TAKE A LOAD OFF JACK!
Our vehicle seems to be a bit overweight, but I also carry a load of doubt. I need something like the Easter story to remind me that the joy comes in the morning. I dived into this to make mistakes and corrections publicly so I might hope there would be an avenue or redemption sooner or later.
I launched into this investigation based on a few seemingly safe assumptions. As a designer I have always had a lot of exposure to every intimate detail of a given geometric structure. As such, I may be aware of opportunities of available space. My job includes letting the engineers know about opportunities within the available geometry. If I am aware of other opportunities in materials or vendor solutions I can also make those known. I have worked on a couple of other space planes and these opportunities came to my attention.
Here is a shuttle on a large booster aircraft. The wings of this shuttle aren’t working to produce lift, so they are parasite mass. The shuttle is protruding enough to be slightly parasite drag. 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 aerodynamic deceleration and runway operations. Both were crafted to emulate the efficient wing of the Concorde, and the wave rider winglets of the XB-70. Every element is aimed to eliminate wasted effort. There is also a possibility for stage separation in the atmosphere in an emergency. We may avoid aerodynamic hazards of staging if we are pushing the two craft apart vigorously. Thus payloads may be rescued even if a booster is lost.
Still we found an issue with packaging fuel tanks in wings and flattened fuselage areas. This led us to consider High Test Peroxide (HTP) instead of cryogenic fuels. Like jet fuel, HTP can fit in wing tanks, but it is heavier than liquid oxygen. Our early studies suggested that we might need as much as 1.5 times as much HTP as LOX for the mission. And rocket formulas pointed towards a ratio of 7 or 8 parts of HTP to 1 part Jet fuel for rockets. We have found new reports that give us better tools to target our fuel ratios.
An AFRL project was published in 2004 called Quicksat. That was a paper airplane study like this one, but with all the heavy engineering and trade studies. It presented us with a good trade comparing LOX and HTP for a vehicle of similar size and mission goals. Their mission differed in using hypersonic speeds with an air breathing booster. It used little rocket thrust on the booster stage, relying on scramjets for acceleration. The orbiter was essentially an X-37 with strap on HTP and JP-7 boosters. Those were expendable. The article acknowledged “inefficiency” of the booster airfoil at low speeds. Gross Take Off Weight (GTOW) could be nearly that of a Boeing 747 in some configurations. Some exciting wing loading on a flying wedge could produce adventures on takeoff. The study still has value though.
I had harvested some crude estimations from data published about the Bristol Spaceplanes Spacecab. I estimated a ratio of 1.5 times the Spacecab cryo fuels for HTP use. That drove mass up on the “Old” Leap (at the bottom) but it was still way less than the Quicksat. When I projected a “new” hypersonic Leap I included some small mass advantages but still saw a huge wet mass. To my surprise the Quicksat mass was not from HTP. They are burning a huge amount of JP-7 in the scramjet mode. If you feed a gas guzzler, the advantage of air-breathing systems LOX savings is negated. Back to the drawing board.
The choice to use more conservative air breathing engines led us back to Spacecab. That appears to be using a gang of turbine engines. These may still yield supersonic performance without negating the value of harvesting atmospheric oxygen. The Quicksat article did publish a table comparing HTP to LOX fuels which I used to establish a more accurate ratio for converting from the Spacecab figures.
A conversation with Michael Carden of X-L Space Systems yielded another valuable clue. Most studies propose a 7 or 8 to 1 ratio for HTP to fuel. Michael suggested a 5 to one ratio where their distillation yields a 100% HTP product. That will also save us a bunch of mass.
Now we are closing in on the target and I think we can boost the payload with no strain. We don’t mind any load that is paying. You also see a very low estimated mass for landing gear because we have a different fix for the takeoff leg. Every ounce counts, but that detail will be published later.
While we began with Spacecab data, we should see other savings. HTP will have lighter tanks than cryogenics, and it is dense so vehicle size is reduced. Since the orbiter changed we have saved some weight in that area too. This helps us to remain reasonable about wing loading and the takeoff roll. Now we have enough fuel tanks with volume for ullage and balance adjustment in supersonic shift. This was also an opportunity to clean up the structural junction to the first stage.
