## Air Pressure and how it Affects Balloons and Rockets

By Robert Brand

### Rockets

One of the big issues for rockets flying to space is the air pressure it must climb through. As a rocket climbs it gets faster and has to push more air out of the way. As it goes higher the air thins and you can see from the table below that it is exponential. Have a look at the 1/100th  fraction of one atmosphere below and you will see that the atmosphere is 1% of sea level. The change is not linear. The atmosphere thins to a tiny percentage at twice that height, but at half the height it is 10% of the sea level pressure.

NASA says: The velocity of a rocket during launch is constantly increasing with altitude. Therefore, the dynamic pressure on a rocket during launch is initially zero because the velocity is zero. The dynamic pressure increases because of the increasing velocity to some maximum value, called the maximum dynamic pressure, or Max Q. Then the dynamic pressure decreases because of the decreasing density. The Max Q condition is a design constraint on full scale rockets.

 fractionof 1 atmosphere (ATM) average altitude (m) (ft) 1 0 0 1/2 5,486.3 18,000 1/3 8,375.8 27,480 1/10 16,131.9 52,926 1/100 30,900.9 101,381 1/1000 48,467.2 159,013 1/10000 69,463.6 227,899 1/100000 96,281.6 283,076

The Falcon9 reaches the speed of sound at 1 min 10 sec into its flight and then reaches Max Q just 8 to 13 seconds later depending on speed,and air pressure variables. Unlike airplanes, a rocket’s thrust actually increases with altitude; Falcon 9 generates 1.3 million pounds of thrust at sea level but gets up to 1.5 million pounds of thrust in the vacuum of space. The first stage engines are gradually throttled near the end of first-stage flight to limit launch vehicle acceleration as the rocket’s mass decreases with the burning of fuel.

Want to know more? This is not full of maths, just some fun stuff about Max Q and reaching orbit.

### Balloons

Well for balloons we have a different issue. Balloons have to displace their weight in gas in the atmosphere and that includes displacing enough gas for the weight of the payload too.

The climb to maximum altitude for the most part is linear. I discovered this when analysing the stats from my first balloon flight. It was linear until it reached the point that the balloon exploded. If you launch a balloon that does not explode, it will slow its climb and then float. My best guess is that as the climb becomes more difficult due to the air thinning thus and thus the displaced gas is getting closer to the weight of the balloon and payload, but the air resistance is getting less. The size of the balloon is also increasing with height and has to push away a greater volume of air to climb, but the number of air molecules in the increased mass is way less. All up it produces a fairly linear climb. The graph (left) from uplift-1 shows he linear climb and the exponential fall with the parachute deployed. For the parachute, the air gets thicker as it falls and thus slows more as the altitude decreases. Note the initial glitch was caused by a strong thermal just as we let go of the balloon. Once out of the thermal the climb was very linear. It is obvious when the balloon burst.

Another view of th same data is shown on the left from UpLift-1’s flight. Note that the rate of climb is linear, but increasing slightly. This would be affected by balloon size and fill amount. The rate of climb may be fast, slow or medium, but that will also change the rate of change of the volume. Not all graphs are the same, but they tend to be similar. Note also that the size of the parachute needs to change with the weight of the payload. The ideal speed for the average payload would be about 5mto 6m per second at the landing altitude, thus landing at Denver, Colorado, USA will require that you make the parachute a little bigger since it is nearly 2Km above sea level and the air is noticeably thinner.

There are good fill charts on the web allowing you to calculate the size of balloon and the amount of Helium or Hydrogen to determine the altitude at which the balloon will explode. More on that another time. The picture at top of page is a weather balloon exploding at altitude.

All up, air pressure can destroy a rocket if its speed is too great and it will destroy a weather balloon if the air pressure gets too low. Both rely on understanding the effects of air pressure, but the dynamics are totally different.

