HiCal, Seals, Pegasus and a Herc

Finally got back to the blog, probably have a few more posts that I would like to get done.

Just a reminder, I have more photos at https://www.flickr.com/photos/114463775@N04/sets/72157646697801283

For this flight of ANITA, a balloon-borne calibration instrument called HiCal was developed and flown to get additional data. The idea behind it is that a pulsing antenna will send a signal in all directions when it is in the line of site of ANITA. Some of the signal will travel directly through the air to ANITA, while some of it will reflect off of the surface of the ice back up to ANITA. The differences between the two signals can be used to look at the effect the surface of the ice has on radio signals coming up through it as well as reflecting off of it. It turns out not we're not exactly sure what impact the surface of the ice has on the radio signal and it is very hard to model. An analogy would be ripples on the surface of a pool and the effect it has on the appearance of objects below the surface. The surface of the snow/ice has waves and ripples and varying degrees of roughness. This flight was largely a proof of concept. The pulser itself was a barbecue lighter hooked up to a motor that used a cam to press the button every 3 seconds. The lighter was hooked up to an antenna inside of a pressure housing. Another issue with flying balloons is the reduced air pressure makes it easier for electricity to arc and the antenna would arc to the computer that it flew with if it wasn't in the pressure housing.

Here you can see HiCal hanging from the hook. The electronics are contained in the rectangular box and the barbecue lighter and pulser are in the cylindrical pressure housing below it.

Here are some photos of one of the HiCal launches. We actually had three HiCal launches, two of which were successful. One of the launches went up a hundred feet or so and then came crashing down. 

The launch is a bit more involved than I expected. They call this a "hand launch", but it still involves bit of prep.

One of the successful launches. HiCal only has limited windows when it can launch.  We would like it to be close to ANITA, but not too close and of course there are the usual weather constraints with a launch.

Here is a photo of crack that formed near McMurdo and you can see a large number of seals near it in the middle of the photo. The sea ice cleared out in front of McMurdo a few weeks ago, but it has since frozen over again. It usually takes a good storm out of the south late in the summer season to blow the ice out into the open ocean. I have never been there for it, but the stories of orcas, minke whales, leopard seal, etc. immediately offshore are pretty amazing.

I had the opportunity to visit the "Pegasus" crash site, don't worry, nobody was killed in the crash.

As I understand it, a C-121J Constellation called "Pegasus" was making a run to McMurdo from Christchurch in 1970. They passed the point of safe return with the understanding that bad weather was headed towards McMurdo. They made it to McMurdo at the same time as the storm and had a hard time seeing the runway. After six or seven attempts, the crew realized they had only enough fuel for one last attempt. The plan was to make the final attempt and if they couldn't see the runway, retract the wheels and make a gradual decent into the snow a couple miles away. However, the pilot was able to see the ice runway on the last attempt and put the plane down. However, snow had started to form drifts on the runway because of the storm. One set of landing gear caught a snow drift and caused the aircraft to spin. The spin broke the landing gear and thus a wing.

Here is view of Ross Island looking at McMurdo from the crash site.

 And here is McMurdo zoomed in.

Lastly, a C-130 head to Pole taking off from Willy Field with one of my coworkers aboard.

Update, Emperor Penguin, calibration pulser

My apologies for not keeping this blog updated. ANITA was cut down a few weeks ago, and the Australian Antarctic Division was able to recover some of the crucial components. I recently made it back to Hawaii after doing some travel in New Zealand. I will try to update the blog over the next few days to document and share some of the highlights.

We buried some antennas in the snow outside of our hangar that we use to calibrate the instrument as it is flying. We can compare the strength and quality of the signal as well as the arrival timing of the signal from the calibration antennas with the known position of the antennas and the gondola as it is flying to get a pretty good idea about the performance of the instrument. I really only share this because during one of our launch attempts, an emperor penguin walked right through the area where the antennas were buried. From my understanding, it's not unheard of for penguins to go wandering or exploring on their own, but it's my impression that many don't survive. We were about six or seven miles from any place where the penguin could get back into the water, if it knew how to get there.

Here is the gondola hanging from the launch vehicle during one of the failed launch attempts. We would show up about eight hours before the scheduled attempt to get the gondola ready. All of the canceled attempts were due to weather conditions that weren't favorable for launch. Launching a balloon requires that the winds speed stay low up to about 2000 feet and they need to be convinced it will stay low and from the same direction for at least a couple of hours. If the winds are too light, the balloon doesn't move, or at least not in a predictable direction and they can't lay out the flight train. If the winds are too strong, the balloon will blow out of the launch pad before it's risen high enough to lift the gondola.

