Spaceport Darwin Low Risk Business Model

Point Stephens NT General AreaA Staged Business Model

by Robert Brand. To be clear, I will not go into the long term business model details, profit and loss figures in a public forum and I will not be exposing any business plans other than a general outline, but the nature of why it is a low risk for the Northern Territory government and my company will be clear. There is almost nothing needed other than to reserve this land until developers wish to fund the development of private launch pads.

I proposed a site for Spaceport Darwin in yesterday’s post and by today there were several people that liked the site, but needed a business model to fully accept that this could happen. I understand that desire to see everything so this morning I am posting the basis of the business model. I was going to wait a week to be able to report more, but to get some credibility, here it is.

Spaceport Darwin will be a staged approach that would see investment grow over time and facilities established as needed. The failure of the past is that massive investment was needed on day one. Another factor is that we can establish credibility over time for the site and with those wanting i invest in launch facilities. With almost zero cost, agreements can be put in place for the first part of the operation and sounding rocket launches can take place before the main area sees a shovel of dirt moved.

Why does our Business Need a Spaceport?

Simply because in two years we expect to test fire our booster / sounding rocket to space. I have worked with CASA and with other groups that would have plenty of objections to where I can launch from. There are also few places to launch to orbit. Insurance companies prefer a water launch and costs are lower if you can lower the risk. Since our long term goals are orbital space, it makes sense to look to a long term site to save money. My company also has an interest in being involved in the running of a spaceport. My background is founded in the civil aviation sector and my education was focused on Civil Aviation electronics and systems. I have also a flying background and interact with CASA on balloon flights to the stratosphere. In our company (being set-up now) I am currently heading a group to build spacecraft and rocket technology. All small points, but with the right people, it makes me ideal to kick start such a business. We also need an area away from major air traffic to launch heavy payloads to the Stratosphere. As a Spaceport is not in constant use, this makes Spaceport Darwin ideal as a launch point for 2-3 ton payloads for stratospheric space observation. With a 2 year start date on a couple of these items, now is the time for me to secure a site for a Spaceport and negotiate an outcome.

Potential Spaceport Services

Apart from fuel storage, gas storage, water, power, staff and other background essentials, I am talking about the end product/ services. The first three below my company requires in two years:

  • Sounding rocket – non orbital – straight up and down
  • Sounding rocket – launched to the east. Payload landing 190km away
  • 2-3 ton payloads sent by balloon to the stratosphere.
  • light to heavy rocket launch facilities – increasing over time
  • 5km runway for landing winged space vehicles
  • Up to 4 launch pads – as demand requires. We are seeing the establishment of private pads in the US at the Kennedy Space Centre
  • Equatorial launches – near polar launches
  • Launches for space tourism
  • Other operations as required

Why be in this business? The current worth of the Space Sector is US$330,000,000,000 per year and Australia is only earning money from the radio astronomy and the space communications service. It is a small player, well positioned to player a bigger role servicing launches, but to be competitive, we must keep our operational costs low and that means being close to a major town. With these requirements met and adequate competition for supply of services to the facility, Spaceport Darwin could well see a significant business in the future. We will eventually have a Space Agency and they will be promoting such objectives. Even securing 1/3 of one percent of the space business would see about US$1B income annually with much of that injected back into the local economy through wages, spending and government fees. It is clear that we can secure much more than this if all services are met.

What is the Proposal underpinning the Business Model?

Stage 1

Legal: The Northern Territory (NT) government would need to place a 15 to 20 year hold on any other development in the proposed area while services are put in place and expanded over time. Stage one also requires the clearing of a future car park to be used as a temporary launch pad. Once stage 2 is implemented, all launches can be moved to their permanentlocation

Technical: A clearing of the Car Park area and a concrete area for launches and testing. The concrete area will be suitable for small launches and balloon launches. The access road, although gravel, should be suitable for large trucks in the dry season. A bunker house with no equipment would be built on the west side of the future Car Park to facilitate a safe house during launches. Not equipment will be left between launches and the building secured and patrolled. Balloon and rocket flights to space will occur from time to time. PlusAerospace (expected name of the company) will manage the site from a launch perspective. That will be source of most of the income

The Car Park clearing will be paid for by grants and other funding. PlusAerospace will look after the mobile plant and other setup as required for launches and will bring shipping containers ready to deploy for the electronics and fuel mixing. The ingredients are of a safe nature until combined and are safe without an ignition source. Only large balloons, sounding rockets and small orbital rockets could be launched from a temporary site.

Point Stephens NTStage 2

Legal: This would only proceed with finance, partnerships and most importantly with customers. A solid commitment from the Northern Territory (NT) government and other legal entities would be needed at that time for long term tenancy and a permanent arrangement for continued services put in place with PlusAerospace as the customer. The government would be responsible for build a sealed road suitable for heavy loads and a 400m bridge suitable for the same heavy loads.

