ULDB Launched--Going Home Soon!

We launched our last flight yesterday (Sunday 28 Dec). This was a test flight of a new design of a super-pressure balloon. This is the largest super-pressure balloon ever launched and successfully floating. The normal balloons we launch are zero-pressure balloons meaning they have ducts that let the balloon vent as the sun warms the gas inside the balloon and causes the gas to expand. At night, or where there is 24 hours of daylight--when the sun is at it's lowest, the gas in the balloon cooled and the balloon sinks in altitude. The only way to counteract this is to fly ballast that you can drop to get the altitude back up. This isn't a big problem in Antarctica as not much ballast is needed since the balloon only drops about 10,000 feet when the sun dips. It is a bigger problem when we launch from a site that has sunset. You simply can't carry enough ballast to maintain nighttime altitude for more than 3 days. The answer to that problem is to fly a balloon that does not need to vent gas. That is a super-pressure balloon. It is built with special materials that make the balloon able to withstand the huge pressures inside the balloon. It will only vary 500-1000 feet in altitude overnight. It has taken a long time to come up with a design that works correctly. Hopefully this will be it. This will likely be my last entry. I will be leaving to go home in 3 or 4 days. The pics above are of the launch and a pic of the ULDB (Ultra Long Duration Balloon) balloon at float taken through a telescope.

Merry Christmas from The Ice

Christmas was actually yesterday here. One our CSBF guys took this group pic of us in front of our Delta transport at work..getting ready to go back in to McMurdo. That's me kneeling in front, second from the left.

Merry Christmas!

ANITA balloon at float through telescope

Mike from Aerostar (the manufacturer of the balloons we use) took these great picture of the balloon for the ANITA payload as it was going into float at 120,000 feet through a telescope. This gives you an idea of the size of the balloon at it's fully inflated volume. The 24 foot tall ANITA payload is dwarfed by the 29,470,000 cubic feet balloon.

ANITA launched! 21 Dec 2008

Saturday, we predicted light northwesterly winds for an 11AM Sunday launch of ANITA. We left McMurdo at 4:30AM Sunday morning and everything again went very smoothly and we launched the ANITA payload at 10:20AM this morning. It was another beautiful launch by our crew. The balloon took this 6,000 pound payload to 121,000 feet. This balloon is a little smaller. The total flight train length is 900 feet and the balloon's fully inflated volume in the stratosphere is 29,470,000 cubic feet. Here are some photos from today. By they way, that payload isn't the heaviest we launch but it is one of the tallest at 24 feet. CSBF is the only organization in the world that performs scientific balloon launches that can launch payloads this big (up to 8,000 pounds).

CREAM Launched ! 19 Dec 2008

The day before (Thursday) we had predicted light easterly winds up to 1000 feet for the CREAM launch and scheduled a launch for 11AM Friday. We left McMurdo at 3AM and everything went very smoothly and we launched at 10:30AM. In this photo you will see why we have to predict winds up to 1000 feet. It is 1000 feet from the bottom of the payload to the top of the balloon. Only 5% of the balloon is inflated with helium. It expands as it goes to float in the stratosphere. This balloon took this 6,000 pound payload to 127,000 feet. The balloon has a fully inflated volume of 40,000,000 cubic feet. You could fit the Louisiana Superdome inside the balloon. There is a video of the launch on the CREAM website:

http://cosmicray.umd.edu/cream/cream-flights/flight-2008.html

Inflation nearly complete:



Balloon released from the spool:



Payload released, collar released from balloon. The collar prevents the inflated portion of the balloon from sailing too much after release from the spool:

Didn't Launch Today

No pic today, but an update. The weather was a little worse than we expected today. It improved greatly by late morning, but not enough. We had expected surface winds late this morning (Saturday) of 3-5 knots (at these low speeds knots and mph are close to the same) and winds at 600 feet of 4-6 knots. Instead surface winds were 4-6 knots and 600 foot winds were 7-9 knots. That's just too much for this delicate system. We will attempt another launch Sunday afternoon. A similar pattern is expected, which means it will be close to being launchable weather.

Erebus Steaming Away

Erebus has been producing a lot of steam the past few days, and combined with a lot of high level moisture produces a thin cloud similar to a contrail. Note the shadow that the trail makes on the slope. Northwest winds at 12,000 feet are blowing the trail to the southeast.

ANITA Payload hang test

Here is a picture from the ANITA payload hang test. We launched this payload in 2006 as well. Here is a link to their website:

http://www.phys.hawaii.edu/~anita/web/index.htm

Pathfinder Balloon Launch

One of the reasons scientists want us to fly their payloads over Antarctica is that they can get a long time at float, as much as 43 days. In the summer a high pressure center sets up in the stratosphere over the South Pole. This is true in the Northern Hemisphere as well in it's summer. It takes a while for the old winter low pressure system to be replaced by the high. The 24 hours of daylight continually warms the thin air of the stratosphere until it reaches a point where a nice concentric high pressure system is anchored near the Pole. Since winds in the southern hemisphere flow in a counterclockwise direction (clockwise in the northern hemisphere) that means we can launch from LDB Camp (at about 77.8 degrees South) and the balloon will float at about 120,000 feet and circle around and come back almost right back over us. In some case science groups want a longer time at float and choose to go around again. The downside to that is that the further from LDB Camp we bring the payload down, the longer it takes to recover it. In some cases the group might have to wait a year to get it back as it takes a lot of resources to recover a payload on the Antarctic Plateau or near the South Pole.

