Week Ending September 27, 2003
Well, we survived the latest operations readiness test. It wasn't
easy. As I mentioned last week, this test was focused mostly on the
period we call "Impact Through Egress". This is the period of time
that begins when the lander comes to rest, and that ends when we've
got six wheels in the dirt. The test went amazingly well, all things
considered. Impact Through Egress is one of the most complicated
parts of the mission. The rover lands in a tightly folded-up
configuration, and over a period of several days it has to unfold,
take a look around, stand up, and find its way off the lander and
down onto the martian surface. We did all of that in this test,
and we successfully drove the rover off the lander right on
Of course, this was an easy test compared to what's to come. At
this point we're just trying to get all the basics down, so the
test conductors didn't throw too many nasty surprises our way.
(There were several nasty-looking rocks right in front of the
rover that we had to find a way around, though.) Future tests
promise to be trickier. And who knows what the actual landings
on Mars will bring.
Week Ending September 20, 2003
You might think it'd make your life easier if you could have an extra
thirty-nine minutes every day. Believe me, it doesn't. We're more than
a week into our latest operations readiness test now, and this business
of living on Mars time really wears you down.
The martian day is longer than the Earth day, by 39 minutes. Our
rovers are solar powered, and they don't know or care if it's daytime
or nighttime on Earth. They only care about the time on Mars.
In this operations readiness test, we're simulating the process of
landing on Mars and getting the rover off the lander. As of today
(Monday September 22nd) we're in our fourth day on the martian
surface. The rover's day starts when it's about 9:00 AM on Mars...
which right now happens to come at about 6:00 PM Pacific time. Tomorrow
it'll be at 6:39 PM, the day after that it'll be 7:18 PM, and so
forth. So a lot of us are doing just what we'll be doing next
January... sleeping during the Earth daytime, and working through
the Earth night. And even worse than that, the start times for our
shifts are 39 minutes later every night than they were the night
before. It's like having jet lag all the time.
Week Ending September 13, 2003
We're into our next Operational Readiness Test now, and this one's
really different. In the last one, we were practicing the process of
driving and doing science on the martian surface. In this one, we're
focusing on landing the spacecraft and getting the rover off the lander.
As I write this, on the morning of Tuesday the 16th, we're about to make
decisions on whether or not to do some final trajectory correction
maneuvers, or TCMs. A TCM is a maneuver you do with a spacecraft's
propulsion system to nudge it a little bit closer to your intended
landing site. In this test, we're simulating the landing of Spirit in
Gusev crater, and the "landing" itself is planned for Friday evening.
Between now and then is the TCM, and if we decide to do it, it'll happen
late tomorrow night. This is all starting to feel very real...
Week Ending August 30, 2003
We're starting to really put the
RAT through its paces. We've
tested the RAT extensively, of course, but so far that's been mostly by
itself on simple test stands, either at JPL or back at Honeybee Robotics
in New York, where the RAT was built. We've also tested the Instrument
Deployment Device (also known as the rover's arm) quite a bit. But until
the last week or so, we had really never had the chance to do a complete
test in which we used a RAT on the end of an arm to grind into a real
Well, we finally did it, and it worked... at least so far. For our first
test, we mounted the RAT on the end of an arm and used it to grind into
some limestone. We don't really expect to find limestone on Mars, but
it's a nice soft rock that's an easy one to start with. Things worked
great. We got a nice hole about 4 millimeters deep, brushed free of dust
so we could see it with all the other instruments. It was a big
But that's not enough. What the RAT really needs to be able to do is
grind into really hard, tough rock like basalt. We've done that with a
RAT on its own, but we still need to try it with a RAT on an arm. So
that'll be our next test, and — if it works — it'll be the
proof we need that the RAT and the arm will really work together
properly on Mars.
Week Ending August 23, 2003
Boy, it's been a crazy couple of weeks. We're still pulling together all
the things we learned from our last operations readiness test, and
already it seems like the next one is almost upon us. These things will
be coming at us fast and furious between now and landing.
In the most recent one, we operated one of the rovers for five straight
simulated martian days, or sols, in the big indoor Mars facility at JPL.