Technical: It would require a large pad for launches and completion of a security perimeter (and fence) that would be easy to patrol and cleared areas for a large concrete launch pad and launch structure. Like the US Kennedy Space Center (KSC) it would need a bunker-like launch control centre 5km away from the launch site with adequate protection. This would need sealed roads from Darwin to support the area. Gas and fuel facilities would be needed and it should be noted that much of the specialist gases used are plentiful in Darwin as they arrive by boat for distribution around Australia. It is likely that facilities would grow for a crawler and fabrication centre and although these items may be a long way away, such assets and pathways will be included in plans for the site ensuring adequate land is available for the service and safety.

Other Business Model Information

It is too early at this stage and some discussions are private in nature, but this staged approach to a business model will also allow a real growth and need dependent expansion that is very low risk. Government partnerships will ensure that risk is kept low and it is expected that a permanent arrangement will be in place with CASA that has to regularly pass review, but will allow launches without jumping through massive hoops each launch. ie, some permanent restrictions at all times. It should be noted that the proposed runway would be built in a location that would be suitable for operation near the Darwin. The current suggested location may be too close to the airport and will need to be located further away. The launch of the tourist flight (rocket motors) could be positioned in the appropriate airspace for the rocket flights.

Comments

I would seriously love your comments on this approach and will respond as needed. I will begin some serious lobbying for this site unless a better one exists, so please place your thinking caps on and let me know your thoughts.

Reading

This following link is a bit old, but will fill you in on some useful background. Cape York and Weipa Spaceports never progressed and people felt bunt by the experience.

http://www.spacetoday.org/Rockets/Spaceports/Australia.html

The following link is also very old and the Christmas Island spaceport also never progressed:

http://members.optusnet.com.au/virgothomas/space/spaceport.html#History

Darwin Area and Spaceport Darwin

Point Stephens NT_2

Point Stephens NT General Area

Spaceport Darwin Proposal

Point Stephens NT General AreaSpaceport Darwin – 55Km Drive from Town.

by Robert Brand. It is clear that Australia needs a Space Agency and the Agency needs to help establish an Australian Spaceport. Given that it is only a matter of time I am very interested in Spaceport Darwin!

What is a Spaceport?

The Oxford dictionary simple states: a base from which spacecraft are launched.

These days, with spacecraft returning to earth for reuse and also for winged spacecraft, the definition must also include landing so a modern definition would be: a base from which spacecraft are launched and landed.

Port Stephens in the Northern Territory of Australia, would seem to make an ideal spaceport. I believe that the land is mainly Crown Land on a perpetual lease to the Northern Territory Land Corporation. There are no buildings on the point and the land appears to be available for development. A gravel road is the only way of getting close to the site and it may currently be unpassable during the wet season. The wet season tends to cause major access problems without high dry road access. Luckily the road traverses only high land, but the rain can make this road impossible to travel. If development starts, the road would need to be sealed from Darwin and also new roadways within the complex.

For those wanting to take a better look, it is on Google Earth and it is the land to the south east of Gunn Point NT Australia:

-12.180 Latitude and 131.160 longitude.

The land is 19km north to south and up to 11km east to west at the furthermost points.

Possible Australian Launch pointsWhy Spaceport Darwin?

In the picture to the right, I have outlined (in red) some areas suitable to launch. It would be ideally suited to an equatorial orbit and possibly a polar orbit. It should also be suited to a sounding rocket launch with a forward landing spot. There are few places that a space port should and can be built. There have been several false starts with Great Barrier Reef concerns and major land rights groups forming a huge lobby in Cape York. Inland sites tend to have severe restrictions on large launches because of the risks of launching over land and an population.

Australia does have Woomera, but it is inland and has massive issues for launching anything other than sounding rockets (straight up and down). Launching over water offers a way lower risk and the cost of insurance. Woomera’s costs are very high at the moment. Commercial launch sites are more competitive. The nearest large town is a day’s travel.

Any launch site needs to be capable of growing with the needs of the site and I expect that this proposed site should be able to grow to 4 launch pads for the future. Obviously it will start small, and grow with the need for local space services.

What Makes a Good Spaceport?

What are the important requirements of a Spaceport. This is not a spaceport for space tourism, but it could easily be included. We are looking at a serious launch facility in this proposal. The possibility exists to launch multistage rockets from this site. So as a launch facility, what essentials or important items do we need?:

  • In a country with financial stability.
  • In a country with political stability.
  • In a country with geological stability.
  • In a country with a well educated workforce.
  • Clear path to the east (equatorial orbit).
  • Clear Path to the north or South (polar orbit).
  • A safe distance from any public building or public road (8Km from launch pad).
  • Fresh Water. Lots of it.
  • Short distance to a major town.
  • Road, train, air and port facilities near by.
  • Ability to isolate the area for launches.
  • Construction work force.
  • Operational work force.
  • In town fabrication.
  • Land ahead capability for sounding rocket flights.
  • Close to the equator for equatorial flights.
  • Expansion for future launch pads
  • Private launch facilities / launch pads
  • 5km or longer runway a possibility.
  • Substantial power services.
  • Calm water in the launch area
  • A substantial distance from any airport
  • A substantial distance from town for safety reasons.

