Author Topic: Columbia STS-35 – Triumph over Adversity  (Read 11832 times)

Offline Ares67

  • Senior Member
  • *****
  • Posts: 12125
  • Oliver
  • Remscheid, Germany
  • Liked: 37
  • Likes Given: 21
Re: Columbia STS-35 – Triumph over Adversity
« Reply #20 on: 04/16/2017 05:13 PM »
A COSMIC CAT SCAN

When Astro’s wide eyes open to the heavens as planned, they will see a different Universe than human eyes have watched for thousands of years. As if peeking around the edge of a blindfold, the human eye only sees a thin slice of a greater scene. Visible light represents only a very tiny part of the radiation that makes up the electromagnetic spectrum that virtually all objects in the sky emit. The ends of the visible light spectrum are not really “ends” at all but are simply the limits of response by the human eye.

The visible wavelengths form just a small portion of the spectrum, yielding “just the tiniest indication of what’s going on” in the Universe, says Durrance.

The electromagnetic spectrum extends across a broad range of wavelengths from very high-energy gamma rays to very low-energy radio waves. Lower energies (infrared) and the higher energies (ultraviolet and X-rays) are largely absorbed by the atmosphere and never reach the ground.

Missing one segment is like taking some of the color from a painting. With ultraviolet and X-rays, astronomers can see emissions from extremely hot gases, intense magnetic fields, and other high-energy phenomena that more faintly appear in visible and infrared light or in radio waves – and which are crucial to deeper understanding of the Universe. The telescopes on Astro were constructed to add these “colors” to man’s view of the stars and galaxies.

In medical terms, Astro-1 with its three UV telescopes and one X-ray telescope will give the Universe a cosmic CAT scan and provide unparalleled information about high-energy celestial objects. “If you were a doctor and a very sick patient came into your office and all you had was a stethoscope and a thermometer, the doctor would have a hard time diagnosing that complex human being,” says Dr. Edward Weiler, Astro-1 program scientist and chief astronomer at NASA HQ in Washington D.C.

“The same is true with astronomy,” he explained. “We need to study objects that are hundreds, thousands, even billions of light years away and all we have is light. Objects tend to give off light in all wavelengths. We need to study things across the color spectrum, just as a doctor has to study a human being with many instruments.”

The ultraviolet spectrum is the region between X-rays and visible light. The UV region is subdivided into the extreme ultraviolet, the far ultraviolet, and the near ultraviolet bands. Ultraviolet light, like most of the electromagnetic spectrum, is not able to penetrate Earth’s atmosphere.

The UV spectrum is just beyond the blue end of visible light. Ultraviolet wavelengths are measured in Angstroms; an Angstrom (A) equals one ten-billionth of a meter. UV wavelengths ranging from about 100 to 3,200 Angstroms are shorter and more energetic than visible light. By comparison, visible light spans the region from about 3,200 to 7000 A. The UV region is further subdivided into the extreme ultraviolet (EUV, 100 to 1,000 A), the far ultraviolet (FUV, 1,000 to 2,000 A), and the near ultraviolet (NUV, 2,000 to 3,200 A) bands.

Many types of celestial objects are interesting to astronomers because they emit most of their radiation in these ultraviolet bands. Invisible ultraviolet radiation is the signature of hotter objects, typically in the early and late stages of their evolution.

“When you’re looking at X-rays and gamma rays, you’re looking at radiation which is given out by basically the highest energy processes – objects of the highest temperatures, pressures, and magnetic fields. It’s really the extreme regions of the Universe – neutron stars, the black holes and the exploding supernovae. If you can’t see the high energy radiation, then you really can’t study these objects,” says Hoffman. “That, to me, is what is exciting about high-energy astrophysics.”

Scientists studied stellar composition by breaking up starlight into spectral components, just as raindrops separate sunlight into a rainbow of colors. Since each element, such as hydrogen and oxygen, emits and absorbs radiation at specific wavelength, they could determine a star’s makeup by analyzing its spectrum, its radiation fingerprint. The strengths of various wavelengths tell us how much of certain elements are present; the ratio of the spectral lines reveals a source’s temperature and density; and the shape of the spectrum shows the physical processes occurring in a source.

Stars and other objects often emit more invisible radiation – radio waves, microwaves, infrared emission, ultraviolet emission, X-rays, and gamma rays – than visible light. From Earth, we can detect some radio and infrared wavelengths, but more radiation is absorbed by the atmosphere and never reaches telescopes on the ground.

“It’s by viewing the sky from multiple wavelengths that we find many new exciting objects which we pull out of the background,” says Dr. Ted Gull, astronomer and Astro-1 project scientist at Goddard Space Flight Center. “And quite often, when we look at old favorite objects that we think we understand so much, we gain a lot of new insight.”


A WIDER VIEW

Results from several rocket-borne instruments and satellites indicate that the solar system, our Milky Way galaxy, and the Universe beyond are rich of UV radiation. However, these early observations have dealt almost exclusively with near and far ultraviolet emissions, because most mirrors and detectors could reach only to about 1,200 A. Only the Orbiting Astronomical Observatory OAO-3, known as Copernicus, which studied relatively bright stars, recorded spectra down to 950 A.

Radiation at wavelengths shorter than 912 A is absorbed by hydrogen, the most abundant element in the Universe, thus making it even more difficult to detect distant sources. Using new technology, Astro will see beyond this cutoff, called Lyman limit. Only a few sources have been identified in the extreme ultraviolet, and discoveries are expected as Astro studies this relatively unexplored region of the electromagnetic spectrum.

The UV band contains lines from many of the light and intermediate mass elements, including hydrogen, helium, carbon, nitrogen, oxygen, and neon. The X-ray band includes some of these elements as well as heavier ones such as iron, silicon, sulfur, and magnesium. These lines represent a tremendous range of gas temperatures and energy states of elements, information needed to interpret the physical conditions of objects.

The X-ray spectrum is just beyond the ultraviolet in an even more energetic region with even shorter wavelengths. X-rays are emitted in wavelengths from 100 A to 0.1 A, but these wavelengths are so short (about the size of an atom) that astronomers usually talk about X-rays in terms of their energy, measured in electron volts. X-rays and all other types of electromagnetic radiation are emitted in particle-like packets of energy called photons. X-ray photons cover energies ranging from 100 to 100,000 electron volts. By comparison, a photon of visible light carries about 2 electron volts of energy.

If we could see the sky in ultraviolet, the cooler stars would fade away. We would see some very old stars growing hotter and producing high-energy radiation near their death. We could see clouds of gas and dust, stellar nurseries with hot, young massive stars. Disregarding the much more numerous cooler objects, we could have a less cluttered view of the crowded areas such as dense star clusters or spiral arms of galaxies.

Looking at the Universe in X-rays, we would see a violent cosmos; stellar blasts, hot stars and galaxies, collapsed spinning stars, powerful quasars, and perhaps material whirling around black holes. Thousands of X-ray sources have been identified, and most known types of celestial objects have been observed to emit X-rays.

The space between stars is not completely empty but is filled with dust and gas, some of which will condense to become future stars and planets. This interstellar medium is composed chiefly of hydrogen with traces of heavier elements and has a typical density of one atom per thimbleful of space. Astro will be able to measure the properties of this material more accurately by studying how it affects the light from distant stars.

Our wider view of the Universe has transformed our picture of it. “Our whole concept of the Universe changed with the advent of space astronomy,” Durrance says. “We used to think of the Universe as fairly smooth and uniform. Now we know that the Universe is a very dynamic place, with all types of energetic phenomenon.”

Offline Ares67

  • Senior Member
  • *****
  • Posts: 12125
  • Oliver
  • Remscheid, Germany
  • Liked: 37
  • Likes Given: 21
Re: Columbia STS-35 – Triumph over Adversity
« Reply #21 on: 04/16/2017 05:16 PM »
PER ASPERA

In February 1978, NASA issued an announcement of opportunity for advanced astronomical instruments that could travel aboard the Space Shuttle and utilize the unique capabilities of Spacelab. The project was to be managed by the Office of Space Science. Forty proposals were accepted for flights on separate missions manifested as OSS-3 through 7; three telescopes – HUT, WUPPE and UIT – were chosen to be put on OSS-3.

