Tag Archives: FORCAST

Reflections on flying on SOFIA. I totally got the SOFIA bug.

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Tonight, Thurs Jun 13th was to be a second opportunity for me to fly and test the FORCAST grism suite on SOFIA. However, that flight had a RTB or return to base, due to an aircraft item that manifest itself inflight. The pilots were awesome and returned us back to Palmdale, CA, safely.They followed their checklists and since most of tonight’s flight was to be thousands of miles over the Pacific, return to base was the right course of action. The flight is now rescheduled for next Tuesday. I am hoping I can remain on the passenger manifest and I can always do remote support.

For those who follow the SOFIA story, it has been a longtime coming. But you just have to admit it, SOFIA is just cool. First of all,airplanes are cool. 747s are even cooler. And to have a hole cut into a 747 to outfit it with a telescope that can point, even in turbulence, is just the coolest of coolness. I know I always knew that, but in all honestly, I did not realize it until I experienced it. I hope you have enjoyed my blog updates on this experience.

SOFIA is also an amazing piece of engineering. If you think about it, a lot of engineering has gone into the airplane, the modifications to support the telescope, the telescope design and operation, all the different science instruments, and the support infrastructure to make it all happen.Thanks to all the people who made this unique observatory possible, and those that are working hard today getting it operational.

For those astronomers out there, a call is on the street for science observing on SOFIA. Proposals are due Jun 28th, 2013 for the 2014 observing cycle.  http://www.sofia.usra.edu/

For those interested in applying to be SOFIA Airborne Ambassadors, definitely check out that amazing program. The current application period is closed. But check in the future for the next call.

http://www.sofia.usra.edu/Edu/programs/ambassadors/ambassadors.html

http://www.seti.org/sofia

SOFIA is a powerful observatory. Its legacy is about to happen. There are not many telescopes out there that can access the infrared skies. By flying above the water vapor in our atmosphere, the infrared sky is revealed to us. Of course, our eyes cannot see such wavelengths, but our infrared detectors can. We can use these tools on SOFIA to answer questions about the formation of the stars and galaxies and their evolution. SOFIA with its 20 year lifetime and its mobility to be operated from anywhere on the planet that has a runway, has only yet to contribute to understanding of what’s out there. It’s an excellent training platform for students and teachers. In fact, on the line ops and the flights I was on, teachers and undergraduate and graduate students participated. What a great opportunity for a grad student to have access to this state-of-the-art telescope! The four I have met these past few weeks are so jazzed about what they are going to observe with SOFIA.

SOFIA after the successful completion of Flight#105, the morning of Jun 12, 2013

SOFIA after the successful completion of Flight#105, the morning of Jun 12, 2013. We got over 8 hrs of time at >= 40,000ft checking out the modes to commission the FORCAST mid-infrared camera with grism complement.

I still have work to do on my small role in the SOFIA story. We collected some (not all) of our grism commissioning data. With next week’s flight, we aim to fill in those gaps. I have data now to reduce and check out our quicklook pipeline that we are tailoring for the observers who request to use of grisms to do their science. And, that long awaited paper on the actual performance of these novel infrared optics I helped develop is now in the works!

I look forward to flying again on SOFIA, as an observer. I have a few ideas of neat things to observe.

I close my blog series with an amusing observation. On my Jun11th flight, I spent most of my time facing the science instrument/telescope area, which is, towards the rear of the plane. I was standing a lot, and occasionally would sit down at the conference area mid-deck to do some data reduction. All that time I stood watching the telescope, participating in discussions about the data, etc. looking aft, I realized I was journeying on SOFIA, as viewed by someone outside the plane, backwards.

Terry Herter (Cornell), FORCAST Principal Investigator & many-time SOFIA flyer, remarked to me, “After a few minutes in the air, you forget you are in an airplane.” And that’s precisely that. I thought I was observing at a telescope observatory.  The only drawback: I could not walk outsideto look at the stars, as I just love to do when I am a dark site, like at an observatory. But that’s okay, I was using state-of-the-art instruments to look at the stars with a different set of infrared eyes.

I’m not sure how the comments section on these blogs work, but I’d be happy to answer any questions. Just drop me a line.  Kimberly.Ennico at nasa dot gov.

The blog author aboard SOFIA during take off on Jun 13, 2013

The blog author aboard SOFIA during take off on Jun 13, 2013. Notebook in hand. Mind on the targets we were to observe that flight. Smile for the adventure and learning ahead.

Time management at 40,000 ft. The temporal realities of an airborne observing flight.

