Super Sale – 48 Hours only

IMG_7340Super Sale – Weather Balloons, HAB Flights and More – 48Hrs

Live in Australia?

Monday 17th November 4pm: We are, as always, raising funds for our Project ThunderStruck. Live in Australia and want weather balloons, want us to take your payload to the Stratosphere, or want to rent HAM radio tracking gear?

Sale Ends 4pm Wednesday 19th Nov 2015

Learn to Launch and Recover HABs

HABs? High Altitude Balloons. We can do just about anything. We can even take you along with us and show you how its done. It is the full course on flying payloads into the stratosphere. Just $500 per car and you drive your own vehicle – it must be in good condition and suitable for dirt roads.. We launch from west of West Wyalong in southern central part of NSW. The course is hands on and you will get to have a tracking radio in the car and be part of the recovery team. You cover all your own personal costs including road assistance coverage, etc.. You will also need a wireless enabled tablet – preferably Telstra connected and a mobile phone, again preferable with Telstra connectivity. Conditions apply. We may be flying this weekend. Maximum people in one car for the above price is three.

Balloons for Sale

We current have 30 x 100 gram  balloons at $10 each + $15 delivery for 1 or 10. We have 2 x 500 gram balloons for $100 delivered in Australia by express post, a 350 gram balloon at $75 delivered in Australia express post and some older 3Kg balloons for $200 each – no guarantees. They are probably 3 years old, but that is all I know.

Helium

We can even rent you 3.4 cubic metre helium bottles (Size E) and balloon regulators. These need to picked up from and returned to Sydney and require substantial deposit of $700 per bottle fully refundable. At this stage it is cash only as we do not carry credit cards. It is also $2 per day per bottle after 1 week’s rental if overdue.

Radios, GPS, Cameras

The HAM radio equipment includes:

  • Yaesu GPS enabled APRS tracker VX-8 two way radio – VHF / UHF dual band
  • Byonics MT-400 APRS trackers – pre-configured with your call sign and SSD
  • GPS units for MT-400
  • Spot 2 and Spot 3 trackers
  • GoPro cameras with external connections for Lithium Iron batteries
  • Lithium Iron Batteries and charger
  •  antennas

Send your Mascot or Sign to Near Space?

We can do it for $1,200, down for the sale from 1,500 and that was a special deal already – marked down from $3,000. Conditions apply.

Payment

Sale ends at 4pm Wednesday 19th November 2015 EDST

A 50% deposit must be made tomorrow (Monday) at a CBA branch OVER THE COUNTER to get this sale discount or goods with the balance on most items by Wednesday. This sale ends Monday at 4pm, but call me to negotiate a price after 4pm. For details on the rental of radio equipment and gas bottles – you can call me on 0467 545 755 or call 02 9789 2773 and leave a message if I am unavailable. You may have to ring for a while to go to the messaging service.

Want to see when we have the next sale. Subscribe to our RSS feed to get our posts and be ready.

http://projectthunderstruck.org/feed/

RFDesign is our latest Supporter

RFDesign-LogoRFDesign to Keep us In Touch

Our Latest Supporter.

RFDesign makes a fantastic modem and other items used in long distance UAVs and other projects. The modem is small and light weight and has amazing capabilities.

RFD900V12_final__42922.1405412794.220.220I have spoken with the head of the company, Seppo Saario. He is a real great guy who quickly got behind Project ThunderStruck. We have discussed their modems before, but this is the first time that we can actually use their equipment in a project, although we intend to use the modems in a lot of balloon projects. This will especially be the case in the coming weeks as we test for ThunderStruck. Given a good yagi antenna on the ground and a well oriented patch antenna on the aircraft, communications up to 80km is possible.

We intend to use these modems for the two way data from Thunderstruck. The units operate at 900MHz and produce  about 1 watt. Two units are paired on the ground by setup via a PC. They can communicate at speeds of up to 56Kb nominally or even higher. Way faster than our needs. Rather than the usual APRS system that we currently use that give updates every 20 seconds or the Spot3 system that updates every 10 minutes, this system is capable of 1 second updates of speed and other data. Our flight controls will also be very responsive if coupled correctly. They will work well with the PIXHAWK flight controllers and I have some good news about support from them shortly.  Just a simple cable is needed to connect the PixHawk Autopilot to the RFD900

pixhawk_store  Cable_R9A_PIX__72503.1405428336.1280.1280_medium

More on PixHawk later. Now about this amazing modem. From their website:

RFDesign is an electronics design and manufacturing company specialising in Embedded systems, Radios, Antennas and high frequency electronics. We are located in Brisbane, Australia with our office located in Acacia Ridge, QLD. 

