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PART 1: Chat with Shuttle folks CHAT WITH SHUTTLE FOLKS
Events in the Shuttle Team Online chat room this week include: Wednesday, July 23, 1000 a.m.-1100 a.m. Pacific: Dian Hardison is a materials expert and determines which types of metals and plastics may be used for different shuttle jobs. Thursday, July 24, 1000 a.m.-1100 a.m. Pacific: John Horack is the Science Communications Coordinator for the STS-94 Mission Scientist Team. These chats will let you interact with the enthusiastic folks who make the shuttle program go. To participate, all you need is a modern Web browser. If you want to ask questions (instead of just observing), you will need to RSVP ahead of time by sending a note to ocox@mail.arc.nasa.gov Other chats are scheduled in the future. For all of the details, visit http://quest.arc.nasa.gov/space/events/interact.html [Editor's note: Melissa is a Shuttle flight controller. She has worked on some recent shuttle missions and is responsible for the Data Processing System - that means all the computer hardware and software on the orbiter, as well as the data buses and multiplexer/demultiplexers, mass memory units and timing units.] FLIGHTS ARE LIKE SIMS, BUT WITH LESS FAILURES
Melissa Bodeau http://quest.arc.nasa.gov/space/team/bodeau.html July 15, 1997 You may have wondered how flight controllers learn what to do during a Shuttle missions. The answer is pretty simple: they take classes, study, and practice! Simulations, or sims, are probably the best way we learn to watch the data on our systems, recognize and deal with failures, work as a team, and address any special needs of a particular Shuttle mission, or "flight." Sims follow a script (that only the people who train us know) and failures are introduced into the system to allow the flight controllers, the flight director, and the astronauts to learn those valuable skills. The only important way a sim is different from a flight is that the astronauts sit in a simulator that generates the data we see instead of sitting in the Shuttle's Orbiter. There are two basic kinds of sims, generic, and flight-specific. Flight-specific sims are specifically for a particular "team" for a particular flight. That means a sim could be for the Ascent/Entry team for STS-85 - only those people who are assigned to that shift on that flight are required to support that sim, although other flight controllers may attend the sim as "OJTs" (on the job trainees). Flight-specific sims are scheduled for a period of several months preceding the launch date of that flight. Generic sims are not related to any flight, although they may use software from a particular flight, and they may be training on tasks that were performed on a specific flight, like a satellite deploy. Generic sims are scheduled for several reasons: to train new flight controllers (and flight directors) and certify them in a particular position, to help flight controllers maintain proficiency at their position, especially if they haven't worked a flight in awhile and are now assigned to a team for an upcoming flight, and to train the new astronauts who are not yet assigned to a flight in how to work with Mission Control while performing their tasks. I am certified for Orbit DPS SPT. What that means is that I have trained to the level to be a "back room" or MPSR (pronounced "mips-er") flight controller responsible for the Data Processing System onboard the Shuttle for orbit phases of flight only, and that I performed to expectations on my "cert sim," which is a particular sim scripted to exercise your technical and communications skills and system knowledge, and that allows trainers and managers to evaluate your readiness to support a Shuttle mission. I worked the STS-76, STS-77, and STS-78 Shuttle missions in 1996. A MPSR is different from a FCR (pronounced "fick-er") or "front room," who are the people you see on TV. MPSRs aren't on TV unless we get called out to the front room by our FCR. (Just a note: FCR is not only what we call our front room flight controllers, but the room they sit in - the same goes for MPSR. NASA is filled with acronyms, and we sometimes use them in ways that can be confusing to those outside NASA.) The reason you have a FCR and a MPSR (at least) on each team/shift is that we serve different purposes. The FCR is the head of the team, and maintains the ultimate responsibility for decisions and assessments, and they have to coordinate among all the other flight control disciplines and the flight director. FCRs have already been MPSRs, and have several years of experience in flight control. The MPSR deals with other MPSRs, and is responsible for more detailed technical assessment of system failures, keeping an eye on timelines and upcoming activities, and providing an extra pair of eyes on the system. The FCR and MPSR are always a team, and work will be divided up based on the workload, what might be going on, and the expertise of the flight controllers on the team. A couple of months ago, I was assigned to support a Generic Orbit sim from 1400-2400 (2 p.m. to midnight). Since I hadn't been "on console" for several months, I reviewed some study materials, like the pre-written procedures we tell the crew to follow for specific failures, and the flight rules that govern our actions based on criteria like how close we are to a payload, the current computer configuration, and other concerns that have all been addressed by technical experts and management. Having procedures and flight rules that are standardized means that our response as flight controllers is consistent, which is important, and it helps in making sure that we don't miss something important, which would be easy to do when things get hectic. I also reviewed some of the console logs that I've kept from previous simulations I've supported. [Editor's note: STS-94 completed a very successful science mission with its landing on July 17. The following report by Joy Carter provides details about what was accomplished in space. This report can be found along with lots more great information about the MSL-1 mission on the Liftoff pages at http://liftoff.msfc.nasa.gov/Shuttle/msl A particularly fine feature of these pages are the daily science stories which really help to explain the purpose of the various experiments. See these stories at http://www.ssl.msfc.nasa.gov/msl1/daily/updates.htm RESULTS OF STS-94
As researchers aboard the first Microgravity Science Laboratory
mission prepared for Columbia's return to Earth July 17, their
counterparts at Spacelab Mission Operations Control Center in
Huntsville, Alabama, began tallying the mission's research
accomplishments -- which often surpassed expectations. "We've
done better than anybody expected," said Mission Scientist Dr.