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So between takeoff at 7:25pm PDT and landing at 5:25am PDT,the flight planners had to keep us literally on track. There is an official flight plan that the pilots will follow and which has been worked out ahead of time with FAA air traffic control. It’s the result of a complex optimization strategy to calculate where one’s targets are in the sky and visible by the SOFIA telescope at given times and locations of this moving airborne platform,along with ensuring not entering no-fly areas, and of length and elevation appropriate for the amount of fuel on board to enable a 10 hour flight, with about 8 hrs at the desired 40,000 ft elevation. In addition, they need to look at seasonal weather patterns, and then on the final iteration of the flight plan, they take into account the most recent weather predictions. In ground-based astronomy,you can lose time on your objects by being “clouded out.” For airborne astronomy when you are above the clouds, your only threats to observation time are weather-related, but weather of another kind.

For more information about SOFIA flight planning see

http://www.sofia.usra.edu/Science/workshops/SOFIA_Workshop_2011/docs/705_FlightPlanningWSNov11.pdf

http://www.sofia.usra.edu/Science/proposals/basic_science/FlightPlans_current.html

Thus, you want to be smart to make the use of this unique facility flying in the skies getting you incredible access to the infrared wavelengths. So when our test plan was created, for each leg, we had prioritized which observations we needed to get done, our “baseline” versus observations of “the nice to have” flavor.  In case we lost time, we aimed to achieve that “baseline.” In case we were more efficient with setting up each observation than originally predicted, we might have more time to tackle the “nice to haves.” In ground-based astronomy where you don’t have such a tight timeline, unless of course the sun is rising or your object has gone below the horizon, you could easily extend your observations by a few minutes or so. For SOFIA, they do keep the leg duration strictly flown as planned with little room for time extension.

For Flight#105, we had 13 legs, of which legs #6-12 were“science.” Legs 1-5 were the ascent legs to get up and out of the LA congested airspace and get us to altitude.  Leg 13was the final descent back to Palmdale, CA. As I mentioned in the previous blog, within a few minutes after takeoff, even while we were still ascending at an angle, we were allowed to get up and walk about the aircraft. We used this time to get our computers and laptops all set up. The telescope operators got the telescope (the door is closed) up and running ready to go when the conditions allowed for the door to open. Actually on flight #105, we had to delay the door opening until we got above some high-altitude cirrus clouds, but it did not impact significantly the post-door opening telescope checkout in time for when we got on our 1st target.

Image of the science instrument & telescope guide game consoles between flight legs.

Image of the science instrument & telescope guide game consoles between flight legs.

We stayed all configured even as SOFIA turned between legs.You can see the computer screen on the right is the telescope guide cameras and the streaks are just stars going through the FOV.

The Flight Planner’s voice was a welcome reminder of the essence of time management. She did not speak that often, but often enough to put in reminders “30 minutes left on leg, 10 minutes left on leg,” etc. So when we started to deviate slightly from the observing plan because the script did not work, or the telescope lost lock on the target, etc. and you found yourself easily losing track of time, she grounded us back to the timeline. Our lead instrument scientist, Jim De Buizer, had to make calls on the fly to get back on track to accomplish the tests per leg. It’s a tough job to stay flexible but creative with how to get things done. And when you lose 10 minutes or so to turbulence, you have to re-insert yourself into the observation timeline to keep ticking off the tasks.

The Flight Planner was also in constant communication with the pilots who were talking with air traffic control to look at flight conditions. So another task she did was ask us about some possible real-time deviations for the next leg to “fly around weather” but still stay in the same area of the sky so that the observations were not affected (significantly). The net result is that you might lose some observation time up front at the trade of not having interrupted observing downstream. That was an interesting trade to see happen. And yes, on SOFIA Flight #105, when we were over the Dakotas and Kansas we had to do two deviations due to weather, but we managed to still get most of the data for those legs as a result. Had we not deviated, we most likely may have lost the entire leg’s observation.

 

View from the Mission Director and Flight Planner’s console

View from the Mission Director and Flight Planner’s console.

The central image shows a live view of where the aircraft at the specific time and also shows (by different colors) alternative flight trajectories in case the aircraft needs to divert for weather. Diverting due to weather happened two times on SOFIA Flight #105.

If you noticed in the pictures I posted, we are wearing headsets. There were not enough headsets for all passengers, so we traded off.The sound inside is like a typical 747 aircraft, maybe a bit on the noisier side (lots of computer racks and not much fabrics to absorb sound), but perfectly fine with ear buds. However, wearing the headsets and monitoring the channels helps immensely to know what is going on. There is no “Bleep. Please return to your seat” automated voice from above, but rather the Mission Director saying on the communication (comm) system “Guys, it’s time to sit down now.” And there is no “call-button” for assistance, you just talk where you are through the headset.