Too finish off the post here is a video of a balloon burst. They are spectacular, especially as the balloons grow to a huge diameter and fill the screen of most wide angle GoPros!:

## Space Education

by Robert Brand

I was fortunate to present at the 13th Australian Space Science Conference at Sydney University a little over a week ago. The only unfortunate thing was a mix-up by yours truly and I ended up there on the wrong day. I was meant to be delivering a talk on “Triple Play in the Space Sector” and poor Alice Gorman, who was hosting the panel, was asking if I had turned up. My biggest apologies ever Alice!

I did however get a chance to present in the education stream and I am including this presentation here. My son Jason came along to help me as it was school holidays. Luckily every talk was about some of the work that he does with me, so it was pretty interesting most of the time.

Below is the PDF version of my PowerPoint presentation. It is interesting to note that we are doing so much that I can easily put together a complete presentation during a few other people’s talks. As you can see I gave my WotzUp website a plug!

## UpLift-1 Raw Data 28th Dec 2011 (Archives)

### UpLift-1 Flight Data 2011-12-28

I have already detailed the top level science that is easily seen from the data returned by radio telemetry from the flight. The radio link returns data approximately every 20 seconds and it has a variety of information as described previously. There are a few plots missing from the start and end of the flight as the tracking system only worked when the receivers could see the balloon. We were effectively over the radio horizon due to the distance from the receivers – much like a light house cannot light the ocean around it unless it is on a high headland. There are also 3 plots missing during the 2.5 hour flight. I have added these in to smooth out the plots, but the estimations are all in red. I have not tried to extrapolate data from the landing as I was not present to see the course it took.

The Database information is available in metric form and not imperial. You will need to convert that yourself, but that is very easy.

You can download the database here for educational purposed and similarly any photos are available for education purposes, but are copyright – Robert Brand 2011

The file contains both flight data and graphs as used in the posts on this website re UpLift-1′s flight. There is also a list of photograph numbers. Many were unusable due to sun, glare, direction of the photo, etc. All photos indicated with a “1′ are available on this website in subsequent posts.

As far as position accuracy is concerned, the data from the telemetry also contain a parameter called HDOP. Firstly let’s look at DOP:

The following information is from http://gpsinformation.net/main/dopnontech.htm

### Dilution of Precision

The DOP factor is used in a very simple equation:

SD(position) = DOP * SD(inputs)

This means that the standard deviation of the position is simply the standard deviation of the inputs multiplied times the DOP factor. Of course, this formula isn’t as simple as it looks, since for GPS a multidimensional solution is required, and therefore matrix mathematics is used. But the idea is good.

One interesting thing about DOP is that it does not depend on the anything that cannot be predicted in advance. It only depends on the positions of the GPS satellites relative to the GPS receiver’s location. The satellite positions can be calculated in advance, so you can determine the quality of your GPS position fix in advance, without even using the GPS system.

### Satellite geometry

DOP only depends on the position of the satellites: how many satellites you can see, how high they are in the sky, and the bearing towards them. This is often refered to as the geometry. The satellites move, so the geometry varies with time, but it is very predictable.

### HDOP = Horizontal Dilution of Position

HDOP is horizontal DOP. It is one component of the total DOP. Others are VHOP for Vertical DOP, PDOP for 3D positions, TDOP for time, and GDOP for geometic DOP. Altogether they =DOP.

UpLift-1  was outdoors and the receiver facing the sky with only a layer of bubble-wrap and Styrofoam that had already been tested for GPS integrity. It offered no apparent impediment to GPS signals. In fact the entire flight was a DOP=1. This is the lowest error estimate and means the horizontal position information was estimated to be very accurate. It has not been included with the figures. The vertical position also appears to be accurate with the repetition of the data and the expected rates of slowing on descent. The smoothness of the curves attests to the quality of the results.

## UpLift-1 Flight Data Pt-2 (Archives)

### UpLift-1 Facts and Figures 28th Dec 2011 Pt-2

Time for some SCIENCE. I have cleaned up all the data from the flight removing duplicated figures and out of place data that sometimes occurs from having lots of receiving stations all trying to add it to the database. The figures are certainly interesting and even fun to see what is going on during the flight.

