Sunday, March 25, 2012

...and the promised pictures!!

I did promise you pictures, didn't I?  :)  Here are some photos taken by the authorized photographers at White Sands.  In addition, Steven's got some pictures of the cracked detector system parts on his FOXSI blog, along with some other shots he took outside the range.

The wrapup and the rebuild...

I last left off with the unhappy news that we're pushing the launch.  But I don't want you to think that's where the White Sands work ended...in truth we had much, much more to do that week!  Here's what happened:

When we decided to delay the flight we also decided to go ahead with the next steps of integration and vibration, as a practice run.  We'll have to redo these when we come back for the real deal, but doing them now gives us a chance to identify and fix problems early.  Integration is the process of connecting our experiment (the payload) with the rest of the rocket (systems for data telemetry, pointing control, and recovery, among others).  These parts were made by a rocket team from Wallops Island, Virginia.  Not only did we physically connect everything and make sure it fits (remember, we had some troubles earlier when we tried this with the first piece...) but we also tried running the power, data, and communication through their systems just like it will be during the flight.  We did several sequence tests, where we run through everything in order as if we are doing the launch...except of course we don't launch anything.  :)  Most of these tests were easy as our system is relatively simple to integrate, but we did have to work out a couple more problems in mating various skins and sections together.

The next step was vibration!  As I told you before, a vibration test is done on a shake table that simulates the shaking the rocket will feel during launch.  Passing this test is absolutely essential to the health of the mission because it means that nothing will break or come loose during the launch.  Many things could go wrong in a vibe test: parts could break, connectors could detach, bolts can come out as if an invisible hand is unscrewing them!  We've never vibrated the electronics side of our payload, so this test served an important purpose.  (Imagine if we came back in August and THEN found that we couldn't pass a shake test!)  Fortunately, the test was a success! All the detectors (well, the ones that were still working after the accident...) showed no damage in the vibe test and still worked just as well afterward.  What's more, there was no change in the alignment of the optics, despite the shims and regluing.  So I'm happy to say that once we rebuild the detector system, all major obstacles to launch will have been cleared!  (Yes, there are always more things that can go wrong, but this takes care of all the obvious areas for concern.)

There was one final step for our work in White Sands, and that was to ship everything back to Berkeley.  Things were a little melancholy last Tuesday as we packed everything back up and loaded up the Fedex truck.  A day later, we unloaded the truck in Berkeley and FOXSI was officially back home!  So what's next?  Well, we have to start over by rebuilding the detector system, but we can use everything we learned along the way, so the process will be much quicker this time.  We first need to get more detectors from our colleagues at ISAS in Japan; as soon as we get those I will begin gluing them onto new boards.  After the boards are loaded and wirebonded, we will start the process of testing and calibrating them...and then...we will bring FOXSI back to the desert and we will fly it!!!  Right now we're looking at an August launch date; I will keep this blog going in the meantime so you can keep tabs on the rebuilding.  :)

Thursday, March 15, 2012

Day 24 (Thursday, March 15)

Yesterday we made the difficult decision to cancel our launch.  Our condition: we have 4-5 working detectors out of seven.  Of these, three survived the cooling accident, and there are concerns that there could be cracks in the readout electronics that may get worse under the vibration of the rocket launch.  There are two new detectors, however, our calibration data for these is minimal (limited to what I could measure in half a day!)  Taking these things into account, it was decided to start over building our detector system from scratch.  This will probably take 3-6 months, so we will try for a new launch in the summer or fall.

I've gotten a lot of questions, so here's some detail of what went wrong in our cooling accident.  We have a cooling regulator that controls the flow of liquid nitrogen to our system.  You can program it to cool to whatever temperature you want.  It knows what the actual temperature is from a temperature sensor inside our system.  Here's the nice part: based on the difference between the actual temperature and the programmed temperature it decides how much nitrogen to allow into the system.  So you can essentially dial in the temperature you want and walk away; it takes care of the rest.  Except, as I found out, you shouldn't do this because it can make a mistake!  It turns out that if the temperature sensor is temporarily disconnected (i.e. if you unplug it and plug it back in) then things go a little haywire and the cooler does not behave properly.  In this case it got confused about what the temperature was and started dumping way too much nitrogen in our system, resulting in much lower temperatures than our system can tolerate.  This actually cracked a couple of components on our detector board, which are not replaceable.  Long story short, we're starting over by building new boards.