Typical view of operations during a SOFIA observation flight

Typical view of operations during a SOFIA observation flight

Typical view of operations during a SOFIA observation flight. We’re wearing headsets to communicate between all the stations on the aircraft.

 Getting back to headsets…it was quite fun, since part of the flight I was sitting at the “conference table” at mid-deck and we were just chatting with the science instrument folks who were near the telescope as if we were across the table. It was very efficient. We could stay at the “conference table” with our laptops hooked to the on-board internet doing the data analysis and report things we saw in the data to our colleagues who were more focused on trying to take the data and keep to the script schedule and interact with the telescope operators who had to do lots of telescope rewinds and target re-acquisitions.Plus, having this arrangement, kept people from crowded at the consoles. Of course, from time to time I wanted to be “at the action” and I would walk and re-plug in my headset up front if a port was open.

Doing data reduction between legs on SOFIA observing flight

Doing data reduction between legs on SOFIA observing flight

The photo above is Luke Keller from Ithaca College, sitting down with laptop, doing some grism 6 data reduction between legs. It was a good thing to share the flight with the imaging team as when they had an image intensive leg, we could escape and look at our data with our data reduction tools.

View from the science instrument consoles during an observation.

View from the science instrument consoles during an observation.

Screens from left to right are: FORCAST control,  FORCAST quick-look image display, Telescope Assembly Status Page, and the Guide cameras.In this image, we are executing a short chop of a point source.

So from our instrument scientist’s log, we had 16 tasks planned over the 6 science legs. We successfully completed 10/16, partially completed 5/16 (mainly due to lost of time from turbulence), and did not complete 1. Or about  88-90% completion rate, depending on how you count it. We’re learning as we go. We’ll use this information from this commissioning flight to improve our observing efficiency during science flights. But remember, these commissioning flights are designed to help us work out the basic modes and capabilities of the instruments and things are expected to not go as 100% as expected.

We have one more commissioning flight Thurs Jun 13th during which we will attempt to do cleanup from Tues’ flight plus address the tasks we had set for that flight (different flight plan is planned as we have different targets).

NGC7027 the “big glazed donut in the sky.” Observing a yummy wavelength calibrator source on SOFIA

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On Leg #7, between 9:45pm PDT (04:45 UTC) and 10:49pm PDT(05:49 UTC), the pilots flew SOFIA along a leg going southeast from middleMontana to northeast Colorado. Our target was NGC7027, a planetary nebula. Ithas a distinctive ring shape, and a frequent wavelength calibrator for infraredinstruments due to having very strong emission lines.

Jim Debuizer, the USRA FORCAST Instrument Scientist, andtest lead for these commissioning flights, affectionately called it the “thebig glazed donut in the sky.” Perhaps he was getting a big peckish?

NGC7027 is a young, and rather dense planetary nebula. It’s notparticularly large on the sky, with its brightest region measuring about ~8arcseconds across in the optical. It’s located about 3000 light years away inthe constellation Cygnus (coordinates 21h7m1.7s RA, +42d14m11sDec). Most planetary nebulae are more extended, covering several arcminutes onthe sky. (As a calibrator note, for those who don’t speak arcseconds: the fullmoon is 30 arcminutes or ½ degree on the sky; 1 arcsec is 1/60th ofan arminute.) SOFIA’s FORCAST mid-IR instrument has roughly a platescale of0.75 arcsec/pixel. Thus, NGC7027 would appear to be ~11 pixels in diameter onthe FORCAST detector. For our grism spectroscopy, we are testing 2.4 arcsec(3.2 pixel) and 4.7 arcsec (6.2 pixel) wide slits, so NGC7027 would essentially“fill our slit.” Thus it would not be a great flux calibrator object as we’dhave “slit losses” but it’s infrared spectrum has well-identified andwell-spaced emission features that would be useful for our wavelength calibrationtask.

Near-Infrared NICMOS imageComposite visible & near-IR image.

NGC7027observed by the Hubble Space Telescope. (left) Near-Infrared NICMOS image.(right) Composite visible & near-IR image.

http://apod.nasa.gov/apod/ap980325.html

http://hubblesite.org/newscenter/archive/releases/1996/05/image/a/

Image showing data reduction of an image of NGC7027 aboard SOFIA Flight#105

Imageshowing data reduction of an image of NGC7027 aboard SOFIA Flight#105

Above is an image of our quicklook pipeline as Iwas processing an acquisition narrowband image (at 11.1um) on SOFIA Flight#105. We used this image to confirm we placedthe target in the slit. The team was also testing out SLITSCAN, anobservational mode that would be used on SOFIA when observing an extendedobject using the grism suite. The positive and negative images are the resultof the chop-nod observing technique used to remove the background.