By 1982 however, control had passed to NASA’s Marshall Space Flight Center and the OSS missions were renamed “Astro.” Two years later, the first flight of the series was tentatively scheduled for spring of 1986 – exactly the same time that Halley’s Comet would visit the inner solar system – and a special Wide Field Camera was added to permit detailed observations of the celestial wanderer. By the end of January 1986, Astro-1 had completed its final checkout and was ready for installation into Columbia’s payload bay, when Challenger was lost.

Offline Ares67

  • Senior Member
  • *****
  • Posts: 12125
  • Oliver
  • Remscheid, Germany
  • Liked: 37
  • Likes Given: 21
Re: Columbia STS-35 – Triumph over Adversity
« Reply #22 on: 04/16/2017 05:18 PM »
After the accident, the instruments were moved from the Spacelab pallets and stored. Periodic checks were made during storage. However, because of the long interval, NASA decided to examine and recertify all of the Astro instruments before clearing them for flight. As a part of this process, questions arose in the summer of 1987 about the quality certifications of the bolts used in the Astro-1 hardware. Support structures and instruments and electronics attachments were inspected for possible faulty bolts. A total of 298 bolts eventually were replaced.

Because Comet Halley was no longer on position for detailed observation, the Wide Field Camera was removed from the payload manifest in the spring of 1987. In March of 1988, BBXRT was added to the Astro-1 payload. Originally proposed in response to the 1978 announcement of opportunity, BBXRT had been developed as one of three X-ray instruments in a payload designated OSS-2. This was renamed the Shuttle High-Energy Astrophysics Laboratory, SHEAL, and proposed for flight in 1992. However, when Supernova 1987A occurred, BBXRT was completed ahead of schedule and added to the Astro-1 payload. The addition would allow study of the supernova and other objects in X-ray as well as UV wavelengths.

HUT was kept at KSC throughout the post-Challenger downtime, although its spectrograph was removed and returned to the Johns Hopkins University in October 1988. Checks had confirmed that, although it was protected from air and moisture by a continuous supply of gaseous nitrogen, its ultraviolet sensitivity had degraded and the spectrograph was replaced. To achieve far- and extreme-ultraviolet sensitivity HUT’s mirrors were coated with iridium. When the UV spectrograph returned to KSC in January 1989, it failed its first acceptance test and a third spectrograph had to be installed; then an aging television camera had to be removed and replaced.

Meanwhile, the other two Astro-1 instruments also underwent recalibration and testing. WUPPE was not shipped back to the University of Wisconsin, but instead a portable vertical calibration facility was built and delivered to KSC. The telescope passed its checks with flying colors in April 1989. UIT also remained in Florida, where the power supply for its onboard image intensifier was replaced in August 1989. By the beginning of fall, all three instruments had been declared flight-ready and just before Christmas were installed onto the two Spacelab pallets in the Operations and Checkout Building. The pallet-mounted UV telescopes, as well as the BBXRT, were moved to the Cargo Integration Test Equipment stand where testing was completed at the end of February 1990.

Offline Ares67

  • Senior Member
  • *****
  • Posts: 12125
  • Oliver
  • Remscheid, Germany
  • Liked: 37
  • Likes Given: 21
Re: Columbia STS-35 – Triumph over Adversity
« Reply #23 on: 04/16/2017 05:19 PM »
Astro-1 was installed in Columbia’s payload bay March 20, 1990. Final integrated testing in the Orbiter Processing Facility between the orbiter, mission centers and satellite relays was completed March 26-28. Payload pad activities included installation of UIT film, removal of telescope covers, final pallet cleaning and BBXRT argon servicing.

The cost of Astro-1/BBXRT now is approximately $148 million, including instrument development fees and mission management charges. The Astro-1 observatory will be one of the heaviest science payloads lifted by the shuttle to date. The three UV telescopes, IPS, igloo and two Spacelab pallets weigh a total of 17,276 pound; add another 8,650 pounds of BBXRT, TAPS and support equipment. At MECO, the orbiter Columbia and her total cargo (including DTO and SAREX hardware) will weigh 267,513 pounds; landing weight is expected at 225,886 pounds.


A NICE OMEN

The long flight delay actually provides Astro-1 with a benefit, the opportunity to observe SN 1987A, the brightest supernova in nearly 400 years, and the newly discovered Comet Austin. All four telescopes will gather information on SN 1987A, located some 170,000 light years away in our nearest neighboring galaxy, the Large Magellanic Cloud.

“Even though it sounds funny since we’re three years after the outburst, we’re probably a little early to get most of the ultraviolet light from the supernova because it’s still being kept in by the shell,” Mission Specialist Robert Parker says. “But we are going to see what we can find.”

About half-a-dozen observations will be made of Comet Austin, which has just looped around the Sun. Hoffman calls its appearance “a nice omen.” – “People had commented that it’s a shame that you can’t look at the comet (Halley). And then all of a sudden a few months ago, what should appear in the sky but a new comet that had never been seen before.”

Offline Ares67

  • Senior Member
  • *****
  • Posts: 12125
  • Oliver
  • Remscheid, Germany
  • Liked: 37
  • Likes Given: 21
Re: Columbia STS-35 – Triumph over Adversity
« Reply #24 on: 04/16/2017 05:20 PM »

Offline Ares67

  • Senior Member
  • *****
  • Posts: 12125
  • Oliver
  • Remscheid, Germany
  • Liked: 37
  • Likes Given: 21
Re: Columbia STS-35 – Triumph over Adversity
« Reply #25 on: 04/16/2017 05:20 PM »
ASTRO-1 – EYE TO EYE

All four of the Astro-1 instruments are reflector telescopes. Most reflector telescopes, including the ones to be carried aboard Columbia STS-35, use a mirror shaped like a parabola, an open curve. Light hitting the mirror will be reflected to the same point – the focus. Even X-ray can be reflected, but only if they strike at a very shallow angle, called grazing incidence reflection; just like light glaring from the curve of an auto windshield. Thus, the X-ray telescope’s mirrors resemble slightly curved cylinders.

To say only that Astro carries four telescopes is to oversimplify. Each telescope is a light collector for an instrument package that carries devices such as gratings to spread light into its many colors, or filters to pass only certain types of light. There are also mechanisms that move mirrors and other items to help direct the light. Finally, a detector records information about the target.

Offline Ares67

  • Senior Member
  • *****
  • Posts: 12125
  • Oliver
  • Remscheid, Germany
  • Liked: 37
  • Likes Given: 21
Re: Columbia STS-35 – Triumph over Adversity
« Reply #26 on: 04/16/2017 05:22 PM »
The four telescopes are:

Hopkins Ultraviolet Telescope (HUT) for studying spectra of faint astronomical objects such as quasars, active galactic nuclei and galaxies in the far-ultraviolet spectra. HUT observations will extend into the region of extreme ultraviolet, the shortest, most energetic ultraviolet wavelengths. Many discoveries are expected as HUT probes this virtually unexplored region.

With its significantly extended wavelength coverage and greater sensitivity than previous instruments, HUT can scrutinize a variety of targets. For example, the brightest quasars have been observed by the International Ultraviolet Explorer satellite, but exposures are very long, the wavelength coverage is restricted to greater than about 1,200 A, and the quality of the resultant spectrum is often quite poor. HUT will observe fainter quasars for shorter periods of time and get better quality spectra with coverage down to the Lyman limit (912 A).

HUT will employ spectroscopy to reveal the chemistry and structure of stars and other objects. The signatures of many elements including hydrogen, helium, carbon, nitrogen, oxygen, silicon, and sulfur will be recorded.

Many technical challenges were overcome to produce an instrument with these characteristics. One property of UV radiation is that at shorter wavelengths photons are energetic enough to be absorbed rather than reflected by the mirror’s surface. Usually this effect can be counteracted by overcoating the mirror with a substance that helps maintain its UV reflectivity. A major innovation of the HUT instrument involves a coating of the rare element iridium, which remains reflective down to about 400 A, permitting spectroscopy in much of the EUV and FUV range.