 Here you can see some of the procedure for prepping the flight train for flight. There are termination packages that are used to cut the parachute and gondola away from the balloon and another cut the gondola from the parachute when it lands.

One day there was a fuel truck out at LDB driving around with a rear tire showing some serious camber. It turns out all of the lug bolts had been broken off and the hub was just rolling along the inside of the rim. Thankfully they took the wheel off and it didn't come off while driving.

I was able to tour the SuperDARN facility while at McMurdo. SuperDARN, Super Dual Auroral Radar Network, consists of over thirty of these stations around the world that monitor the ionosphere by bouncing radio waves off of it. As the plasma moves, it causes a dopler shift in the returning radar signal which can be used to determine the movement and position of the ionosphere in different regions. Small changes in the ionosphere near the poles help predict larger changes of the ionosphere elsewhere. The ionosphere helps provide protection from space weather, so changes in it can have an impact on power grids,satellites, and astronauts. SuperDARN is also not nearly as photogenic as ANITA. 

Here you can see the display from the McMurdo site.

Here you can see one of the helicopters slinging an ATV out to some field camp. I liked the rudder on the ATV.

Ob Tube and Solar Panels

These next few posts will be of old photos I would have liked to have posted earlier.


The Observation Tube or Ob Tube is a tube they insert into the sea ice just a short walk off the coast. It is something I hadn't heard of until this trip, but apparently they have done it at least once before in the last few years. It is only open early in the season as the tube itself actually hangs from the sea ice and would sink if the sea ice were to break up.

It was definitely one of my neatest experiences here, but probably also the least impressive in photos.
In this first photo you can see the tube you climb down. I barely fit into the tube and climbing up was definitely challenge. At the bottom there is a box you can sit on in a sort of hexagonal room with windows on each face so you get a 360 degree view. I did this in late November I think and the 24-hour sunlight had started to help a lot of sea organisms to flourish so the visibility in the water wasn't as legendary as it is early in the season but was still fairly impressive.

My camera started fogging up almost instantly. The water was about 29 degrees and the Ob Tube was probably pretty close to that. I was standing on the surface for a while and it was a bit cooler up there so the cold camera was ready to condense whatever moisture there was in the tube. There were multiple panes of glass which were a bit dirty which also showed up a lot more in photos than in real life.

These two photos show brinicles which are like stalactites on the underside of the sea ice. They are hollow tubes and form as the sea water freezes on the underside of the sea ice. During the freezing process salt is forced out of the water. This makes the surrounding water saltier and thus denser. Because it is saltier, the freezing temperature is lower so it doesn't freeze, and because it is denser it sinks. As it encounters less salty water below, it causes that water to freeze. The brinicle is actually a tube with the salty, cold water flowing down the middle and freezing the surrounding water at it's edges.

There's an interesting video of the process and effects on youtube:

https://www.youtube.com/watch?v=lAupJzH31tc

I found out that somebody had to poke holes in all of the cells of the honeycomb backing of our solar panels and was glad it wasn't me. There is some concern that the sealed cells will build up pressure as the balloon travels to float and could damage the solar cells. The maker of these panels actually buys solar panels for homes, removes the cells and then makes new lighter weight panels. Each panel has three frames, and we have eight total panels on the gondola. This first photo shows most of one panel.

Now for something completely different. I found this youtube video talking about some of the Weddell seal research that is being done here. At least one of the researchers in the video is still here and gave the talk that I saw on Weddell seal research.

https://www.youtube.com/watch?v=2qlaBS7SQ4Q

Mele Kalikimaka

Merry Christmas to those up north. My apologies for not keeping this up to date. The internet has been pretty slow when I've had time to go on it. Now that ANITA is flying, I should be able to upload some more photos and work on the blog.

Here are some photos of the ANITA III launch. We scrubbed a number of times due to weather. The balloon launch requires low wind up to about 2000 feet. They would also like the wind to be blowing in a consistent direction up to that level. The wind also needs to blow in a consistent direction so they can lay out the flight train. Here they want things to be below 5 knots. It's also tough to predict the weather as it can vary dramatically over short distances and there aren't many weather stations. We had one attempt that had blowing snow as we came over the transition onto the ice shelf, but dead calm at LDB which is only about 7 miles away over flat ice. However the winds up at about 500 feet were blowing pretty good so we couldn't launch that day.