For moreinformation about chopping & nodding on SOFIA, see my earlier post at https://blogs.nasa.gov/cm/blog/mission-ames/posts/post_1369351626283.html

Image showing data reduction of an IR spectra of NGC7027 aboard SOFIA Flight#105

Imageshowing data reduction of an IR spectra of NGC7027 aboard SOFIA Flight#105

Above is an image of our quicklook pipeline as I wasprocessing our R~300 8-14um spectra (not fully-calibrated). We still need toremove the atmosphere. The strongest atmosphere issue are ozone absorptions at~9.5 microns. The emission features of the nebula are shown in our spectra. Ifyou look closely at the 2D spectra on the left, you can see we aligned the slitto capture two edges of the disk, showing as two bright lines on the edges ofthe slit.

We were observing this object with our grism spectra suite. Wetook data on this same object last week and started to use it as a sanity checkon our in-progress flux calibration in addition to a wavelength calibration. Belowis an overlay of two of our grisms (5-8um and 8-14um) with the spectra ofNGC7027 as observed by ISO years ago. We now have spectra to cover 17-28um and28-34um, and are working on their respective calibration steps. We are usinganother well-studied source, Arcturus (AlphaBoo) as our flux calibrator. Thereason why the 8-14um spectra in the image below is off is because the data setwe took was near-saturation so our various conversions were not optimal. Werepeated the observations at lower exposure to repeat the exercise.

Our working comparison of our short wavelength grism suite data of NGC7027 with previously published observations by the Infrared Space Observatory

Our working comparisonof our short wavelength grism suite data of NGC7027 with previously publishedobservations by the Infrared Space Observatory.

It was unfortunate that during this leg (Leg #7) that we hitturbulence and had to stop observing for a few minutes. We got slitscan(observational technique for extended objects) observation in (the goal of theleg), but sadly did not a requested long wavelength grism spectra of thisobject. However, we obtained other spectra on other objects using themissed-grisms later in the evening. It’s all going to be able piecing togetherthe puzzle now.

“Contents may shift during your flight.” Well, I may have, but not this 2.5 meter diameter telescope aboard SOFIA.

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After boarding, we had some time before the doors closed. Asafety briefing was held. Upon entry to SOFIA, one objective, as this was arelatively “full flight” with 30 people, was to stake out a seat for take off(a comment was even made of the ‘Southwest Airlines’ way). Seats are scatteredabout the airplane for specific purposes and prior to this flight, mycolleagues and I had worked out our seating. We could only send one representative to the “conference table” seatingarea, so Martin Garay (a student at Ithaca College) and I were sentto business class, while Luke Keller (our grism lead, astronomy professor atIthaca College) sat at the “conference table” midway along thetelescope deck.

Sketch of the seating on the telescope deck on SOFIA.

Sketch of the seatingon the telescope deck on SOFIA. There are additional seats on the upper deck.

During the prep for takeoff, I took the moment to inspectthe on-board safety information card. It re-iterated what we learned in egresstraining and what was described as we boarded. Indeed the inside of this 747SPis very different from your normal airline experience and being aware of yoursurroundings wherever you are is important.

ompilation of photos of the SOFIA on-board safety information card.

Compilation of photosof the SOFIA on-board safety information card.

The engines started at 715pm PDT (local time), and we tookoff around 7:27pm PDT. It was a good 50 seconds for takeoff. And essentially, itfelt like a normal jet takeoff sitting up in the business class section.However, unlike a normal airline ride, within a few minutes we were allowed toget out of our seats. It was just so surreal to be walking down/up the planeduring the descent. It sort of felt wrong, as we are accustomed to the strict ruleson commercial aircraft, but it was so important to use any leg designed tobring the aircraft to the 40,000 ft science altitude, to do non-science thingslike setting up computers and testing connections between the systems. On thisflight, every second counts! And that theme was certainly reiterated throughoutthe night.

By 8pm PDT we were at 35,000 ft. The pilots had already completed3 legs of a 13-leg flight plan.

And at 825pm PDT, the telescope door opened! Within minutes,Joe Adams, the FORCAST lead instrument scientist, had started his first scriptto check out the detector frame rate settings.

One of the first data acquisitions of SOFIA Flight #105. Target is R Leo.

One of the first data acquisitionsof SOFIA Flight #105. Target is R Leo.

