LAUNCHER EVOLUTION ADVANCED PROTOTYPE
This is our vision for the next generation of space launch. This is an orbital system that will be the model for our first prototypes. The technology is reachable, and we will grow this in affordable stages. Stay tuned for the hardware!
- KEY TECHNOLOGIES
- DENSE FUELS
- TANKS AND STORAGE
- UNMANNED BOOSTERS
- AIR BREATHING PROPULSION
- EMERGENCY PROTECTION
- UN-MANNED ORBITERS
- MANNED ORBITERS
- ORBITER REENTRY FEATURES
- ORBITER LANDING
- GETTING OFF THE GROUND
- VEHICLE AND MARKET POTENTIAL
- THE EXODUS TEAM
This small venture has spent the winter projecting a look at a new way to access space launch. We have assembled a technology and a few leaders to grow the vision.
1. KEY TECHNOLOGIES
HORIZONTAL IN LINE LAUNCH STAGING…WHAT IS “H.I.L.L.S.”?
This is the joining of two delta wing aircraft, nose to tail, to operate as one aircraft powered by the first stage until separation to deliver the second stage and payloads to orbital missions.
PATENT US 8528853 B2 http://www.google.nl/patents/US8528853
By moving our orbiter to the front, the mass of its wings is working to produce lift. This allows the booster wings to shrink, saving mass there. The smaller craft also becomes a nose cone to the larger craft instead of increasing frontal area. By using a blended wing body form we add the efficiency of a lifting fuselage per the concepts of Burnelli. The lifting bodies maximize internal volume and still allow runway operations. Stage separation in emergencies can rescue payloads or crews for lower insurance rates.
2. DENSE FUELS
We found an issue with packaging cryogenic fuels tanks in wings and flattened fuselage areas. This led us to consider High Test Peroxide (HTP) and jet fuel instead of cryogenic fuels. Like jet fuel, HTP can fit in wing tanks, but it is heavier than liquid oxygen. That is offset by lighter tanks and smaller airframe size.
Published reports for other space planes reinforced our interest in HTP:
- Oxidizer Selection for the ISTAR Program (Liquid Oxygen versus Hydrogen Peroxide) https://archive.org/details/nasa_techdoc_20030006267
- Quicksat: A Two-Stage to Orbit Reusable Launch Vehicle Utilizing Air-Breathing Propulsion for Responsive Space Access http://www.sei.aero/archive/AIAA-2004-5950.pdf
With HTP we can effectively fill the gaps between the structures and follow the airfoil form fully. This delivers the required fuel for the mission and allows vacant tank volume for in-flight balance in supersonic flight. We will also maintain low pressure (30 psi) in these tanks, so structural strength is aided, and mass is further reduced.
PEROXIDE AND JET FUEL TANKS
We will choose to use more conservative air breathing engines. We may propose to use turbine or ramjet engines. These still yield high supersonic performance without missing the value of harvesting atmospheric oxygen.
MASS ESTIMATION COMPARISONS
Wing loading is not too unreasonable in historical comparisons.
So fuel will shape the mission and the vehicle. But it will also affect costs in shipping and storage. Peroxide also comes off as a fairly clean and affordable fuel.
3. TANKS AND STORAGE
Rocket cost can’t be divorced from the storage and transportation of rocket fuel. This is what you can expect with cryogenic fuels; not a cheap plan to deliver cold fuels.
Hydrogen peroxide and jet fuel are room temperature low cost storage issues. Thin tanks and fuel bladders work in about any shape. Even plastic water tanks work, as seen here at Frontier Astronautics’ facility in Wyoming.
4. UNMANNED BOOSTERS
To reach orbit by horizontal launch is a challenge. We need a first stage that is nearly single stage to orbit capable. New propulsion may take us there, but there is no reason to take air breathing engines to orbit. Better to leave that mass behind in favor of customer payload.
By offering an unmanned booster, customer payloads or crew are not on that craft in the event of an emergency. The booster may be recovered by manual controls, or ditched in a safe place. Being able to save the payload or crew by separating the upper stage will reduce insurance costs. Being able to avoid the launch facility, personnel and communities on the ground is also important. Any potential to save one or more stages is frosting on the cake.
The orbiter fins align with the junction mechanisms and with matching structures on the booster. Both craft have vertical beams on a common line for hard point junctions.
Thus the orbiter vertical tail provides structural strength for the junction of the two stages.
Looking forward through part of the booster shows all the mechanisms clustered in the structures. This series of illustrations animates the pin release and piston separation sequence.
