts to service, maintain and repair the 290 tons of Station that will be in place. Spacewalking astronauts will face 5,578 parts which can be replaced outside the pressurized modules.

NASA had hoped to be able to maintain the Station with about 150 hours of spacewalks per year, equaling about an EVA per month. The agency was shocked at the end of 1989 when D. Bryant Cramer, an engineer with the project, drew up estimates that 1,700 hours of EVAs per year would be needed. A 12-person panel headed by astronaut William Fisher then was formed to determine the exact spacewalk requirements.

On March 19, 1990, The New York Times raised a storm of concern over the issue, publishing interim findings of the panel which indicated that 2,200 hours of EVA would be needed per year. The finding was based on analysis of the parts on the Station’s exterior, their likelihood of failure and the time needed to replace them.

The newspaper said that NASA experts “characterize the figure as alarmingly high.” In addition, maintenance and repair efforts would start being required when the Station was only 60-70 percent complete. NASA administrators countered that the number of hours quoted by the Times formed the worst case scenario.  “So far, the information gathered indicated that astronauts will need to spend between 700 and 2,200 hours a year outside the Space Station in spacesuits to perform maintenance. The lower estimate works out to a spacewalk about once a week,” NASA said.

The higher estimate was based partially on aircraft flight line maintenance data that may not be applicable to the Station, said John Aaron, Space Station project manager at JSC. NASA officials told Congress the assumption made by the estimate that a component would break down every day was not valid. The complete study was still in the formative stage, they said, and teams were looking at ways to reduce the EVA time.

“It’s normal to go through this sort of thing,” said Charles Price, a NASA robotics engineer who co-chaired the panel with Fisher. “When you have an apparent problem, you put your good people on it and get cracking.”

NASA Administrator Richard Truly said in an editorial reply to The New York Times article, “We are building the Space Station as a laboratory for a multitude of scientific purposes and opportunities, and to provide a foundation for plans to venture outward in the solar system over the coming decades.” He further added, “It is neither surprising nor disturbing that problems are uncovered in this design process… It is normal and has occurred in all major NASA programs.”

Space Station Director Richard Kohrs said, “I think as we work it harder and harder, we’ll drive those numbers down.” The opposite proved to be the case. As the panel approached completion of its study, The New York Times again broke open the story on July 11, 1990. The estimate of EVA time had increased to 3,800 hours per year.

Such a figure would translate to nearly a spacewalk per day. In its entire history, the U.S. has gained only about 400 hours of spacewalk experience. The newspaper quoted an unnamed NASA engineer as saying the Station would require 7,000 hours of maintenance before it became permanently occupied and an additional 5,000 hours before its 1999 completion.

Spacewalking has always loomed as one of the most dangerous activities in space. The EVA situation is worsened because development of new pressure suits has been halted for budget reasons. NASA was working on two versions of advanced suits – one was hard and the other was soft – which would have been less complicated, easier to wear and maintain, and quicker to don. Present plans now call for the spacewalks to be conducted using the current shuttle suits.

The Times said the unreleased Fisher/Price report had forced NASA “to mount a crash search for design changes and other ways to reduce the estimated hours of maintenance.” A new team at JSC, headed by engineer William E. Simon, had been formed to find solutions.

The lifetime of parts might be increased, but doing so would increase Station development costs and was termed “not realistic” by Price. Robots might be able to handle an increased maintenance load, but the robotic technology needed is new and untried. Several repair tasks might be combined into a single operation. Standardization of parts might ease the replacement tasks.

Despite such possible solutions, the Times quoted another unnamed JSC engineer as saying, “These numbers (for EVA time) are pretty resistant to easy fixes.” Voices are now being raised in Congress and even within NASA that the EVA requirement could be a “showstopper” for the Station program. “These numbers suggest the Station cannot be built,” the Times quoted an unnamed JSC engineer.


A DREAM OF FREEDOM

“We’ve always prided ourselves on our pioneer spirit that built America. Well, that spirit is a key to our future as well as our past. Once again, we’re on a frontier. Our willingness to accept this challenge will reflect whether America’s men and women today have the same bold vision, the same courage and indomitable spirit that made us a great nation.”

- U.S. President Ronald W. Reagan, January 28, 1984


So far, the U.S. has spent approximately $4 billion to design Freedom. While its complexity does not rival that of DNA, its promise does. DNA makes all life possible on Earth. The Space Station will make life possible throughout the solar system. To turn our back on Freedom Station now could spell the end of our dreams of the Moon and Mars.