There are way more requirements or “should haves” like fuel handling facilities, but the ones above are a great start. Let’s see how Spaceport Darwin shapes up.

Essentially we have a green light on all of the above points. The only issue is the need for road works once the site becomes operational.

There are issues with the northerly launch, with a tight flight path between some islands. There is land only to the south.

Another benefit is the local waters to the east are only about 10m to 15m deep. This is well within normal scuba diving capability (usually 27m depth max for sports diving). Recovery of rocket components that may parachute to the water can easily be recovered.

A large observation area for the general public can be placed on the southern end of the complex Launch days attract many people that want to get close to the launch of a major space vehicle – even a small launch. It is essential to keep people 5Km from any launch. The launch pad should be 8Km away from public property. All of this is a green light for Spaceport Darwin.

There is a small national park to the east only a 10km kilometres away. It is small and only 8km wide. Human access is only by boat. Another small piece of land is crossed by any spacecraft launched to orbit and it is 170Km to the east. Most rockets will be in space or near to space by that time and the land is sparsely populated. This is perfect for a sounding rocket flight with a winged glider returning from space. There is even a sealed runway at Oenpelli Airport. This is 200Km distance from the launch site at 95 degree bearing and within gliding distance for a landing. The rocket would land in Van Diemen Gulf.

Electric power is not far away and fresh water is readily available from underground sources and large tanks can be filled over time before any launch. Water recovery following a launch is also possible.

There is plenty more to look at and assess, but Spaceport Darwin has a lot of positives and with operations cost being 60% or more for a launch, having local staff living in Darwin with a short drive each day is very attractive. Below is the Van Diemens Gulf map. Note most flights are likely to be in space or close to space as they pass over the land to the east. The population density is extremely low.

Space Port Darwin - Van Diemen Gulf NT

Spaceport Darwin Benefits

Spaceport Darwin will:

  • Attract high tech staff to the area
  • Increase local tourism
  • Improve unemployment figures
  • Create innovation in the region
  • Attract foreign companies and investment
  • Improve roads and services
  • Focus attention on the region as a global Space Hub
  • Have a 5km runway in the region for emergencies once fully operational.
  • Be a space tourism launch and landing site.

This discussion will continue over time. Please leave your comments about this site.

– and yes, there are crocodiles!

Fuels for Space Flight

Handling Hypergolic_Fuel_for_MESSENGER spacecraftFuel for Thought.

by Robert Brand. Fools and Fuel. It is the one thing that you can’t avoid and possibly the biggest risk to spaceflight. Fuel.

ThunderStruck will start with the premise that we are going to use the safest fuels and the greenest where ever possible.

Since we are initially talking about booster capability, we are looking at solid fuels and for safety, we will also not use hypergolic fuels as they are very dangerous.

This excerpt from Wikipedia:
https://en.wikipedia.org/wiki/Hypergolic_propellant

A hypergolic propellant combination used in a rocket engine is one whose components spontaneously ignite when they come into contact with each other.

The two propellant components usually consist of a fuel and an oxidizer. Although commonly used hypergolic propellants are difficult to handle because of their extreme toxicity and/or corrosiveness, they can be stored as liquids at room temperature and hypergolic engines are easy to ignite reliably and repeatedly.

In contemporary usage, the terms “hypergol” or “hypergolic propellant” usually mean the most common such propellant combination, dinitrogen tetroxide plus hydrazine and/or its relatives monomethylhydrazine and unsymmetrical dimethylhydrazine

Our booster will have a mass of about 2500Kg to 3,000Kg with fuel and the fuel will be about 2/3rds of the mass.

Below is a list of most common space fuels in use today. Please look up any words that you don’t understand.

We will discuss the Specific Impulse and Density Impulse more in a later post.

Specific Impulse:

Wikipedia:    https://en.wikipedia.org/wiki/Specific_impulse

Specific impulse (usually abbreviated Isp) is a measure of the efficiency of rocket and jet engines. By definition, it is the total impulse (or change in momentum) delivered per unit of propellant consumed and is dimensionally equivalent to the generated thrust divided by the propellant flow rate. If mass (kilogram or slug) is used as the unit of propellant, then specific impulse has units of velocity. If weight (newton or pound) is used instead, then specific impulse has units of time (seconds). Multiplying flow rate by the standard gravity (g0) before dividing it into the thrust, converts specific impulse from the mass basis to the weight basis.