PISTON PRESSURE BOOSTED SEPARATION
This leaves some booster aerodynamic thoughts to be explored.
Orbiter vertical surfaces are inboard to preserve a clean flow along the joined wings. The wings target the vortex demonstrated by the Concorde. This helps assure efficient lift at low speed without complex flaps. When joined the craft should be optimized to climb efficiently during air breathing flight, accelerate, and transition to hypersonic flight under rocket power.
We can provide full scale Siemens NX CAD models that may be used for CFD which consider the possibility of B-70 type winglets. We understand the “waver rider” concept, as well as potential use to help balance the CG during supersonic center pressure shift. Fuel transfer may not have to be the only way to manage the center of gravity.
After this study was progressing we gained some expertise from Gary Johnson on some lessons from the past. “ Here attached is a little photo essay I did a while back, on shock impingement heating. It based on an incident that very nearly caused the loss of an X-15 half a century ago. This is important, because as it currently exists, your booster craft has parallel nacelles for its air breathing engines.”
Our study provided some ideas, but not all the answers. At least we are finding some answer men to cover this and other issues. Meanwhile any copy-cat will inherit some regrets if they go after easy answers!
This kind of launch may take the unmanned booster on quite a trajectory, possibly making a skip across the ocean or a return to base. At some point it needs to be called home for reentry and a landing. Engines may be closed by the inlet cones for thermal protection during reentry. With the orbiter gone the leading edges are largely rounded for thermal loads and drag to slow reentry speeds.
Will it be on final approach to the old shuttle landing strip? To save mass our landing gear is reduced to a nose wheel and two skids, per the X-15. Like that craft it will have a dedicated launch vehicle, but not one you might expect.
5. AIR BREATHING PROPULSION: AN IMPORTANT KEY
We illustrate simple cylindrical engine installations in part for fast service removal, replacement, and servicing between missions. Reality will probably be more complex as Gary Johnson pointed out.
For a prototype, engine development may be part of the early missions. There have been many air breathing propulsion designs proposed, but this is not an easy performance realm. We may consider proposing turbine based systems in the outboard positions for low speed and takeoff operations. These have been reliable and efficient in the past, but they may also be a bit heavy and complex. The Concorde, XB-70, and SR-71 are all complex installations.
Even a greatly simplified view of Concorde engines suggests sophisticated understanding of shock wave and flow management. This delivered supersonic speeds with greater fuel efficiency than rockets. Engine vendors are proposing new designs for supersonic business jets which may offer promise for better things to come.
TURBINES ARE NOT THE ONLY OPPORTUNITY
In 1999 Orbital Sciences did a study of modification of a D-21 drone to use for space launch. Their proposal would use avionics from their Pegasus launcher and the X-34 for economical development. A ram jet engine is considered for these missions. We have senior ram jet expertise in house now.
Gangs of engines in square inlet configurations are seen on the XB-70 and the Concorde. The SR-72 has inlets and airframe configured and tuned for Aerojet turbine and scramjet engines. Our goal is not extreme speeds until leaving the atmosphere. To harvest atmospheric oxygen cannot come at the cost of a massive fuel burn penalty or huge development costs. To field a serviceable test bed that can climb at supersonic speed and switch to rockets is a better goal. Identifying efficient air breathing propulsion may require flight testing. Our platform proposes to deliver variable test opportunities.
6. EMERGENCY PROTECTION
GOOD PLANS OFTEN EXPERIENCE A BUMP IN THE NIGHT. Even near the earth aviation does on occasion experience a bump in the night.
Unfortunately not every collision has a happy ending, as we saw with the space shuttle. That orbiter never had a problem that wasn’t associated with the booster stage. With in-line staging we literally leave the booster problems behind us. In an emergency we can separate the stages and make insurance companies and passengers pretty happy.
GETTING OUT OF DODGE
We did look at one way that we might avoid a bump in the night for a blind unmanned spacecraft. To augment guidance systems we hope to offer UAV style ground control with cameras. This installation is an opportunity to challenge vendors too. We propose to use a Surmet Alon brand Aluminum Oxynitride dome for this installation. It has a “Star Trek” connection for being called “transparent aluminum”. But it has a far more stellar performance than aluminum in optical, impact, and thermal durability.
The auto industry has a term; “crush zone”, which suggests a cushion for impact. In space any small object, even plastic foam, can be a lethal weapon. For our mission these impacts may go unnoticed until thermal issues begin to invade your structures. During reentry it is too late to do a space walk to make repairs.