Yet the questions hovering around the project are more numerous now than when it was proposed in 1984. The challenge of the 1990s lies in making sure the dream Station does not end up a nightmare.

(Dixon P. Otto, Countdown, August 1990 – edited)


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Re: Discovery STS-41 – Tales of Brave Ulysses
« Reply #369 on: 10/09/2016 10:03 PM »
Ulysses, by Jove!


A generation ago the flyby of a spacecraft past Jupiter was front-page news. But a recent courtesy call there paid by the deep-space probe named Ulysses seems to have caused a stir only among space physicists, who were nonetheless thrilled by the craft’s performance and experimental results.

A joint venture of NASA and the European Space Agency, Ulysses will cruise over the Sun’s polar regions in 1994 and 1995. However, first it had to brave what ESA project manager Derek Eaton termed the “completely filthy radiation environment” enveloping Jupiter, so that the planet’s gravitational energy could yank the probe high out of the ecliptic plane. Ulysses plunged north to south around the giant planet’s far side, coming within 380,000 kilometers of the colorful cloud tops at 12:01 Universal Time on February 8, 1992.

The spacecraft had actually sensed the impending encounter six days earlier, when it breached Jupiter’s enormous magnetosphere while still roughly eight million kilometers away. Some members of Ulysses’ research team were caught off guard by this early crossing. They had anticipated that the boundary (called the magnetopause) would lie much closer to Jupiter, as it was during the 1979 Voyager visits.


FAT PANCAKE

According to U.S. project scientist Edward J. Smith, a temporary lull in the solar wind let the magnetosphere balloon outward rapidly as Ulysses approached. The upstream bloating distorted the normally teardrop-shaped magnetosphere into something more akin a fat pancake.

As a result, during its two-week stint inside Jupiter’s magnetic bubble, Ulysses detected surprisingly few energetic charged particles (ions and electrons) at higher latitudes, but plowed through large doses of them as it crossed the magnetic equator.

Smith notes that two Pioneer probes encountered a similarly flattened Jovian magnetosphere during their visits in the early 1970s, and thus this geometry may be more the norm than the exception. “Planetary scientists have tended to forget about the Pioneer encounters,” he observes, “and adopt the Voyager results (a compressed, plump magnetosphere) as the model.

Hopefully, Ulysses has helped reestablish a proper, more balanced view.” Smith adds that the new data will prove particularly useful in planning the scientific work of the Jupiter-bound Galileo spacecraft, whose orbit will plunge it repeatedly through the sheet of circuit-zapping charged particles concentrated near the magnetic equator.


FAT DOUGHNUT

Some of Ulysses’ nine instruments offered convincing confirmation that Io, innermost of the four large Galilean satellites, is the dominant source of ions in the Jovian magnetosphere. The moon’s volcanoes spew roughly one ton of sulfur dioxide and other gases into space every second. The molecules soon become ionized and create a fat doughnut of plasma along Io’s orbit.

Ulysses discovered that this torus was only about half as dense as during the Voyager flybys, confirming the suspicions of ground-based infrared astronomers that volcanic activity has fallen off in recent years. The torus also proved to be surprisingly fragmented and clumpy, apparently in response to episodic eruptions on Io.

The sulfur and oxygen ions do not remain in the torus indefinitely, and Ulysses found that significant numbers of them ha migrated to the very edges of the magnetosphere. The flyby also demonstrated that droves of ions were cascading down the field lines and into Jupiter’s upper atmosphere, causing strong auroral discharges that were monitored back at Earth by the Hubble Space Telescope.

Although Jupiter was not Ulysses’ primary objective, the mission’s roughly 120 scientists – drawn from a dozen nations – already have plenty of interesting data to pore over. These results will not radically alter the knowledge of Jovian physics gleaned from the trailblazing efforts of the Pioneers and Voyagers. But, as ESA project scientist Klaus-Peter Wenzel observed son after the February flyby, “Some of the textbooks will have to be rewritten.”

(Sky & Telescope, July 1992 – edited)


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Re: Discovery STS-41 – Tales of Brave Ulysses
« Reply #370 on: 10/09/2016 10:06 PM »
Ulysses spacecraft ends historic mission of discovery

Provided by the Jet Propulsion Laboratory, Pasadena, California
Published: Thursday, July 2, 2009


Ulysses, a joint NASA and European Space Agency (ESA) mission, officially ceased operations Tuesday, June 30, after receiving commands from ground controllers to do so. The spacecraft charted the unexplored regions of space above the poles of the Sun for more than 18 years.