A propulsion system with a higher specific impulse uses the mass of the propellant more efficiently in creating forward thrust, and in the case of a rocket, less propellant needed for a given delta-v, per the Tsiolkovsky rocket equation. In rockets, this means the engine is more efficient at gaining altitude, distance, and velocity. This is because if an engine burns the propellant faster, the rocket has less mass for a longer period of time, which makes better use of the total force times time that was acquired from the propellant. This is much less of a consideration in jet engines that employ wings and outside air for combustion to carry payloads that are much heavier than the propellant.

Density Impulse:

https://www.quora.com/What-is-density-impulse-and-why-do-propellants-with-higher-densities-have-higher-density-impulses

Impulse density is a way of measuring the performance of different propellants regardless of their density. It’s a measure of how much force per time (impulse) you’ll get from a given volume of propellant. Higher density fuels have a higher Impulse Density because Impulse density is basically the propellants Specific Impulse multiplied by it’s density.

As comparison Lox-Butane and Lox-Methane both have a specific impulse of 365s, but the average density of Lox-Butane (at 1000psi) is 890.62kg/m3 while Lox-Methane is 823.34kg/m3. So Lox-Butane’s Impulse Density = 890.62 * 365 = 325076.3Kg-f-s/m3 and Lox-Methane = 300519.1Kg-f-s/m3.

This basically means that per Kg of Lox-Methane you’ll get the same Isp as Lox-Butane, but Lox-Butane can be stored in a smaller tank.

ROCKET PROPELLANT PERFORMANCE
Combustion chamber pressure, Pc = 68 atm (1000 PSI) … Nozzle exit pressure, Pe = 1 atm
Oxidizer Fuel Hypergolic Mixture Ratio Specific Impulse
(s, sea level)
Density Impulse
(kg-s/l, S.L.)
Liquid Oxygen Liquid Hydrogen No 5 381 124
Liquid Methane No 2.77 299 235
Ethanol + 25% water No 1.29 269 264
Kerosene No 2.29 289 294
Hydrazine No 0.74 303 321
MMH No 1.15 300 298
UDMH No 1.38 297 286
50-50 No 1.06 300 300
Liquid Fluorine Liquid Hydrogen Yes 6 400 155
Hydrazine Yes 1.82 338 432
FLOX-70 Kerosene Yes 3.8 320 385
Nitrogen Tetroxide Kerosene No 3.53 267 330
Hydrazine Yes 1.08 286 342
MMH Yes 1.73 280 325
UDMH Yes 2.1 277 316
50-50 Yes 1.59 280 326
Red-Fuming Nitric Acid (14% N2O4) Kerosene No 4.42 256 335
Hydrazine Yes 1.28 276 341
MMH Yes 2.13 269 328
UDMH Yes 2.6 266 321
50-50 Yes 1.94 270 329
Hydrogen Peroxide (85% concentration) Kerosene No 7.84 258 324
Hydrazine Yes 2.15 269 328
Nitrous Oxide HTPB (solid) No 6.48 248 290
Chlorine Pentafluoride Hydrazine Yes 2.12 297 439
Ammonium Perchlorate (solid) Aluminum + HTPB (a) No 2.12 277 474
Aluminum + PBAN (b) No 2.33 277 476

More discussion on fuels in a future post and we will explain our initial choice of booster propellant. The results of an explosion can ruin a flight or kill people. Safety is the big issue. More on that too in a later post.

aptopix india rocket fuel explosion

Greetings Fellow Rocketeers

Did I say that we were Building a RocketDream Chaser spacecraft Graphic on top of a Rocket for Launch?

by Robert Brand. No we haven’t, but here is the buzz – we are developing significant rocket technology.

It was ThunderStruck team member David Galea that headed his email with “Greetings Fellow Rocketeers” and it may stick because ThunderStruck is building rocket technology. We may be building more rockets later but right now we are specifically building a booster for a bigger rocket. A booster that could make it to space all by itself with a ThunderStruck suborbital winged craft as the payload (mounted right on top of the thruster). The rocket will be configured as a sounding rocket – not orbital. The picture (above right) is a similar craft, but a way bigger craft, on top of a bigger rocket. Non the less it will look similar.

Rocket Basics

This will take years to build and it may result in a static test fire in the Australian desert in the next year or two depending on financing. None the less, it will be an amazing opportunity for a small company to gain considerable traction in the rocket building field.

The info here is a basic format that hopefully high school students can understand.

Rocket design commencesRockets and Maths

Mathematics is essential in building space equipment, space craft and navigating in space to mention a tiny bit. Without maths, rockets would explode from over-pressure or fail to get to space because we over-engineered it and it was too heavy to be a work horse.