Ultramet offers an idea for thermal protection that we may expand on. Using carbon foam as a lightweight filler, aerogel is added to improve thermal protection. We would enlarge this in the nose and wing caps to provide a thermal “crush zone”. A variety of thermal protection systems may cover the outer shell, including tiles, ceramic composites, or carbon-carbon. When damaged, these are fragile shells. A deeper zone of carbon foam and aerogel is light, but may slow incoming plasma and gasses. Some penetration is tolerable in this material.
A second inner wall of the wing cap is a solid carbon-carbon barrier, which will not tolerate a prolonged thermal battle. To relieve this, there is an open passage, a tunnel through the carbon foam. That opening encourages the flow to pass to the rear of the wing cap. At that point it is vented ahead of the elevons. If the fairings are still in place, they would be ejected to allow the gasses to vent.
THERMAL CRUSH ZONE
It’s not enough to consider reusability as a means to profit. Insurance costs could be reduced with this so survivability also rates as high value. Added reliability must be part of planning our future, and reusable systems require it. Going back to Apollo is not a road to the future. This is not just a launcher, it is an orbiting service station. As the X-37 has demonstrated, a fly-back space station has far more utility than a throw away system. And we cannot afford to postpone affordable access to low earth orbit. No serious exploration or mining of the solar system can go ahead without sensible access to low earth orbit.
7. UNMANNED ORBITERS
The satellite market is rewarding enough but servicing that market is more so . A fly-back orbiter is a valuable concept proven by the Boeing X-37B. Being able to deliver a similar success story with a reusable booster can reduce G forces and add safety features. It also opens up entirely new market applications.
ROUGH SCALE TO THE X-37 AT 29 AND 54 FT. LENGTH.
This early X-37 study indicates that they once considered HTP and JP as we are doing now. Currently the X-37 uses highly toxic fuels that we will avoid. Besides, we have a source of 100% HTP here in Wyoming!
So how much can be done with the prototype that we have been illustrating? The prototypes may only have room for a small payload. That is no challenge to the heavy launch companies, but then our size is scalable. Steps will be important when they reach the right audience.
The largest payload would be 66 inches in diameter by 166 inches long, or about 5 feet diameter by 14 feet long. That allows a pretty big payload if not including a kicker motor.
Unlike vertical launch we do not just kick the fairings off and boot the satellite. We have to move the payload vertically, or lateral to the centerline after the doors open. One might use a robotic arm, but we illustrated a simple extending arm with linear actuation. This will still allow the satellite to be tested before it is released. We can recover it and return it to base for servicing if needed. That’s the difference between a launch vehicle and a service vehicle.
Smaller payloads are possible, including non-orbital experiments. Materials, products, and biology can be tested and returned to earth. The X-37 has orbited for as long as two years delivering classified services for the Air Force. How many services can you imagine here? What would be the value of returning an inoperative satellite for salvage? Those are a few opportunities to return things. But there is value in bringing home things that have never been to earth. If there is any mining in space this is the safest way to bring home samples. Would you want loads of rocks coming home on parachutes in your town? But this could be the means for regular service to runways and paying customers.
One alternative that we also show is a cube satellite dispenser. Using a 12 inch cube we now illustrate the revolving “Gatling gun” dispenser. This can hold 180 cubes or 60 cubes and 60 12 x 24 inch rectangular satellites. The military may want a fast satellite replacement supply on orbit at all times.
Having an orbiting dispenser one could make many orbits between launches for dispersal. Today the small customer is like a kid on a skateboard shagging a ride behind a taxi. You have to follow the paying customer and the ride may be a bit risky. We need to take these customers to work as valued business.
There is extra room under these payloads that offers another opportunity. We have tanks available for servicing fuels or oxygen for satellites or stations. Larger tanks may be delivered for orbital refueling. This is a space station and a service station at the same time. If a small step delivers many small parts one can build greater visions far beyond low earth orbit.
8. MANNED ORBITERS
If unmanned development goes well, manned versions will add real value. Many safety features are available for this application. One basic modular vehicle can be configured for either mission.
COMPOUND CURVED GLASS???
Didn’t I warn you about transparent aluminum? We propose to use Surmet Alon brand Aluminum Oxynitride for this installation too.
If we offer a manned version, it will need durable high temperature windows inside and out. Our cargo area was cylindrical for typical payloads, and this fits a pressure vessel as well.
MODULAR..CARGO OR CREW
Unfortunately the “Launcher Evolution Advanced Prototype” (LEAP) is a bit tight. Is there a customer for a wide body out there?