Changes to the orbiter also aligned the fin and junction structures with structures on the booster. We eliminated four stage pin actuators and two separation cylinders as another mass reduction.
Looking forward through part of the booster shows all the mechanisms clustered in the structures. This is an improvement over the previous mid-stage proposal.
This series of illustrations animates the pin release and piston separation sequence. Now the engineers can go to work shaving the un-needed mass off of my heavy-handed models!
PRESSURIZED FOR SEPARATION
We will explore more booster solutions soon, including some of the skins and service considerations. This changes every week as problems and solutions are discovered. We have seen that propulsion choices have a big influence on performance. We want to get back to new possibilities in that area. Is anyone out there interested in innovation in air-breathing propulsion?
DO YOU MISS FLASH GORDON? LET’S BRING BACK THE FLASH!
Oh the adventures of space as we saw them in the days of our youth in the 1940s. Well at least I was there in the 1940s…lol! Still there were some real visionaries even back then. Let’s look at my evolving vision and our stellar influences. Buck Rogers launches our voyage into the space future.
I haven’t invented rocket guns yet, but the Russians did try a gun in some of their designs. Nasty recoil I expect! I did a Google search to understand that “verticle fin”, but Google just asked me if I meant vertical. I guess they didn’t have grammar cops back then. Or did it actually tickle? Well, I’m tickeled anyway! America did have big rocket cruisers with steel glass though. Hold that thought, I will come back to it later. At least they did seem to make a few concessions to aerodynamics beck then, not just a cone on a can.
Now Flash Gordon has a nice tail dragger design here, complete with blueprint views. Something about that shape reminds me of…Blue Origin? I guess the “whose is bigger” contest started way back then huh? I went with Buck Rogers on the landing skids though, Those wheel pants need more thermal protection. (pants on fire!) My own space experience didn’t start very far from this design though.
CFFC KITTEN IMAGE FROM AEROSPACE GUIDE
Dr. James Victor Hugo Hill invited us to help design a space ship for kit builders. Wouldn’t that look great sitting in your garage? I was wary of bubble canopies and started asking questions though. I contacted people involved with the space shuttle glass. Guess what? It only comes in flat panes, not in compound curves. So I suggested a fix, and less anhedral but the boss didn’t like it.
As a self-unemployed space man I began to explore CAD, blended wing bodies, and FLAT glass.
“El Tigre” was an X-Prize idea that couldn’t move as fast as Scaled Composites. Money helps! But if we can’t have Flash Gordon, perhaps we can have…
WAIT A MINUTE…IS THAT CURVED GLASS I SEE? Worse than that, it’s…
COMPOUND CURVED GLASS???
Oh the sacrilege! Or not? Remember that steel glass idea on Buck Rogers battle cruiser? Didn’t I warn you about the Star Trek transparent aluminum last week? We propose to use a Surmet Alon brand Aluminum Oxynitride 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.
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.
Unfortunately the “Launcher Evolution Advanced Prototype” (LEAP) is just as tight as the old monoplanes of the 1930s. Customer for a wide body out there?
Perhaps 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.
I AM SO CONFUSED…WHICH WAY IS UP?
OH…AWAY FROM THE BLUE!
That concludes a lot of revisions and considerations for the orbiter. Now we need to go back to finish updates on the booster stage. We have some improvements to stage junction and separation to update. The booster is actually the big key to the mission. New propulsion and potential aerodynamic advantages give a lot to the concept. And like Flash, Buck, and Kirk we need to get this off the ground before we can put the landing skids to work.
AIRPLANE MODEL, CAD MODEL, BUSINESS MODEL
WHY PLAY WITH MODELS? Balsa wood is a long way from space. But space is a long way from earth, and one must learn to deal with the ocean of atmosphere between here and there. I believe that an aspiring pilot should get familiar with sailboats before taking on flying lessons. Sails are airfoils and rudders guide us through waves and turbulence much like a light plane. Part of our learning curve should be intuition mixed with education and experience. Common sense is hard to fabricate.