We hit pockets of turbulence during ascent and near the“weather” areas we had been warned about, and although the aircraft seemed tobe moving up/down/sideways, the telescope moved as well. It was mesmerizing tosee the FORCAST instrument and its counter weight moving about the cabin andyet the position of the star in the telescope guide camera was “rock solid.”Indeed, contents shifting during flight, but not this telescope! Two timesduring the light, the turbulence got bad enough that we had to return to ourseats and the telescope was “secured,” but both episodes lasted less than 10minutes.

From Jim Debuzier’s (the lead instrument scientist) log, hewrote: “09:45 [UTC] Turbulence like a roller coaster. Everyone’s sitting(whether they wanted to or not), and the telescope is in local. Riding it outuntil we can start observing again…)”

What was fascinating was that according to the missionmanager, we probably lost about an hour due to turbulence. We had to sit downabout 2x during the flight for a period of 10-15 minutes. I lost all track ofdurations of things, as I was focused on what data we lost by these unexpectedinterruptions. But each time we faced turbulence, we just took it in stride.Around 08:20 UTC (1:20am PDT) we also needed to do small flight diversion fromour Leg #9 to avoid some baby tornado clouds. This time the timing was good aswe were doing some calibration flats which did not need a target so we couldstill take data during the diversion.

You can see what the actual flight path was by visiting http://flightaware.com and searching onNASA747.

Screengrab of actual SOFIA Flight#105 flightpath Jun 11-12, 2013 from Flightaware.com

Screengrab of actualSOFIA Flight#105 flightpath Jun 11-12, 2013 from Flightaware.com

Screengrab of actual SOFIA Flight#105 altitude & speed Jun 11-12, 2013 from Flightaware.com

Screengrab of loggedSOFIA altitude and speed for Flight#105 Jun 11-12, 2013 from Flightaware.com

Kudos to the pilots for giving us a very good flight andworking with the weather patterns!

One thing to mention, as we were free to move about thecabin, each of us had to carry with us a EPOS, emergency passenger oxygensystem. In case there was a depressurization at 40,000ft, there would not beenough time to get to the nearest seat for oxygen masks. It was a smallnuisance to carry a bag with you everywhere, but it did not get in the way ofgetting the work done, planning, executing, and analyzing the data on theinstrument.

One of the passengers, a member of the DAOF staff, carrying his EPOS, the khaki-green pouch on a shoulder strap.

One of the passengers,a member of the DAOF staff, carrying his EPOS, the khaki-green pouch on ashoulder strap.

My inaugural (and international, it would appear) flight on the Stratospheric Observatory for Infrared Astronomy (SOFIA). Eh?

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I’ve just completed my first flight on the StratosphericObservatory for Infrared Astronomy, SOFIA. Wow. What an interesting experience.I’ll break down my comments on this first flight into several shorter blogs.

When I awoke late morning (as I was trying to get onto anight shift), I obtained the list of targets planned for tonight’s flight. Weare still commissioning these “modes” on SOFIA so we chose bright, standardobjects that have been observed regularly by other instruments over the years.

Tonight’s targets were R Leo (a red giant star), NGC7027 (aplanetary nebula), alpha Boo (also known as Arcturus, a K1.5 IIIpe,orange giant star), R Cass (M-type, red giant variable star of MiraCet type) and T Mic (a M7-III giant, semi-regular pulsating star). Thetargets were taken from a list of calibrators we assembled and chosen becausethey were visible to a USA-domestic flight plan for SOFIA for the middle ofJune. If we flew at another time, we would have used other similar typeobjects. But these five objects would be our guides on this flight.

With the target list came a list of the specific measurementswe planned to make on each target. We’ve had to deviate from the original planI helped write months ago, only because the two previous flights had been cutshort. So this revised plan tackled the largest holes we needed to address.

At 5:25pm local time, I attended the Crew Briefing. Here theMission Director Charlie Kaminski did a roll call of all the people to flyaboard SOFIA tonight. There were 5 staff (pilot, co-pilot, flight engineer andtwo safety techs), three telescope operators (only two are needed, and one wasin training), the FORCAST science instrument support team (for both imaging andgrism modes, about 9 of us), Dana Bachman (SOFIA EPO lead) and 4 SOFIA AirborneAmbassadors, Beth Hagenauer (NASA Dryden PAO) who was shepherding a televisioncrew (about 4-5 people), Tom Rolling (NASA Ames) who ran an EMI test betweenhis water vapor monitor facility and the FORCAST instrument, the support stafffor the on-board MCCS system, and the Mission Director and Flight Planner. Allin all, thee were about 30 folks on this flight, a complement typical for theseearly flights where lots of activities are occurring simultaneously.


Flight Plan for SOFIA Flight 105 as presented during the Pre-Flight Briefing
Flight Plan for SOFIA Flight 105 as presentedduring the Pre-Flight Briefing.