The telescope was designed and built by members of the Center for Astrophysical Sciences and the Applied Physics Laboratory of John Hopkins University, Baltimore, Maryland. HUT Principal Investigator is Dr. Arthur F. Davidsen.

Offline Ares67

  • Senior Member
  • *****
  • Posts: 12125
  • Oliver
  • Remscheid, Germany
  • Liked: 37
  • Likes Given: 21
Re: Columbia STS-35 – Triumph over Adversity
« Reply #27 on: 04/16/2017 05:24 PM »

Offline Ares67

  • Senior Member
  • *****
  • Posts: 12125
  • Oliver
  • Remscheid, Germany
  • Liked: 37
  • Likes Given: 21
Re: Columbia STS-35 – Triumph over Adversity
« Reply #28 on: 04/16/2017 05:26 PM »
Wisconsin Ultraviolet Photo-Polarimeter Experiment (WUPPE) for studying the polarization and intensity of ultraviolet radiation of hot stars, galactic nuclei and quasars. WUPPE will yield clues about the shape and size of objects by studying the way their light is polarized.

Usually waves of light move randomly; however, if the light is polarized, all the waves move up and down in the same direction. By measuring how much the light is polarized, WUPPE can help determine the geometry of stars, the strength of magnetic fields, and the nature of gas and dust between the stars. The polarization of ultraviolet radiation has never been measured before.

WUPPE measures the polarization by splitting a beam of radiation into two perpendicular planes of polarization, passing the beams through a spectrometer, and focusing the beams on two separate array detectors. Light scattered by interstellar dust is often polarized or oriented in a specific plane. This has been detected in visible wavelengths but has never been studied in the ultraviolet. Ultraviolet radiation is more readily absorbed or scattered by gas and dust than is visible light.

Polarized light seems to be most prevalent in regions where interstellar dust and magnetic fields are found together. Polarization can be used to study both dust and magnetic fields that would otherwise be invisible and can reveal the strength of magnetic fields of some stars and galaxies. Used in conjunction with photometry, which measures the brightness of sources, it can be used to discern much about the size and shape of objects.

Some stars and star systems emit polarized radiation, hinting that their geometry is nonspherical – perhaps the star is spinning so fast that it is slightly flat; perhaps radiation is scattered by electrons in the distorted atmospheres of hot stars; or perhaps the star is actually a binary star system so close that one member may be eclipsed by the other. Stars, other than our Sun, are so distant that we cannot directly see their structure. However, from the intrinsically polarized radiation of a star, scientists may be able to deduce information about its hidden geometry.

WUPPE will also use photometry to measure the brightness of sources and spectroscopy to study their ultraviolet emission. Photometry is the measurement of the intensity of the electromagnetic waves which form light and the other wavelengths of radiation. WUPPE spectra cover the wavelengths between visible light and the exotic higher energy ultraviolet wavelengths bands viewed by HUT. For many objects, the WUPPE spectra will be combined with HUT spectra to obtain greater insight into the nature of sources.

The targets WUPPE investigations are primarily known objects, in our galaxy and beyond, for which comparative data exist in other wavelengths. The telescope was developed by the University of Wisconsin, Madison, Wisconsin. WUPPE Principal Investigator is Dr. Arthur D. Code.

Offline Ares67

  • Senior Member
  • *****
  • Posts: 12125
  • Oliver
  • Remscheid, Germany
  • Liked: 37
  • Likes Given: 21
Re: Columbia STS-35 – Triumph over Adversity
« Reply #29 on: 04/16/2017 05:28 PM »
Ultraviolet Imaging Telescope (UIT) for imaging objects such as hot stars and galaxies in broad ultraviolet wavelength bands and with a wide field of view, about one-third wider than the Moon. It includes image intensifiers and two 70-millimeter cameras with enough film to make 2,000 exposures per flight. Images are recorded directly onto a very sensitive astronomical film for later development after the shuttle lands. A series of 11 different filters allows specific region of the UV spectrum to be isolated for energy distribution studies.

UIT will take the first extensive set of detailed ultraviolet photographs of the sky, most of which has never been imaged in the ultraviolet. In the 20 years that astronomical observations have been made from space, no high-resolution ultraviolet photographs of objects other than the Sun have been made. Nonetheless, our brief glimpses of the UV sky have led to important discoveries in spiral galaxies, globular clusters, white dwarf stars, and other areas.

This instrument can see areas larger than the apparent size of the Sun viewed from Earth and will detect fainter ultraviolet sources than any seen before. Its film will capture nearby galaxies, large clusters of stars, and distant clusters of galaxies. The wavelength range of UIT covers the ultraviolet spectrum from 1,200 to 3,200 A. A 30-minute exposure (the length of one orbital night) will record a blue star of 25th magnitude, about 100 million times fainter than the faintest star visible to the naked eye on a dark, clear night. Since hot objects emit most of their energy in the ultraviolet, the ultraviolet imaging will focus on the search for hot stars in the rich, crowded field of a globular cluster.

UIT is the first instrument that can take UV images of an entire cluster 10 to 20 arc minutes across, about one-half the size of the apparent diameter of the Moon. Since UIT makes longer exposures than previous instruments, fainter objects will be visible in the images. Astronomers can use these images to pinpoint interesting ultraviolet objects throughout the cluster and study their relationships.

Such clusters are an ideal laboratory for studying stellar evolution, because all the some 100 thousand to 1 million stars in each cluster were formed at the same time from gas with the same initial chemical composition. However, the mass of stars in a cluster varies, and the stars evolve at different rates determined by their individual masses. The more massive stars shine more brilliantly, use their nuclear fuel supply more rapidly, and age more quickly. The range of stellar masses when a cluster forms determines the cluster’s appearance today; therefore, the properties of sample stars in a cluster can be related to their evolutionary history.

“The UIT is best described as a sophisticated telephoto camera with super-sensitive film and a violet filter,” wrote Philip Chien in the March 1991 issue of 73 Amateur Radio Today. “Imagine a telephoto camera with a field of view 25 percent wider than the full Moon with ultra-low light film with an effective ISO (ASA) of a couple of hundred thousand (in comparison with the 100-400 film you’d normally purchase). It has a filter so violet the human eye can’t see it, further into ultraviolet than Hubble’s capabilities. Also, instead of an 18 or 36 exposure roll film, you have a film pack with over 1,000 exposures of 70mm film! That’s one heck of a telephoto camera!”

The telescope was developed at NASA’s Goddard Space Flight Center, Greenbelt, Maryland. UIT Principal Investigator is Theodore P. Stecher.

Offline Ares67

  • Senior Member
  • *****
  • Posts: 12125
  • Oliver
  • Remscheid, Germany
  • Liked: 37
  • Likes Given: 21
Re: Columbia STS-35 – Triumph over Adversity
« Reply #30 on: 04/16/2017 05:29 PM »
Broad Band X-Ray Telescope (BBXRT) for viewing high-energy objects such as active galaxies, quasars and supernovae. It is actually two 8-inch telescopes with a field of view that is more than half the width of the Moon. BBXRT will make the first high-quality, high-energy spectra of many X-ray sources discovered by earlier satellites. It can see fainter and more energetic objects than any yet studied, measuring radiation from heavy elements such as iron, oxygen, silicon, and calcium. Variations in the spectra will tell us about violent events, such as matter being destroyed in the core of a galaxy or stellar explosions.

BBXRT will provide astronomers with the first high-quality spectra of many of the X-ray sources discovered with the High Energy Astronomy Observatory 2, better known as the Einstein Observatory. BBXRT uses mirrors and advanced solid-state detectors as spectrometers to measure the energy of individual X-ray photons. These energies produce a spectrum that reveals the chemistry, structure, and dynamics of a source.

X-ray telescopes are difficult to construct because the X-rays are so energetic that they penetrate mirrors and eventually are absorbed. A mirror surface reflects X-rays only if it is very smooth and the photons strike in a very shallow angle. Because such small grazing angles are needed, the reflectors must be very long to intercept many of the incident X-rays.