It went amazingly well, considering it was the first time we'd ever
tried it. Unknown to us, the engineering team down in the test facility
had glued pennies to about half a dozen of the many rocks that are
scattered about the scene. We first spotted a couple of them in Navcam
images, and then we zeroed in on them with
Pancam images. Deciding that
they'd be interesting targets to go after (they had, after all, been put
there to tempt us), we drove the rover over to one of them, reached the
arm out, and got data on it with all of the arm-mounted instruments.
This sounds deceptively simple, but in fact it was astonishing to have a
machine as complicated as ours accomplish something that complex on the
first try. And to prove that we really did it, here's the
Imager picture of the penny itself. (The strange "flaring" of the
image along the upper left edge of the penny comes from having a very
shiny metal edge in a brightly-lit room... this camera wasn't designed
for shiny metal surfaces!) What we've proven, for the first time, is
that we can use some of our instruments to pick a small target from a
distance, drive over to it, and investigate it in more detail with the
Now we just have to practice this stuff over and over and over again
until we get extremely good at it.
Week Ending August 16, 2003
We just completed a very successful ORT (Operations Readiness Test) and
our instruments performed beautifully. We were able to maneuver the
rover arm into the perfect position to examine something interesting on
a "martian" rock in JPL's giant indoor "sandbox." We're extremely busy
right now assessing our performance, but next week I'll reveal what we
Week Ending August 9, 2003
Wow, what a week! It's been the biggest week by far since we've
launched, and one of the biggest weeks since we started the project.
As I write this, we're four days into a five-day "Operations Readiness
Test", or ORT. In an ORT, we simulate — in as much detail as we
possibly can — the process of operating a spacecraft. And this is
the very first ORT in the history of this project in which we have
actually simulated the process of operating one of our rovers, with
all its instruments, on Mars.
The rover isn't on Mars, of course, But we do have a complete rover,
very much like the real ones, in a giant indoor "sandbox" at JPL. The
sandbox is full of rocks, and we're driving the rover around and
operating it exactly as we will on Mars next January.
It hasn't all been smooth sailing. In fact, we've made a bunch of
mistakes, some of them pretty significant. But that's what an ORT is
for. We're using these tests to shake out all the bugs, to find all
our weak spots, and to figure out how to fix everything so that once
we get to Mars it'll all work the way it's supposed to.
Despite all the challenges and problems and mistakes of a "first ORT",
I have to say that I'm incredibly proud of the job the team has done.
We've taken beautiful pictures with
Pancam and we've taken lots
of data with
Mini-TES. We've used the
pictures to pick a rock target to
drive to. (We named the rock "Brain", since that's what it looks
like.) We've driven the rover to the rock, and right now the rover
is close enough that tomorrow we're going to try to reach out and
look at it with the
Microscopic Imager, the
APXS, and the
I don't know if we'll succeed or not — driving rovers on Mars is the
kind of business where you never know for sure if you'll succeed. But
these are very exciting times for our team.
Week Ending August 2, 2003
We've now completed checking out the science payload on Opportunity,
so both rovers are done now. On Opportunity, all of the instruments
look good. If each one operates on Mars exactly the way it's operating
in space today, we'll get beautiful data from each and every one of
On Spirit, we're still dealing with a problem with the Moessbauer
spectrometer. We had thought that maybe the reason the Spirit
Moessbauer data that we took a couple of weeks ago looked funny
was simply that the instrument didn't behave the same way in zero-g
that it does on Earth. We know now that that's not the case, since
we just learned that the instrument on Opportunity is working
just the way it did back on Earth. So something else is going on.
If we had to use the Spirit Moessbauer on Mars just like the way
it's behaving now, we'd get science data that's not perfect but
that's still useable. We think that we may be able to improve the
situation by reprogramming the way the instrument operates a bit.
So that's something that we'll be looking at very hard in the
coming weeks and months. We've got five months to get this worked
out, and we're going to take our time with it.
So: The bottom line is that out of our ten science instruments on
the two rovers, nine are working well and the other one is going to
keep us busy for awhile.
Week Ending July 26, 2003
We're getting ready to practice in a "sandbox." The "sandbox" is a facility at the
Jet Propulsion Lab that contains martian-like dirt, rocks, simulated
sunlight, and a replica of the rover. Much of our effort this week has
been focused on preparations for a test that uses this facility to help
us learn to command the rovers on Mars. The test is called PORT-3 —
Post-Launch Operations Readiness Test (formerly known as Surface
Operations Readiness Test). We will operate a bank of computers in one
building at JPL to drive the model of the rover in another building.
To prepare for PORT-3, the science team has been ironing out details in
teleconferences, downloading software to practice, and
building sequences. These
sequences will command the rover in the sandbox to approach a rock
target, position its arm near the target, and tell science instruments
on the end of the arm to make contact with the rock.
It takes weeks to prepare for a test like this. But we're doing our
homework and we'll be ready.
Week Ending July 19, 2003
One down and one to go. We did an in-flight checkout of all the
instruments on Spirit last week. This was the first time we had
turned the payload on since launch, so it was a big event! Fortunately,
things are looking good.
Microscopic Imager and
APXS are all looking
completely normal. There's one thing about the
Moessbauer that looks a little funny, but we're working on it and
we don't expect it to be a big problem on Mars. So we've got one
good-looking payload on the way. We'll do the same thing on
Opportunity the week after next.
Week Ending July 12, 2003
We spent this week preparing for one of the first big events of the
mission... the first cruise checkout sequence.
All of our science instruments were turned off at launch, and they've
been off ever since then. Mars is where they'll do their job, so there's
not much point in having them turned on all the way to Mars. But launch
is a dangerous and violent event, and we want to take enough data
during the cruise to Mars to be sure that the instruments survived
the launch and are working properly. So this coming week we're going to
send commands to all the instruments on Spirit, turning them on and
We've had to do a lot of work to prepare for this. We have what we
call a "testbed" on the ground, which is a very accurate replica
of the rover and all its instruments. Before you send any commands
to a spacecraft this complicated, it's a good idea to try them
out on the ground first, and that's what we've been doing, in the
testbed, this week. Everything has looked okay, so we expect the
commands to work properly once we send them to the spacecraft.
We don't expect to see much in the data that we get back next week,
of course, since the rover's safely tucked inside the aeroshell.
It's dark in there, so the pictures from all the cameras, for example,
will just be black. But even from black images we can tell whether
or not the cameras are healthy, and that's all we need to know. The
pretty pictures and exciting spectra can come later. If everything's
in good shape, we'll all breathe a sigh of relief. And if something's
gone wrong, we can start figuring out what to do about it now, instead
of having to wait until we're on Mars next January.
So fingers are crossed, and we'll see what we see next week.
July 7, 2003
The Mars rover Opportunity took flight this evening, at 11:18 PM
Eastern time. We had a little excitement on our first launch attempt,
when a problem with the liquid oxygen fill-and-drain valve on the
first stage of the Delta II caused a hold with just seven
seconds to go in the countdown. But the launch team did a fantastic
job, recycling the vehicle for a second launch attempt about 40
minutes later. Our rocket — the first Delta II Heavy — gave us a
perfect ride. Opportunity is in good shape, and on her way to
Week Ending July 5, 2003
We're still waiting. It's been a long week in Florida, and Opportunity
is still on the ground. The biggest problem we've had is the cork
insulation on the outside of our launch vehicle. The glue they were
using to keep the cork on wasn't as sticky as they had hoped it would
be. The problem is caused by liquid oxygen. Our rocket uses a lot
of super-cold liquid oxygen, as the oxidizer that it combines with
fuel to get its thrust. When the liquid oxygen is loaded into the
tank inside the rocket, the skin of the rocket gets very cold, and
it shrinks a little bit. When this happened, some of the cork was
popping off the outside of the rocket because the glue holding it in
place wasn't sticky enough. They've switched to a better glue, and
now the cork stays put. Problem solved.
But that wasn't our only problem. The other one was that there is a
crucial battery inside the rocket that died a couple of days ago.
It's been replaced, and once some tests are finished we'll be ready
to go. In fact, as I write this on Monday morning in Florida, we may
be just 12 hours or so from launch if all goes well. The weather's
looking good. Watch this web site for news updates, and cross your