Features:

  • Long range >40km depending on antennas and GCS setup
  • 2 x RP-SMA RF connectors, diversity switched.
  • 1 Watt (+30dBm) transmit power.
  • Transmit low pass filter.
  • > 20dB Low noise amplifier.
  • RX SAW filter.
  • Passive front end band pass filter.
  • Open source firmware SiK (V1.x) / tools, field upgradeable, easy to configure.
  • Multipoint software capability with MP SiK (V2.x)
  • Small, light weight.
  • Compatible with 3DR / Hope-RF radio modules.
  • License free use in Australia, Canada, USA, NZ

 Interfaces:

  • RF : 2 x RP-SMA connectors
  • Serial: Logic level TTL (+3.3v nominal, +5v tolerant)
  • Power: +5v, ~800mA max peak (at maximum transmit power)
  • GPIO: 6 General purpose IO (Digital, ADC, PWM capable).

Specifications:

  • Frequency Range:  902 – 928 MHz (USA) / 915 – 928 MHz (Australia)
  • Output Power: 1W (+30dBm), controllable in 1dB steps ( +/- 1dB @=20dBm typical )
  • Air Data transfer rates: 4, 8, 16, 19, 24, 32, 48, 64, 96, 128, 192 and 250 kbit/sec ( User selectable, 64k default )
  • UART data transfer rates: 2400, 4800, 9600, 19200, 38400, 57600, 115200 baud  ( User selectable, 57600 default )
  • Output Power: 1W (+30dBm)
  • Receive Sensitivity: >121 dBm at low data rates, high data rates (TBA)
  • Size: 30 mm (wide) x 57 mm (long) x 12.8 mm (thick) – Including RF Shield, Heatsink and connector extremeties
  • Weight: 14.5g
  • Mounting: 3 x M2.5 screws, 3 x header pin solder points
  • Power Supply: +5 V nominal, (+3.5 V min, +5.5 V max), ~800 mA peak at maximum power
  • Temp. Range: -40 to +85 deg C

Software / GCS Support:

The software solution is an open source development called “SiK” originally by Mike Smith and improved upon by Andrew Tridgell and RFDesign. A boot loader and interface is available for further development and field upgrade of the modem firmware via the serial port.

Most parameters are configurable via AT commands, Eg. baud rate (air/uart), frequency band, power levels, etc., please see the 3DR wiki for commands below for now.

V2.x firmware has been updated to support multipoint networking on the RFD900.

V1.x (non multipoint) is suitable for point to point links – the sourcecode is located at:   https://github.com/RFDesign/SiK

The user manual / datasheet can be found here : RFD900 Datasheet

A software manual for SiK firmware is here : RFD900 Software manual

RFD900 configuration tool: http://rfdesign.com.au/downloads/

RFD900 binary firmware repository: http://rfdesign.com.au/firmware/

3DR/RFD900 compatible configuration tool : http://vps.oborne.me/3drradioconfig.zip

Wiki for the 3DR radios (RFD900 has same commands): http://code.google.com/p/ardupilot-mega/wiki/3DRadio

Integrated support for configuring the RFD900 radios is supported by APM Planner, with other GCS solutions in development.

The default settings are at 57600 baud, N, 8, 1, and 64k air data rate.

Software features include:

  • Frequency hopping spread spectrum (FHSS)
  • Transparent serial link
  • Point to Point, or Multipoint networking
  • Configuration by simple AT commands for local radio, RT commands for remote radio
  • User configurable serial data rates and air datarates
  • Error correction routines, Mavlink protocol framing (user selectable)
  • Mavlink radio status reporting (Local RSSI, Remote RSSI, Local Noise, Remote Noise)
  • Automatic antenna diversity switching on a packet basis in realtime
  • Automatic duty cycle throttling based on radio temperature to avoid overheating

website, http://rfdesign.com.au for more information.

Building a Workshop for ThunderStruck

Building the ThunderStruck Workshop3A Space Grade Workshop

Every boy and every man needs their man cave. Jason’s and my man cave has a  digital TV, radio and a small fridge.  That is where the frivolous part of our work gear ends. The rest is state of the art technology for building a spacecraft. As you know Jason has a big event in April next year – yes we are again trying for April 2015. He will be trying to break the sound barrier with a 2.5m long delta winged glider launched from over 41Km altitude. The trick is to be able to control it and to land it. There are three or four phases to his project, but none the less, the ultimate aim is a working spacecraft and you can’t just build those in your back shed…. or can you? There are three stages to the concept testing:

  • Transonic – Jason’s upcoming flight
  • Sounding rocket return from space – straight up and down
  • Re-entry from orbit

I am betting that with the right equipment I could build all three stages in my garage. I doubt that it will come to that and I expect stage three to be built in a well equipped laboratory and workshop. None the less stage 2 will go into space and i will probably do a lot of the early work right here, so our workshop has to be state of the art and we are starting out with a strip of test points right next to our workbench.