Monday, March 12, 2012

Day 20 (Sunday March 11)  Hurting but alive...

More bad news, folks.  We broke almost all the detectors in the cooling accident.  Two of them looked ok on data readout, two looked completely broken, and the other three were somewhere in the middle, with parts working and parts not.  The situation's pretty dire because we didn't think we brought any *good* working spares!  We did bring five extras, but they never worked particularly well in the lab -- that's why they didn't make it into the final buildup.  You better believe there were some long faces around the lab today...one of the worst FOXSI days ever!

But it's not all bad news.  After many attempts to figure out a way to revive the broken detectors we ended up putting in our spare detectors...and found out they work better than we thought!  Two of the original detectors survived the cooling catastrophe, and of the five extras we put in two are working pretty well and we might be able to revive one or two more.  So that gives us at least 4 out of 7 working detectors, with the possibility of more.  Getting these detectors ready will be a ton of work.  They have to undergo a full testing and calibration process...something that took us several weeks at the lab, but here we will need to do it in a few days!  We also have to prepare these detectors for flight by staking down parts and gluing temperature sensors on them.  And add onto that the time we lost (at least a day) in troubleshooting this problem...the race is on!!  It's gonna be a lot of full days and late nights but I am confident we can do it.  FOXSI lives!!

Saturday, March 10, 2012

Day 19 (Sat March 10)

Bad news, folks.  Today I learned the hard way not to leave a cooling system unattended.  Our detectors (the parts that make up the camera of the telescope) are meant to be used at -25 degrees Celsius.  To get that temperature we have a liquid nitrogen cooling system that supplies the detectors with just enough nitrogen to keep them at the temperature we want.  This is a great system if it's properly set!  Unfortunately after I programmed the settings I did not double-check that these settings had properly registered, and the cooling system started the cooldown and just kept going...all the way to -190 degrees!!!  As soon as I discovered this I stopped the cooling and shut down all power.  We put a bag around the detector system and flooded it with dry nitrogen so that as the temperature comes back up water won't condense on the electronics.  Now there's nothing to do but give it time to warm up...and tomorrow morning check to see if the detectors still work.  :(  I have the feeling I won't be sleeping well tonight...everybody wish me luck on this one!!

Friday, March 9, 2012

Day 18 (Friday, March 9)

FOXSI just cannot catch a break!  We came in today with the intention of doing a quick and easy operation in the morning.  Guess what?  Not so easy!  The operation was to place the experiment in the hollow metal cylinders that form the outer shell of the rocket, called the "skins" of the rocket.  These skins are just a little larger than our experiment and get quite hot during the launch.  To do this fitting, you have to use a crane to hoist the experiment into the skin, then bolt the skin to a special fitting ring to join the two together.  Well, when we tried this there was a big old gap on one side between the ring and the skin!  (By "big," we're talking millimeters, but that's big in engineering terms.)  It took well into the afternoon to come up with a solution.  The best solution is to ship it all the way back to the facility that made it and have them machine it down.  But this would cost us a few days in the schedule, and we have no room for that!  However, there is a machine shop at a NASA facility nearby that could do the job.  After some frantic attempts to get in touch with them they generously agreed to take care of it right away (late in the day on a Friday afternoon/evening!) and had the job done in a few hours.  (Never met those guys, but I'll gladly buy them a beer if I ever do.)  We tried the procedure again and everything fit like a glove.  Yet another problem arising...yet another problem solved...!  :)

Thursday, March 8, 2012

Day 16 (Wednesday, March 7)

Back in the saddle after two days off this weekend in SF.  (Being surrounded by water and people felt so strange after weeks in the desert!)  The last couple days have been occupied with blanketing the entire payload.  The blankets keep everything at their correct temperature...the optics at room temp...the detectors at -25 degrees Celsius.  Keep in mind that outside this environment a fantastic fireball of an explosion is taking place, so thermal isolation is really important!