Next we had a briefing about the weather, with emphasis onexpected areas of turbulence. Granted it’s never clear when you will hit unevenair, but it was a good mental exercise to think through each flight leg to seewhat might get dropped if the turbulence got too rough to control thetelescope. So we were expecting to have “weather” when we flew over northernMontana, Nebraska and Missouri due to the summer thunderstorms. The timelinefrom doors closed to data transfer at end of flight was discussed. And each keysystem: aircraft, telescope, and science instrument, reported on theirreadiness.

Upon inspection of the flight plan, it was remarked “You areall going into Canada” and we all inspected that yes the transition from Leg 8to Leg 9 did cross at the Montana/Canadian boarder.  In flight, the Flight Planner actually announcedaround 12am PDT (07:00 UTC) when SOFIA entered into international airspace,even if just for a few minutes. That was very cool, eh?

Mapping of observational targets/objectives to each flight leg

Mapping of observational targets/objectives to each flightleg.

A SOFIA flight is highly orchestrated. For this particularflight, as we were using specific targets for calibration, we dedicated singlelegs to one object.  Within minutes afterthe crew briefing ended, it was time to walk over to SOFIA, which had beenmoved out onto the tarmac, and climb aboard!

Boarding SOFIA for flight observations

We board SOFIA from the taxi-way. The plane had beenrefueled and ready to go hours before our take-off.

Oh, a special surprise! A friend from a leadershipdevelopment program we did together about 3 years ago (my, has time flown!), EdTeets, a meteorologist & atmospheric physicist from NASA Dryden, came togive the pre-flight weather briefing. That was awesome Ed!

My friend Dr. Ed Teets, atmospheric physicist, from NASA Dryden given the weather briefing for SOFIA Flight #105.

My friend Ed Teets, atmospheric physicist, from NASADryden given the weather briefing for SOFIA Flight #105.

This ain’t your normal in-flight safety demonstration video. SOFIA Emergency Egress Training.

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Note: Photos taken during of a safety video during atraining class, not of optimal quality, but enough to capture a pretty unique airplaneand its emergency procedures.

I have returned back to Palmdale, CA, the base of operationsof NASA’s Stratospheric Observatory for Infrared Astronomy, SOFIA. This weekthere are scheduled two flights to 40,000 feet to complete commissioningactivities of the FORCAST mid-IR imager with grism complement and some firstscience activities of the Cycle 1 period. The two flights are Tues Jun 11thand Thurs Jun 13th, sunset to sunrise.

Tuesday marks my first flight on SOFIA. Being a newbie, I amrequired to attend egress training. I took this class along with a student fromIthaca College who is helping with our grism data pipeline and four SOFIA AirborneAmbassadors, education specialists from El Paso, Texas. All the other flyershave had this training.

For more information about the SOFIA Airborne AmbassadorProgram, check out this link.

http://www.sofia.usra.edu/Edu/programs/ambassadors/ambassadors.html

The briefing started with a description of the location ofthe exit doors, and hatches. To note in this 747SP there are no over-the-wingexits, and no floor lighting to illuminate the path out. The two side doors actjust like any other jet egress doors, each equipped with an evacuation slide.And no, we did not test the slide deployment on the plane, as that costs tensof thousands of dollars to repackage the slide and recertify it for flight.

A lot of discussion was about the location of the oxygenmasks and life preservers because depending where you are sitting on the plane,or what station you are at during flight, the location varies. We were shown amultitude of oxygen masks. The figure below shows top left: standard drop-downmasks that we are commonly familiar with, top right: EPOS, or emergencypassenger oxygen system (also known as a smoke hood), bottom right: the masksfor the pilots and the mission manager (also includes a communication system),and bottom left: portable oxygen tank which is part of some of the specialseats on the telescope deck. There are masks in the toilets, and some areportable to carry with you if you are moving about the cabin. The presentationwas a video plus a hands-on demonstration.

Photos from SOFIA pre-flight safety training. Compilation of videos-stills showing the variety of oxygen masks on board

Photos from SOFIA pre-flight safety training. Compilation of videos-stills showing the variety of oxygen masks on board.

We went over locations of the fire extinguishers, first aidkits, AED (automated external defibrillator) and emergencysurvival kits. On each flight, there will be 6 crew members, with 4 up on theupper deck (pilot, co-pilot, flight engineer and tech) and 2 safety techs onthe telescope deck. But with on order 20-30 passengers scattered between bothdecks it really is important to know where all this special equipment is located.Nothing is standard on this 747SP.

We looked through the emergency survival kit and handled thedifferent radios and beacons in case we need to assist the crew. We alsolearned that the Mission Manager serves as the main point of contact fordirection in case of an unexpected emergency.

