Aerospace Team ONLINE

UPDATE #11 - February 20, 1998

PART 1: Upcoming Chats
PART 2: Final preparation before the Space Shuttle simulation
PART 3: Half-way point in the test - two weeks to go!
PART 4: Subscribing & Unsubscribing: How to do it

UPCOMING CHATS

Chat with Christopher J. "Gus" Loria (Major, USMC) 
NASA Astronaut Candidate (Pilot) Time and Date to be
announced. Gus is here to fly the Vertical Motion Simulator
the world's largest simulator.  He will be flying the latest 
simulation of the shuttle orbitor.
Read his bio at http://www.jsc.nasa.gov/Bios/htmlbios/loria.html

Tuesday, March 3, 1:00 p.m.- 2:00 p.m. Pacific Time: Fanny Zuniga, 
Aerospace Engineer will chat in English and Spanish. 
Registration information at
http://quest.arc.nasa.gov/aero/chats/#chatting.
Fanny is currently testing a model of the High Speed Civil 
Transport in the 12' Pressure Tunnel at Ames. Read her biography 
http://quest.arc.nasa.gov/aero/team/zuniga.html
and journals prior to joining this chat.
http://quest.arc.nasa.gov/aero/events/test.html

Tuesday, March 10, 9:00 a.m.- 10:00 a.m. Pacific Time: Frank Quinto, 
Wind Tunnel Test Engineer 
Frank is the Test Engineer in the 14 by 22-foot Subsonic 
Tunnel at Langley Research Center. Registration information at
http://quest.arc.nasa.gov/aero/chats/#chatting
Read his biography and journals prior to joining this chat. 
http://quest.arc.nasa.gov/aero/team/quinto.html

Thursday, March 19, 11:00 a.m.- 12:00 p.m. Pacific Time: 
Jason Hill, Flight Simulator Technician 
Jason is responsible for maintaining two of NASA's flight 
simulators. Registration information is at
http://quest.arc.nasa.gov/aero/chats/#chatting
Read his biography prior to joining this chat.
http://quest.arc.nasa.gov/aero/team/hill.html

FINAL PREPARATION BEFORE THE SPACE SHUTTLE SIMULATION

by Chris Sweeney

February 6, 1998 

The Space Shuttle simulation begins its five-week simulation in the
Vertical Motion Simulator, VMS, beginning on 9 February. We are in final
preparation stages now for this. Two weeks ago, on 26 January, we
began our cab integration process. This involves communicating between our
math model of the Space Shuttle aircraft and all the hardware we use
during the simulation. We make sure the communication links between our
host computer and the cab (the simulated flight deck where the
astronauts will sit and fly) is working. The control inceptors (stick,
rudder pedals, brakes) are all checked as are all of the buttons,
switches, knobs, dials, and instruments in the cab. 

We are at the end of this process and everything looks good to 
begin on Monday. We are finalizing our check cases that ensure the
computer is outputting the correct data. This simulation we are
investigating the hydraulic Auxiliary Power Units (APUs) of the
orbiter. We will study if getting more powerful APUs will make it easier
for the astronauts to land the Space Shuttle, especially if one or more of
the three APUs fail.

HALF-WAY POINT IN THE TEST - TWO WEEKS TO GO!

by Fanny Zuniga

February 12, 1998 

Off to a slow start but we're finally rolling. We are behind and
everyone's thinking about how to make up for lost time. 

Monday: We have completed 70 runs to check accuracy, repeatability, sample
time for each data point, and agreement with previous test results. We are
done with the checkout phase of the test! We are finally ready to change
the model to the first takeoff configuration and start doing some
research. 

On another front, some parts of the minituft imaging system are broken,
including the strobe lights and the lens on the camera. We are still
trying to fix it, but we may just have to give up on the tuft images for
this test. 

Tuesday: We had our share of problems today. We got dumped on by "El
Nino"; roads were flooded and making it hard for people to get to work.
So, this morning the model was ready to run, but we did not have a full
crew to run the tunnel. Even the weather is slowing us down. Then, part of
the tunnel controls quit working. We didn't get to run the tunnel until
near lunch. This sort of stuff not only slows us down, but gets on our
nerves. This job can be interesting and frustrating at the same time. 

