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Multidisciplinary
Design, Analysis, and
Optimization Branch
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EDUCATIONAL ACTIVITIES: THE NASA AEROQUIZ
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Week of 9/3/01:
Q:
"Here you are, sir. You'll be in seat 14A. Have a nice trip." The
airport ticketing agent smiles and hands you a boarding pass.
As you walk towards the waiting area near your gate, you notice from
your itinerary that your "flight equipment" is no longer the familiar old
turboprop aircraft that usually services your route. Instead, it is an
Embraer ERJ-135. "Huh, that's one of those relatively new regional
jets. They're not that big. So seat 14A must be way back near the tail."
You're curious, so you queue up the wireless modem in your laptop and
take a look at the 135's seating accommodations on Embraer's web page.
"Technology sure is great," you think. But your bemusement turns to
panic when you see that the ERJ-135 has only 13 rows of seats on the
port side and only 12 rows of seats on the starboard side! "I don't
have a seat!" you exclaim to the ticket agent. "I have to be in
Hoboken by noon!"
"Don't worry, sir," laughs the agent.
"We have a seat for you."
How can that be?
A:
I guess it is like in these buildings where, to accomodate for
superstitious persons, the 13th floor has been simply omitted in
the numerotation. The floors go directly from 12 to 14.
Congratulations to Nicholas Cousineau.
To soothe all the triskaidkaphobics out there, airplane seating nomenclature
is a lot like hotel and skyscraper floor labeling! The fear of the number
13 can be traced to Norse mythology. Odin threw a dinner party one night
in Valhalla and invited 11 divine friends. Unfortunately, the evil
trickster Loki crashed the party and brought the count to the devil's
dozen. When the good-guy god Balder tried to throw Loki out on his ear,
Loki killed him with a spear made of mistletoe (a kind of "kryptonite"
for Norse gods).
- The Aeroquiz Editor
Week of 9/10/01:
Q:
The classic film "Willy Wonka & the Chocolate Factory" celebrated its
30th anniversary last week with a special edition VHS tape and DVD release.
In the movie, young Charlie Bucket and his Grandpa Joe experience
weightlessness as they float around inside Wonka's Bubble Tower.
Would you be surprised to learn that NASA's Glenn Research Center
has a facility roughly the same size and shape as Wonka's tower called
the "Zero Gravity Research Facility"? Can Glenn researchers down bottles
of Wonka's "fizzy lifting drinks" and float around inside?
A:
They would not float. They would fall.
Congratulations to Scott White.
NASA Glenn's Zero Gravity Research Facility is a shaft 155 meters deep.
Built in 1966, it provides scientists with a method to perform low gravity
experiments here on Earth. Experiments packaged inside a cylindrical
drop vehicle are dropped down the shaft and experience microgravity
conditions (on the order of 0.000001 gee) for as long as 5.18 seconds.
The air in the shaft is evacuated to eliminate aerodynamic drag.
Contrary to popular opinion, the facility is not staffed by Oompa Loompas!
- The Aeroquiz Editor
Week of 9/17/01:
Q:
Zaphod and Arthur spotted the orbiting casino resort station as
they approached the desert world of Kakrafoon. In a few minutes,
Zaphod had maneuvered their ship so that the two spacecraft were in
circular orbits that were identical in every respect, except the
casino was ten kiloquats ahead of Zaphod and Arthur. "I can't wait
to have a pan galactic gargle blaster," said Arthur. "Let's increase
our speed so we can catch up!"
"No, silly," replied Zaphod. "To catch
up, first we need to slow down."
How would that help?
Our apologies -- Combine a couple of power outages with a business trip and
the Aeroquiz is out of commission for a week.
- The Aeroquiz Editor
Week of 9/24/01:
Q:
Zaphod and Arthur spotted the orbiting casino resort station as
they approached the desert world of Kakrafoon. In a few minutes,
Zaphod had maneuvered their ship so that the two spacecraft were in
circular orbits that were identical in every respect, except the
casino was ten kiloquats ahead of Zaphod and Arthur. "I can't wait
to have a pan galactic gargle blaster," said Arthur. "Let's increase
our speed so we can catch up!"
"No, silly," replied Zaphod. "To catch
up, first we need to slow down."
How would that help?
A:
The spaceship is in a stable circular orbit, so increasing the
tangential velocity will increase the centripetal acceleration,
throwing the orbit out of balance and increasing the stable
orbital diameter. They must slow down to drop towards the planet,
then Eddie the onboard computer will tell them when to point
upwards and apply thrust in order to rendezvous with the casino
from below (if he has finished calculating the reason for the
existence of tea).
Congratulations to Andrew White.
As the laws of Kepler and Newton help to point out, increasing your
orbital speed in the direction of flight will only put you in a
higher, eccentric orbit with a longer orbital period. Counterintuitively,
you would immediately start to fall behind your rendezvous target. This
problem vexed the astronauts and ground engineers of the earliest Gemini
rendezvous mission until the details were worked out.
A more appropriate thing to do might be to slow down, drop into a lower
eccentric orbit, perform an orbital circularization maneuver, and wait
until you've passed underneath your target. Then you could perform
the opposite sequence to rendezvous.
- The Aeroquiz Editor
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