The image at right is a basic configuration. Solid fuel with an air core and a thrust and nozzle at the bottom. Looks simple, but the maths have to be done first to get an estimation of the pressure we can expect and the strength of the tank and the weight of the tank with different metals. note that as the fuel burns down from the inside towards the metal of the tank, the area burning is greater and the pressure thus increases in a big way. You can change the fuel configuration to burn slower or have less thrust, but that could change simplicity of equation below so we will assume that the fuel is the same for the entire burn. That has been done and we came up with two limits on the mass that we can now work with. The optimum design will be in the middle somewhere.

After putting a rough design on the table with a mass of 2,000Kg fully fueled, we managed to get to space with a big payload and a coasting altitude of 150Km or more. This was with a speed of 1.5Km (or more) per second at the 30 second burn when the fuel is exhausted.

A second design with 3,000Kg mass fully fueled only managed a bit less than 25km altitude. The optimum booster, configured as a sounding rocket lies somewhere in between. The next part of the work is to consider the options. That is:

  • Do we use more thrust and increase the tank and nozzle pressure?
  • We we increase the fuel load and mass?
  • Do we reduce the fuel load and mass?
  • Do we change the fuel and increase the pressure and even the burn time?
  • Do we reduce the mass of the payload (250Kg in this initial desktop design?
  • Do we reduce the mass of the rocket?

These are just a few of the options, but how do we calculate these things – Mathematics of course.

Below are the maths for the heavier second design that only got to under 25Km configures as a rocket. It would have made a poor booster.

NOTE: this is a simple bit of maths for model rockets, but it applies to the bigger ones too. It is not the whole deal, but will give a good estimate for the first pass.

David Galea’s maths for the second configuration performance:

ThunderStruck Rocket Flight Profile – Estimated Calculations

There are three basic equations to find the peak altitude for the rocket

  • Max velocity v, the velocity at burnout = q*[1-exp(-x*t)] / [1+exp(-x*t)] = 916
  • Altitude reached at the end of boost = [-M / (2*k)]*ln([T – M*g – k*v^2] / [T – M*g]) = 13,191.684 m
  • Additional height achieved during coast = [+M / (2*k)]*ln([M*g + k*v^2] / [M*g]) = 11,515.9877 m

Total Height Achieved = 24,707.67 m

All the terms in these equations are explained below on the method for using the equations.

  1. Compute Some Useful Terms
    • Find the mass M of your rocket in kilograms (kg): 2950kg
    • Find the area A of your rocket cross-section in square meters (m^2): 0.342m^2
    • Note that the wind resistance force = 0.5 * rho*Cd*A * v^2, where
      rho is density of air = 1.2 kg/m^3
      Cd is the drag coefficient of your rocket which is around 0.75 for a model rocket shape.
      v is the velocity of the rocket. You don’t calculate this drag force, though, since you don’t know what “v” is yet. What you do need is to lump the wind resistance factors into one coefficient k:
      k = 0.5*rho*Cd*A = 0.5*1.2*0.75*A = 0.1539
    • Find the impulse I and thrust T of the engine for your rocket. I= 3907501 Ns , T= 118841.27 Ns
    • Compute the burn time t for the engine by dividing impulse I by thrust T:
      t = I / T = 3907501 / 118841.27 = 32.88 seconds
    • Note also – the gravitational force is equal to M*g, or the mass of the rocket times the acceleration of gravity (g). The value of g is a constant, equal to 9.8 meters/sec/sec. This force is the same as the weight of the rocket in newtons.
  2. Compute a couple of terms, I call them “q” and “x”
    • q = sqrt([T – M*g] / k) = sqrt([118841.27 – 2950 * 9.8] / 0.1539) = 764.427
    • x = 2*k*q / M = 2 * 0.1539 * 764.427 / 2950 = 0.079759536
  3. Calculate velocity at burnout (max velocity, v), boost phase distance yb, and coast phase distance yc (you will sum these last two for total altitude).
    • v = 764.427*[1-exp(-0.079759536*32.88)] / [1+exp(-0.079759536*32.88)] = 660.916
    • yb = [-2950 / (2*0.1539)]*ln([118841.27 – 2950 *9.8 – 0.1539*660.916^2] / [118841.27 – 2950 *9.8]) = 13191.684
    • yc = [+2950 / (2*0.1539)]*ln([2950 *9.8 + 0.1539*660.916^2] / [2950 *9.8]) = 11515.9877

Rocket SoftwareDavid says: I have double checked my calculations with wolfram alpha (https://www.wolframalpha.com) with the same results.

Well fellow Rocketeers, we will continue to let you know about our big adventure with things that could “go BANG” as we develop our technology.

The Screen shot at right is a basic program that you can get for free or you can buy a more professional version for model rocket hobbyists. None the less it is fine for early desktop modeling.

We will keep you in touch with the professional software that we will eventually choose and use for the serious design phase.

All you students, please get your head down and study maths. We will need to have capable people working in the space sector as Project ThunderStruck becomes an Australian Space staple.

