This week I began my work at NASA Johnson Space Center (JSC). My job is to write software regression test protocols for the guidance, navigation, and control software on a lander prototype. We normally refer to the software as the GN&C package. It basically tells the flight computer and flight computer software (FCS) what to do as far as maneuvering the vehicle.
The vehicle I'm working on is called Morpheus and will with any luck be the next machine we place on the moon. It may take some instrument up after a few more years, but only time and funding will tell. Below is a picture of the lander with me for scale.
I encourage you to also follow the Morpheus blog from NASA (here). Videos of tests will be posted there, but I'll also repost. The first few tests the lander was tied down to the ground. Then it was hung from a tether and allowed to ascend and land on its own. Some of the tests worked well, but others had problems as is in the video below. Most of those issues have been solved and we are now just working on some control lag problems.
More tests were planned very soon, but the rocket started a fire in the test field and we can not light the engine again until the investigate has cleared up, hopefully by early July. Until we do more field tests I'm working in the NSTL (Navigation Systems Testing Laboratory) trying to do regression analysis. In general fixing a bug in software can break other features. When the software is flying a very expensive lander with around half a ton of explosive rocket fuel that is a very bad thing. I'm using spacecraft simulation code to prove that certain changes don't cause issues with the flight and trying to develop software modification protocols that allow rapid updates.
The icing on the cake was really my first day when I happened to hear that Gene Kranz (the flight controller for many years, made famous in the movie 'Apollo 13') was speaking. I attended his lecture and it was amazing. He really has the passion that I love seeing in people. Mr. Kranz was excited for what our generation can do, but concerned that we may currently lack the leadership to do it. I agree completely with his statement and all of us in the room are striving to learn those vital skills that he talked about. The Apollo missions would have never left the ground without leadership, teamwork, and persistance. While we may have many times the computer power of the 1960's I'm worried we have fewer of these important personal qualities.
The final week of field camp consisted of a swap between geology/geophysics students, preparation of final reports, and a final presentation.
For the first day (Monday) of the geology/geophysics swap I was helping the geologists with my homebrew resistivity rig. After some small problems in the morning the device cooperated, and we took a like across a fault, seeing massive jumps in conductivity over the gouge area. The second day I was actually out with the geology professors hand mapping some of the surface geology in the area. Tom and Neil were very instructive and were able to measure a strike and dip on things that very few would term 'outcrop'. Nonetheless the data plotted nicely!
After the mapping came independent projects and final reports. Cullen and I decided to collect a gravity line across the dry union fault near Salida (the area of the first field trip). I ended up staying at camp to help the geologists process their data and Cullen went with Guang to collect the line. The results were stunning and the calculated fault dip angle is 87 degrees.
Processing the magnetic data was quite a challenge. To take the data we place flags along the path we walk, take their coordinates and press mark at each flag. The instrument is collecting a magnetic reading every 1/10 of a second. I ended up writing code that assumes a constant walking place between flags and linearly interpolates positions between. The code then re-writes a new datafile that can be plotted by OASIS. The quick code hack was not perfect and really should have already been in the software that came with the instrument. Hopefully over the summer I'll have time to perfect the code and write a nice GUI to go along with it. (Error checking would also be nice)
Finally on the last day of camp we had to give a presentation of the results. Cullen and I talked for about 40 minutes and then there was much discussion between the faculty of our image. We had everybody excited about what we should try next year! Unless plans change it is likely that Cullen and I will TA next year.
Now I'm at NASA in Houston, TX. Towards the end of this week I'll start a weekly post about the work here. It's very exciting work with a flying vehicle and guidance software. Stay Tuned! Below are a few pictures from the group trip to Pike's Peak. A copy of the final report can also be downloaded HERE.
This week was seismic week for us here in Canon City. We carefully selected a site that crosses from sediment into basement, but the nature of the contact is unknown. It ran across the property of a nice couple who moved here from Iowa three years ago. They are interested in the geology and were more than happy to have us tramp all over with magnetic, gravity, and finally seismic gear including a larger thumper mounted on an ATV.
The first part of the week involved Cullen and I working on a mounting system to attach the thumper for the four-wheeler. Seismic surveying works on the premise that different rocks have different wave velocities as a function of the type of rock, fluid content, etc. We set out a long line of geophones (basically a vertical seismometer) and then hit the ground very hard to induce a signal. From the return of the signal we can learn a lot about what the subsurface looks like.
For some surveys we hit the ground with a sledgehammer, shoot it with a gun, or even use dynamite! In this case we tried a new device that pulls a 40kg weight up with an electric motor and then drops it. There is also a giant rubberband that accelerates the weight towards the ground. There is currently a battle going on between naming the machine the seismic thumper device or the seismic thumper and utility device. We added weights, battery mounts, and even a flashing safety light to the four-wheeler.
Before we could even use the thumper the control box failed due to a cable issue, so I had to rewire the control system (actually just a solenoid control) and mount the switch in a box on the ATV. It was a midnight patch up, but it worked well all day!
The survey was laid out on Wednesday. The line was almost 750m long, then we even rolled it forward! Geophones were placed every 10m and the thumper was shot at each geophone three times to 'stack' the data (this helps us reduce random noise). We don't have any images yet, but tomorrow we begin processing. The line took a day to layout, a day to shoot, and tomorrow morning to roll up. Several long days for us here. I also put together a quick video of the thumper shooting.
On a side note, we also took a great hike and field trip in the past week, so I've added a few photos of the Collegiate Peaks, and Tunnel Drive Trail.