Traditionally, X-ray telescopes have used massive, finely polished reflectors that were expensive to construct and did not effectively use the available aperture. The mirror technology developed for BBXRT consists of very thin pieces of gold-coated aluminum foil that require no polishing and can be nested very closely together to reflect a large fraction of the X-rays entering the telescope. Because its reflecting surfaces can be made so easily, BBXRT can afford to have mirrors using the very shallow grazing angles necessary to reflect high-energy photons. In fact, BBXRT is one of the first telescopes to observe astronomical targets that emit X-rays above approximately 4 thousand electron volts (keV).

BBXRT also was developed at Goddard Space Flight Center. BBXRT Principal Investigator is Dr. Peter J. Serlemitsos.

Offline Ares67

  • Senior Member
  • *****
  • Posts: 12125
  • Oliver
  • Remscheid, Germany
  • Liked: 37
  • Likes Given: 21
Re: Columbia STS-35 – Triumph over Adversity
« Reply #31 on: 04/16/2017 05:29 PM »




Offline Ares67

  • Senior Member
  • *****
  • Posts: 12125
  • Oliver
  • Remscheid, Germany
  • Liked: 37
  • Likes Given: 21
Re: Columbia STS-35 – Triumph over Adversity
« Reply #32 on: 04/16/2017 05:31 PM »
POINTING THE PAYLOAD

The best instruments in the world are as worthless as junkyard scrap unless they can be pointed with extreme accuracy. This task falls to the Spacelab hardware connecting the four telescopes to the shuttle. Spacelab is a laboratory facility designed and built by the European Space Agency. Astro will use parts of this facility, including the Instrument Pointing System (IPS) and a pair of pallets – U-shaped carriers about ten feet long and 15 feet wide. The pressurized lab module will not be used for Astro.

The unpressurized pallets are anchored in the shuttle payload bay, and a pressurized cylindrical container called the “igloo,” located at the head of the two pallets, houses subsystems that provide such services as power, telemetry, and commands to the instruments. The crew will operate Astro from control positions on the aft flight deck of the orbiter cabin.

The IPS, a gimbaled support structure that can be pointed in various directions, is attached to the pallets. The three ultraviolet telescopes are mounted and precisely co-aligned on a common structure, called the “cruciform,” that is attached to the pointing system. An image motion compensation system was developed by the Marshall Space Flight Center to provide improved pointing stability. A gyro stabilizer senses the motion of the cruciform which could disrupt UIT and WUPPE pointing stability. It sends information to the image motion compensation electronics system where pointing commands are computed and sent to the telescopes’ secondary mirrors which make automatic adjustments to improve stability.

A star tracker, designed by the Jet Propulsion Laboratory, fixes on bright stars with well-known locations and sends this information to the electronics system which corrects errors caused by gyro drift and sends new commands to the telescopes’ mirrors. The mirrors automatically adjust to keep pointed at the target.

The pointing system flew on Spacelab 2 in July 1985, when it was used to point an array of solar telescopes. Fine pointing of the IPS was hampered during the mission due to a series of software errors in its computer commands. “The (Astro-1) IPS is a new and better instrument,” Mission Specialist Bob Parker says. “We all learn from our mistakes, and instruments learn from their design flaws on their first flight. That’s why Spacelab 2 was literally called a development checkout flight… We all know a lot more about the software and hardware than we did on the first flight.”

Offline Ares67

  • Senior Member
  • *****
  • Posts: 12125
  • Oliver
  • Remscheid, Germany
  • Liked: 37
  • Likes Given: 21
Re: Columbia STS-35 – Triumph over Adversity
« Reply #33 on: 04/16/2017 05:32 PM »
The fourth Astro-1 instrument, the Broad Band X-Ray Telescope, uses a less complex pointing system called the Two-Axis Pointing System (TAPS). The X-ray telescope and TAPS, developed at the Goddard Space Flight Center, were designed to be flown together on multiple missions. This payload will be anchored in a support structure place behind the UV telescopes in the shuttle payload bay.

TAPS has two gimbals, one within the other, that rotate to point the telescope. BBXRT is attached directly to the TAPS inner gimbal frame. The TAPS will move BBXRT in a forward/aft direction (pitch) or from side to side (roll) relative to the payload bay. A star tracker uses bright stars as a reference to position the TAPS on a target. As the gyros drift, the star tracker periodically recalculates and resets the TAPS position.

BBXRT and TAPS are commanded through the shuttle’s computers from the Goddard Space Flight Center in Maryland.

Offline Ares67

  • Senior Member
  • *****
  • Posts: 12125
  • Oliver
  • Remscheid, Germany
  • Liked: 37
  • Likes Given: 21
Re: Columbia STS-35 – Triumph over Adversity
« Reply #34 on: 04/16/2017 05:33 PM »
SWEEPING THE STELLAR GAMUT

“We’re carrying instruments that in the past mainly have been used on small rockets. Instead of getting a few minutes of observing, we’ll get nine or ten days continuous observing time. We think this has tremendous scientific potential.”

- Vance Brand, Commander STS-35


- Experiment teams will coordinate science observations
- Over 80 hours of observation time
- 250 observations of over 120 individual objects
- Science targets encompass entire scale of cosmos from planetary studies to investigations of clusters of galaxies
- Complementary ultraviolet and X-ray observations
- About 1/3 of all targets will be co-science investigations by all four instruments


The investigators backing the Astro project carry with them a wide array of interests. Likewise, the Astro-1 mission will attempt to gain information on a wide array of targets sweeping to gamut from the youngest to oldest stars – and more.

Today, our Sun is a stable, middle-aged star, but some five billion years hence it will swell and swallow the inner planets including Earth. A red giant, it may eject a shell of dust and gas, a planetary nebula. As the Sun fades, it will collapse to an object no bigger than Earth, a dense, hot ember, a white dwarf. Astronomers predict that most stars may end their lives as white dwarfs, so it is important to study these stellar remains. White dwarfs emit most of their radiation in the ultraviolet, and one of Astro’s main goals is to locate and examine them in detail.

Stars with 10 to 100 times more mass than the Sun burn hydrogen rapidly until their cores collapse and they explode as supernovae, among the most powerful events in the Universe. These stars are initially very hot and emit mostly ultraviolet radiation. Astro will chronicle the life cycles of stars. Astro instruments will locate hot, massive stars of all ages so that astronomers can study these phases of stellar evolution.

Stars may congregate in star clusters with anywhere from a few to millions of members. Often, there are so many stars in the core of a cluster that is impossible to detect the visible light from individual stars. Because they shine brightly in the UV, Astro will be able to isolate the hot stars within clusters. The clusters are excellent laboratories for studying stellar evolution because the stars residing there formed from the same material at nearly the same time.

However, within a single cluster, stars of different masses evolve at different rates. We can study stellar evolution by looking at clusters of different ages. Each cluster of a given age gives us a snapshot of what is happening as a function of stellar mass. By examining young clusters – less than a million years old – and comparing them to old clusters – ten million years old – we can piece together what happens over a long time.

The UIT survey will help determine the relative numbers of very small, star-forming galaxies. Their hot star populations radiate brightly in the ultraviolet, making these galaxies easier to find with UIT than with visible light telescopes on Earth. The UIT also will try to identify extremely distant star-forming galaxies in the early phases of their evolution.

Astro will view the recent explosion, Supernova 1987A, which spewed stellar debris into space. Supernovae forge new elements, most of which are swept away in expanding shells of gas and debris heated by the shock waves from the blast. Astro will look for supernova remnants which remain visible for thousands of years after a stellar death.

Beyond the Milky Way are at least a hundred billion more galaxies, many with hundreds of billions of stars. They contain most of the visible matter in the Universe. The galaxies form clusters of galaxies that have tens to thousands of members. X-ray and ultraviolet emission will allow us to study the hottest, most active regions of these galaxies as well as the intergalactic medium, the hot gas between the galaxies in a cluster.