ThunderStruck Spacecraft Development Begins

BOR-4 breakdownWinged Spacecraft Takes Form

Our Australian ThunderStruck team has commenced design of the ThunderStruck Spacecraft. This graphic (right), courtesy of Project Thunderstruck team member David Galea, is just a doodle to break down the benefits of the USSR BOR-4 design. Yes, we started with a 50 year old design and have worked our way forward as the basic air frame is a solid design that has a good flight track record. We then looked at Dream Chaser which looks surprisingly similar, but with a modern interior. We too will have a similar design to both of these but with some big differences. Our starting length will be 3m (10 feet); our unfueled mass is expected to be 400Kg and optimum payload return will be 50Kg. It will have hypergolic fuel for the space flight – main thrust and hypergolic thrusters. If our air-frame can’t support the mass, then we will increase the lift or size. The fuels under consideration are not like the very dangerous Hydrazine used extensively for most NASA missions, but much safer fuels that are pretty safe for humans. They often don’t pack the punch of Hydrazine, but safety is our biggest goal so long as the thrust is powerful enough to do the job.

This from Wikipedia: https://en.m.wikipedia.org/wiki/Hypergolic_propellant

A hypergolic propellant combination used in a rocket engine is one whose components spontaneously ignite when they come into contact with each other.

The two propellant components usually consist of a fuel and an oxidizer. Although commonly used hypergolic propellants are difficult to handle because of their extreme toxicity and/or corrosiveness, they can be stored as liquids at room temperature and hypergolic engines are easy to ignite reliably and repeatedly.

We are now go for liftoff in eerrhhhh …in 6 years… But we have started. We are choosing a suitable fuel at this time – one that is relatively safe for humans and still able to provide the thrust needed to de-orbit and maneuver. There are new fuels – not as powerfully as many of the well known thruster fuels, but sacrificing power for safety could be a really good thing if the numbers stack up.

Our Invasion of Space has Begun.

Let’s rewind a bit. ThunderStruck is a Spacecraft under development. This story is about our spacecraft that we are building for actual flight many years from now. We also have a transonic test vehicle that has yet to fly, but we hope early next year we will get permission to fly the craft in northern Queensland (QLD) – probably a little North East of Longreach, QLD. There may be more test vehicles and even the design of our spacecraft may end up radically different from our

At this time, the Thunderstruck transonic test vehicle has been on hold, but it too will benefit from the spacecraft design kicking off since they may share common components. The Spacecraft will be slow to design and build compared to the transonic testing flier, but we have to start this if we are to finish it in a timely fashion. So back to our spacecraft design.

It is expected that we will partner with a university that will assist with the build. At this time we are closest to Sydney University and we know that they have similar goals of working with a winged re-entry flier.

It is clear that we are not relying on using the Russian BOR-4 as a blueprint, but it is a starting point. It is also clear that the BOR-4 and the Sierra Nevada Corporation’s Dream Chaser share a lot of common air frame characteristics. So Dream Chaser was the next craft to go under the microscope.

Critical to the design and thus one of the first components to understand is the type of fuel that will be needed. This may determine that we need a bigger craft to carry the tanks or that the shape must be different to handle the large tanks.

Dream Chaser Graphic on top of a Rocket for LaunchDream Chaser (pictured right) is large and has a crew. Our craft does not have a crew and the ThunderStruck spacecraft is small in comparison.

Dream Chaser can launch on top of a rocket and we expect ThunderStruck to do the same. ThunderStruck is way smaller and potentially has folding wings and thus could sit inside a fairing making the ride more comfortable.

ThunderStruck will have a docking ring and the ability to swap old and new payload canisters. ie to provide a new empty canister to , say, an asteroid service craft and bring back a full set of samples.

ThunderStruck will evolve and its capabilities will change as we grow. Our aim is to make the smallest rocket launched spacecraft with wings for re-entry and an exchangeable payload.

 

ThunderStruck Progress.

Pajero Jan 2016

Pajero Tracking Vehicle Update

We are on the move after several delays. The proof is in the progress since our last post. We are now talking boosters from our balloon platform to get us to space and we are working on our technology. Balloon test flights are being planned for late January / early February

So lets look at what my son, Jason (13), and I have done and are doing about the tracking vehicle. We will have more, but we are planning on at least having our 4WD SUV ready for the trans-sonic test as soon as we get this approved by CASA – the Australian Civil Aviation Safety Authority.

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Hobbyking Collaboration

HobbyKingThunderStruck Welcomes Hobbyking

I am excited to announce that Project ThunderStruck and Hobbyking are collaborating on testing many of Hobbyking’s systems and parts to the extreme. That includes incorporating many of them into the ThunderStruck X-2 vehicle for testing in September this year. Those units will experience close to zero atmosphere, temperatures approaching -60C, higher radiation (well a bit more than normal).Micro- gravity and Gee Forces of 2.5G maximum..