### Temperature.

Unfortunately, UpLift-1 did not have an external temperature sensor – just a payload sensor. The payload sensor will be useful to see the stresses that the payload has to handle, but due to the thermal properties of the capsule (polystyrene is an insulator) and the thermal wrap around the electronics (bubble-wrap) the payload temperature will be both reduced and delayed slightly. The capsule did have some small penetrations that made its insulation poor and the transmitter also produced some small amount of heat that would have affected the cooling effects slightly. It was mainly the bubble-wrap that protected the electronics from the -40 to -50 degrees Celsius (  -40 to -68F). So what happens and why the cold temperatures?

The atmosphere has many layers and the first that we live in is the Troposphere. The following (Troposphere and Stratosphere) are from Wikipedia:

#### Troposphere

The troposphere begins at the surface and extends to between 9 km (30,000 ft) at the poles and 17 km (56,000 ft) at the equator, with some variation due to weather. The troposphere is mostly heated by transfer of energy from the surface, so on average the lowest part of the troposphere is warmest and temperature decreases with altitude. This promotes vertical mixing (hence the origin of its name in the Greek word “τροπή”, trope, meaning turn or overturn). The troposphere contains roughly 80% of the mass of the atmosphere.

The tropopause is the boundary between the troposphere and stratosphere.

#### Stratosphere

The stratosphere extends from the tropopause to about 51 km (32 mi; 170,000 ft). Temperature increases with height due to increased absorption of ultraviolet radiation by the ozone layer, which restricts turbulence and mixing. While the temperature may be −60 °C (−76 °F; 210 K) at the tropopause, the top of the stratosphere is much warmer, and may be near freezing. The stratopause, which is the boundary between the stratosphere and mesosphere, typically is at 50 to 55 km (31 to 34 mi; 160,000 to 180,000 ft). The pressure here is 1/1000 sea level.

Our balloon flight will start at the bottom of the Troposphere 34C (93F) at ground level, pass through the thin Tropopause at a bit less than 17 km (56,000 ft), where temperatures could be as low at -50C (-68F) and into the stratosphere where temperatures could warm to just above or below freezing. The climb will end in the Stratosphere when the balloon expands until it explodes and then falls back to earth and back through the cold. The chart below provides critical data on payload temperatures:

Above we see the effect of passing through the very cold temperatures of the Troposphere and then the warming of the Stratosphere – even though it is only warming to about freezing! The descent takes the already cold payload back through freezing conditions in the Troposphere again further cooling the payload to a maximum of -12C (10.4F) before warming to a balmy +3C (+37.4F) by the end of the flight. By the time of recovery 2 hours later the  payload had warmed to outside temperatures.

### Thermal delay

The chart below shows an approximation of the outside temperatures encountered during the flight plotted alongside of the payload temperatures:

There is a good possibility that the temperature in the Stratosphere was above freezing as the payload was warming up substantially. It is not likely to have been from the electronics as the transmitter was extremely low power with a small duty cycle (10%).

### Battery Conditions due to Temperature

Simply put, batteries fail when they get cold. This got a little colder than I would have liked. Extra bubble-wrap would have been helpful or sealing the camera penetration better would have helped. In future, I will do both. The battery volts dropped to very low levels due to the cold, but since they were Lithium batteries they worked okay at -12C (10.4F). Battery volts had fallen from 5.8V at the start of the flight to 5.1 in the extreme cold and returned to 5.8v by the time of recovery of the capsule.

In the graph above the battery voltage had started to recover as the capsule landed on the ground. The size of the batteries meant that they would have remained cold the longest even though the electronics warmed up relatively quickly the thermal mass of the batteries took much longer to warm. The batteries were inside the many layers of bubble-wrap.

More on the flight data in the next post

## UpLift-1 Flight Data Pt-1 (Archives)

### UpLift-1 Facts and Figures 28th Dec 2011 Pt-1

Time for some SCIENCE. I have cleaned up all the data from the flight removing duplicated figures and out of place data that sometimes occurs from having lots of receiving stations all trying to add it to the database. The figures are certainly interesting and even fun to see what is going on during the flight.