Too sleepy to write more now...good night, everyone!

Saturday, March 3, 2012


Day 11 (Friday, March 2)

Yet another scrub for the Caltech launch!  :( :( :(  This one got much closer -- they had the rocket on the rail and raised it vertical, then aborted about a half hour before launch.  This time the culprit was the high winds…both at the surface and at high altitudes.  If the winds are strong but steady, usually the launch can go as planned, but if there's a lot of direction-changing then it's not possible to fly.

Today we're flying back to California -- thus the sudden blog frenzy since I've finally got a little spare time on the plane to catch up!  This will just be a short weekend trip; we want to get right back here Monday to continue the alignment tests.  I'll be happy for the couple days off, especially since my favorite person in the whole world will be picking me up from the airport!  I haven't gotten to see him much over the last couple of months and I really hope he will come to visit me in New Mexico too!!  :)

I had a late flight so I had a little time to kill in El Paso before heading to the airport.  So I decided to take a little side trip to Ciudad Juarez in Mexico, just across the Rio Grande.  I parked on the U.S. side and walked over the bridge connecting El Paso with downtown Juarez.  The winds were so strong on that bridge that sand kept flying in my eyes!  I only had about an hour to spend in Juarez so I just went for a little walk down the main commercial stretch and stopped for a cerveza in a little bar.  Coming back across the bridge you go through U.S. customs and immigration, kind of like at the airport.

Day 8 (Tuesday, Feb. 28)

Today's the day we had planned on going home, but (surprise!) it turns out there's more work to do!  We've pushed our California return back to Friday to give us a few more days to work out some problems with the optics and the detector system.  Since we're staying longer this means we'll get another chance to watch them attempt to launch the CalTech rocket!  (That's the other team that's here now.)  That's on the schedule for Thursday night / Friday morning.

Some of the most important work was to epoxy (glue) a holder onto an optic that had slightly detached.  This piece holds the optic in the telescope but had come off due to degraded epoxy.  Could this have happened during vibration tests?  As you can imagine, when the rocket launches the instrument gets shaken quite a lot, at amplitudes up to 10 times gravity!  One of the tests we have to do is to make sure the equipment can hold up under that kind of vibration.  So we put it on a special table that mimics the vibration of the rocket to check if any parts break.  This vibe test has been done a couple of times on this optic over the last year…maybe the detachment happened then but we just didn't notice until we tried to install it in the telescope.  Obviously this led to a lot of concern about the state of the other optics, but we checked them all and they all have a good layer of intact epoxy.


Day 5 (Saturday, Feb. 25)

Not much to report today -- we spent almost all day getting images from all the optics.  Unfortunately we found two detectors that suddenly stopped working.  :(   We'll have to pull these off and do some individual testing in the lab.

Oh one more note -- breakfast today was delicious chorizo and eggs on an outdoor patio at a cafe overlooking the old historical town square.  :) :) :)


Day 4 (Friday, Feb. 24)

After a few late evenings and with the prospect of a 4am launch to watch, we slept in today and showed up to the base in the afternoon…where we found out the launch is scrubbed (canceled)!  So that team's launch is slipping, and if everything checks out they'll probably go sometime next week instead.  We're scheduled to briefly return to California next week, so we might have to miss it.  :(

On the plus side, the alignment problem with most of our optics is fixed.  Our resourceful engineer Paul fashioned some small pieces (shims) to fit just underneath the piece that holds the optics in.  These are very thin pieces of varying thickness, so by placing them all around the optic you can ever so slightly change the angle of the optic so that it's pointing right onto the detector.  Getting the combination of pieces right and fitting them amongst all the other hardware on that fixture is not an easy task, and it took most of the day and evening yesterday. One optic has more severe problems and will need some more personal attention.

With that settled, we moved on to checking the alignment using X-rays instead of a laser.  For this test we built up the detector package (the cameras) on the telescope tube…this is the first time that the optics and detectors have been installed at the same time.  We then used a high-power X-ray generator to illuminate the optics and took an image of this.  The result was just what we wanted to see: an almost-perfect circle on the detector plane!  This is the first real FOXSI image and represents the culmination of years of work, and was especially gratifying for me to see since most of my efforts have been spent getting these detectors to work!