The next step in my SOFIA adventure will be a crew briefingon flight day around 5pm, where specifics of each flight leg will be described.There will be an on-board safety summary as well. I was out here for line opstwo weeks back and I have to admit I never really looked for the safetyequipment, so rest assured now that I now what I need to look for, I can spotthe equipment exit areas that were discussed in the briefing tonight!

I close with a still I took from the safety video showingthe escape hatch from the upper deck of the 747SP. Apparently you have to grabhold of a special handle (and there only a few) and rappel down. I really hopeit does not come to that, but I am glad I know about the upper hatch, escaperoutes down through the nose gear and side doors.

Demonstration video of escape route through the cockpit sealing of a 747SP

Adieu from Palmdale, CA, for now, until returning for SOFIA commissioning flights

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We completed night 2 of line ops for the mid-IR cameraFORCAST on SOFIA. Our tests included script validation of the main observationmodes for the imaging and spectroscopic (grism) channels, optimization ofdetector bias, and exploring a new way to improve the flat fields for theimaging modes. During part of the night, we were slowed down by debugging ofscripts, an activity we were glad we found issues with now, rather than inflight. As a result of the delays, not all the planned tests were completed,but May 28th is the next line ops for this instrument.

We did manage to get our first grism spectral tests in, butmore testing remains for May 28th where my colleagues will take over the testing. I will be on call for data analysis.

I head back to my home in Boulder, CO, today, after a powernap. I will be returning to experience a flight on SOFIA on Jun 11th.Until then another line ops is scheduled for May 28th, followed bycommissioning flights on May 30, June 4, June 6, and June 11th.  I’ll be on call for dataanalysis and wishing my colleagues clear skies, good script runs, and completion of the readiness tests. SOFIA soon enters formal science flights at the end of June, and we want to give the larger community a high performing instrument with an observing strategy to optimize time and signal-to-noise.


SOFIA on the runway at NASA’s DOAF, Palmdale, CA during FORCAST line ops May 2013.

Who's Sitting in the Driving Seat when you Fly the Infrared Friendly Skies?

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Note: The pictures in this blog are taken from a recent line operations (when SOFIA is not in flight, but being operated on the runway) on May 23, 2013. As the program is in its iterative operations phase, these pictures capture the inside of SOFIA on this date. There will be additional preparations to enable the required safe readiness for the flights, the first set for May 30th.

At one level SOFIA is quite simple: you want to point the telescope at for target, hold there on the instrument sensor array for a set amount of time, maybe repeat the observation to allow for better signal-to-noise, and then move on to the next target. At another level, SOFIA is quite complicated as you have a moving observatory (in several degrees of freedom, i.e., forward, left, right) that is trying to target, “peak up” and stay on target for several minutes by which the observatory and/or the target has moved enough.

Mission Director: He/she is responsible for ensuring the flight meets the success criteria and is safe. They run the readiness reviews and summary the milestones for the flight campaigns. They also make decisions if needed to deviate from plan. They keep track of how well we are executing the plan.

The Flight Planner: On the plane he/she sits next to the Mission Director. Lots of work is done ahead of the actual flights to map out an optimized series of “flight legs” to maximize the time spent on target. As the telescope has a fixed position within the aircraft (aft-port), a leg towards the West (in the Northern Hemisphere) means the sky target is in the south; a leg towards the North means the sky target is in the west, etc. When SOFIA flies in the Southern Hemisphere, this gets reversed.

More information about SOFIA Flight Legs can befound at SOFIA Flight Plans
Description of SOFIA console layouts

The Telescope Operators. Sitting close to the telescope, they monitor the telescope set-up and operations and real-time interfaces with the science instrument. Each science instrument will have different requests for the telescope assembly. They also perform the Line Of Sight rewinds periodically. Normally this is scoped out in advance but this is envisioned to be a manual operation performed with agreement the Instrument Scientist’s okay. For example, you don’t want to interrupted an observation, so you are watching the clock and the angles in real time to know when this activity is needed.

More information about SOFIA Line of Sight can befound at SOFIA Line Of Sight Rewind

Instrument Scientist. Each science team will have an Instrument Scientist who knows the “ins and out” of the instrument and the subtleties of changes to observations or techniques. He/she is in constant communication with the Telescope Operator as well as the Principal Investigator of the observations. Science Instrument observations are run mainly by pre-written and pre-tested scripts, but sometimes there are some manual observations that the Instrument Scientist can execute.

The many roles to complete a SOFIA Science Flight

There is also a lead for the MCCS, the Mission Controls and Communication System, to supervise the performance of that critical subsystem. This software controls the communication between the science instrument and telescope as well as all the archiving of any data taken during the line ops or flight.