Model airplanes offer a good tool for learning aircraft design and computer design tools. Even our mistakes have to be fully detailed and developed before we know what to try next. So now we are presenting a design study that is not yet fully analyzed or designed to explore the possible future. We need to visualize some of the new technologies that can deliver new solutions. This will encourage investment in validating these improvements. Modeling the technology is part of building a better future. But the technology still needs a reason to exist, a case for investment. We need more than airplane models; we also need business models.
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. They will want solid technical people to validate real intellectual property. There should be potential to scale up to a market that will grow into these new opportunities. Even small prototypes should have value, but a huge market should be waiting in the wings.
Exodus Aerospace owns a small part of the answer in the patents for Horizontal In Line Launch Staging (HILLS). Much of this design also revives many ideas from other innovators that are now valuable in this application. This combination may allow a body of talented engineers to deliver the vision. This will probably require a coalition of mature space firms mentoring smaller vendor teams. We can launch the business in stages even as the prototypes grow in stages. Low Earth Orbit (LEO) is a valuable key that may be overlooked in our passion for Mars and deep space adventures. Affordable LEO service an crucial door to new space business success.
Gold miners rarely got rich in the gold rush, but hardware sellers always did. In the new space race delivery depends on offering the supply of the right hardware. Now the right hardware is the “Wright stuff”; wings to space. If you aim to dominate this growing market to space you will need the “million motor mindset”.
This was the mindset at Honda when they went after a global market for lawnmowers. The old flat-head lawnmower engines of the past would not make that work. “The ME engine (G150/200) introduced in 1977 represented Honda’s effort to develop a new family of powerplants that could maintain the high quality associated with Honda products yet be affordable enough to compete in the global market. Named ME (Million Engine) as an expression of the company’s high sales expectations, the product was given a challenging mission: to help sell one million units and build the foundation on which Honda could establish Power Products as a third major operation.” Lawn Mower Development: Global Expansion for Honda Power Products Honda delivered serious products and serious sales, and this world beating mindset is needed for our space future. Our little space plane needs to take a lesson from history to make the big sale.
Aviation in the 1930s was revolutionized by all metal monoplanes like the Boeing 247, and the Lockheed Electra. These, like the DC1 and 2 were limited to 10-12 passengers.
“The Boeing Model 247 was an early United States airliner, considered the first such aircraft to fully incorporate advances such as all-metal semimonocoque construction, a fully cantilevered wing and retractable landing gear. Other advanced features included control surface trim tabs, an autopilot and de-icing boots for the wings and tailplane.”
“The Lockheed Electra delivered real excitement to the world in pioneering aviation events. In May 1937, H.T. “Dick” Merrill and J.S. Lambie accomplished a round-trip crossing of the Atlantic Ocean. The feat was declared the first round-trip commercial crossing of that ocean by any aircraft. It won them the Harmon Trophy. Probably the most famous use of the Electra was the highly modified Model 10E flown by aviatrix Amelia Earhart.” (Wikipedia)
We needed these small steps and big excitement to justify the vision that that Douglas could grow a big fat money-maker in the DC-3. But it was a customer who motivated commercial success by asking for more room for passengers. Size does matter!
“The DC-3 resulted from a marathon telephone call from American Airlines CEO C. R. Smith to Donald Douglas, when Smith persuaded a reluctant Douglas to design a sleeper aircraft based on the DC-2 to replace American’s Curtiss Condor II biplanes. (The DC-2’s cabin was 66 inches (1.7 m) wide, too narrow for side-by-side berths.) Douglas agreed to go ahead with development only after Smith informed him of American’s intention to purchase twenty aircraft.” Douglas DC-3 From Wikipedia, the free encyclopedia
Aerospace is witnessing a revolution as reusability becomes fact, not just the conjecture of dreamers. But this is still the dawn of this new age of innovation. Returning a vertical launch booster is a great feat, but may face more effective solutions. 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. Reusable boosters and orbiters must be part of fully reusable function. But that function will only come with customer demand.
Small steps become big steps if they encourage faith in the vision. Even suborbital ventures generate enthusiastic interest in the public circles. Satellite markets already have value, and a game changing solution will have customers. Having ownership of the key patents can make a difference that those early aviation pioneers lacked. Our prototype is a small player in the launch market, but it has potential to grow. There are engineering assets available to meet customer needs. We are ready for the visionary customer who needs a world beating solution.
How much can be done with the prototype that we have been illustrating? This vehicle may have room for a payload sized between the Orbital Sciences Pegasus and Minotaur. That is no challenge to the heavy launch companies, but then vehicle size can be scaled up when it is proven. 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. We may see some limitations in payload mass though.
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. This becomes more than a launch vehicle if it can also be a service system.
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 just a few of the opportunities to return payloads. But there is also 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 over your town? But this alternative could be the means for regular service to runways and paying customers.
Not all satellites are all that big. 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. Now it would take quite a governmental discussion to launch all that, but someone may value a super constellation. Or possibly, the military may want a fast satellite replacement supply standing by on orbit.
How serious are we about cube satellites? Having an orbiting dispenser one could make many orbits between launches for dispersal. This still allows you to test satellites before launch, and you could have lots of backup on board. 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 was a little extra room under these payloads that offers another opportunity. Along the sides at the bottom we have two tanks available for refueling satellites. Larger tanks may be delivered for orbital refueling depots. This can be more than a launcher, it can also be a space station and a service station. If a small step delivers components to assemble on orbit, the vision is validated. Regular small deliveries can be assembled for bigger missions built on orbit, or on the Moon. While some investment is needed for development, the long term economy is real. Deep space can be delivered without deep pockets.
This suggests establishing regular unmanned operations with many service roles. We have witnessed launch operations growing more reliable, including the unmanned X-37 missions. It is not unreasonable to expect such a demonstration from a new system. Demonstrated economy, safety, and innovation are in reach now.
We are already witnessing innovation that we need for the future. No one technology will deliver the entire solution. Now is the time to consider new roads to the future. We will illustrate new ideas weekly in a search for answers. We don’t have all the answers, but we might have some of the questions. Are you ready to boldly go?
GOOD PLANS OFTEN EXPERIENCE A BUMP IN THE NIGHT. Even near the earth aviation does on occasion experience a bump in the night. My favorite story involves a flock of geese.
“US Airways Flight 1549 was an Airbus A320-214 which, three minutes after takeoff from New York City’s LaGuardia Airport on January 15, 2009, struck a flock of Canada geese just northeast of the George Washington Bridge and consequently lost all engine power. Unable to reach any airport, pilots Chesley Sullenberger and Jeffrey Skiles glided the plane to a ditching in the Hudson River off midtown Manhattan. All 155 people aboard were rescued by nearby boats and there were few serious injuries. The pilot in command was 57-year-old Chesley B. “Sully” Sullenberger, a former fighter pilot who had been an airline pilot since leaving the United States Air Force in 1980.” Wikipedia
I love this story because Captain Sullenberger is a true “sky pilot”. He had them praying, baptized, and saved all in one thrilling ride! 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 leave the problems far behind us.
GETTING OUT OF DODGE
We had time to model the skins, structures, tanks, and other features in more detail now. Soon we will be able to detail payload accommodation and services.
READY FOR BUSINESS
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 inform 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.
In the auto industry we had a term, “crush zone” which suggested some cushion for impact. In space any small object, even plastic foam, can be a lethal weapon. Danger comes from birds, space debris, collisions, or debris from our own vehicle. 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. Our crush zone may put other vendors to work.
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. But if damaged, these may be fragile shells. A deeper zone of carbon foam 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 barrier, but it may not tolerate a prolonged 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 though. The added reliability that this will deliver must be part of planning our future. 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. Next week we can look at the potential to deliver services never before available to us.
To reach orbit in horizontal launch is a challenge. We need a first stage that is nearly single stage to orbit capable. Even then we projected a need for the orbiter to make some contribution to the effort. We had to make room for more fuel to achieve orbit. As such we may have a slightly larger vehicle for similar payload capacity. Published data on mass varies widely as some are only targeting limited fuel for orbit and reentry. And some may publish misinformation too? Here is how we stack up, in the middle of the pack…ouch that is a big fuel mass! Well it is being adjusted down real fast now, probably wet mass of 86,000 lbs. Then we start chasing more mass ghosts!
we have a rough outline of structures to transfer loads when attached to the booster and allow room for fuel. More details will be added for payload service later.
FUEL AND STRUCTURES
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 in Wyoming!
THE X-38 HAD STRAP ON ROCKETS, LITTLE ON BOARD PROPULSION AS A LIFEBOAT.
We anticipate composite structures rather than the metal frames of the X-38.
WE ARE LARGER THAN DREAMCHASER WITH CONFORMAL FUEL TANKS
Here is an illustration of how high pressure fuel tanks get around structures. We will use some low pressure with HTP, but we can fit close to the structures. We do pay a penalty in fuel mass, but hope to reclaim some of that from other components. Our structures show similar spacing here. But we lack a crew pressure vessel to aid structures. We may get some of that from low pressure fuel tanks.
WE WILL USE A TOP HATCH INSTEAD OF A REAR HATCH.
WE ARE SLIGHTLY SMALLER THAN THE (DEAD) ESA HERMES
Our structures are spaced farther apart…were theirs metal?
AND SPEAKING OF DEAD BIRDS…WE ARE SIMILAR TO ORBITAL SCIENCES PROMETHEUS.
We will be learning more about composite construction as we go along. Scaled Composites is displaying good examples of this kind of construction. Compared to metal aircraft they often build large panels with fewer frame structures. Stressed skin can cover a larger part as seen in this tail section. Frame reinforcements are built in to the panel.
SS2 TAIL STRUCTURES
INNER AND OUTER CABINS ARE CONFORMAL WITH FEW STRUCTURAL ELEMENTS. HOWEVER THERE IS A LOT OF STRUCTURE UNDER THE CABIN IN THESE WINGS. OUR WINGS PASS AROUND THE PAYLOAD.
Now we see the zones opened up for fuel tanks and engine access. More changes will follow as we consider skins, and opportunities to use them to reduce structures. Service access and thermal protection will become issues down the road too.
I expect to find this is still heavy; I got my start designing truck frames! My model airplane was designed with the same heavy hand. We found the fiberglass to be so robust that I had to go in and carve a LOT of unnecessary structures out!
This leads to a valuable point: no one could possibly deliver a complete launcher design single handed. We know a series of vendors who can build prototypes. They will be straightening me out as we go along. This is a look at the future that will only come in steps, with collaboration from all over. There is a pit that stumbles a lot of “new space incubators” that only encourage business in their own state. Sorry, that’s a STINKUBATOR.
We publish this to motivate consideration of new solutions, and a lot of vendors have ideas waiting for us. We can expect a consortium of new and old space technologies to be involved to deliver goals. It will not come out of tiny teams or geniuses. How long did it take us to discover the “Hidden Figures” of NASA history? It needs big teams, big dreams, and big bucks.
As a draftsman I used to deliver blueprints to the shop, but now we can deliver vision to the next generation. My illustrations are pointing out both the open and closed doors. These are based on somewhat reachable new and old technologies. We paint a future for the bold to explore. If Gene Roddenberry’s “Star Trek” inspired engineers, than we of industry can do the same. It’s only a paper Airplane, but Low Earth Orbit is important. “Once you get to earth orbit, you’re halfway to anywhere in the solar system.” Robert A. Heinlein We can’t afford to have unaffordable orbital access.
RETURN TO BASE
Life is hard for an orbiter. The vehicle needs thrusters in space so we have those and a couple of extra ones. The main engine needs a bigger nozzle for space but there is little space on the vehicle with the booster pressing in from behind. The reentry needs a clean shape with a curved bottom and a “duck tail” that will motivate a nose high attitude. Then it has to return to level flight to the runway, deal with possible crosswinds, enter ground effect and join the runway. We prefer to land with the belly down when possible as well.
A BELLY FULL!
ON YOUR OWN
OPEN WIDE AND…
HEY! EXTEND THE NOZZLE INTO PREVIOUSLY OCCUPIED SPACE!
AN ABLATIVE EXTENSION COULD BE EXPENDABLE.
OR WE COULD MOVE THE WHOLE ENGINE WITH ACTUATORS.
THEN ONE COULD GIBMAL THE ENGINE BY RETRACTING THE ACTUATORS.
THE UPPER BODY FLAP “DUCK TAIL”
MAY BE SHAPED TO SPLIT HOT FLOW AWAY FROM THE VERTICAL SURFACES
WHILE SPLIT LOWER SURFACES INFLUENCE PITCH AND ROLL
This not a shape that we have seen proposed before, but it fits our horizontal launch designs. It 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. We can’t pay to do this but we can let you look it over for your own interests. Anyone who has the tools has potential to do more than we can do now. I have no problem letting real players evaluate and consider the potential. The real refinement comes when the smart guys have a chance to get paid.
WITH THRUSTERS, CROSSWINDS SHOULD BE NO CHALLENGE…FIGHT BACK!
WRONG END OF THE RUNWAY? NOT IF YOU CAN LAND SHORT…
OR DO A QUICK TURN? (Well I can’t find enough runway photos!)
SERIOUSLY, FLYING INTO GROUND EFFECT IS A LOT EASIER TO DO THAN…
SO WITH THRUSTERS WE CAN DO THIS TOO. ON A WIDE STABLE BASE.
SO WHO NEEDS LANDING GEAR?
So we have considered ways to join the craft and cut mass. We try to watch for aerodynamic needs for reentry and the final landing. Now we should have time to locate fuel tanks and payload while refining the structural notions. CAD tools can illustrate notional ideas if we don’t stray too far from known practices. But the picture will always change as engineers find a path to hardware. Analysis and innovation will change everything. These images are already changing every week. I may not recognize this if it ever gets built!
TRIAL BY FIRE? PASS THAT TEST!
The auto club used to say “Bring them back alive”. That would be a good idea for customer payloads and passengers too. Our orbiter aims to reach orbit from a runway without having a payload fairing as big as my house. That has meant avoiding the tall “V” tails that would disrupt our launcher’s idealized wing. Now we need to be able to handle the inferno of reentry without the usual control surfaces. By now you know that I won’t have any problem with UNusual control surfaces! 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.
There is another segment of this landing though. After surviving the fireball of a meteorite, we want to be able to fly as a decent aircraft on the final approach to the runway. We don’t want a lifting body that only flies level when it is forced to do so while suffering from excessive drag. A flying brick is not reassuring to customers. We need good control in level flight and a good way to meet the runway without a lot of extra weight and complexity.
For control during reentry the ESA demonstrated a very uncomplicated solution. This uses only a split body flap, but doesn’t offer a lot of promise for making a runway landing. This is adequate for the meteorite phase of reentry, but what do we do next for a gentle lading?
First, we have moved the vertical surfaces inboard to preserve a clean flow along the joined wings. This helps assure the air breathing and rocket boosted delivery to space.
Separation in space keeps us away from aerodynamic issues at staging, and we can open up the orbiter body flaps to keep them clear of the rocket engine plume. No drag in space!
For roll and pitch control during reentry the lower body flaps are split per the ESA example above. The elevon fairings remain in place during the early reentry phase. The small elevons might not suffer extreme damage, but they are probably not especially effective during the fireball phase.
When temperature, speed, and altitude drops the fairings may also be dropped. In level flight the elevons and rudders offer more effective control for the final approach.
FAIR THEE WELL!
Now you’re looking at that landing and wondering, “what’s missing from this picture?” Well we want to save some fun for next week, right?