In case there is any confusion, this is not a sponsorship and no money is changing hands. They will be a major supporter of our project, but they are also receiving support and services from Project ThunderStruck, so this is a mutually beneficial arrangement.

Jason will be testing all the First-person Point of View (FPV) using balloon flights and steerable parachutes. This will be amazing fun and we hope to bring you some real time video during the flight.

Stay tuned for some amazing fun and again, thanks to Hobbyking for all the support.

ThunderStruck X-2 Speed Profile

Balloon Flight with ThunderStruckCalculating ThunderStruck X-2 Speed

Recently we spoke about the spreadsheet that we have created to calculate the speed to be achieved by the ThunderStruck X-2 craft. We took into account a range of figures and that gave us some big design changed to ensure that we could meet the Mach 1.5 speed that we wanted for the experiments on board. Those changes took into account the drag of the vehicle, the angle of the nose cone, the size of the fuselage, gravity at altitude, air density and more. For the sake of the initial calculations we did not bother with the drag of hitting Mach 1 as we believed the air density to be so thin that it would not stop us achieving the speed that we needed.

I am pleased to say that team member Todd Hampson has now incorporated the transonic factors and ongoing supersonic factors into the spreadsheet and I am pleased to say that we were right. There is very little variation in our calculated speed if dropped from 45km altitude. Lower altitudes certainly had issues, but not if dropped from 40km and above. Although we are aiming for 45km using hydrogen, it is possible conditions like potential grass fires my limit us to Hydrogen

The addition factors that we have added to the spreadsheet are:

  • Base Drag
  • Area Rule
  • Transonic Wave Drag
  • Supersonic Wave Drag
  • Friction Drag

Remember that this spreadsheet is designed to measure an aircraft in a vertical dive into the ground. You can see it slow with thick air to very low speeds. None the less we intend to transition to horizontal flight at below 10km altitude, to the remainder of the graph becomes meaningless at that point.

One of the outputs of the spreadsheet is a set of figures. Below are the figures for 45km altitude release and below that for 40km altitude release. Both heights break Mach 1 sea level equivalent.

 45km stats

Above: Figures showing the results of a 45km release.

Below:  Figures showing the results of a 40km release.

40km stats

Mach 1 at Sea Level and Mach 1 at Altitude

Simply put, altitude does not really change the speed of sound. Temperature does. It is the biggest factor. Because the speed of sound is lower at altitude where the temperature can be as low as -60C, many people feel as if we are cheating if we only break Mach 1 at the altitude that we are traversing. They want to see the speed of sound broken as if we were doing it at sea level. We have provided those calculations here. The chart automatically compensates for the increased effects of the speed of sound at a given altitude by assuming a standard set of temperatures at those altitudes. These vary by time of year and region. We will publish the set of tables that we have used for this in a future post for reference.

For our purposes, the figures used will be accurate enough for the calculations. Why do we know this? Because they do not vary much at the altitudes that we are breaking the sound barrier. The coldest air in our flight will be in the jet stream and is well below 20km altitude.

We intend to give others on-line access to our spreadsheet in the near future, when we are assured all the bugs are ironed out. At this time the spreadsheet looks stable and accurate.

Below is our Velocity Profile showing Max speed in Mach figures. Remember the speed of sound changes with altitude and this is adjusting the Mach figures for the air temperature at each altitude point. The bump near the 15km is the point where the craft decelerates going through the speed of sound. Given its proximity to the ground and the density of air, it is very possible that we will hear a sonic “boom” from this event.

 45km Velocity Profile

The graph below is the Acceleration Profile in Gee Force. The bump at 15km is showing the additional drag going through the sound barrier to subsonic speeds. there is a similar bump centred at 39.5km, but the air is so thin, it is extremely attenuated and not visible and thus it has little effect.

45km Acceleration Profile

Below is a graph showing the Velocity vs Time for the first 125 seconds. After this time, the aircraft will level out.

45km velocity vs time - 125 seconds
From the top graph – Velocity Profile – if Thunderstruck X-2 continued its dive to the ground, it would hit at Mach 0.27 or 320kph . This is a lot slower than the Mach 1.5 it achieved at 39.5km. Lets hope that the landing will be a lot smoother!

Trimming ThunderStruck for Speed

X2 shadow Trimming ThunderStruck Needs Extreme Knowledge

by Robert Brand

This post is very technical. I will try and make it a little easier to understand. I will not go into very deep into the various aspects that slow the craft, nor will I get into every aspect, just the major aspects that will cause us issues.

