Readers Questions

Robert Brand at a recent London Space Conference

Robert Brand at a recent London Space Conference

Answering the Hard Questions

Hi, I’m Robert Brand, father of our intrepid pilot, Jason. I am well known in the international space sector and even had the privilege of having Apollo astronauts attend my talks, including Buzz Aldrin attending one of Navigating to the moon. I have had a long career linked to the space sector and it started when I helped wire up systems for Apollo 11 communications when I was 17 years old.

I will attempt to answer these questions. They are not the more general ones in the FAQ but they will always be interesting questions. One reader suggested that his question may have been stupid, but I believe that there are not too many stupid questions, just stupid answers. So ask away. I expect that I will be the only one that may ending up looking stupid!

 Reader Earle asks:

If you use a super-pressure balloon, when it get’s to it’s highest altitude would it be possible to burn the hydrogen in the super-pressure balloon to gain more altitude ?

scramspace_highres3Robert Brand: I am afraid there is insufficient density of oxygen to burn with it and if we carried it up there, it would be heavy and stop the balloon reaching anywhere near the height it obtains with just the hydrogen. The atmosphere is so thin that you cannot gather it without a mass of machinery. Again this would stop it getting far off the ground. This is the domain of Scram Jets. Jets that can scoop up enough air by going super fast (Mach 7 and over) and then compress it and mix it with fuel from on-board tank for combustion. Australia has been a great research country for SCRAM jet technology, but the last prototype went down when the rocket carrying it, to get it to its cruising altitude, failed and we lost our last experimental vehicle. By the way, bubble wrap is like a super pressure balloon. It is inherently strong enough that the bubbles of air in the material expand a bit, but do not pop. We use bubble wrap as an insulator wrapped several times around electronics and batteries that we carry through the jet stream where outside temperatures can get to -60C. It works much the way double or triple glazed windows insulate, or the way birds or animals of many types fluff their feathers or fur to trap air to keep warm.

8 comments on “Readers Questions

  1. I am a little bit concerned by the aircraft configuration you have chosen. Have you done any calculations or simulations for transonic stability and strength? It will wreck your vehicle if you do not think about it carefully.

    • My son’s CAD drawings are a little limited by his capability in this area. It will be a modified Delta wing configuration. the wings will be a lot smaller and the winglets (up and down from the wingtips) will also be the rudder (dual ganged). The wings will be symmetrical = that is – no lift. It will fly by having a good set of elevators using ganged servos with a coupling stage to stop oscillations and servo fighting. The units will provide push pull to the control surfaces. The system will also probably have a pop out canard with lift. It will help with the low speed flight – something that delta wing craft are notoriously bad at doing. Please feel free to comment on this configuation. Why the “up/down” winglets? the bottom ones have wheels. The winglets are there for drag reduction, but we sacrifice the standard tail for the dual rudders, so reduced drag / increased drag. Should tend to equalise. There will be a wheel in the front of the aircraft too. it will just protrude on landing. If any of these items creates a problem in the wind tunnel. we will rethink the arrangements.

    • Simulations will also start when uni is back – we will probably have a couple of interns assisting with the project.

  2. Hi,
    First of all what a wonderful project! I wish you all the best.

    I have a question regarding CASA and remote piloting an RPA/Model Aircraft via FPV.
    It’s my understanding that FPV flying is essentially illegal in Australia due to the CASA requirement that a RPA/Model Aircraft pilot be looking at their aircraft for the entire duration of the flight. Of course I’m no expert in this field though so I’d be happy to hear that there’s an exemption or something I don’t know about. Is this something you’ve discussed with CASA?

  3. Hi,

    I have a question on the maximum weight of the payload and wether you need some sort of authorization to fly a balloon in to space.

    Secondly, which places do you recommend as the best to launch the balloon?

    • Well, firstly we are not flying to space, just close to half way. We are also seeking approval from our Civil Aviation Safety Authority – that is essential. We would need to launch in a remote site away from aircraft truck routes. It is not too hard to find such places in Australia.

      As for payload we are looking at building our craft with a 50kg capability

  4. Interesting idea but why you are trying to do this could be better communicated. Why do you want to break the sound barrier? What is achieved by doing this? If you manage to communicate this to a non-STEM audience successfully you may see more donations coming your way

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