UPDATE # 20 - August 5, 1997

PART 1: Upcoming back to school edition
PART 2: Chat with Shuttle folk
PART 3: NASA's Navy sails for the boosters
PART 4: Surprising and exciting burning balls
PART 5: Status of Columbia's processing
PART 6: Subscribing/unsubscribing: how to do it

UPCOMING BACK TO SCHOOL EDITION

Teachers across America (and elsewhere in the world) are preparing
to begin a new school year in a few weeks. In recognition, Shuttle
Team Online will be providing a special back-to-school edition in
about two weeks. This gem will provide an overview of the Shuttle
Team Online project with suggestions on how teachers can best
participate.

Look forward to this special edition, coming to your email box soon!

CHAT WITH SHUTTLE FOLKS

This week, Mike Ciannilli visits the Shuttle Team Online chat room.
Mike Ciannilli is a fuel cells engineer at NASA Kennedy Space Center.
Mike is a member of the team responsible for servicing the orbiter
when it returns from a mission, testing various systems to make
sure they are ready to fly again. Mike also conducts the launch
readiness testing of orbiter fuel cell flight systems, ground support
systems, and launch pad systems.

Mike's chat is Wednesday, August 6, 1000 a.m.-1100 a.m.

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

For all of the details, visit
http://quest.arc.nasa.gov/space/events/interact.html

NASA'S NAVY SAILS FOR THE BOOSTERS

Wayne Ranow
http://quest.arc.nasa.gov/space/team/ranow.html

July 22, l997
The SRB Retrieval ships departed their dock located at
Cape Canaveral Air Station, Florida, on 30 June and
set sail for a pre-determined position 150 nautical
miles out in the Atlantic Ocean. The pre-departure
weather briefing held with NASA managers and Post
Flight managers was completed and all the weather
forecasts were bleak. The shuttle launch was given a
90% chance of violating the weather parameters. This
did not deter the retrieval team and we headed out to
sea with all the confidence we needed to make sure of
an on-time and successful launch. We needed an
on-time launch because a delay would spoil most of
our 4th of July plans.

The 150-mile trip out to our mission support position
was uneventful but pleasant with calm seas and
slightly overcast skies. We awoke on launch day to a
heavy cloud cover and thunder showers in the
splash-down area. Communication with the launch
site managers indicated slightly better conditions at the
launch site, and the countdown was progressing. This
was good news to the retrieval team and we set out
preparing the ships for the early afternoon launch.

Finally after a short delay, the shuttle lifted off and
was heading our way. Unfortunately the clouds were
too thick for us to see the booster separation and they
were not spotted until just before the main parachutes
were deployed. Those parachutes were a welcomed
site as the 184,000 pound boosters floated toward the
deep blue ocean surface at the rate of 50 miles per
hour upon impact. The entire crew let out a cheer
accompanied by the loud double sonic booms. It's
time for us to go to work!

The SRBs were painting a clear target on the ship's
radar indicating 7.5 and 8.7 miles from the ships.
After a short 45-minute sail (ships speed is 15 knots)
we arrive to find all the hardware in good shape with
one main parachute tangled on each booster. Divers
are released to free the parachutes which must be cut
free of the booster. This is accomplished easily with
the divers swimming down to 105 feet below the
surface and using a T-handle cutting device very much
like a firefighter uses to release a person trapped in a
car. With the tangled parachute free, we begin the
process of reeling each of the three main parachutes
onto reels aboard the ship. The next item to recover is
the pilot parachute, and we then moved on to the
drogue parachute and frustrum.

With all the parachutes on board, the captain
maneuvers the ship close to the booster floating
vertical in the water. The small boats are loaded with
dive gear and divers are sent into the water to swim
the DOP (diver operated plug) down 110 feet and
insert it into the booster nozzle. Once this is complete,
an air hose is connected and the divers proceed to the
surface. Upon verification that all divers are back in
the small boats, we proceed to blow air into the
booster thereby forcing the water out through the DOP
de-watering hose. This takes about 30 minutes of
pumping air and the booster rises and falls to a
horizontal position we call the log mode.