BBXRT will be used to study a variety of sources, but a major goal is to increase our understanding of active galactic nuclei and quasars. Many astronomers believe that both are actually very similar objects that contain an extremely luminous source at the nucleus of an otherwise relatively normal galaxy. The central source in quasars is so luminous that the host galaxy is difficult to detect.

The mechanism producing the luminosity of the central source is not known for certain, but most theories suggest that matter is being consumed by a black hole weighing about a billion times as much as the Sun. X-rays are expected to be emitted very near the central engine of these objects, and astronomers will examine X-ray spectra and their variations to understand the phenomena at the very heart of quasars.

It is known from optical studies that quasars have changed over cosmological time scales; near the beginning of the Universe they were far more numerous than they are today. BBXRT will be used to examine very distant – and thus very young – quasars to see if their X-ray emission is different from relatively nearby quasars.

Investigators are interested in clusters of galaxies, congregations on tens or thousands of galaxies grouped together within a few million light-years of each other. When viewed in visible light, emissions from the individual galaxies are dominant, but X-rays come mainly from hot gas between the galaxies. In fact, theories and observations indicate that there should be about as much matter in the hot gas as in the galaxies, but all this material has not been see yet. BBXRT observations will enable scientists to calculate the total mass of a cluster and deduct the amount of “dark” matter.

The HUT also will probe the centers of galaxies and quasars where black holes may lurk. By looking into the central regions of such objects, investigators may be able to determine what is really there, how dense the hydrogen atmospheres are, how abundant helium is, and how the objects resemble or differ from one another. The nuclei of normal galaxies also have been difficult targets to study; spectra from HUT will be used to examine the stellar populations of these objects, in particular providing information on the hottest stars.

Closer to home, there are many objects in our own galaxy that are the target of the HUT observations. Very hot objects that emit much of their energy in the 900 to 1,200 A region are of special interest. These include certain binary star systems, pairs of stars mutually attracted by gravity. If the two stars are close enough, some of the larger star’s material may be transferred toward its compact companion star, creating an accretion disk of hot, swirling material. On a grander scale, similar processes may be taking place around black holes and the centers of quasars as matter is attracted to them.

Within the solar system, the outer planets are of interest to the HUT investigators, especially Jupiter, its moons, and its magnetosphere. Jupiter’s moon Io constantly releases ionized material into the surrounding region of space where it interacts with the Jovian magnetic field. The HUT observations address a number of problems related to ion abundances in this plasma (ionized plasma), injection mechanisms, and the energy balance between particles and magnetic fields. In addition, FUV and EUV observations of all outer planets will be made to investigate auroras and gain insight into the interaction of each planet’s magnetosphere with the solar wind.

Many astronomical objects selected for study by the Astro-1 observatory are of keen interest to most or all of the instrument teams. Simultaneous observations will bring together much new information that can be compared to reveal new physical relationships. For example, studying the M87 galaxy with all the Astro instruments may help us understand why this galaxy emits energetic jets of radiation and may uncover evidence of a super massive black hole at its center. While UV spectra and X-ray images have been made of this interesting galaxy, Astro instruments will take the first ultraviolet photographs and obtain the most detailed UV and X-ray spectra yet made of M87.

HUT, UIT, WUPPE and BBXRT will provide unique observations of nearby galaxies, such as M83, which are called starburst galaxies because of increased star formation seen there. Astronomers do not know why galaxies have a sudden burst of star formation, but this process may be triggered by the gravity of a neighbor galaxy or it may result from processes similar to those in inactive galaxies. Astro-1 may help clarify the relation of the increased star formation to galaxy interaction or active galaxy nuclei.

Multiple observations are scheduled at specific times to study stars and other sources that vary in intensity, size, and structure. For example, in eclipsing binary systems, as stars orbit around each other, first one star and then the other will be blocked from view. In this case, carefully timed spetroscopic and polarimetric data recorded simultaneously by HUT, WUPPE and BBXRT will provide new insight into the structure of the individual stars and the gas flows between them.


IF HUBBLE, THEN WHY ASTRO?

The Astro-1 observatory and the Hubble Space Telescope may seem like redundant projects at first glance. Both observe the Universe in infrared, visible, and ultraviolet radiation, covering some of the same spectral regions. However, the capabilities of the two observatories are different, and they complement each other well.

UIT, photographing a circular field area somewhat larger than the apparent diameter of the Moon, is very well-suited for photographing a nearby cluster of stars or a nearby galaxy and pinpointing interesting ultraviolet sources. HST covers an area about 170 times smaller, its resolution is much higher, and it studies visible as well as ultraviolet wavelengths; it examines individual, much more distant sources in great detail.

Surprisingly, little imagery is available at UV wavelengths, so UIT’s survey of relatively large portions of the sky will be useful for identifying ultraviolet sources that can be scrutinized more closely by HST and other observatories. “I think we’ll be providing a lot of information to the Hubble people of new ultraviolet targets,” Astro-1 Payload Specialist Ron Parise says.

HUT and WUPPE are both ultraviolet spectroscopic instruments, and HST also is capable of high-resolution UV and visible spectroscopy. While HUT’s wavelength coverage does overlap with HST, its primary capability lies at more energetic wavelengths below 1,200 A, a region inaccessible to HST. Almost nothing other than the brightest stars has been observed in this critical region, and spectra in this region will be unique.

“There are a lot of very interesting phenomena which occur between the cutoff wavelength of Hubble and down to 400 A. One of the things that we’re interested in is trying to determine the amount of helium in the Universe,” Astro-1 Payload Specialist Sam Durrance says. “This is a fundamental quantity, and the only way we can really address it is by looking at the wavelength where helium emits light – that’s down around 500 A.”

WUPPE also makes sensitive polarization and spectroscopy measurements at ultraviolet wavelengths. This capability is available on HST, but the size of the spectrograph apertures is very different. The smaller apertures on the HST instruments are optimized for admitting the light of individual stars. WUPPE and HUT have much larger apertures, permitting them to observe many faint, extended sources such as galaxies or galactic nebulae that cannot be observed efficiently with HST. For spectra of large objects that are closer to our galaxy, HUT and WUPPE will be many times more sensitive than HST, while for distant quasars or other very faint stellar objects, using HST will be advantageous.

There is no other large X-ray telescope operating at this time. BBXRT together with the Roentgen satellite Rosat, a cooperative West German/UK/U.S. mission to be launched on an unmanned Delta II rocket in June 1990, will supply the X-ray data on targets that HST is studying at other wavelengths. X-ray spectral measurements performed with BBXRT will be particularly valuable since quasars will be a primary for both it and HST.

From its 360-mile-high vantage point, Rosat will undertake a 1 1/2-year mission to produce the first complete map of the heavens in the X-ray region of nature's electromagnetic spectrum. "With all of these missions, we are entering a decade of discovery and exploration," said Ed Weiler, NASA's chief astronomer. "These telescopes are totally unique, and yet they are totally complementary.”

NASA and its teams of astronomers plan to piece together like a giant puzzle the discoveries to be made with the Great Observatories, the Astro-1 observatory, Rosat, the Cosmic Background Explorer (placed in orbit last November) and other major instruments scheduled for launch this decade.

Launched in late April 1990, the $1.55 billion Hubble Space Telescope is the first of the four Great Observatories, the cornerstone of NASA's ambitious astronomy program. The second of the quartet, the Gamma Ray Observatory, is currently slated for a November Space Shuttle launch. The third and fourth Great Observatories - the Advanced X-ray Astrophysics Facility and the Space Infrared Telescope Facility - are planned for launches in 1997 and 1999 respectively.

The Gamma Ray Observatory will scan the heavens for sources of the very highest energy emissions, particularly quasars, the most distant of objects, believed by theorists to be galaxies in early formation. Rosat's sky chart of X-ray sources will serve as a road map for the Advanced X-ray Telescope Facility, allowing the much larger observatory to focus on selected targets. The last of the Great Observatories, the Space Infrared Telescope Facility, will specialize in the study of low energy events, searching for the relatively cool cores of new stars in their earliest formative stage.

