Parabolic Flights – More than just the “Vomit Comet”

We have posted online the past several weeks that we are currently gearing up for a new parabolic flight campaign in Houston, TX.  But what is involved in a parabolic flight campaign?  What is a parabolic flight?  And why do we even do them?  Hopefully, this brief overview will answer these questions, or at least provide an initial framework for where to go next.

A parabolic flight campaign is the entire mission associated with the parabolic flights.  For this campaign, that involved a pre-Test Readiness Review (TRR) on Friday, June 5^th, followed by the actual TRR the following Monday (as well as loading the plane and installing hardware), four consecutive flight days (Tuesday-Friday), unloading the aircraft on Friday, with a backup day on Saturday.  Since we study plants, that means all of our planting must be done beforehand, and must be done so that each day, we can have the same age of plants.  For this campaign, that means planting dormant plates and activating them in a staggered pattern, so that we can have (for example) 8 day old plants on Tuesday, Wednesday, Thursday, and Friday.  Since we will be in Texas, and not close to UF, we also have to arrange travel, lodging, meals, and set up a portable workstation and laboratory to do the work we need to do while we are there.  A lot of planning goes into one of these campaigns, usually starting about three months before we depart.  But it is this planning that makes these campaigns possible—and the more planning, the more successful it is too.

Image credit: "Zero gravity flight trajectory C9-565" by NASA - C-9B Flight Trajectory, NASA Reduced Gravity Research Program. Licensed under Public Domain via Wikimedia Commons - http://commons.wikimedia.org/wiki/File:Zero_gravity_flight_trajectory_C9-565.jpg#/media/File:Zero_gravity_flight_trajectory_C9-565.jpg

A parabolic flight uses commercial aircraft to achieve true zero gravity by adjusting its angle of flight.  The diagram (above) shows one parabola and how the plane is able to achieve this altered gravity state.  In our case, we will fly forty parabolas in one flight, for a campaign total of 160 parabolas.  We depart and arrive at Ellington Airport (formerly Ellington Field) in Houston, TX.  What about the nickname, “Vomit Comet?”  Though it is not the official name of the aircraft (that would be “Weightless Wonder”), it does accurately reflect the relatively high rate of motion sickness induced by this kind of a flight pattern.  Anti-motion sickness medication is usually administered to all flyers prior to each flight, and from experience, they really do work.  The flight is very smooth also.  Save for an abrupt end to each of the zero gravity portions, the rest of the flight is more akin to a boat’s motion than a roller coaster.  Weightlessness is truly a unique feeling.

We use parabolic flight to see rapid responses to zero gravity, hyper gravity, and changes in gravity in general.  NASA has used parabolic flight in the past to train astronauts, and many other institutions and organizations have used them for testing their systems and techniques in zero gravity, prior to true spaceflight.  Being a plant space biology laboratory, we are particularly interested in plant response to gravity.  Plants have not evolved to respond specifically to zero gravity, and thus in order to adapt to this new environment; they must engage previously-existing pathways.  What parabolic flight allows us is to look at what happens first—the plant’s initial response to a change in gravity, whether that is from normal 1g to 2g (beginning of the parabola), 2g to 0g (middle), or 0g to 2g (end).  Spaceflight allows us to look at adaptation to a prolonged zero gravity environment, which is extremely valuable.  Combined with parabolic flight, we can generate a more complete picture of how plants respond to changes in gravity. 

Here is Dr. Paul explaining a little more about what it is like to ride on the "Vomit Comet".

