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 schedule.

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.

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.

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...

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 rock.

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 confidence builder!

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.

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 Microscopic 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 other instruments.

Now we just have to practice this stuff over and over and over again until we get extremely good at it.

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 found.

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 Moessbauer. 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.

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 them.

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.

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.

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. Pancam, Mini-TES, 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.

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 taking data.

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.

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 Meridiani Planum.

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 fingers...

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