Some Facts first:

• Altitude of the launch site is about 90m or 300ft above sea level. flat farmland was chosen for lack of trees and easy access for recovery.
• Morning was chosen for air stability and lower wind levels.
• Weather: Clear with little to no wind. Summer.
• Flight launch: 10;53 28th Dec 2011 EDST (23:53 27th Dec 2011 UTC).
• Flight landing: 13:40 28th Dec 2011 EDST (02:53 28th Dec 2011 UTC).
• Flight time: 2 hours 47 minutes.
• Maximum Recorded Altitude: 26.181km – 85,896 feet – 16.2681 miles.
• Distance traveled: 45.6km (28 miles).
• Direction from launch of 72 degrees.
• Rate of climb: 3m/sec (5ft/sec) near sea level to near 5m/sec (8ft/sec) at the burst point.
• Payload temperature during flight: 34C (93F) at ground level to -12C (10.4F) minimum.
• Maximum recorded rate if fall: 33m/sec (110ft/sec)
• Anomalies encountered: Thermal at the time of release caused 9m (30ft) initial rate of climb.
• Balloon: Totex 350g (optimum fill 1.2m, actual fill 1.35m diameter)
• Gas used for lift: Helium
• Payload: Polystyrene box with a bit less than 1/2kg weight (1lb) including parachute.
• Camera: GoPro 7mp still camera set to take photos every 30 seconds – lasted entire flight. Housing included
• Tracking was via Amateur Radio APRS with Internet and direct reception in vehicle. 145.175MHz Packet radio.
• Transmitter from Argent Data system with GPS rated for over 60,000 feet and 1/2 watt transmitter.
• Antenna – precision tuned vertically mounted dipole.
• Transmitter Power: 2 x mounted on-board Lithium 3V pile batteries.
• Reporting time: 20 seconds.
• Thermal insulation for transmitter: Polystyrene capsule and three layers of bubble wrap.

The first bit of data showed that UpLift-1 climbed very quickly. At first I could not believe the rate of climb, but there it was climbing at 9m per second. I now know that this was an anomaly. The simplest and most likely explanation is that at the time that we released the balloon we were in a thermal area where the hot air at that spot was rising quickly were near by air was falling. As it was early in the day, upper air thermals had not formed so the affect was short lived. So here is the graph of altitude for the flight:

At the very start of the flight there is a slightly different rate of climb caused by the thermal that dissipates at about 2km. From then on the climb is steady and near flat. The rate of climb being mainly determined by the size of the balloon (air resistance and lift) and the wright of the payload. As the air thins, the balloon expands keeping the air resistance somewhat the same, but as altitude increases, the ability to lift is also reduced. The result is a fairly consistent rate of climb. At the maximum altitude the balloon bursts and the payload is released. The parachute is ineffective in the free air and the rate of fall is determined by air density producing a somewhat parabolic curve. For most balloon flights with a reasonable rate of climb, the climb to fall ratio is usually between 3:1 or 4:1 for flight estimations.

The rate of climb graph shows the linear and parabolic effects more clearly”

In the graph above, you can clearly see the high initial rate of climb and the slowing of the rate as it left the thermal event. The rate was not flat, but slowly climbed from 3m/sec (5ft/sec)  to near 5m/sec (8ft/sec) at the burst point. There is a fairly long period of time following the burst point before the payload reaches terminal velocity of greater than 33m/sec (110ft/sec) – remember that the plots are 20 seconds apart. There is one plot during the initial fall that indicated that the payload was accelerating and was showing 9m/sec (30ft/sec) fall and accelerating until terminal velocity is reached – the point where air resistance stops any further acceleration due to gravity.

The payload – a foam box weighing less than 1/2kg (about 1lb) has plenty of air resistance at sea level, but very little in the thin atmosphere. As it falls the air density increases and the rate slows. Where the rate of climb was determined by fairly linear forces, the rapid descent is clearly non linear when plotted against time.

