| Questions | Question 1 | Question 2 | Question 3 | Question 4 |
|---|---|---|---|---|
| A. Decision to be made(Phrased as a question.): | How will the vehicle take off, taking advantage of research in efficient propulsion and smart materials? | How will the wing(s) appear, taking advantage of biomimetic research? | How will the vehicle dock? What smart materials can help? |
What features will be noted on the drawings, other than those referenced in questions 1, 2, and 3? |
| B. Critical Factors Involved | Propulsion Research Current propulsion use Smart materials Limits provided by atmosphere, weight, and reusability Propulsion for high-speed exit of atmosphere. |
Current wing design Biomimetic Research Wing design research Smart materials Wing use for descent |
Geometry of dock at international space station Geometry of dock at satellites Using tethers for docking Smart materials Fine-tuned propulsion / steering for docking |
Capacity for people, cargo Weight requirements Characteristics so can be reusable Steering devices Take-off and landing gear |
| C. Information known | New research indicates that a new shuttle could take off as well as land like an airplane (based on recent high-speed achievements). No air in space, so wings and propellers useless! Also very cold, density is zero, and low pressure (could these be indicators for smart materials involving propulsion?) Propellers produce much thrust needed for vertical lift in takeoff, while wings provide lift for horizontal movement. X-class aircraft take advantage of this. Pathfinder airplane uses solar energy to produce electrical energy to fuel engines that turn propellers all along length of wing. Propellers can be driven by human force (turning gears on a bicycle). Turbines rely upon high-pressure, quickly moving gasses to produce more thrust. Ramjet engines work as turbines do, but high-speed air is rammed into engine (for pressure), so it is ideal for high-speed aircraft but not useful in low-speed craft. X-15 airplane uses rockets at take-off until air is fast enough to effectively make ramjet work. Then rockets disabled and ramjet works on its own. Rocket carries all of its own oxidizer (oxygen) and fuel. Doesn't use external atmosphere, so functions in any environment. Solid rockets must be exhausted (no turning off before fuel is gone), while liquid rockets can be stopped as needed. Ion / Solar-Electric Propulsion: solar energy fuels electric generators that charge ions moved as high-pressure gas out of engine. Fueled with xenon, which is an abundant resource. Very slow to accelerate. 83 kg xenon gives 2.5 kW or 3.4 horsepower in one year. Space Tethers: Spacecraft is attached to satellite or space station, which moves it about itself, then releases it appropriately, in the right new direction. If tether is conductive, as it passes through differing magnetic fields, it would create electricity. Tethers reaching into Earth's atmosphere could be used to propel objects into space or from space back to earth. Laser / Solar Sails: Light produces force, so focussed light (lasers with lenses) could produce wind in sails. 10 gigaW laser for 16-gram vehicle. Space elevators: A floating tower that moves in Earth's orbit could help move things from Earth to space with elevators along the tower. Would be very expensive to begin construction. MR Fluid used for noise reduction by creating friction damper. Could be effective to quiet propulsion? S-M Alloys have been used in smart rotor for helicopter, where rotors are easily tunable. |
Airplanes have wings with several control surfaces and moving parts; new wing design uses smart materials to limit moving parts and make control surfaces only present when needed. Wing should be straight for good lift & stability at slow speeds, then sweep back at high speeds (swing-wing design). Area is related to lift, so high-area wings important after stability achieved (delta wing). On rockets, no wings upon descent, just parachutes attached to the nose cone. Fins or wings needed on rockets to help stabilize, especially early in take-off. Biomimetics involves using natural design ideas to create product with multifunctional components. Wing design research focuses on smooth wings and fins made of flexible materials, that can move between configurations to supply movement. Several miniscule fliers have been created with smart materials, often based on insect flight because of great weight-lift ratio. Smart materials respond to heat, electricity, and magnetism. They are very reliable, have low power requirements, are fast-acting, and highly controllable. Piezoelectic Materials require input of voltage to change shape, or change of shape creates electricity. Current research uses a piezoelectric actuator to change wing and fin shape, for swimmers and wings that don't have external moving parts, are stronger, and more efficient in movement. Shape-Memory Alloys change shape (to remembered shape) in response to temperature. Used in walking, swimming, slithering, and flying robots. Atmosphere varies in pressure, temperature, and density with altitude. These changes could trigger change in aircraft to new wing orientations to take advantage of best modes of flight. Rotors for take-off with straight wings and moderate area, then sweep back wings with high area. Sails and parachutes can be used to control movement and landing at high altitudes. |