What do interceptor-class jets and plants have in common? A lot more than you might think…

In April of 2013, our lab performed an experiment with Starfighters Aerospace, located in Kennedy Space Center.  This company uses Lockheed F-104s to create the same extreme g-forces felt during suborbital missions.  These craft are able to fly at Mach 2.2 and are able to climb to altitudes over 90,000 feet.  For more information, visit http://www.starfighters.net/

But what do Starfighters have to do with plants?  Our experiment looked at plant transcriptome response to suborbital flight profiles.  The basic question we asked was, “What would plants feel during a suborbital flight?”  We were also asking if an untrained civilian (represented here by our two PIs, Dr. Rob Ferl and Dr. Anna-Lisa Paul) could be tasked to perform certain functions during the flight, such as taking various measurements and harvesting plants in a special chemical fixation unit designed at Kennedy Space Center called a KFT.  We also flew more plants in the two separate cargo holds, one of which was pressurized.  We are currently analyzing the data from microarrays, which tell us the transcriptional profile of the plants from KFTs, and will soon be analyzing the differences in atmospheric pressures, in addition to the g-forces felt on this kind of flight.

The flight itself consisted of a high-speed takeoff, three lateral turns, a high-speed, low-altitude run, followed by a 90-degree vertical climb.  The F-104 then turned upside-down, resulting in about 10 seconds of zero gravity, then began the high-g descent.  This profile is similar to the forces that will be felt on suborbital craft, the only difference being the amount of time in zero gravity.  The entire process was repeated two to three times for each flight.  The video below is a montage of the two flights from that day that represents the flight profile and some of the activities performed onboard.

Dragon is back! Samples on their way...

Dragon on deck

Imaging phase is over - awaiting sample return

It is with a small sense of relief, and a large sense of gratitude, that we now close down the LMM image gathering segment of the APEX-03 experiment. The crew at GRC have been fantastic and we deeply appreciate their efforts. Now we return our focus to the flight operations that center with our colleagues at KSC. Having successfully managed the flight operations and the ground control operations, the team at KSC is back in our forefront, monitoring the packing and stowing of the APEX samples for return on Dragon.

We will all be watching for a safe departure of Dragon from the ISS and a successful splash down.

Third and final APEX harvest and imaging off to a great start

This morning at about 0230 EST CDR Butch Wilmore began the setup and actual final harvest of the APEX-03 experiment on the ISS. The harvest went extremely well. CDR Wilmore's expertise and attention to detail, plus his familiarity with the APEX experiments, all contributed to a fast and efficient harvest that was amazing to see.

The last imaging plate was installed into the LMM to complete the harvest activity, and the imaging team at GRC is and will be hard at work for the next 28 hours collecting the final sets of on orbit images of Arabidopsis gene expression.

Outstanding stuff!

Second LMM Imaging Session: Video of astronaut closing up the LMM

Here is a part of the process that we have not been able to show previously. This video shows the front window of the glovebox that holds the stage of the LMM. You can see our petri plate sitting on the stage (it is sitting flat in this perspective, presenting a side view with the white tape wrap visible, just to the left of the glove).Later in the video you can see CDR Wilmore swing the glovebox and LMM back into the FIR rack in preparation for closing up the rack panels. Once this is complete the rack is powered on and the team from GRC takes over to command the images.

and busier...

Well, we survived the first set (flight and ground) of LMM operations – one set down, two to go. We need to keep long and unusual hours, and we trade off shifts to allow the other to get some rest. Being from Florida, driving to the base at 0200 in the snow is a new reality… As said earlier – we are busy, but it is the price of being able to do exciting science in an amazing environment.

Below is a composite image of one of the roots we collected with the orbital LMM this week. It shows a section of root expressing two different fluorescent gene reporters, one tracked with GFP and the other tracked with RFP. The white light image is stacked with the red and green images to produce this map off gene expression and adaptation to spaceflight.

Also below is a time lapse movie of astronaut Cdr. Butch Wilmore working with our experiment,captured with a cell phone from one of the monitors. We have already posted some snippets of his operations, but the time-lapse is pretty fun to watch.
Some of the corresponding Ground Control operations can be seen below as well; Allison Mjoen of KSC is the pseudonaut.

and finally, a small look at the outside of GRC building 333, which houses the LMM GIU and the Telescience Support Center.