Hello and welcome to Pass The Torque. I'm your host, Katy Cawdrey. This is your co-host, Gus.
Earlier this week, you met Dr. Edward Cheung and had a chance to ask him your
questions. Today he's back with some of your answers. I'll let him take it away!
I heard there is a device in space that you invented and called Aruba. Can you
tell us a little about this? Okay. Thank you, Israel, for the question. I
really have had a long history with NASA and one of the projects I've worked on
is the Hubble Space Telescope and as you know we used to visit the telescope for
servicing on several occasions and build new hardware and upgrade and repair the
telescope and one of those missions we realize late in the game that we had a
problem a vulnerability with the hardware, with the system, and so we were
tasked with solving this problem and the problem was quite quite important
because it could cause the draining of Hubble's batteries and as the electrical
lead on the project I was tasked with solving this problem. Now, early on I
realized there were a couple of neat aspects about this device. It was going
to be very important to to save Hubble frankly in case there's a problem and
also that the device would be sitting on the outside of Hubble and that the
astronauts would be the one to install it. So, I decided to name this device the
Aruba box and actually I have some pictures that I can show you. If we look
at the screen now, this is the Aruba box during its construction. You can see the
sign Aruba on there. The next image shows it in space, the large round object
on top is the Earth and then we are looking out of the shuttle cargo bay on
this white panel that that has the Aruba box mounted on it. In the next image you
see this panel mounted onto the Hubble Space Telescope so you can see the Aruba
box sitting there on the outside. In the background, you see the starboard wing of
the orbiter. And then in the top you see the curvature the Earth. So this is one of my favorite
pictures of that mission and here finally you see a view from the flight
deck of the shuttle you're looking up at the Hubble and you can see
the Aruba box sitting there. The reason I called it the Aruba box is, as
I said before, I knew this would be handled by the astronauts and actually
John Grunsfeld who installed the system actually spoke the name of our island
over the interstellar communications, if you would, and that was really great
opportunity for our island to be recognized and I really wanted the people of Aruba
to realize that they have a really direct link to space and that the young
people in the Aruba can consider themselves being able to work for NASA
one day they work on their educational goals and achieve their educational
aspirations. Can you tell us more about other projects you are involved with? In
addition to many years with Hubble, since then I've worked on several
International Space Station projects and this has been in our next role as
our project which is to study satellite servicing, to study robotic satellite
servicing, so instead of using a human crew using a robotic crew to
repair a satellite and we have been doing a series of these demonstrations,
called the robotic refueling mission, and doing this building this hardware and
testing them on the International Space Station. All these experiments have been
used to evaluate technologies to refuel and refurbish satellites and all this is
to feed our larger parent project called Restore-L, now renamed
OSAM-1, which is a satellite servicing mission. So in our case we
build hardware for the shuttle to bring to ISS and then in the future we will be
flying our own mission in order to restore and refurbish satellites. The
project is called OSAM. Do parts and space rust? Does Hubble Space Telescope
have to be replaced within a certain period of time to avoid service
interruption? That's an excellent question, it gets at the heart of all the
years of work we've been doing servicing Hubble, and in the future
serving future spacecraft, but getting back to your original question it seems
obvious to say that there is no rust in space because there's no air. But I think
there's more to that question. We all know about oxygen, which is O2. Diatomic
oxygen is two oxygen molecules stuck together and we breathe it every day. O2.
But there's also a second form of oxygen called ozone, or O3, and that's
three molecules of atomic molecules of oxygen combined together and they
tend to hang out in the upper atmosphere and protect us from the sun's UV rays.
And then yet there's a third form and it's called atomic oxygen, which is the
individual atoms of oxygen split, usually by the UV light of the Sun, and this is
very rich, although very very low pressure, in outer space. This atomic
oxygen really is a very good corroder and you talked about rust, which is
essentially oxidation or corrosion, and that's the same thing. It's the
interaction of the material with oxygen. Atomic oxygen is very volatile, it's
very corrosive, and so it will also cause a rust so to speak. I actually have
here some samples of some material that came off of Hubble. It flew
on the Hubble for 20 years and you can see
little silver flakes inside and that's because the atomic oxygen has degraded
the insulation and caused these silver flakes to come off. So it's very
corrosive. So this attacks the outside of the spacecraft of the satellite because
as soon as it comes in contact with satellite, it reacts and then is used up.
The outside has to be designed appropriate to handle this corrosion,
this rust if you would. On the inside, it's not that affected by atomic oxygen but
as I'll answer in other questions, there are other effects on it, and there is age.