Satellite similar in size to rocket; probably cannot dock onto it Satellites are somewhat rectangular, so could tether to flat side; should avoid tethering to side with solar panels. Shuttle docks at center of station, apparently arriving from bottom, away from solar panels. Shuttle appears to dock nose-up, so shuttle is vertical relative to horizontal of station. MR Fluids change from fluid to solid when the electric or magnetic field changes. Fluid changes in elasticity, viscosity, and plasticity. Used as damper (cushion), for speed control, force-feedback, position sensing. Maybe for docking? Piezoelectric materials also used for subtle changes (antennas, bifocals), yaw and rolling sensors, position sensors, impact sensors, canceling out sound and vibrations. Magnetostrictive materials expand when exposed to a magnetic field. Pressing / pulling to change shape produced magnetic field, as well. Used in sensing, noise control, dampening. S-M Alloys used for implants tat must expand after being placed. Could be used for locking space craft into dock? S-M Alloys have been used in release mechanisms with possible extensions to space dock release. S-M Alloys are useful like MR Fluids, because material can go from super elastic to brittle. Applications include cell phone antennas, flexible glasses. Parts important for docking (brainstorm): Slowing, sensing location, subtle adjustment, contact with dock, lock with dock. Then unlock and propulsion away from dock with sensors and subtle propulsion changes. |
Must have seating for 20 people plus room for cargo Total take-off weight at most 2,041 tons Fuselage produces some lift in airplanes, weight in airplanes and rockets. Should be streamlined. Airplane landing gear = struts, wheels, and brakes, usually retractable to reduce drag. Rocket nose cone usually where passengers ride, while cargo and passengers usually in fuselage of airplane, shuttle. Wings and fins on rocket provide directional stability. On rockets, all parts except nose cone discarded in space. Shuttle is a reusable rocket (rocket propulsion, airplane descent and landing system) though fuel tank is discarded after use. Boosters also used again (parachute down). Shuttle uses parachute to slow its landing. S-M Alloys are used in braking systems, open/ close systems, dampening, deicing ("Smart skin"). Piezoelectric Materials also used on wings as "active flow control sensors for monitoring airframe health." Steering relative to wings and fins, usually. Smart materials could be used for this, as embedded in wing/fin, as well as sensors to avoid collisions and sense and respond to wind change. Space Station is 335 to 460 km from Earth Average person weighs 135 pounds + 20 pounds personal luggage. |
| D. Information needed (question) | Weight of fuel and tanks? | none | none | Weight and dimensions of shuttle? Dimensions of X-planes (X-15)? Dimensions of airplanes?Is cost feasible for development? |
| E. Resources
for fact-finding |
Web search
http//www.tomatosphere.org/ |
N/A | N/A | Web search http//www.tomatosphere.org/ http://www.dfrc.nasa.gov/ |
| F. Answers to each question |
Shuttle External Fuel Tank = 78,100 lb. (empty) and 1,667,677 lb. (full of liquid hydrogen and oxygen), length = 154 ft, 28.6 ft diameter, 2 million Liters of fuel used up by 300 km above Earth Shuttle Solid Rocket Boosters = 84100 kg with more than 1 million pounds of solid fuel, generates 2.65 million pounds of thrust, length = 47 m, used up 50 km from Earth See right column for airplane and X-15 data. |
Shuttle Orbiter = 75000 kg (empty); length = 121 ft, height = 57 ft, wingspan = 78 ft Entire shuttle at takeoff = 2,000,000 kg; length = 56 m; can carry payload of 65,000 lb. up to 60 ft long and 15 feet in diameter X-15: single seat; thrust up to 57,000 lb. up to 6.7 Mach, alt. 354,200 ft, 50 ft. long, 22 ft. wingspan, 13 ft. high tail, launch weight 31,275 lb. (12,295 lb. at burnout) Airplane 757-200: 155 ft long, 125 ft wingspan, 44.5 ft height, 127,800 lb. empty, fuel = 76,000 lb., payload ave. = 56,000 lb. |
| Possible Decisions | Negative Consequences |
Positive Consequences |
|
|---|---|---|---|
A. PROPULSION |
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1. Aircraft-style propulsion system with "smart" wings that converts to rocket-style once at 350,000 feet. |
Take off loud and requires horizontal space. Fuel for rocket mode in space makes vehicle more heavy than modes using reusable fuel sources. Fuel is not environmentally friendly, reusable. Traffic may be difficult to control and monitor. |
All parts reusable Weight more reasonable than all-rocket propulsion because not all fuel (e.g. air for winged flight) must be stored in tanks. Conversion of body shape using smart materials creates aerodynamic, efficient vehicle. See "smart" wing pros/cons below. |
|
2. Rocket propulsion system, with aircraft components for landing (like space shuttle) |
Take off loudest Fuel tank destroyed and rocket boosters may be damaged in parachute landing. Weight very heavy, with all fuel stored in tanks - MAY EXCEED REQUIREMENTS. Fuel is not environmentally friendly, reusable. Take off requires several miles of clear space. Traffic may be difficult to control and monitor. |
Most parts reusable. |
|