Michael Robinson, looking back at the wealth of science information
collected during the course of this 16-day mission, set to end
Thursday at 5:47 a.m. CDT when the Space Shuttle lands at
Kennedy Space Center in Florida.
"A highlight of the mission is that everything worked so well," said
Robinson, of the Marshall Space Flight Center in Huntsville, where
the microgravity science mission is managed. "All orbiter, Spacelab
and payload systems have performed superbly. We are very pleased
to have been able to take full advantage of this reflight opportunity,"
added Mission Manager Teresa Vanhooser, also of Marshall:
This record-setting mission provided fundamental
new knowledge in the principal scientific fields of
combustion, biotechnology and materials
processing.
More than 200 fires, or combustion experiment runs were conducted
on MSL-1. Only 144 had been scheduled for the mission.
A study of the phenomena of soot resulted in discovery of a new
mechanism of flame extinction caused by radiation of soot. Scientists
found that the flames emit soot sooner than expected. These findings
have direct impact on spacecraft fire safety, as well as the theories
predicting the formation of soot -- which is a major factor as a
pollutant and in the spread of unwanted fires.
Seventeen tests were completed in the soot study -- three more than
originally scheduled -- on this mission and the shortened April
Shuttle flight. "Every one worked and yielded good data," said lead
scientist Dr. Gerard Faeth of the University of Michigan at Ann
Arbor. "That's beyond my wildest dreams."
Another combustion study -- this one on spherical flame structures,
or flameballs -- resulted in the MSL-1 crew igniting the weakest
flames ever burned either in space or on Earth. Flameball powers are
as low as one watt -- or 1/50th the power of a birthday candle. The
study also resulted in the longest burning flames ever ignited in
space, burning for the entire 500-second duration of the experiment
run. These tests provide new information for models of weak
combustion processes needed to develop cleaner, more fuel-efficient
internal combustion engines.
From the experiment, said lead investigator Dr. Paul Ronney of the
University of Southern California in Los Angeles, "We can learn the
burning limits of fuel mixtures. It gives us an idea of just how lean a
fuel can be -- and still burn. It may lead to better gas mileage and less
auto emissions." Other benefits include improved fire safety for
future spacecraft.
Experiments processed in MSL-1's unique, levitating furnace facility
known as TEMPUS yielded the first measurements of specific heat
and thermal expansion of glass-forming metallic alloys. These
measurements -- never taken before on Earth -- are fundamental
measurements necessary for modeling industrial materials systems
needed to manufacture new and better products.
The study has resulted in more than 120 melting cycles with
zirconium, with a maximum temperature of 2,000 degrees Centigrade
and was able to undercool to 340 degrees -- the highest temperature
and largest undercooling ever achieved in space. The TEMPUS
investigators also have provided the first measurements of viscosity
of palladium-silicon alloys in the undercooled liquid alloy which are
not possible on Earth. One TEMPUS lead investigator, Robert J.
Bayuzick of Vanderbilt University in Nashville, said, "I'll go out on
a limb and say this is the most successful mission in microgravity
research that's ever been flown. It went perfectly." His study
focused on the changes that certain metals undergo as they are cooled
from a liquid to a solid state in a containerless environment. "What
we showed," he said, "in this particular regime is that relative to one
another, there's no difference in the effect on nucleation between the
moderate flow and the turbulent flow conditions. That's a unique
result. This kind of experiment has never been performed before,
ever, in history."