Part two shortly with links to both imperial and decimal data data sets.

## UpLift-1 Launch (Archives)

### UpLift-1 Takeoff 28th Dec 2011.

We found a clear grassed area next to an old Railway water tank used for filling steam engines. The contrast was great – the old and the new. This story is going to be a bit instructive so lots and lots of pictures. First I had my son Jason (9) laid out the clean plastic sheet for the filling operation. We placed items in the corner in case a breeze kicked up the corners and destroyed the balloon. We also used Latex gloves to stop acids and other oils from transferring from our hands to the balloon and potentially causing an early failure of the balloon when the UV and other chemicals in the air act on it. We could also have used clean cotton gloves. The problem there was two fold. Sweat from our hands filled the gloves and needed to be changed occasionally to prevent and drops from landing on the balloon. The second problem was that every time we wanted to use duct tape, our gloves stuck very well to the tape! That is me on the left taping the hose to the balloon to protect it and getting the gloves stuck to the tape. There were cable ties under the tape and I used the tape to protect the balloon from sharp edges. The cable ties held the balloon to the flexible PVC tube. I also had the other end of the tube over the balloon fill regulator on the helium tank. That was just sealed with duct tape.

The camera batteries were charged the night before and the camera then required special care. We had it in a sealed box with desiccant overnight to ensure that there was as little moisture as possible in the camera. This would otherwise cause condensation during the flight and fog the images. It was inserted quickly into the housing and the almost closed housing was flushed with helium from the filler hose. This ensured that water in the air was removed and the housing was sealed. The camera was turned on and set to commence taking photographs – the counter on the front began incrementing every 30 seconds. Both the camera and the transmitter were mounted in the capsule. The picture shows the camera in place secured with blocks of polystyrene  and the transmitter in place with the GPS receiver at the top. The payload bay was covered and sealed with duct tape and the capsule was ready to fly. All that waited was to fill the balloon.

It was a great moment. Rankins Springs’ first near space mission. The countdown proceeded with the kids leading the chant. At zero, my son Jason released the balloon and it was away. Note the old steam engine water tank behind Jason – the old and the new. At about 270 metres the distant APRS receivers saw the balloon’s transmissions and we breathed a sigh of relief that we would be able to track and recover the balloon. We saw the updates every 20 seconds on our smart phones with all the details of the flight. We watched as the balloon stayed in clear view right up to 5km. We kept losing site of the tiny white dot, but the odd reflective glint from the shiny black duct tape brought our eyes back to the tiny 1.35m (4.5ft) white dot up in the clear blue skies of central NSW.  It should be noted, that none of these photos have been altered. They are directly from a number of cameras. The colours have not been corrected! The final job was to pack the car and chase the balloon.

It was serendipity that the first photo snapped by the payload camera at around 270m (900ft) was of the town itself. A wonderful memento of the occasion.

Below is the photo from Rankins Springs. You can click on most of the photos above and below to see a large version of the image (requires that you click through an intermediate page). I have uploaded the image of the town in the highest format possible.

60 seconds after release (below). This photo looking east above Rankins Springs:

## Success – UpLift-1 Recovered (Archives)

### UpLift-1 Flies to 26.161km Altitude

A quick update to tell you of our success. My son Jason (9) and I did it – 26km up – 15 miles – For 15 minutes we probably had the highest thing on planet earth. We got about 1/4 the way to space! In the photo at right, that is Jason in the field with the balloon about to launch.

The weather was clear and the skies almost clear of clouds when we launched the UpLift-1 weather balloon from Rankins Springs near Goolgowi in central NSW (Australia). We were an hour late but had about 20% of the town out to help! I think that we were told that the area had about 120 people and Rankins Springs has about 50 residents.

The flight lasted about 2 hours 40 minutes and landed about 4 fields from the road and we had great difficulty in driving to the landing site.