There is the Science Team who is on board for the in-real-time data reduction and assessment, in case an observation needs to be redone again or done differently,  a principal investigator who decides the priorities of the science observations for the flight and directs the science team and  two pilots and a flight engineer for flying the aircraft.

Finally, there is space allocated for ride-along teachers and other guests who can participate in SOFIA science.
 
To learn more about the SOFIA Airborne Ambassador program check out SOFIA Airborne Ambassadors Program

'To Chop, Nod, or not Chop, Nod. That is the question.' SOFIA FORCAST May 23, 2013, line-ops.

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I am out here in Palmdale, CA, not for a SOFIA flight (yes Iknow that’s where most people’s interest peaks) but for a critical step calledline-ops, or operations on the flight line. Essentially we are going throughexactly what we plan to while the plane is at altitude and work on end-to-enddata testing, assessing observation timing, and communication, both among thedifferent people needed to complete the observation and also between we humansand the highly complex software subsystems.

At 2130h May 22, crew briefing. We covered the mainreadiness topics: Weather (winds, humidity), Required Personnel, AircraftStatus and Configuration (System Engineer reported out), Telescope Status,Mission Systems Status (Flight Systems reported out), Operational Timeline(roll out, people on, telescope door open, telescope door closed, people off,roll back to hangar), Mission Rules (don’t connect laptops to the internalsystem and wireless at same time, bring drinks in closed containers, getpermission before entering roped off areas, etc.), Safety & EmergencyProcedures (exit doorway locations, footwear required), and Test Summary.

Being on SOFIA is not like flying on a normal 747 jet. Ihope from the various photos in this blog entry and others, you’ll see it’s got“other things” like computer racks, a whole data collection and archivingserver farm on board (the MCCS), conference tables, and various electricalpanels needing access for maintenance or operation. It’s got airline seats(with the normal seatbelts) for takeoff and landing and places to store your laptopbags, but the similarities end there.

So last night we got through some key tests. We did a pupilcheck (to optimize alignment of the FORCAST instrument to the telescope). Nextwere a series of inspections of the telescope boresight (telescope centered ona star) and how that appeared on all the imaging (all filters) and spectroscopy(for all grism and slit combinations) modes. We learned we had a systematicoffset in our slits, but we updated the .ini file to address this. Then we didsome testing of the basic modes. We tested chop-nod-dither in the SIRF and ERFcoordinates. SIRF=Science Instrument Reference Frame (rows & columns on thedetector array). ERF=Equatorial Reference Frame (RA/DEC on the sky). There isalso a third coordinate system, the TARF=Telescope Assembly Reference Frame (elevation,x-elevationangles). Yes, astronomers love their coordinate systems.

Below is a photo of one of the chop-nod tests, on a bright targetstar. It’s chop-nod-match mode. Left is the Science Instrument Console withquick look software showing a reduced subtracted image (you see the positiveand negative star images). The right image shows a series of display for thetelescope guide camera and telescope display.

Examples of short throw chop-nod testing SOFIA FORCAST

With the remaining hours for this night, we started probingthe space of the chopping throw vs. angle. Below is an example of a large chopthat was bumping up against a hardstop of the secondary, so we spent the restof the night investigating that issue. The scale bar on the lower left of thatguide star camera image is 1 arc minute.

Example large chop testing SOFIA FORCAST

The telescope door was closed at 0500h. Sunrise was at0545h. We’ll regroup later tonight to address the series of tests for tonight.There will be a crew briefing at 2130h to assess readiness for tonight.

Oh, surprise to me, we had internet on lineops, soI was tweeting away in near-real time we did our testing and I also got someIDL coding done for the pipeline end-2-end tests.

Stairway to the stars. Climbing aboard the SOFIA Airborne Telescope

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We got the “go” to proceed with line ops. SOFIA, a 747SP,was towed out of its hangar onto a side-runway, and away from any air traffic. Theheading is 130.5. This is important as it tells us what view angles areavailable from the telescope. The telescope looks out the aft-port side of theaircraft. (Aft=back of wing, Port=left side, when viewed from the back, facingthe front). So at this heading, we are looking at the N-E portion of the sky.Our calibration targets include TDra, NSV25184, RUCyg, muCep, and TCass, allpretty bright stars.

We walked out from the hangar to the craft and can come/gofrom the craft during the night. Of course, this is not what will be likeduring the flight. Below is a picture of our ingress/egress path on the plane, 

a “true stairway to the stars.”  I learned that for the flights, we would do a similar activity, meaning we donot board within the hangar, but board after the craft has been towed out tothe runway.

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