Day 3 (Thursday, Feb. 23)

Yesterday more of our team arrived and we got down to business!  First was to set up the long aluminum tube that holds our experiment and start putting in the "optics."  These are the parts of the telescope that reflect and focus X-rays.  Unlike visible light, X-rays are hard to reflect: they usually pass right through materials or else they get absorbed.  To reflect them you need to reflect at a very small angle off of an extremely smooth and precise surface.  Our telescope has seven optics and each of them has seven mirrors nested together within it.  Producing these mirrors and finding a way to line them up together in a secure way without distorting any of them took years and a lot of effort, and we have our NASA colleagues from Alabama to thank for all this hard work!

Unfortunately we almost immediately ran into our first big problem.  (Well, ok, our first big problem HERE at the base; I'll tell you some other time about all our trials and tribulation during the design, testing, and calibration phases…)  We found that our telescope is not well aligned, meaning that the optics are not pointing precisely at correct points on the detectors (X-ray cameras).  We found this by pointing a laser at the optics and placing a piece of paper where the detectors will go so that you can see the focused pattern, or in this case the UNfocused pattern.  The offset is not so bad that the experiment won't work, but we'd like to do better!  So we spent yesterday and today trying to come up with a way to fix the alignment.

Some exciting news: we're overlapping by about a week with the previous sounding rocket team.  They're scheduled to launch very late Friday night / early Saturday morning (around 4 am)…and we can go watch!  We unanimously agreed that the chance to see a rocket launch, even if it's not ours, is well worth staying up til the wee hours of the morning…and we have plenty of work to keep us busy til then!


Day 1 (Tuesday, Feb. 21)

Yesterday the "advance team" of Steven and I arrived in New Mexico!  The closest airport is El Paso, Texas, which is right on the Mexican border across from Ciudad Juarez.  To get to where we're going you drive about 45 minutes north along the Rio Grande to Las Cruces, where we'll be staying.  From there, you drive east over a pass through a small mountain range, out into the desert valley where the White Sands Missile Range is located.  It's real desert!  Around you, you see only a few desert plants, an occasional tree, the craggy mountains in the distance, and a whole lot of absolutely clear blue sky without a single cloud.  At night the stars are vivid and there's a whole lot more of them than I'm used to seeing from San Francisco!

White Sands Missile Range is a Navy base and NASA has an area they use for sounding rocket flights.  That means several layers of rules to follow…those of NASA, the Navy, Orbital Sciences, and NSRC (the company that NASA contracts with to integrate and fly the rockets).  We've navigated through that web to get access to the base and permission to use our radioactive sources, X-ray generator, and lasers.  This week we'll find out if all those hurdles have been cleared.   One of the biggest rules is, no photos!  But they do have a couple official photographers who can take pictures for us, so I'll post those as we get them.

Today we met many of the folks who work in the NASA part of the base; everyone was very helpful, with several people jumping in to help us unload our two trucks that met us there with all our equipment and the parts of the payload.  We got everything unloaded, unpacked, and set up…tomorrow the real work begins!

Friday, March 2, 2012


Intro

Welcome to Lindsay's FOXSI blog!  This isn't an official project blog, just something I'm throwing together so friends and family can keep up on my adventures in the desert.

A little intro:  FOXSI is an experiment that has an X-ray telescope and camera to make X-ray images and spectra of the Sun.  FOXSI was born in three places: the Space Sciences Laboratory in Berkeley, California, the NASA/Marshall Space Flight Center in Huntsville, Alabama, and the Institute of Space and Astronautical Science in Sagamihara, Japan.  All these pieces are being put together right now at the White Sands Missile Range in New Mexico, where FOXSI will launch on a sounding rocket at the end of March!  The information we get from this 15-minute flight will give us feedback on our technology and allow us to look for never-before-seen signals from the quiet part of the Sun.

We'll be out in White Sands from late February to early April for the preparations and launch.  The flight is planned for March 30…stay tuned to see how we do!