After lunch tunnel problems and software problems kept us from running
until early evening. Basically, we are in the part of our test where we
think we are getting good data but now are faced with various mechanical
and software problems that keep us from running the tunnel. We are hoping
to start the last phase of test soon. That's the phase where we should be
very productive and get most of our useful results. When everything is
working well, we can accomplish a lot in a little time. 

Wednesday: Halfway point of the test - at least on the calendar! We
started with 5 weeks (25 days), minus 2 days for holidays that occur
during our test. That left 23 days. Remember, we are running two full work
shifts each day, so we had a total of 46 work shifts for the entire test.
We started late 2 days, that's 42 shifts total. Those two days cost us 8
percent of our test!!! Including today we have 24 shifts left for the rest
of the test. Then the checkout phase we just finished took longer than
planned, so we're more behind. We did plan extra time into our schedule
for
problems (we call this "contingency" time). But we don't like being this
far behind this early, because that means we've used up most of our
contingency time before we really even got started. 

We are going to have to really crank it up! We decided that, starting
Thursday we would work two 10-hour shifts (instead of 8-hour shifts) to
make up for some of our lost time. This means day crew runs from 6:00 am
to 4:00 p.m. and night crew runs from then until 2:00 a.m. the next
day. Ouch! We also will run on Saturdays if enough of the crew volunteer.
Ouch, Ouch! The good news is that this will only last a few weeks, sort of
like cramming for a final exam. Another way to make up for lost time is to
extend the test past February 20 if we can get extra time in the
tunnel. This could happen if it's OK with the next test to use the tunnel.
Unfortunately, our model is scheduled for use in another tunnel (at
Langley Research Center in Virginia). So even if we could get more time in
the tunnel, we have to pull the model out after February 24, so we
could only get two extra days at the most. 

We are really starting to make progress in getting our research runs made,
so let me explain a little more of what were looking for. Some of the runs
we are making right now have involved changing the angle of the flaps at
the front (leading edge) and back (trailing edge) of the wing. I can't
show you pictures of this, but imagine the front and back of the wing
droop downward. We say that the flaps are "deflected." We basically check
dozens of combinations of leading edge and trailing edge flap deflection.
Deflecting the flaps makes the wing act like it has more curvature. The
result is that both Lift and Drag go up, but not always in the same
amounts. We are looking for combinations that work well for takeoff and
landing. For takeoff, since the airplane is trying to speed up and climb,
we want lots of lift without increasing drag too much. On the other hand,
for landing we want to fly as slow as possible; we need all the Lift we
can get. Because we are slowing down and descending we don't care very
much if there is a lot of Drag. So we can look for a combination of flap
deflections that gives us higher Lift than we would use for takeoff. Not
only are we looking at flap deflections, we have several different shapes
or types of flaps to try. This will give us plenty to do. 

We also want data with the horizontal tail on and off. We do this so we
can determine the effect the tail has on the model's aerodynamics. We can
then figure out how much the wing is contributing to the overall Lift. 

Thursday: At this point we are making better progress, but we lost several
hours yesterday and again today to software problems. We are getting
nervous about finishing everything, so we are starting to look for things
to cut out of the schedule. We might drop some of the repeat runs that I
described earlier because we have more confidence in our data and we need
to save time. In testing, we are always trading off speed (number of runs)
and risk (confidence in the data quality). 

Good news is that we have enough volunteers to run an 8-hour shift this
coming Saturday. That should really help. 

Friday: As of this morning we have about 295 runs remaining and 20 shifts
left, not including weekends. We have decided to toss out any runs that
were just for imaging the mini tufts since we've pretty much given up on
getting the system to work. Since we are behind schedule and the balance
has been behaving so well, we finally made the decision to cut most of the
repeat runs. 

Saturday: There was some excitement this morning. We thought we had lost a
bunch of our model parts. That would really mess up our test plans. It
turned out that all the parts are here. We had one part labeled
incorrectly, which messed up the system we use to identify all the parts. 

We just passed run # 200! We made 21 runs in 8 hours! Now we're cruising! 

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