We have satellite derived wind charts available that give us an idea of what the winds are doing in the stratosphere, but these need to be verified with real measurements using balloons. Normal meteorological balloons launched from McMurdo, South Pole, and a few other stations around Antarctica rarely get above 100,000 feet. In order for us to measure winds to 120,000 to 130,000 feet we launch a small plastic balloon (small by our standards) with an instrument package attached that reports back it's altitude, latitude/longitude, and time. From this information we calculate wind speed and direction. This balloon will float for about 7 days before the package runs out of battery life. It tells us a lot during that time.

As you can see from the pathfinder track below the circulation center is over the Ross Sea and isn't over the Pole yet. That agrees with the satellite derived wind analysis. The satellite derived wind chart is valid at a pressure level of 5 millibars(mb) or 5 hectopascals(hPa) which at this time is pretty close to 120,000 feet. What that means is that conditions are not right in the stratosphere for launch of the big science payloads, but they are acceptable for launch of a smaller test balloon flight. We will try to launch that tomorrow.

BESS Flight Track from 2007:


Pathfinder Launch:


Current Pathfinder Track:


Satellite Derived Wind Chart (Data is courtesy Climate Prediction Center):

More pics for Brookside

We had a few hours of clearing today so Chris took some more Brookside pics for me. I never mentioned it but in the previous picture (my profile pic) I am standing with White Island in the background. It's about 12 miles away, almost due south of LDB Camp. In another post I had pictures of Mt. Erebus, the active volcano that is 25 miles due north of LDB Camp. It is so due north that we use it's peak to set true north on our wind measuring instrument (anemometer) and our theodolite. Mt. Erebus was steaming a bit today so I thought I would get a pic with it steaming in the background. Back in 1990 it did erupt enough to throw small rocks onto the Williams Field/LDB area. I also have some pics of me on our launch vehicle, "The Boss"...that's the one that was picking up the CREAM payload and the one we'll use when we do the launches.

Go Bulldogs!

Good thing for Monday--Snow on Tuesday!

As I mentioned in the previous post it was a good thing we were correct about Monday and were able to complete the hang test, because we were right Tuesday being bad. It was even a little worse than we expected as the snow was even heavier. Chris Schwantes took some pics of a couple of our guys (Joe and Curtis) having a bit of fun. That guy in the red shirt in the doorway peeking out on the fun as Joe is about to get hit with a snowball...that's me. I am going to put together some things this week to demonstrate how we forecast here..the tools we use. I can tell you, for someone who grew up in East Texas and has lived for about half his life in the Houston area, I still get a big kick out of snow like this. This was a GREAT snow..the flakes were huge!

Successful Hang Test Completed for CREAM Payload

Before a science payload can be declared flight ready we have to hang it on the front of our launch vehicle and connect through our electronic systems, parachute, and flight termination systems. In order to test all communications we have to do this between noon and 5:00PM so it could communicate with the TDRSS satellite. The satellite is out of range at other times. The TDRSS satellite is how we and the scientists and communicate with our systems after launch when the balloon is more than 250 miles away from McMurdo. We also need a nice sunny day in order to test the solar panels to make sure they charge the batteries. Also, the solar panels themselves are quite fragile. They cannot withstand more than 10 miles an hour of sustained wind, and only 12 miles per hour in short gusts. So that's the forecasting challenge for me (and Chris our new meteorologist)..to predict a day in advance when we can take the payload outside and have those weather conditions or better between noon and 5:00PM. This is a pretty big deal since the hang test requires people at our home facility in Palestine, Texas to be on duty and it also requires the scheduling of time on the TDRSS satellite through their operations at White Sands Missile Range. On Saturday we identified Monday afternoon as the best time for the test, as the weather would deteriorate Tuesday afternoon and the rest of the week. The forecast correct and we had nice sunny skies and winds within acceptable levels. Winds were generally 5 to 8 miles per hour, with some periods of 10 to 11 miles per hour but that was all within limits. All of the CREAM and CSBF personnel in Antarctica and Palestine worked hard to complete this test and everything was completed by 4:00PM. You will see in my next post that our forecast of bad weather for Tuesday certainly came true. We were very glad to catch this window of nice weather. I have attached some pics of the CREAM payload, one inside before it was completely assembled, and then outside on the launch vehicle. Here is a link to learn more about the CREAM project:

http://cosmicray.umd.edu/cream/cream.html