At least claustrophobia will not be a problem with a big “Vista Cruiser” view. There should be plenty to see for passengers, whether touring or commuting to work on the moon mines.
9. ORBITER REENTRY FEATURES
We have to enter the atmosphere with the nose high and the belly serving as a heat shield. There must be control of pitch, roll, and yaw in temperatures reaching 2000 degrees or more.
The booster’s nose is removed from the aft of the orbiter, so there is room for a nozzle extension to move aft into that vacant zone. This will yield an efficient vacuum nozzle and reduce radiant heating of adjacent surfaces.
Since body flaps can open, they are further removed from radiant heat damage during operation of the main engine.
A MOVABLE ABLATIVE NOZZLE EXTENSION COULD BE EXPENDABLE.
THIS CLEARS THE RADIANT HEATING OF ADJACENT FEATURES
For roll and pitch control during reentry the lower body flaps are split. The elevon fairings remain in place during the early reentry phase.
We now have an upper body flap to replace the old “duck tail” to keep the nose high during reentry. Most of our turns can be by roll and pitching up during reentry. Rudders are less effective at high angle of attack, and the thin vertical surfaces are sheltered from most thermal issues.
We will need have better control surfaces to manage pitch, roll, and yaw at lower altitudes. To allow full flying elevons we remove two small protective fairings after staging. The small elevons might not suffer extreme damage, but they are probably not especially effective during the fireball phase.
Cutting the fairings off as a flat leaves an edge to break off some boundary flow. This may keep some thermal issues from invading the seam between the flat and the full flying elevons. The elevons are blunt to ease thermal loads.
At lower altitudes the “duck tail” flaps drop to allow bottom flaps and elevons to work in level flight. Better yaw control comes as the rudders get better flow.
10. ORBITER LANDING
With level flight and good control surfaces we can get into ground effect at the runway. We still want a gentle touchdown with minimal mass. So we effect a half-vertical landing.
With all these thrusters, the orbiter should be using them on final approach. In ground effect this may allow a “Soyuz” like cushion, reverse thrust, and little or no actual skid on the landing feet. This becomes a hybrid semi-vertical landing, but on a wide stable base.
SO WITH THRUSTERS WE CAN DO THIS TOO. ON A WIDE STABLE BASE.
SO WHO NEEDS LANDING GEAR?
That concludes a lot of considerations for the orbiter. Now we need to go back to reveal one final mass reduction and energy saver for the takeoff roll.
11. GETTING OFF THE GROUND
We have presented a case for horizontal launch with several notions to reduce mass. With Hydrogen Peroxide oxidizer we still face some high takeoff weight figures. Getting a heavy aircraft off the runway without adding more mass for flaps and mechanisms is a challenge. By The Concorde wing achieved a vortex that aided lift at a high angle of attack. That inspired our design to emulate this or any similar form that can enhance lift on the takeoff roll.
For an in-line two stage vehicle, our challenge includes reducing the ground structural loads on the junction of these two aircraft. If we considered a rail launch we might have a “sled” that could provide a cradle to support the two stages. That would allow us to have only light weight landing gear at the end of the mission. We could also provide a hydraulic lift to elevate the craft to the ideal angle of attack before even starting the takeoff roll. That will deliver the ideal angle of attack before we even start the engines. Looking at Concorde images, that AOA appears to be between 10 and 30 degrees.
Rail launch will have other issues. When a vertical launch fails it either explodes, or is deliberately blown up, destroying the rocket, its payload, and often the launch facility. Such damage could also be produced by sabotage, causing long launch delays to other missions. Even our horizontal launch vehicle might fall directly on the rail. A rail launching system would require a dedicated facility with considerable construction cost. Adding that cost to limited available sites and risk is not our goal.
Other solutions have been demonstrated in the past. The ME 163 rocket fighter used wheels only for takeoff, then they just dropped them…on whoever got in the way! The Rockwell Star-Raker proposed to do the same thing, only with much larger gear and more serious damage potential.
There is a way to do this without a dramatic increase in your insurance costs. And Boeing is already doing this on a small scale. Their Phantom Eye drone has a huge hydrogen fuel tank, high takeoff mass, and little tolerance for heavy landing gear. To keep mass down they use only light landing gear, leaving takeoff to a launch cart. Nothing falls out of the sky, as the cradle stays on the runway. This probably has an auto-pilot to stay on the runway. That looks like a good start that we can build on. We can add the cradle and some propulsion at the same time.