Studies conducted in the multipurpose Middeck Glovebox have
demonstrated its value in supporting a variety of experiments in
microgravity -- including those on this mission in the areas of liquid
and bubble behavior, fluids-based heat transfer devices, and
solid-liquid mixtures. In a testimony to the glovebox's usefulness,
the crew has performed well over 100 test runs in the facility -- more
than double the number planned.
Real progress has been made during this mission in learning how to
control and position liquid drops, according to Mission Scientist
Robinson. Experiments on this mission have demonstrated that
quiescent positioning and control of the rotation of a liquid drop can
be achieved using acoustic levitation in the microgravity of space.
The investigation of internal flows in a free drop has provided
information on the dependence of acoustic torque on acoustic
pressure and the internal flows in a liquid drop. This study is
allowing researchers to assess a potential method of mixing which
could lead to improvements in chemical manufacturing, petroleum
technology, and the cosmetics and food industries.
In another glovebox study on MSL-1, researchers have obtained the
first data for the nonlinear free decay frequency for a totally free
drop, and the first accurate data for drop deformation as a function of
acoustic pressure. This has led to discovery of an effective method
for bubble positioning and manipulation in microgravity. These
findings could lead to techniques that eliminate or counteract the
complications that bubbles cause during materials processing.
Large droplets of fuel were ignited and information collected on the
burn rates, flame shape and radiation emitted in another glovebox
experiment. This study resulted in the first microgravity experiment
in which droplet arrays were burned.
In a novel and unplanned twist to this experiment, scientists --
pleased with the single-droplet tests -- decided to expand the study to
run tests using two droplets. The pairs of drops were positioned on a
fiber and ignited simultaneously. This provided a bonus to
researchers as they observed the interaction of the droplets. The
experiment's lead investigator, Dr. Forman Williams of the
University of California at San Diego, called the view of the two
droplets "the most beautiful set of twins I've ever seen." Only 52 test
runs were planned on MSL-1. Yet 125 runs were completed -- a 240
percent science return. Information from the study is expected to
improve theoretical models of combustion.
In the Coarsening in Solid-Liquid Mixtures Experiment -- also in the
glovebox -- researchers studied a process that can cause metals to
weaken or fail in alloy products, such as turbine blades in aircraft
engines. By examining this process in space, the design and control
of metals processing on Earth may be improved.
In another experiment, researchers were able to take a very pure look
at the combustion process without the effects of gravity. The Droplet
Combustion Experiment has provided scientists with fundamental
knowledge of the burning process -- and may provide a method for
verifying which complex, chemical model accurately describes the
process. It may also lead to cleaner and safer ways to burn fuels.
In this experiment, researchers pushed the envelope of knowledge of
combustion by setting a fire at the lowest atmospheric pressure yet
during a mission. The study's lead investigator, Dr. Forman
Williams of the University of California at San Diego, said, "On the
ground, there have been a lot of studies on heptane. But all have been
less than 2 millimeters in diameter. This is the first complete burn of
a 3-millimeter diameter heptane droplet," Williams said, "because
in the atmosphere of normal air, we were able to observe a fuel
droplet that burns for a longer period of time." Additionally, as a fuel
droplet burned in a spherical shape, the heat dissipated outward, and
actually extinguished the flame before all the fuel vapor was
completely burned away. This gave researchers that very pure look at
the combustion process.
During MSL-1, samples were processed in the Large Isothermal
Furnace to study the diffusion of tracers, or impurities, in melted
germanium -- an element widely used as a semiconductor and
alloying agent. This mission marks the first time diffusion in
semiconductors has been studied in space. Findings may have
applications for improving the performance of electronic components
made from semiconductor materials, such transistors and integrated
circuits.
The Physics of Hard Sphere Experiment, which examined changes
that occur during transition of a substance from liquid to solid and
solid to liquid, could improve the design of metallic alloys and
processing techniques. Initial findings from this mission show model
crystals in this experiment grew faster in space than on Earth. Also,
the time scale for particle movement or diffusion is considerably
different than in low-gravity.
Researchers have gained yet a better understanding through MSL-1
of what makes certain types of heat transfer devices fail in space. In a
study involving the Capillary-driven Heat Transfer Device, scientists
have examined the device's ability to transfer heat away from a
particular location. In the future, these devices may be used to
transfer heat from electrical equipment to radiators on spacecraft.