As planned via commands beamed to the spacecraft earlier in the day, Ulysses switched to its low-gain antenna at 4:09 p.m. EDT. As a result, ground controllers could not pick up a signal from Ulysses, which also had been commanded to switch off its transmitter at 4:15 p.m. EDT.

When Space Shuttle Discovery launched Ulysses October 6, 1990, the spacecraft had an expected lifetime of five years. The mission gathered unique information about the heliosphere — the bubble in space carved by the solar wind — for nearly four times longer than expected.

"This has been a remarkable scientific endeavor," said Richard Marsden, Ulysses mission manager and ESA project scientist. "The results Ulysses obtained have exceeded our wildest dreams many times over."

Ulysses made nearly three complete orbits of the Sun. The probe revealed for the first time the three-dimensional character of galactic cosmic radiation, energetic particles produced in solar storms and the solar wind. Not only has Ulysses allowed scientists to map constituents of the heliosphere in space, but its longevity also enabled them to observe the Sun over a longer period of time than ever before.

"The Sun's activity varies with an 11-year cycle, and now we have measurements covering almost two complete cycles," Marsden said. "This long observation has led to one of the mission's key discoveries, namely that the solar wind has grown progressively weaker during the mission and is currently at its weakest since the start of the Space Age."

In addition to measuring the solar wind and charged particles, Ulysses instruments measured small dust particles and neutral gases from local interstellar space that penetrate into the heliosphere. Ulysses had an unprecedented three chance encounters with comet tails, registered more than 1,800 cosmic gamma-ray bursts, and provided findings for more than 1,000 scientific articles and two books.

"The breadth of science addressed by Ulysses is truly astonishing," said Ed Smith, Ulysses project scientist at NASA's Jet Propulsion Laboratory in Pasadena, California. "The data acquired during the long lifetime of this mission have provided an unprecedented view of the solar activity cycle and its consequences and will continue to keep scientists busy for many years to come."

Ulysses' successes have not been confined to scientific data. The extended mission presented significant challenges to the NASA-European operations team. In particular, critical parts of the spacecraft became progressively colder with time. In recent years, scientists led a major effort to prevent the onboard hydrazine fuel from freezing. The operations team continually created methods to allow the aging space probe to continue its scientific mission.

In early June, the Ulysses mission team received a NASA Group Achievement Award. Another milestone occurred June 10 when Ulysses became the longest-running ESA-operated spacecraft, overtaking the International Ultraviolet Explorer, which logged 18 years and 246 days of operations.

"The Ulysses team performed exceptionally by building and operating a research probe that would return scientific data for analysis no matter what challenges it encountered," said Arik Posner, Ulysses program scientist at NASA Headquarters in Washington, D.C. "The knowledge gained from Ulysses proves what can be achieved through international cooperation in space research."

The Ulysses orbital path is carrying the spacecraft away from Earth. The ever-widening gap has progressively limited the amount of data transmitted. Ulysses project managers, with the concurrence of ESA and NASA, decided it was an appropriate time to end this epic scientific adventure.

ESA Ulysses Mission Operations Manager Nigel Angold points out that more than a year ago, "We had estimated Ulysses would not survive further than July 2008. However, the spacecraft didn't stop surprising us and kept working a full year, collecting invaluable science data. It's nice to be going out in style."


http://sci.esa.int/ulysses/

http://solarsystem.nasa.gov/missions/profile.cfm?MCode=Ulysses


NSF STS-41 Hi-res images

http://forum.nasaspaceflight.com/index.php?topic=19709.0


Offline Ares67

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Re: Discovery STS-41 – Tales of Brave Ulysses
« Reply #371 on: 10/09/2016 10:07 PM »

Offline Ares67

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Re: Discovery STS-41 – Tales of Brave Ulysses
« Reply #372 on: 10/09/2016 10:08 PM »

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Re: Discovery STS-41 – Tales of Brave Ulysses
« Reply #373 on: 10/09/2016 10:10 PM »
Going out in style

Just like the man said… “It’s nice to be going out in style.”

So, here we go.









Next stop:

Atlantis STS-38 – Roundtrip Ticket


I’m targeting December for this one, but please be patient with me.

One thing I can promise:

I’ll be back again, and again, and again, and again...


- Oliver, aka Ares67


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