Designing a supersonic aircraft needs knowledge of supersonic aspects of airflow and pressure/shock waves. In a previous post we looked at the basic limiting factors and those important to getting us past Mach 1. This post will look at other factors that will cause us to make small changes to ThunderStruck to ensure we reach the maximum speed possible and get as close to Mach 1.5 as possible. We previously discussed the following:

  • Varying gravity due to altitude
  • The angle of the nose cone
  • The width of the fuselage
  • Altitude
  • Vehicle mass
  • Wing and Vehicle Drag Coefficient
  • Reference Area of the object in the direction of motion

In this post we will now look at other aspects of the design that will slow the crafts acceleration during its flight:

  • Base Drag
  • Area Rule
  • Transonic Wave Drag
  • Supersonic Wave Drag
  • Friction Drag

These factors take into account compressible air flows and incompressible air flows. Look them up, but simply Transonic and supersonic flows are compressible, subsonic flows are incompressible.  They are reflected in the items above.

If you would like to look at the Maths for these issues, there is a great document from Sydney University that can be viewed on the link below:

http://web.aeromech.usyd.edu.au/AERO2705/Resources/Research/Drag_Coefficient_Prediction.pdf

Base Drag

My knowledge here comes from rockets – same as the document. A flat based rocket does not have Base drag when it is firing its engines as the air flow does not have a pressure problem when compared to having a flat rear end! Below is a snapshot of the pressure differentials at the rear of the craft. There are more and bigger pressures not shown here, but you can clearly see the problem. as a rocket flies horizontally with its engines ignited, there is no void. The moment the engine ceases ignition, these pressure waves appear – Base Drag.

X2 Base Drag Pressure snapshot

Looks like a tapered fuselage at the rear of the craft is super important to acceleration towards the ground and again as the craft decelerates due to the thickening air density. It will need to taper from half way along the main wing part to the rear and go from 300mm to 50mm– enough for a parachute to be deployed – about 50mm. Whether we add a tapered cap, taking the final taper to a point for even less drag is not important at this stage. It will look better without the cap in drawings.

This important diagram from the linked document. This shows the flight of a rocket accelerating to Mach 1.6 (Dashed blue line) and then decelerating to to low speed (the solid black line). All the various drag issues are in this typical diagram. Base drag however is the difference between the two. There is no base drag during the rocket burn and then there is base drag once the engine ceases ignition.Drag issues in Transonic and Supersonic Flight

By gently tapering the fuselage to a point, we avoid disruption the boundary layer and any turbulence. For the X2 ThunderStruck flight the fall and acceleration will also look like the deceleration. Base drag will almost be eliminated.

Area Rule

We have spoken about this in an earlier post. That is keeping the cross-sectional area of the craft constant – so thinner where there is space (area) allocated to the wings. Area ruling will be somewhat addressed by the taper to the rear as discussed above in Base Drag. It is a fairly small effect unless you were spending significant time near the speed of sound. The X-2 ThunderStruck craft will spend 15 seconds between Mach 0.9 and Mach 1.2. I believe that it will be small and this is where the area rule has the biggest effect – but still small. There will be no additional change for area rule.

Transonic and Supersonic Wave Drag

The taper of the rear of the craft will minimise Wave Drag – both Transonic and Supersonic. Some playing with Wing Design may change the Wave Drag, but we will ignore it at this stage. I am not looking to play with the design unless there is a strong case. In the diagram above the Transonic Wave Drag begins at about Mach 0.9 and Mach 1.2 and Supersonic Wave Drag continues upward from that point.

Friction Drag

Friction drag occurs at low speeds with laminar flow being disrupted and the airflow becomes turbulent. We will have stalled at that stage and thus this is of no interest since we have an aircraft. We should have landed! This is ignored.

Trimming the Design

We have determined that we need to do two things. Stop the leading part of the winglets from protruding in front of where it joins the wing and to taper the fuselage. We will provide a picture of the new design shortly. Here is a render of the current X2 design without the new modifications:

X2 - Clouds2

The X2 ThunderStruck craft will have minimal impact regarding its maximum speed. I will reveal the new graphs shortly showing the speed at any given altitude point. As the air is extremely thin at our launch altitude, the increase in drag above 35km from the items above will not likely to be affect our top speed much as previously calculated, but may increase the deceleration slightly. That is the max G force as we slow. I will publish the updated results soon.

Finally a scan of the pressure waves from front to back on the X2 craft before we trim the craft:

X2 Pressure_Cut_Raised

A Flight to Mars – 2022

Mars - 2022Mars – 2022 CubeSat Mission

Here is the ThunderStruck proposal for a payload to Mars – 2022 for our Ion Engine Shakedown flight. This presentation was one on many 15 minute presentations at NSW University. Where all others focused on cubesat missions close to earth, this would be the first to Mars and presents a unique opportunity for Australian Space Research.

Given that most of the audience would not have a clue about ThunderStruck, I had to first explain the project and then the opportunity. Not much could be said about the Opportunity as we will be looking for cubesat builders to tell us what they can achieve closer to the date.

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