The air hose is then disconnected and reeled back
aboard the ship, and the divers proceed to connect the
tow which consist of a 200-foot nylon shock line
connected to 2000 feet of plastic coated steel cable.
The connection is made to a 40-foot tow pendant
which is already connected to the booster forward
skirt dome. The captain then maneuvers the ship away
from the booster while the tow winch operator spools
out the tow wire to approximately 1500 feet behind the
ship. The 24-hour trip back to Hangar AF begins and
the retrieval team gets a well deserved break after
working non-stop for 6 hours. The evening meal is
served and afterwards some watch videos, some read,
some try to catch up on their sleep, and of course
some of us write the necessary reports, but no matter
what each person does, everyone is proud to have
been a part of another shuttle launch.

Upon arrival at Port Canaveral on 2 July, we are
greeted by the usual crowd of family, friends, and
Space Shuttle buffs snapping photos of the spent solid
rocket boosters being towed on the ships hip through
the locks and up the Banana river to Hangar AF where
the SRBs will be removed from the water, placed on
rail dollies, washed, safed, inspected, and moved into
the hangar for disassembly and shipment back to the
respective vendor for refurbishment. The disassembly
process takes three weeks and eighty people working
two shifts to complete. Information and data gathered
during the disassembly is shared with the entire
NASA and contractor community to insure the next set
of solid rocket boosters are equally as safe and reliable
as the previous set.

SURPRISING AND EXCITING BURNING BALLS

Paul Ronney
http://quest.arc.nasa.gov/space/team/ronney.html

July 23, l997
We were able to complete two tests during STS-83,
and the results were very exciting. We learned a
couple of things: First, the flame balls lasted a lot
longer than I had expected them to. Before STS-83, I
had made some estimates as to how long I thought the
flame balls could live before they drifted into the walls
of the chamber. Gravity is not at zero in space; even at
one or two millionths of Earth gravity, I predicted that
they would drift into the wall after less than 500
seconds due to buoyancy effects. But in hindsight, I
realized I was using a formula that I had developed
based on our experiments in drop towers in an
aircraft. It doesn't really apply to a spacecraft where
the gravity levels are so much lower. It's because I
was looking at the rate at which a flame ball would
drift when the speed was relatively high and the
viscosity effects were relatively small. However, in
space they're drifting much more slowly. It's like a
BB in molasses. So they're drifting at a much lower
rate when the gravity levels are so much lower. We
knew what to expect on STS-94 based on STS-83, so
we changed our data taking strategies a little in order
to spread out the data collection over a 500-second
period, instead of emphasizing the early part.

Since they were still burning after 500 seconds, the
first thing I wanted to change for STS-94 was the
experiment duration to make it run longer.
Unfortunately that was one thing that was
"hard-coded" into the programming that controls the
experiment. That's not something we can change
between flights, because while it's not a difficult thing
to do just to change a number, we would have to retest
and reverify everything, and there was no time to do that.

Another thing we would have liked to do for STS-94
was refill the empty bottles after STS-83 with new
mixtures, however we couldn't because there was not
enough time to mix new gases. We just had to refill
the bottles with the same gas. There were only about
two weeks in which we had access to Spacelab, from
the time shuttle returned to the time the experiment
teams were allowed access to their experiments. There
was limited time available to the scientists because the
orbiter was being prepared for reflight in record time;
it was about 82 days between flights. All of the
normal activities between flights had to be squeezed
into a shorter period of time.

The second surprise from the STS-83 experiments
was that we could see that the flame balls slowly
drifted apart from one another. Even 5 minutes after
the burn had started they were still slowly drifting
apart. The drifted at a rate given by a simple formula:
drift speed = (1/(distance between 2 flame balls)^2). It
turns out that, given some assumptions, this can be
predicted theoretically. Still, the assumptions I made
are rather crude, so I'm not too confident about the
results yet, even though it seems to show the right trend.