The benefits of these systems are that they weigh less than
conventional units because they operate on evaporation and
condensation, and are more economical because they do not require
power. The experiment's lead investigator, Dr. Kevin Hallinan of the
University of Dayton, Ohio, said, "With the science learned on this
mission, we've been able to characterize boundaries of what we call
unstable operations which accelerate this transition to this failed -- or
disrupted state. We are closer to our goal of understanding why the
Capillary-driven Heat Transfer devices have failed in space -- yet
succeed in 1-G (on the ground). We are confident new designs can
be rendered that will work."
A plant growth experiment on MSL-1 is examining the effect of
space on certain types of plants. Scientists hope the study reveals
how to manipulate processes to improve plant growth on Earth.
Findings may also verify evidence that plants grown in microgravity
require less metabolic energy to produce lignin, permitting greater
production of secondary metabolites -- a source of many medicinal
drugs. Secondary metabolites also may be used to attract, repel or
poison insects. Plants being studied aboard MSL-1 include a source
of the antimalarial drug artemisinin; a plant used in chemotherapy
treatment of cancer; and a species widely used in the paper and
lumber industries.
More than 700 crystals of various proteins were grown on MSL-1
during its 16-day mission. Knowledge of protein structures is very
important to our everyday lives, as many diseases involve proteins,
either directly or indirectly. The microgravity environment of space
allows researchers to grow larger and higher quality crystal
specimens. Back on Earth, scientists will perform X-ray diffraction
studies on the specimens to determine their structures. Better
understanding of a protein's structure could allow scientists to design
more effective drugs to treat diseases such as cancer, diabetes,
alcoholism, chagus, AIDS and Alzheimer's.
In addition to contributing new scientific knowledge, the first
Microgravity Science Laboratory has served as a bridge to America's
future in space, spanning the gap between today's Spacelab and
tomorrow's International Space Station. It has used Spacelab as a
transition vehicle -- testing hardware, facilities and procedures that
will be used on Space Station.
Flying for the first time on MSL-1, the EXPRESS Rack, designed
and developed at Marshall, demonstrated quick and easy installation
of experiment and facility hardware in orbit. The rack will be used on
Space Station.
Two payloads -- the Physics of Hard Spheres Experiment and the
Astro/Plant Generic Bioprocessing Apparatus Experiment -- were
flown on MSL-1 to check the design, development and adaptation of
EXPRESS hardware. During this mission, the two experiments were
transferred from the Shuttle middeck to the EXPRESS Rack,
operated, and then returned to the middeck. "The procedure went
beautifully with no problems," said Cindy Sanderson, EXPRESS
Operations Controller at Marshall. "We're very satisfied with our
demonstration of the EXPRESS rack," said Mission Manager
Vanhooser: "The goals we set were accomplished."
In all, 25 primary experiments, four glovebox investigations and four
accelerometer studies flew on this mission of Columbia. The
experiments were contributed by scientists from four international
space agencies -- NASA, the European Space Agency, the German
Space Agency and the National Space Development Agency of
Japan.
A gauge to the amount of science research conducted aboard this
mission is the record number of commands sent from Spacelab
Mission Operations Control Center at Marshall to experiments aboard
Columbia. The more than 35,000 commands sent broke the previous
record of 25,837 set in 1994.
"Now," said Mission Scientist Robinson, "as Columbia prepares to
return to Earth -- its mission accomplished -- it is time for researchers
to get down to the task of analyzing the data. That's going to keep
everybody very busy for quite awhile."
STATUS OF COLUMBIA PROCESSING
Below and in the future, we'll provide some details about the post flight work being done after STS-94 and the subsequent processing of Columbia as it gets ready to fly again as STS-87. These reports will contain jargon and unfamiliar terms; our intent is not to confuse you, but to provide a glimpse at all the steps involved. Detailed daily reports about Columbia's processing can be found at the NASA Shuttle Status web site at http://www-pao.ksc.nasa.gov/kscpao/status/status.htm Since the last updates-sto message, Columbia landed safely at the Kennedy Space Center on July 17 at 6:46 a.m. local time. The orbiter was rolled from the landing strip to OPF bay 2 where it was spotted at about 12:20 p.m. Postmission assessments are currently underway. Initial assessments of tile damage from the 16-day flight is reported to be less than average. The orbiter thermal protection system sustained a total of 90 hits of which 12 had a major dimension of 1-inch or larger. Time critical experiments were removed on Friday. The orbiter's residual cryogenic reactants were off-loaded over the weekend. Preparations for removing the MSL-1 Spacelab module will begin tomorrow after the payload bay doors are opened.
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