After a while things do wear out, they they get degraded by radiation, and will
require repair and refurbishment, which is a very big part of how we have Hubble
in space for such a long time. Thank you for the question. Which of all the
projects you've worked on have you enjoyed the most? Yes, this is a very
interesting question. I think I'm going to really key in on a particular word
that you're asking in the question, which was "enjoy." And I must say that all this
developing of hardware, building it, operating in space, including the Aruba
box for example, is really rewarding and fun. But in the past, my favorite project
has been our flight in zero gravity, which is where I spent with a
team, a week-long mission floating in zero gravity, and on experiencing what it
would be like to be an astronaut, to float around, and to experience the
magic and the uniqueness of zero-g. So that, I would say, would be the
most enjoyable and fun project I've been involved with.
What inspired you to be part of NASA?
Well, it was luck actually. I've had a long career and it was really luck. I
was giving a talk for my doctoral dissertation, and someone who worked at
Kennedy Space Center thought it would be a good fit for me, so that's how I got
started and I just happened to have the preparation to be able to accept the job
and I'm thankful for being prepared. But, yeah, I'm just very
appreciative of this fortunate circumstance. Tell us more about that car
you're sitting in. How fast can it accelerate compared to a
space rocket? Okay. Let's explore it a little bit. As I
said before, I don't really drive my car all that fast, but we can use test
results from magazines and TV shows to understand and relate to its
its acceleration with respect to a space vehicle. A little bit of math first.
Let's first explore this with some math and we know that a common
performance measure of cars is a zero to 60 time. Now my car accelerates at 0-60
in 3.3 seconds, so that's one way we can assess its acceleration.
Now 60 miles an hour happens to correspond very close to 100
kilometers an hour. So 100 kilometers per hour,
we don't want to get to municipal seconds, so 100 thousand meters per 3600
seconds means that we're at a speed of 27 or 28 meters per second. Now our
gravitational acceleration, or the G, is 9.8 meters per second squared.
Or let's give it more or less 10 meters per second squared, to round it up a
little bit. So it takes about 2.7 seconds at 10 meters per second squared to get
to 27.7 meters per second. So 1g of acceleration would
take a car to sixty miles an hour in 2.7 seconds. So my car could do 3.3, so it's
acceleration is not quite as strong as 1g so that that's one information. The
next thing we can look up readily is the acceleration of the space shuttle. And as
you can see in this graph, with my car in the blue line slightly less than one g,
we can see that the space shuttle accelerates at times four G, over four times as much
as my car. So clearly the space shuttle is much quicker
and higher acceleration than a car would be, or any car would be, even a
top fuel dragster wouldn't hit four G's. What is your favorite part about your
job? Yes, as I keep saying, I hope I'm not
repeating myself, I had a very fulfilling career at NASA and I've done
all kinds of things. I've been inside the space shuttle and it's been a really
wonderful couple of years. But I honestly have to say that my proudest moment of
this job is not what I've done. It is what our organization, NASA, has done. For
example, two weeks ago we had the 50th anniversary of the Apollo 13 mission and
we all know its story and how that ended and how NASA really pulled together to
save these three crewmen. We had a special screening arranged by NASA to
the NASA family of the movie, Apollo 13, which is one of my favorite space movies
actually, and I really felt privileged to be sitting there watching the movie and
to feel part of this team. Obviously these men, this story, played out when I
was a young boy. I can't take any credit for what they did, but
I see in how they worked the way my co-workers work on a day-to-day basis,
solving problems. I really feel that we are representing the drive, the
the means of solving problems that these men showed during that mission. And I
feel really proud about that. So, basically, I feel really proud to be a
very small part of a very big thing. That's the main thing that makes me
proud, makes me happy, that that I am a very small part in a very big and
storied and historic and amazing organization, such as NASA. Thanks so much
Dr. Ed. And thank you for some really great questions. Make sure you join us
again next week to meet another one of our NASA engineers. See you then.
So, one of my hobbies is pinball machines and this is my collection here. My oldest
machine is the one I started with, it is a Space Shuttle.
Its pieces have been signed by various astronauts that I've worked with. It's
been signed by Mission Flight Director Gene Kranz, Guenter Wendt, and others in
the Apollo program. We have a Whirlwind, which is a hurricane theme, it has a fan
that blows on you at certain times like a hurricane. Of course, we talked about
the Space Shuttle. My next machine here is called Medieval Madness. It has a
castle that blows up with a drawbridge and gate and all that. It's very lively.
And then, lastly, along the row here is my Twilight Zone. This one is very heavy
with all kinds of toys and ramps, including additions I've made. It's a very
well-known machine for people to modify and enhance. This is my collection.