We generally showed up about 7-8 hours before the actual time of the launch attempt to start all the checkouts.

I'll see if I can get a video of the launch that I can share for those of you who weren't able to see it.

Here is the balloon right after release from the spool. The balloon itself connects almost directly to the parachute which is the orange thing in the middle. The balloon inflates as it rises due to the decrease in pressure as you go up. They have a collar on the balloon itself to make a "bubble".

The wind had shifted direction well before launch, but after they laid everything out so they knew they were going to be doing a bit of driving. It is always impressive to see. There are times they have to back up because the winds are so light, and times that they almost run out of balloon pad because the winds are so strong.

In this photo you can see the crew chief pulling the cable to release the pin that lets ANITA off of the Boss.

Our solar panels deployed flawlessly. I'll also see if I can get the video of the test of that in Palestine.

It flew just about directly overhead from where I was watching. After the incident in Australia a few years ago where a payload crashed into the vehicle that an unaffiliated photographer had parked at the edge of the launch pad even though he had been asked to move it, there have been many changes regarding safety. One of the more frustrating ones is the requirement that we be inside a building if the flight train is laid out pointing within about +/- 60 degrees of the viewing area. There was one scrubbed attempt that we were required to be inside the building for. I was glad we didn't launch that, but I know some of my coworkers would have liked to have been able to leave sooner.

Lastly, a photo of the remaining ANITAns at our Christmas dinner. I believe most of the others that were down here made it back North on Christmas Eve thanks to the crossing of the dateline. Dinner was delicious as always.

First launch attempt is tomorrow

Sorry for not keeping this updated. At this point we will be making our first launch attempt tomorrow. It probably would not launch before 10am local time 12-11-14.

Launch viewing should be available here:

http://www.csbf.nasa.gov/antarctica/ice.htm

I'll try to get another post up soon, but it will probably be an early start for me tomorrow, so I don't know when I will get around to it.

Thanks.

11-15-14

 Just a reminder, I have more photos at https://www.flickr.com/photos/114463775@N04/sets/72157646697801283/

The internet at my dorm is spotty which is a big part of the reason I haven't been updating the blog.



Here you can the gondola assembly over a few days.

We have since added on the bottom ring of antennas which is not in the photo, but I'll add one later.

I thought I spotted a seal pup on the way back from work one day so a few of us walked back after dinner to see if it was one, and sure enough there was a seal pup out on the ice.

In this photo you can see the seals on the ice on the left of the photo, they look like dark blobs. LDB where I work is a blur on the horizon in the middle of the photo. Scott Base, the New Zealand base, is partially visible on the right. One of their vehicles is coming up the road.

Here's LDB from that same spot.

This is a shot from LDB of Mount Erebus (the volcano on the left) and Mount Terror (on the right)

I also went on a hike around Ob Hill with some people because I heard that there was another seal pup over there. Here you can see that seal pup with its mother. I'm hoping the other seal in the photo is pregnant and will go back to see if there is another seal pup. More on seals, they are one of the few 1,000 pound predators that you can approach with their young without risking seriously injury. I didn't approach them, but it makes it a lot easier for the biologists. The next few photos are from that hike.

Here are some people walking down Ob Hill.

Here you can see ANITA hanging outside of our hangar. Again, the bottom ring of antennas has been added on, but I don't have a good photo of it yet.

I think I took this picture to show you what it looks like here on a cloudy day. This is looking out towards Mt Erebus from LDB.

I also went on a tour of the pressure ridges which are near Scott Base. The Kiwis have visitor parking and a parking meter.

Here is a photo of part of Scott Base with Ob Hill in the background. McMurdo is on the other side of that pass.

A number of Kiwis were out flying their kites.

Here are the seals from the pressure ridge tour. These are the same seals that are in the first set of photos. The next photos are also from the pressure ridges. The ridges form as the Ross Ice Shelf pushes the sea ice into Ross Island. The sea ice has no where to go so it forms these waves that eventually compress enough to cause the ice to buckle. All the sea ice melted last year, so the ice isn't as thick as multi-year ice. Thicker ice makes for taller features. The features are much more impressive in person than in the photos.

One of the ridges in the middle right of the photo looks like a dog.

Here you can see footprints left behind. In certain situations such as this one, the snow around the footprint gets blown away and the compressed snow of the footprint becomes elevated.