Offline Ares67

  • Senior Member
  • *****
  • Posts: 12125
  • Oliver
  • Remscheid, Germany
  • Liked: 37
  • Likes Given: 21
Re: Columbia STS-35 – Triumph over Adversity
« Reply #35 on: 04/16/2017 05:35 PM »
COLUMBIA’S COMPLEX SCHEDULE

"The mission planning we have done is timed to the very minute. We are pushing it to get as much science as we can."

- Ted Gull, Astro-1 project scientist, Goddard Space Flight Center


The launch of mission STS-35 is tentatively scheduled for May 9, 1990, at 12:50 a.m. EDT. The available launch window extends until 3:03 a.m. EDT. Columbia will aim for an orbit about 220 miles high and inclined 28.5 degrees to the equator. This will place the shuttle above most of the glow phenomenon caused by the atmosphere, and avoid most of the South Atlantic Anomaly, a low-lying region of radiation. On Spacelab 2 in 1985, Challenger could only achieve an orbit 50 miles lower than planned when one main engine shut down about six minutes into the flight. While 50 miles might not seem like much, it was enough to disrupt several experiments and necessitate a large replanning effort.

While the shuttle will have about a two-hour window in which to launch, delays as short as a half hour would change the day/night cycles critical to observing. Because of the complex teamwork to make an observation, massive replanning might be needed once Columbia is on orbit. In such a case, the crew says they hope their Text and Graphics System (TAGS), a fax machine that would provide updates much easier than the shuttle’s teleprinter, works without a hitch.

If all goes as planned, the IPS will be powered up and tested about three hours after Columbia’s launch. The ultraviolet telescopes will not be turned on until twelve-and-a-half hours after launch to make sure that all residual gases have vented; any significant traces could allow high-voltage electricity to arc and cause a short circuit.

As the instruments are gradually turned on, they will be tested, then aligned. BBXRT and TAPS will have a much simpler activation and will be operating less than three hours after launch. The shuttle will maneuver to aim the payload bay at each new target so the IPS and the TAPS can point towards the astronomical objects. TV cameras in HUT and WUPPE will help the crew in pointing the telescopes.

Once operational, the four telescopes will be operated for 24 hours a day until about twelve hours before landing. On every orbit, two or three shuttle maneuvers will enable the IPS and TAPS-mounted instruments to view specific or desired astronomical sources. Lead Flight Director Gary Coen says observation targets will change every half hour, which will create a busy schedule. “In order to optimize the number of stars we can see and the galactic objects that the scientists can point at, we have a pretty tight maneuver schedule,” he says. “Over the course of the nine-day mission, we’re doing some 240 attitude maneuvers to repoint the orbiter and to allow the IPS and the BBXRT to get new targets.”

The telescopes often will work together, taking different measurements of the same object. “The three ultraviolet telescopes we have are co-pointed generally at the same target all the time,” Payload Specialist Sam Durrance says. “We’re unique in that we can make several types of observations simultaneously on the same target.” During other times the ultraviolet telescopes will view different objects from the BBXRT. Computers on the ground will turn data from three instruments into “quick-look” results enabling investigators to assess their observations during the mission. UIT’s film must be developed after the flight.


Here is a day-by-day summary of STS-35 major activities.

Flight Day 1 – Ascent / Post-insertion, Unstow Cabin, Astro/BBXRT Activation, SAREX Setup, DSO

Flight Day 2 – Astro/BBXRT Observations, SAREX

Flight Day 3 – Astro/BBXRT Observations, SAREX

Flight Day 4 – Astro/BBXRT Observations, SAREX, AMOS

Flight Day 5 – Astro/BBXRT Observations, SAREX, Space Classroom, AMOS

Flight Day 6 – Astro/BBXRT Observations, SAREX

Flight Day 7 – Astro/BBXRT Observations, RCS Hotfire

Flight Day 8 – Astro/BBXRT Observations, SAREX, DTO, FCS Checkout

Flight Day 9 – Astro/BBXRT Observations/Deactivation, SAREX/Cabin Stow, Deorbit and Landing

Observations will terminate about 15 hours before landing, with final deactivation of the UV telescope systems coming eight hours before landing and the BBXRT powerdown coming five hours before touchdown at Edwards Air Force Base, California. The mission is presently scheduled to last for nine days, with landing coming on orbit 140. However, if enough power is conserved and pending landing weather, the flight will be extended an extra day.

Offline Ares67

  • Senior Member
  • *****
  • Posts: 12125
  • Oliver
  • Remscheid, Germany
  • Liked: 37
  • Likes Given: 21
Re: Columbia STS-35 – Triumph over Adversity
« Reply #36 on: 04/16/2017 05:36 PM »
ASTRO GROUND SUPPORT

Astro-1 marks the first shuttle mission to be controlled by three NASA installations. Columbia will be directed as usual from Mission Control at Johnson Space Center, Houston, Texas. STS-35 will be conducted from Flight Control Room One (FCR-1) on the second floor of the MCC located in Building 30. The teams of flight controllers will alternate shifts in the control center and in nearby analysis and support facilities. The handover between each team takes about an hour and allows each flight controller to brief his or her oncoming colleague on the course of events over the previous two shifts.

The four flight control teams for STS-35 will be referred to as the Ascent/Entry, Orbit 1, Orbit 2 and Orbit 3 teams. The ascent and entry phases will be conducted by Flight Director Wayne Hale. The Orbit 1 team will be headed by STS-35 Lead Flight Director Gary Coen. The Orbit 2 team, responsible for activation and deactivation of the Spacelab payload, will be led by Al Pennington. The Orbit 3 team will be directed by Bob Castle.

The flight control positions in the MCC, and their responsibilities, are:

Flight Director (Flight) – Has overall responsibility for the conduct of the mission:

Wayne Hale (Ascent/Entry), Gary Coen (Orbit 1), Al Pennington (Orbit 2), Bob Castle (Orbit 3)

Capsule Communicator (CapCom) – By tradition an astronaut, responsible for all voice contact with the flight crew:

Mike Baker (Ascent), Ken Bowersox (Entry), Kathy Thornton (Orbit 1), Story Musgrave (Orbit 2), James Voss (Orbit 3)

Dec. 1990 changes: Marsha Ivins (Orbit 1) for Kathy Thornton

Flight Activities Officer (FAO) – Responsible for procedures and crew timelines; provides expertise on flight documentation and checklists; prepares messages and maintains all teleprinter and/or Text and Graphics System traffic to the vehicle:

Steve Gibson (Ascent/Entry/Orbit 1), Jeff Davies (Orbit 2), Lee Wedgeworth (Orbit 3)

Dec. 1990 additions: Ann Bowersox (Orbit 2), Fisher Reynolds (Orbit 3)

Integrated Communications Officer (INCO) – Responsible for all orbiter data, voice and video communications systems; monitors the telemetry link between the vehicle and the ground; oversees the uplink command and control processes:

Harry Black (Ascent/Entry, Orbit 1), Robert Moolchan (Orbit 2), Joe Gibbs (Orbit 3)

Flight Dynamics Officer (FDO) – Responsible for monitoring vehicle performance during the powered flight phase and assessing abort modes; calculating orbital maneuvers and resulting trajectories; and monitoring vehicle flight profile and energy levels during reentry:

Timothy Brown (Ascent), Matt Abbott (Entry), Ed Gonzales (Orbit 1), Philip Burley (Orbit 2), William Tracy (Orbit 3)

Dec. 1990 changes: Ed Gonzales (Ascent), Timothy Brown (Orbit 1)

Guidance Procedures Officer (GPO) – Responsible for the onboard navigational software and for maintenance of the orbiter's navigational state, known as the state vector:

John Turner (Ascent), Dennis Bentley (Entry)

Dec. 1990 changes: Dennis Bentley (Ascent), John Turner (Entry)

Trajectory Officer (Trajectory) – Also known as "TRAJ," this operator aids the FDO during dynamic flight phases and is responsible for maintaining the trajectory processors in the MCC and for trajectory inputs made to the Mission Operations Computer:

Steve Stich (Ascent), Debbie Langan (Entry), Brian Perry (Orbit 1), Dan Adamo (Orbit 2), Mark Haynes (Orbit 3)

Dec. 1990 changes: Brian Perry (Ascent), Steve Stich (Orbit 1), Carson Sparks (Orbit 3)

Environmental Engineer & Consumables Manager (EECOM) – Responsible for all life support systems, cabin pressure, thermal control and supply and waste water management; manages consumables such as oxygen and hydrogen:

Dave Herbeck (Ascent/Entry, Orbit 1), Leonard Riche (Orbit 2), Peter Cerna (Orbit 3)

Electrical Generation and Illumination Officer (EGIL) – Responsible for power management, fuel cell operation, vehicle lighting and the master caution and warning system:

Charles Dingell (Ascent/Entry, Orbit 1), Robert Armstrong (Orbit 2), Robert Floyd (Orbit 3)

Payloads Officer (Payloads) – Coordinates all payload activities; serves as principal interface with remote payload operations facilities:

Mark Kirasich (Ascent/Entry, Orbit 1), Debra Bulgher (Orbit 2), Robert Galpin (Orbit 3)

Data Processing Systems Engineer (DPS) – Responsible for all onboard mass memory and data processing hardware; monitors primary and backup flight software systems; manages operating routines and multi-computer configurations:

Mark Erminger (Ascent/Entry, Orbit 1), Paul Tice (Orbit 2), Gloria Araiza (Orbit 3)

Dec. 1990 changes: Gloria Araiza (Orbit 2), David Tee (Orbit 3)

Propulsion Engineer (Prop) – Manages the reaction control and orbital maneuvering thrusters during all phases of flight; monitors fuel usage and storage tank status; calculates optimal sequences for thruster firings:

Keith Chappell (Ascent/Entry, Orbit 1), Lonnie Schmitt (Orbit 2), William Powers (Orbit 3)

Booster Systems Engineer (Booster) – Monitors main engine and Solid Rocket Booster performance during ascent phase:

Mark Jenkins (Ascent), Kenneth Dwyer (Entry), Tom Kwiatkowski (Orbit 3)

Dec. 1990 changes: TBD Kenneth Dwyer or Frank Markle (Entry)

Guidance, Navigation & Control Systems Engineer (GNC) – Responsible for all inertial navigational systems hardware such as star trackers, radar altimeters and the Inertial Measurement Units; monitors radio navigation and digital autopilot hardware systems:

Stephen Elsner (Ascent/Entry), Edward Trlica (Orbit 1), Kenneth Bain (Orbit 2), Linda Patterson (Orbit 3)

Ground Controller (GC) – Coordinates operation of ground stations and other elements of worldwide space tracking and data network; responsible for MCC computer support and displays:

John Snyder (Ascent/Entry), Per Barsten (Ascent/Entry), Mike Marsh (Orbit 1), Henry Allen (Orbit 1), Chuck Capps (Orbit 2), Lynn Vernon (Orbit 2), John Wells (Orbit 3), Frank Stolarski (Orbit 3)

Dec. 1990 changes: Terry Quick (Orbit 2) for Chuck Capps

Maintenance, Mechanical, Arm & Crew Systems (MMACS) – Formerly known as RMU; responsible for Remote Manipulator System; monitors Auxiliary Power Units and hydraulic systems; manages payload bay and vent door operations:

Kevin McCluney (Ascent/Entry, Orbit 1), William Anderson (Orbit 2), Paul Dye (Orbit 3)

 Flight Surgeon (Surgeon) – Monitors health of flight crew; provides procedures and guidance on all health-related matters:

Jeff Davis (Ascent), Brad Beck (Entry), Denise Baisden (Orbit 1), Larry Pepper (Orbit 2)

For STS-35, flight surgeon shifts will overlap the crew handover times between Red and Blue teams.

Public Affairs Officer (PAO) – Provides real-time explanation of mission events during all phases of flight:

Billie Deason (Ascent), Jeff Carr (Entry/Orbit 1), Brian Welch (Orbit 1), James Hartsfield (Orbit 2), Kyle Herring (Orbit 3)

Dec. 1990 changes: Brian Welch (Ascent) for Billie Deason


But the three ultraviolet telescopes in the observatory will be directed from the Payload Operations Control Center (POCC) at Marshall Space Flight Center, Huntsville, Alabama. Astro-1 will be the first mission directed from the MSFC. The POCC is the nerve center for payload operations during the Astro mission. It is the site of communication between the crew, the mission support team, and the instrument teams. The POCC is staffed by teams of scientists and engineers who developed the Astro telescopes.

The mission manager and his team will conduct the mission from the POCC. Throughout the mission, they monitor the health of the UV and X-ray telescopes, IPS, TAPS, the computers, and the many subsystems designed to take care of Astro’s needs while on orbit. They prepare and update as necessary the mission timeline, a shift-by-shift schedule of crew activities and procedures.

The fourth telescope, BBXRT and its special TAPS pointing system will be operated by a special POCC team at Goddard Space Flight Center, Greenbelt, Maryland. However, some members of the BBXRT team will be stationed at the Marshall POCC to participate in the science planning, and all commands issued to the payload will be coordinated with the mission management team at Marshall. The Goddard POCC will be linked to the Marshall POCC via voice communication so that teams at both places can confer.

Transmissions to and from Columbia will be broadcast on two separate channels – one devoted to science operations, the other devoted to orbiter flight operations. Science operations will be the subject of communications on the air-to-ground one (A/G-1) channel, with the Crew Interface Coordinator (CIC) at the POCC using the call sign “Huntsville,” and the crew using the call sign “Astro.” Orbiter operations will be the subject of communications on the air-to-ground two (A/G-2) channel, with the spacecraft communicator (CapCom) in the MCC using the call sign “Houston,” and the orbiter hailed as “Columbia.”

Offline Ares67

  • Senior Member
  • *****
  • Posts: 12125
  • Oliver
  • Remscheid, Germany
  • Liked: 37
  • Likes Given: 21
Re: Columbia STS-35 – Triumph over Adversity
« Reply #37 on: 04/16/2017 05:38 PM »
RUNNING THE ASTRO RELAY

Astro’s X-ray telescope requires little attention from the crew. A crewmember turns on the BBXRT and the TAPS at the beginning of operations and turns them off when the operations conclude, but the telescope is operated from the ground. After the telescope is activated, NASA personnel can “talk” to it via computer. First, they will activate power and heaters and check out the TAPS pointing system alignment. Before science operations begin, stored commands are loaded into the BBXRT computer system. Then, when the astronauts position Columbia in the general direction of the source, the TAPS automatically points the BBXRT at the object.

On every shuttle mission crew time is a valuable asset that must be shared by experiments and used efficiently. The Astro-1 observatory instrument operations complement each other nicely because the UV telescopes are operated around the clock by an onboard crew, while the X-ray telescope is controlled completely by remote ground-based operators.

The Astro ultraviolet telescopes and IPS are controlled from the aft flight deck, a work area located at the rear of the cockpit. From here, a payload specialist and a mission specialist can monitor the instruments and command them to precise viewing positions. The aft flight deck has two dedicated Spacelab keyboard and display units, one for controlling the IPS and the other for operating the scientific instruments. To aid in target identification, this work area includes two closed-circuit television monitors: one displays the HUT data and star fields, and the other displays the WUPPE data and star fields.

Making observations involves a tremendous amount of teamwork from the crew, like running a relay. “It’s a very complex, interrelated observing schedule,” says Jeff Hoffman. Mike Lounge or Guy Gardner, depending on the shift, maneuvers the shuttle to point the payload bay in the general direction of the astronomical object to be observed. “We use the orbiter for course pointing,” Lounge says. The maneuver is performed very slowly, taking about ten minutes, in order to save fuel and keep from disturbing the delicate telescopes.

As Columbia swings into position, a mission specialist, either Parker or Hoffman, commands the pointing system to aim the telescopes toward the target. He also acquires guide stars to help the pointing system maintain stability despite orbiter thruster firings. A couple minutes are needed to lock onto the target.