Some of the Things We Found Surprising on STS-94

After the first couple of tests, I noticed there were
some strange glitches in the data. They didn't seem to
be from an instrument malfunction because they were
very regular, and so I thought, "Maybe it's some sort
of acceleration event." Sure enough, when we looked
at the orbiter's thruster firings, they correlated exactly
with those glitches. So we realized that the flame balls
were much more sensitive to small g-disturbances
(gravity disturbances) than I had expected. So after
that, we asked for "free drift" when we were doing the
tests, meaning no thruster firings. The thruster firings
are used to keep the shuttle facing the same way with
respect to Earth. If the thrusters aren't fired over a
period of minutes, the orbiter drifts out of its attitude
(position); the thrusters are fired to bring the orbiter
back into attitude again. The orbiter can be allowed to
go without thruster firings up to about 20 minutes,
before it gets too far out of attitude, and must be
brought back into attitude. However, by going into a
free-drift condition, we were able to get much better
results, and the data we received were really clean. We
hadn't asked for free drift for the mission, because we
didn't think it would be important, and we weren't
sure if Johnson Space Center (JSC) and Marshall
Space Flight Center (MSFC) could coordinate
everything, but it worked out really well. When you
think about it, a little flame ball surrounded by a large
volume of hot gas is a very sensitive accelerometer.

The other weird thing we found on STS-94, which
totally baffles me, is that all the flame balls seem to
have almost exactly the same power, emitting the same
amount of heat per unit of time (Power =
(Energy/Time)), between 1 and 2 Watts per flame ball.
(I did an experiment during the mission to see what
the emission of a birthday candle is and, by
comparison, the power is about 50 Watts.) We used
widely different mixtures, and I would have expected
them to have a widely varying heat emission per unit
of time. But that's not what we have seen. So the
flames that we burned are fifty times weaker than a
birthday candle, and in fact are the weakest flames
ever burned. The different mixtures also produced
different numbers of flame balls, and burned at
different pressures, and different viscosities. I had
designed the test to span a wide range of conditions,
and to see them all behave nearly the same was a shock.

What's Next?

We've taken a quick look at most the data. Now we
must generate precise numbers, putting into account
all the small corrections that we can. We're also
thinking about what we're going to do if we have a
SOFBALL-2 experiment, which we think is pretty
likely. It might be on another shuttle mission in three
years, STS-107, a follow-on MSL-2 mission, or it
may have to wait until the Space Station era. It will
probably be about 6 years from now before Space
Station is completed to the point where it has the
facilities for us to do the experiment.

We've thought of many things we want to do
differently, particularly from an operational
standpoint. Instead of having a 500-second limit as a
hard limit, we were thinking of having it as an
adjustable parameter. We also spent a lot of time
waiting for data to be downlinked after it was taken,
whereas we would have liked to go on to the next test
and downlinked the data later at our convenience, even
if the crew had gone to lunch or to sleep. Things like
downlinking the data don't require the crew's
attendance, but the way the experiment was set up was
not that flexible. We couldn't say, "Just press on the
next test and we'll get the data later on." So, I think
we'll have the capability for more ground commanding of
things and more flexibility for the sequence of events
if and when we get a follow-on mission.

Now that the mission is completed, I and other
members of the crew may make public appearances,
such as an appearance at Marshall Space Flight
Center, to talk about what happened during the
mission. But within a few weeks, I'll "turn into a
pumpkin" as far as the astronaut program is
concerned. If there is a follow-on mission and if
payload specialists are needed, I'll put my name in the
hat. I want to keep my chances alive, but this
assignment is over and if I get another assignment, it
will be a completely separate situation.

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's payload bay doors
were opened to remove the MSL-1 Spacelab module.  The process was
delayed because of problems with an overhead crane. A controller
was replaced on the overhead crane and then the Spacelab was
removed from the cargo bay and returned to the Operations and
Checkout Building.

The residual hypergolic fuels were drained and routine functional
testing of the forward reaction control finished. Leak checks and
deservicing of an oxidizer cross-feed line began, but were then put
on hold while workers prepare for Shuttle main engine removal,
slated to begin Aug. 6.

Preparations to deservice freon coolant loop No. 2 are complete
and the pump package is now slated for replacement.

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