If we add electric hub motors we can begin to provide acceleration without as much fuel burn. The cradle vehicle can be heavy enough to operate on a runway in crosswinds and still be fast. Electric cars are demonstrating great performance potential and this is renewable energy without volatile fuels. Notice that takeoff is not the only drain when aircraft use fuel while moving on the ground, and waiting on the runway. The electric can wait all day without draining fuel from the flight vehicle.
A launch cradle vehicle offers protection from another hazard. The Concorde experienced a tire failure that threw debris and caused a fatal crash. A cradle truck can shield the aircraft from tire and other debris that could damage thermal protection or fuel tanks.
But there are other issues to consider. Launching an aircraft does not always happen in ideal weather conditions. In a crosswind, takeoff and landing can be very challenging. In flight an aircraft can “crab” or turn upwind, while the actual flight direction remains at an angle to the direction the craft is pointing. This can be difficult when you are operating as a ground vehicle, where tire scrub would be pretty severe!
But again, solutions in the past have addressed this issue. The Boeing B-52 has fully steerable landing gear which can crab at an angle during takeoff or landing.
So now we are getting a conceptual look at the future of horizontal launch. With enough mass, rubber on the ground, acceleration energy, and crosswind capability we may be “go for launch”.
In the lowered position fueling, services, and payload mating can be performed in a hangar. The vehicle can move the aircraft as needed, and wait on the runway for clearance to take off.
ON A ROLL
This may be a stretch, but driver-less vehicles may add another capacity. In an emergency, the robotic vehicle may be able to return to the upwind end of the runway and meet the combined craft for a rendezvous landing. The robotics guys are full of tricks these days! Has range control ever asked a malfunctioning vertical launch vehicle to return to the pad? Range destruction often destroys both vehicle and facilities. How are your insurance costs?
12. VEHICLE AND MARKET POTENTIAL
We have not presented a completed design or even a feasibility study at this point, that will require some funding. But we approached some of the known issues with possible solutions to make the mission. With the energy savings of the launch cradle, this may be worth evaluating properly. Is it time to dust off the horizontal launch concept again? We delivered an illustration; can we pay the smart guys to deliver validation? This is modeled in Siemens NX software so it is compatible with CFD programs. If you have such tools we can deliver the solid models to you to analyze. The real refinement comes when the smart guys have a chance to get paid.
We have a generation of orbiters like the shuttle and the X-37 demonstrating uses for reusable orbiting spacecraft. A fly-back orbiter like the Dream Chaser has a lot of potential for services beyond just throwing great mass into orbit. But these spacecraft are still hampered with heavy aerodynamic fairings and throw away boosters. Fly-back boosters and orbiters must be part of fully reusable function.
Business models look for customers with problems that have no other solution. Investors need to know that they will own a tool that others cannot duplicate or build cheaper.
Exodus Aerospace owns a part of the answer in the patents for Horizontal In Line Launch Staging (HILLS). Affordable access to Low Earth Orbit (LEO) is a valuable key that is being ignored in our passion for Mars and deep space adventures. We are ready for the visionary customer who needs a world beating solution.
13. THE EXODUS TEAM
Our team is small, but growing and we may have some assets still under development. A project as big as this needs a lot more development. It would be wise to show that competent leadership and execution can be delivered. We have part time help and advisers with some experience now. Who can build on this base?
We are affiliated with X-L SPACE SYSTEMS owner Michael Carden, and FRONTIER ASTRONAUTICS owner Tim Bendel in Chugwater Wyoming. Michael is a veteran Air Force Space Systems officer with program management experience in that role. He has also served the new space community with his firm and Beal Aerospace. His interest in ejector ramjets has us planning more development in that area. He also sells 100% HTP and better fuels to come.
Exodus Aerospace also has consulting engineers and retired aerospace managers now.
KEY EXODUS TEAM PARTNERS, AND ADVISERS:
Cunningham, Jon David
Beasley, Joseph Craig
We have other vendor teams available for air advanced breathing propulsion, airframes, and guidance systems. For prototypes we would offer design and analysis through established design firms. Fabrication teams are available who have experience from Scaled Composites and Skunk Works projects. These shops have facilities, skills, and human resources from their established customer businesses. We can offer them work without causing high overhead to investment partners.
Wings to space…the Wright Stuff
DAVID I. LUTHER
EXODUS AEROSPACE LLC http://www.exodusaerospace.com/
905 15TH ST WHEATLAND, WY
CAGE CODE: 7LVC8