During the flight, the electronics got to -12C (12F) and the outside temperature got down to about -50C (-58F). As it climbed out of the Jet Stream, the atmosphere warms up to a balmy 5C on a good day. The low temperature caused the battery voltage to drop to 5.2v on the normally 5.8v battery. After it warmed up on the ground, the battery voltage returned to 5.8 volts.

The maximum recorded altitude was 26.181km – 85896 feet – 16.2681 miles. More in a couple of days. Some photos below for hold you over until the full story can be posted. The tracking worked perfectly.

Launch Site:

Path:

Landing site (X):

Recovery:

Rejoicing with a ginger beer (soda/soft drink):

One of the recovered photos:

More in a couple of days…

## The Space Show (Archives)

### Robert Brand – Guest on The Space Show

Robert Brand was a guest of Dr David Livingston on the Nov 1st 2011 edition of The Space Show. The program disussed Do-It-Yourself Space and was well received by all that heard it. The WotzUp website and the various missions were discussed at length during the broadcast.

The Space Show page for the show archive can be viewed by Clicking Here to View

The page details are as follows:

Guest: Robert Brand.

http://thespaceshow.wordpress.com/2011/11/02/robert-brand-tuesday-11-1-11/

## UpLift-1 APRS Tracking (Archives)

### APRS – The Best Balloon Tracking Solution

There are many ways to track balloons. There is the Radiosonde, Mobile Phone (3G), HAM radio APRS and many more. Since I both work in Radio Telecommunications and I am a HAM radio operator (VK2URB), then it is an easy choice. The amateur radio APRS system is ideal.

So what are these systems in brief:

Radiosonde: Wikipedia says: “A radiosonde (Sonde is French for probe) is a unit for use in weather balloons that measures various atmospheric parameters and transmits them to a fixed receiver. Radiosondes may operate at a radio frequency of 403 MHz or 1680 MHz and both types may be adjusted slightly higher or lower as required.” This sounds more like a license is required and special Radiosonde equipment is needed.

GPS enabled mobile / cellular smart phones: We all know what these are, but do they work?. Firstly you had better hope that your payload drops in a coverage area. These work by sending an SMS to the phone on the balloon and it then relays its position back to you via another SMS. Mobile telephone coverage in rural areas might not allow you to get a fix on the balloon as it parachutes back to earth. There is also the issue of the GPS receiver. Most do not work at heights over 60,000 feet (20kms) and thus you do not know how high it got or when it is descending. Many people on a tight budget try to use cellular phones and many have great success.

UHF Tracking: Similar to Radiosonde, yet it operates on a low power UHF channel, often used for garage door openers, etc. It transmits the co-ordinates for the GPS location and must be tracked by radios especially set up to receive the transmissions. The data is often ported to the internet for display on a web page. Handheld yagi antennas are directional and look like UHF yagi TV antennas seen on rooftops and are used to track the payload when it is on the ground or in the air.

Note the unusual off-white unit connected with wires in the top picture – it is the special high altitude GPS receiver. It will work up to very high altitudes but sacrifices some accuracy.

The picture above is the APRS Test Track around a street block on a hill near my home. Not precise, but very close. I was shaking the thing as I walked to make it hard for the system. I walked counter / anti clockwise from near the top without shaking and then where it goes a funny in the last quarter of the short walk I was really shaking it wildly. The unit reports on many details. These are:

VK2URB-11 is the balloon call sign

2011-09-10 02:59:41z is the date and time in GMT/Zulu

7 km/h was my walking speed

248 degrees was my bearing

alt 80m was my height above sea level

05.8v was the tracker battery voltage

20C was the temperature – about 70F

The other data is pressure, HHMMSS, and number of GPS satellites, the digipeater used (if used) and the iGate used.