These are the test points and systems for building and testing the electronics of ThunderStruck. On the other side of the garage, we will be building the airframe and will have a bench with a frame to rotate the fuselage so that we can access every part of the craft. It will be nearly 3 metres long. The systems shown here are for mains; DC power, network; audio; antennas, signal generation, receivers, transmitters; amplifiers; earth; USB and much more. Out of site on the left will be a servo test panel for the digital systems for the ThunderStruck craft. That is Jason enjoying finishing the test panel.

It is also where Jason keeps his HF radio, so the workbench doubles for Amateur Radio activities. We will soon have an iGate for and VHF APRS gateway and a great place to as we dominate a hilltop in the heart of Sydney. Fellow Amateur Radio operators will know what I am talking about. That is Jason below with his radio. Behind Jason is our 50 volt and 12 volt supply rack and battery banks as well as many of our radio systems. There are two racks and to the right of them is a cupboard with about 32 draws for our smaller items.

Building the ThunderStruck Workshop

Below you can see the upper part of the test gear rack has a long way to go. Top left is our general computer – mainly for Internet access, top centre is our laboratory power supply. The bench is currently half width. As we toss out some old rubbish, we will be able to rid the area of equipment and double the width of the workbench

Building the ThunderStruck Workshop2

The moment we completed the work today, Jason built a Styrofoam aircraft out of scrap and he intends it to fly. None the less, the workshop is shaping up to be a phenomenal asset for building spacecraft. …..and what do two guys do with a spacecraft ready workshop? An easy guess – Build ThunderStruck of course.

Stability

Creating Stability Between Supersonic Dive and Subsonic Level Flight

Here is the problem. During the supersonic dive, the weight is ideally forward to ensure that, as an airflow is felt by the aircraft, the drag of the tail keeps the craft oriented in vertical dive. That is assisted bythe drag across the aircraft and a low centre of gravity near the nose. During level flight below supersonic speeds the centre of gravity must be further back and ideally between the wings.

Jet fighter design has all sorts of tricks to alter the centre of gravity (or appear to) to make he changes needed. This can be as simple as changing wing shape or even extend more wing during lower speed flight. Some aircraft even have had swung wings. It is hard to control the major variations between the lift and drag that changes dramatically between subsonic and supersonic flight. None the less they do not need the dramatic changes in the centre of gravity that we are engineering.

ThunderStruck will be essential a poor flier as we are, at this stage, proposing symmetrical wings. The problem is that nothing is perfect and even the subtle differences between the wings can give on more lift than the other and create spin. Because of Bernoulli’s law, you might have supersonic flow on the wings, nose, or any other curvature way before you reach Mach 1. Battling with supersonic airflow below mach 1 is difficult and de-stabilising. We will be experimenting with dropping light airframes with a camera at the nose. Before we reach controlled airspace, we will deploy our parachute and have a reserve one for safety. We will watch carefully to see the effects on stability.

The diagram below is one solution to moving the mass required for stable flight in both modes. The pump must be fast and the liquid must stay “thin” and not become viscus. We will need baffles to slow the sloshing around during the changeover. These divide the tanks into chambers with some small holes joining the chambers to allow them to fill.

Centre of gravity adjustment transitioning from dive to level flight

There are other solutions such as screw thread that will shift the battery and electronics forwards or backwards. Since the flight is short the transition only needs to be one way, the design is thus simplified. I am not a fan of shifting the battery and electronics around. It will take a large movement to have the desired effect and it could cause wired t break if they get caught on something. I personally favour pumping the fluid from forward to back as shown above. Moving it down during horizontal flight creates even more stability by creating dihedral effect between the wings on an otherwise symmetrical aircraft.

Dihedral in aircraft is the inclination of an aircraft’s wing from the horizontal, especially upwards away from the fuselage. in this case it is the centre of gravity that I am measuring it against and this indicates that the weight is below the wings and the aircraft will be easier to fly.

Below is another thought on using systems, but this time we vent the fluid without the need for a pump.

gravity does the work for us and we remove the liquid away from any potential problems within the aircraft. Making it lighter will also make it more controllable once out of the dive.

gravity does the work for us and we remove the liquid away from any potential problems within the aircraft. Making it lighter will also make it more controllable once out of the dive.

Whatever system we chose, we will be writing it up here. we need to fly the craft and we also have access to a wind tunnel for subsonic tests.