At the same time, a payload specialist reconfigures each instrument for the upcoming observation, identifies the celestial target on the guide TV, and provides any necessary pointing corrections for placing the object in the spectrograph apertures. He then starts the instrument observation sequence and monitors the data being recorded.

“Once the observing sequence has begun, we begin to evaluate the data,” Sam Durrance says. “We see the data in real time for two of the instruments. We actually see the spectrum come on the video monitor (to check if) that looks like what we were expecting.”

Because the target acquisition and operational workload is high, the payload and mission specialists work together to perform these complicated operations and evaluate the quantity of observations. “If we have trouble with one of the instruments acquiring data, our scenario says that I will continue to get as many of the three instruments observing as I can,” Durrance says. “I will turn the observing over to Jeff while I try to troubleshoot the problem with the instrument that is not working.”

The crewmembers are cross-trained to handle each other’s tasks. “That’s an important part of training,” Jeff Hoffman says. “If Mike wants to go off and grab a bit to eat, I can work an orbiter maneuver – I know how to do that. Mike has been trained to operate the Instrument Pointing System to back me up. Bob and I have both had a certain amount of training in operating the scientific instruments.”

While observations can only be made on the night portion of an orbit, lasting about 30 minutes, the crew remains busy for most of the time. Even as the payload specialist is completing an observation, the other crewmembers are preparing for the next maneuver and previewing software to guide the IPS to the next target. “Typically, we have a few minutes between observations to collect our thoughts, look at the next target,” Durrance says.

The Astro mission also will be a pathfinder for Space Station Freedom. “I’m really looking forward to this mission for what it will teach us about how to do science operations continuously and for relatively long duration,” says Mission Specialist Mike Lounge, who, when not flying and training, works on Space Station projects.

Offline Ares67

  • Senior Member
  • *****
  • Posts: 12125
  • Oliver
  • Remscheid, Germany
  • Liked: 37
  • Likes Given: 21
Re: Columbia STS-35 – Triumph over Adversity
« Reply #38 on: 04/16/2017 05:39 PM »
SHIP-TO-SHIP

The hectic observing schedule – as well as the need to minimize activity in the middeck while a shift is sleeping – leaves little room for secondary activities during the flight. However, two unique activities not related to the observing work will take place.

Payload Specialist Ron Parise, a licensed amateur radio operator (WA4SIR) will operate the Shuttle Amateur Radio Experiment SAREX-II, attempting to communicate to schools and ham operators on the ground. “The public needs to feel they are a part of the space effort, says Lou McFadin, principal investigator. “This brings the space effort into the living room. They can be part of it.”

SAREX can operate in either the voice or, most important for computer-oriented hams, packet radio robot mode. Packet communications involves typing messages via computer keyboard which are then transmitted in a short burst. SAREX will operate in the amateur radio 2-meter band at a frequency between 144 and 146 megahertz.

SAREX crew-tended operating times will be dictated by the time of launch. As a secondary payload, SAREX will be operated by Parise during his pre- and post-sleep activities each day. This means that wherever the shuttle is above Earth during those operating windows, amateur stations can communicate with Columbia. Currently, those windows provide coverage for Australia, Japan, South America and South Africa. The continental United States has little or no coverage except through a network of ground stations in other parts of the world in conjunction with relay links back to the United States.

Another part of the SAREX is the radio robot, providing an automated operation which can proceed with little human intervention. The robot will generally be activated during one of the crew-tended windows and deactivated during the next one. This gives approximately twelve hours on and twelve hours off for the robot, with the operational period chosen to cover all of the U.S. passes. The packet TNC is a Heath HK-21 with special robot software written by Howie Goldstein (N2WX).

SAREX has previously flown on missions STS-9 and 51-F in different configurations, including the following hardware: a low-power hand-held FM transceiver, a spare battery set, an interface (I/F) module, a headset assembly, an equipment assembly cabinet, a television camera and monitor, a payload general support computer (PGSC) and an antenna with a fast scan television (FSTV) module added to the assembly.

The original antenna on STS-9 and 51-F could only be used in the overhead windows, which interfered with Earth observations. The new antenna, made by the Motorola Amateur Radio Club of Shaumburg, Illinois, mounts in a flight deck side window where it’s out of the way and doesn’t require any particular orientation. Antenna location does not affect communications and therefore does not require a specific orbiter attitude for operations. The equipment is stowed in one middeck locker.

SAREX is a joint effort of NASA and the American Radio Relay League (ARRL)/Amateur Radio Satellite Corporation (AMSAT). “We are real excited,” says John Nickel, treasurer of the JSC Amateur Radio Club and the technical representative of ARRL. According to Lou McFadin during STS 51-F astronaut Anthony England conducted more than 1,300 different conversations. “It’s a way the general public can participate in an active spaceflight,” he says. “Most people do not get as close to the space program as we do here. It’s very exciting to talk to a person in space.”

“Another thing that the experiment is going to attempt to do is a ship-to-ship contact with the Soviet Mir Space Station,” Parise says. “It turns out that the two crewmembers who are on Mir currently (Anatoly Solovyov and Alexander Baladin) are both amateur radio operators.” Parise cannot predict when such contact can be made, if at all. The two spacecraft must be within about 2,500 miles of each other, and that will depend on the shuttle launch date and any intervening Mir maneuvers. The Soviets readily agreed to the idea, but technicalities could interfere with the plan.

Any Columbia-to-Mir contact would be much easier from the Soviet side than from the U.S. because Mir’s ham shack includes a 25 watt transceiver and an outside antenna, while Columbia has an inside antenna and 5 watt transceiver. Contact between the two vehicles is complicated by two factors. The most obvious problem, the Doppler shift, actually turns out to be fairly insignificant.

More complicated is the motion of the two spacecraft. Since the spacecraft are in different orbits at different altitudes, and travelling in different directions, the range between the spacecraft and the line-of-sight angle changes quickly. One minute you’re several thousand kilometers from each other, the next you’re right next to each other, and then you’re several thousand miles away again.

Unlike the earlier ham radio shuttle flights, Astro-1 will be launched into an orbit with an inclination of 28.5 degrees, the typical orbit for most shuttle flights. The STS-9/Spacelab 1 mission with Owen Garriott (W5LFL) and 51-F/Spacelab 2 with Tony England (W0ORE) flew into higher inclination orbits for better Earth observation capabilities. The irony is that the Soviet space station Mir is in a 51.6 degree orbit, halfway between the STS-9 and 51-F orbits. If STS-35 would be launched into a higher inclined orbit, longer opportunities for Mir contacts could be possible.

When the contact comes about, it will mark the first direct communication between Soviet and U.S. spacecraft. The communications between the spacecraft of the Apollo-Soyuz Test Project were relayed via ground links. The radio linkup would come as the 15th anniversary of ASTP approaches in July. And appropriately, the Command Module Pilot for the Apollo and now STS-35 Commander, Vance Brand, will be brushing up on his Russian to mark the anniversary of that fete with another first from space. "I'll have to drag out some books," says Brand. "I'm pretty rusty.'

The chat could serve to spur new support for cooperative space ventures between the United States and the Soviet Union, possibly even exploration of the moon and Mars proposed by President Bush. During the past two years, U.S. and Soviet experts have met quietly, looking for potential avenues of cooperation. Though the Apollo-Soyuz mission he participated in was a success, Brand cautions against naive optimism about the fruits of a future cooperative venture.

"The project itself would not drive good international relations," warns Brand. "If we are going to talk about a Mars mission, I think it would require a 10- to 15-year preparation period. You would want to have a good feeling about where you thought international relations were going.” He favors the United States tackling the Mars exploration on its own. A more sensible cooperative venture with the Soviets would involve a mission in which a NASA Space Shuttle docked with the Mir to demonstrate a rescue capability, Brand said.

Offline Ares67

  • Senior Member
  • *****
  • Posts: 12125
  • Oliver
  • Remscheid, Germany
  • Liked: 37
  • Likes Given: 21
Re: Columbia STS-35 – Triumph over Adversity
« Reply #39 on: 04/16/2017 05:40 PM »

Tags: