Now that ORT6 is over, and ORT7 is several weeks away, we are continuing to run tests for the various instruments. Last week and this week are dedicated to testing how effectively the RA can acquire and deliver samples to TEGA and MECA, using different materials. We have already done the very fine baghouse dirt (a few microns), and are in the process of testing a coarser grain (up to 3mm) as well as a rocky substance that requires the arm to using the RASP, or Rapid Active Sampling Package. This comprises the ISAD, or Icy Sample Acquisition Device. this is effectively a Dremel tool bit on the backside of the scoop that drills into the rock or ice sample, filling the scoop with (hopefully) enough sample to analyze. This testing goes under the category of Payload Verification and Validation (PVV). The RA has many requirements, meaning, lots of testing. We have started to do some testing with MECA as well, but I'll get into that in my next entry.

Good question regarding the abbreviations. As with all jobs, we have our own jargon. I try to define whatever terms I use, but sometimes a refresher is good for all.

RA stands for Robotic Arm and TEGA stands for Thermally Evolved Gas Analyzer. Both of these are instruments, which we call payloads, on board the lander.

We have EMs or Engineering Models, for each payload, which are used for testing. There are several payloads on board, and for a complete description of each, check out our
website.

We do our testing in the PIT, or Payload Interoperability Testbed. Basically, we want to understand how each instrument behaves, as well as how they work together (the Interoperability part of the acronym).

Finally, the whole team, scientists, engineers and other specialists, come together several times before landing to run tests, as if the lander were on Mars. We use the model lander as a stand in during these Operational Readiness Tests/Training, ORTs. The T can be for Test or Training, depending on your point of view.

Has anyone found the website useful? Or would you prefer me to talk about each instrument? The comments help me determine what to talk about, so keep the questions coming.

As I said last time, these ORTs are an interesting look at how surface operations will run. I worked the midnight to 8AM shift again, but this time, I stayed later a few times and shadowed some of the leaders so I could learn about surface operations.

The ORTs are designed to find the bugs in the system, on an operational level. Obviously, the power supply issue, but there were a few other errors that cropped up; pointing was off on some pictures, other parameters on instruments were set incorrectly which results in undesired effects (<- very diplomatic of me).

That's why we have these tests. The point of this one was nominal ops, getting to a TEGA delivery. We had some issues with that, above the power one. As I shadowed the ops team, I got to see decisions made on a flight-like basis (how they would be handled in actual surface ops) and test basis. This last basically meant that when the RA was unable to acquire a sample and get ready to deliver, and instead of fixing it as they would in flight, they declared a test-ism, sprinkled some "magic dust" and declared the Arm ready to go. My team that was running the model had to fix the arm and make it ready, something that would be impossible on the real spacecraft.

Well, the latest round of Operational Readiness Tests/Training is over and we finished with moderate success.

The aim for this round was nominal operations, meaning no one was intentionally causing hiccups to test the science team's ability to react. This all centered around a sample delivery to TEGA. That didn't happen. The trench came out beautifully, with multiple layers and different colors; brown, red, brown, yellow and brown. This may not sound interesting, but very few people knew about this, and the team was able to get nice color images that match up very nicely.

From that trench, the RA was able to acquire a sample and get into position to deliver to TEGA. But twice, as TEGA was prepping to receive the sample, it faulted. So last week was dedicated to debugging this issue. It only took a day, but we figured it out. Current limit was set too low, a change from the default that someone made. Quite embarrassing. But we were able to test both sequences from the ORT and show that both worked. Or would have, anyway.

Stay tuned as I have some other stories from the ORT. If you have a question about any aspect of the ORT, please ask. It's a fascinating look at Mars Mission operations.

Starting last Wednesday, the RA team was in town digging the trench I mentioned in the last blog. We didn't quite get down to 20cm, however. The Arm was giving everyone a lot of trouble, by faulting out on an over torque-limit error. The motors that drive the joints are quite large, and when changing directions the torque can get quite large, and thus the failures.

The trench is about a meter square, and the arm takes about a centimeter or so with each tier it digs. Each tier takes about 50 minutes to dig and we did actually get through two tiers with no problems. But each fault took an hour or more to recover from. Actually getting the RA powered back on only took a few minutes, but analyzing the data from each fault and then rewriting the sequence to continue the dig took a lot of time.

A few late nights and several headaches, but we managed to get down over 10 centimeters. The science team will certainly have some interesting pictures to analyze, after all the time we spent prepping the digging area. But I'll tell you more about that over the rest of the week. I'll be working the midnight to 8AM shift.

As I said, we have been preparing for the upcoming ORT (Operational Readiness Test) for the last several weeks. A lot of the software testing has been done, and we're mainly fine-tuning the tests at this point. The work is now shifting to more of the physical setup.

This round of ORTs will include some hefty RA work, just to prepare for the test. The Arm will be digging a large trench, around 20cm deep and about a meter square. Several of us spent much of Friday prepping the digging bin with different soils. We managed to get quite dirty doing so! After we put the bin back in place, we spent time arranging the area around the lander, including getting rocks of appropriate sizes AND abundances for the region we are studying.