### Pluses and Minuses

APRS is could always be better and there are not too many iGates (APRS gateways into the Internet) in rural areas, so you must check first. In fact I have chosen to have my balloon drop near Parkes for that very reason. There is an iGate in Parkes and the Digipeater (digital repeater) at nearby Mt Canobolas will also pick up the transmissions from my balloon. I have also chosen an area for good 3Gcellular coverage to assist with tracking and maps. Just to be sure, I will have a digipeater in my car so that if I am not too far away the position will be relayed by my car to the Internet for easy tracking. The unit I have chosen is specifically bought for ballooning. It is from Argent Data in the US. The unit weighs only 160 grams (5.6 ounces). It transmits half a watt (500mW). It is pictured top right and is a pre-release model.

The next issue is finding it when on the ground. Radiosonde and APRS are well suited to this task, but the APRS has a few tricks up it’s sleeve. Fist it might be able to radio its GPS co-ordinates to the Internet tracking system. As I get close with the digipeater, it will also do that job if no other iGates are in range. Secondly it may be picked up directly by my handheld radio, nice, but since it only transmits for 1-2 seconds, it will be hard to get a fix on the unit. Finally I can decode the data with my iPhone and simple read its exact co-ordinates. Nice! That is the directly decoded packets on the right. I did the test inside my house so the GPS coordinates will not be seen.

On the minus side, there is the need for an amateur radio license and access to the expense and homemade equipment that is either out of reach of some people financially or technically.

I also replaced the long general purpose whip antenna that you can see on the top image with a highly tuned light weight dipole. It is made of hollow brass and this also makes it easy to slide some stiff wire inside the antenna for tuning. The wire was then soldered in place to get the tuning very precise. This maximizes the antenna’s radiation ability at the precise frequency of the APRS system. We are using VHF at 145.175MHz. The pictures below show the modification. The work was done by my good friend Bruce who I have worked with on and off for over 40 years. He is also an amateur radio operator (VK2ZZM) and I am very appreciative of his advice and help on the APRS side of this project.

The white Styrofoam under the unit is the lid of the UpLift-1 capsule. The antenna is mounted on a small printed circuit board, The copper wire is used to add strength to the copper on the board in case of mechanical failure that may make the copper peel from the board.

The rear side above showing the bolts that pass through to the battery mounts on the tracker unit. A small amount of “locktight” was placed on the nuts to make sure that mechanical vibration did not make them fall off.

This is a state of the art network analyzer. It is measuring Return Loss. Send a signal to the antenna and what is not radiated comes back. The dip means that it is tuned to the frequency and radiating well. It is right on the tracker frequency. The Marker frequency. It is perfectly tuned and radiating the signal – not much is being reflected back into the cable. It is best practice as far as radio is concerned.

I will post a link to the tracker website that I will be using just before the day, but this link will let you see the few test drives that I have done in Sydney: http://aprs.fi/

## UpLift Weather Balloon Series (Archives)

*** Recovered From Archives ***

Posted By On 22 Aug 2011.
My name is Robert Brand and I am involved in space missions and Balloon Flights to the upper atmosphere. I don’t just read the space news and I like doing things, so Do-It-Yourself (DIY) Space was a natural. Unfortunately high altitude weather balloons don’t get into space, but they do get a long way up. Many make it over 20 miles / 30 kms and the atmosphere is so thing that it is getting close to space. My son Jason (age 9) will also be a big part of tracking and recovering the craft

The UpLift series is a record of my personal weather balloon launches in Blog form. Here you will find everything that you ever wanted to know about high altitude balloon flights, but in more of a blog form – I simply do not have the time to make it a reference site. I will try and not miss anything important and I expect that for the Australian enthusiast, there will be enough detail to even know how to approach CASA (Australia’s Civil Aviation Safety Authority) for a permit to fly. Some flights may occur outside of Australia, but if they are launches instigated by me, they will still carry the name.

The series will be numerically numbered so UpLift-1 is the first flight.

The flights will normally originate from a point in central New South Wales (NSW). They will use amateur radio tracking and where possible they will involve schools and other educational opportunities. They will carry as much scientific payload as possible and the data will be available on these pages. This will include full flight information, time, height, atmospheric pressure, etc as well as photos and videos.