3. Rocket-style propulsion system only |
Take off loudest Most parts not reusable. Weight very heavy, with fuel all stored in tanks-MAY EXCEED REQUIREMENTS. Fuel is not environmentally friendly, reusable. Traffic may be difficult to control and monitor. |
Take off requires several miles of clear space. Only nose cone reusable. |
|
4. Aircraft-style propulsion system with "smart" wings that uses ionic propulsion at 350,000 feet |
Take off loud and requires horizontal space. Acceleration very slow. Traffic may be difficult to control and monitor. |
All parts reusable, including very sturdy ionic engine Weight very light; ionic propulsion uses relatively light fuel(xenon & solar energy) very efficiently. Solar power is always obtainable, environmentally friendly. See "smart" wing pros/cons below. |
|
5. Aircraft-style propulsion system with "smart wings" that uses sail at 350,000 feet |
Take off loud and requires horizontal space. Currently, a tremendous amount of energy is required to generate the laser to "push" the sails. This means a high weight of fuel for generating energy to make the light. Deploying sail could be complex, error-prone procedure. Traffic may be difficult to control and monitor. |
All parts reusable (except sail?) Weight could potentially be very light, as fuel could be harnessed solar energy. Sail travel could be very fast. See "smart" wing pros/cons below. |
|
6. Aircraft propulsion system with "smart" wings that uses space tethers at 350,000 feet. Aircraft will have ionic, rocket, or sail-powered propulsion for subtle travel changes. |
Take off loud and requires horizontal space. Limited to using only previously tethered "stops", unless a means for tethering from space craft is developed. Miscalculations from angle and time of release from tether could cause space craft to be misguided. Movement of people and cargo from space craft will require robot arms or tubular tethers that must span from vehicle to station/satellite. See pros and cons of sail, rocket, or ionic propulsion, also in this section. Vehicles would need to be monitored to prevent "traffic jams" when tethers are unavailable for docking. |
Very light - Fuel storage is simply for take-off portion of flight and small ionic/solar-powered travel changes. Tether system creates an easy, fool-proof means of routine space travel. Tethers can harness electric energy for use on space vehicle or station/satellite. See "smart" wing pros/cons below. Space traffic would be easily monitored (assuming it is all dependent on tethers). |
|
7. Smart Rotor (shape-memory alloys) used for take-off, wings for acquiring high speeds up to 350,000 feet, then rocket. Wings and Rotor used for landing. |
High weight of all 3 travel components (rotor, wing, and rocket) probably means a high fuel requirement. Additionally, rocket fuel must be stored in tanks. Fuel is not environmentally friendly, reusable. Traffic may be difficult to control and monitor. Rotor would have to retractable (requiring a lot of retraction space), else would not be aerodynamic and may be damaged upon reentry. |
Take-off the limited in noise/area, requires very small amount of space All parts reusable Can leave from any location. Rotor tunable for high efficiency of travel (using smart materials). Takes advantage of efficient means of travel (rotor, wing, and rocket) for different parts of it (take-off, acceleration, and space travel). See smart materials pros and cons below. |
|
8. Space elevator (with access by helicopter or airplane). Small laser-sail, ionic, or rocket powered "taxis" move to locations from end of elevator. |
Construction of elevator very time-consuming, labor-intensive, and expensive. Departure location limited only to location of elevator. There are varying pros/cons to different "taxi" styles (see above). |
Take-off very quiet, requiring the least amount of space. All parts reusable Fuel minimal- needed only after space craft leaves elevator "tracks". Fuel could even be stored at end of tracks, so it could fuel up very minimally before its short voyages. Elevator could be used several times per day, allowing for high-frequency and relatively inexpensive space travel. Moving cables on elevator can harness electrical energy as they pass through magnetic fields. Weight minimal due to fuel requirements. Sail travel could be very fast. Concern about high-temperature re-entry of vehicle into Earth atmosphere is avoided; vehicle remain at end of tracks in space. Space traffic leaving Earth and reentering the atmosphere would be easy to monitor and highly controllable (assuming all traffic is dependent on the elevator). |
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B. SMART WINGS |
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1. Electroactive polymers for changing between contracted and expanded wing configuration, to get flapping |
Steering would probably be limited to tail rudder, unless "flapping" could be fine-tuned. Method of flight is very new to pilots; would require training on new methods of flight. |
Biomimetic - if designed correctly, could provide very efficient, maneuverable means of flight. Small amount of moving parts on wings. |
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2. Electroactive polymers to expand wing area and position with altitude and speed change |
Materials make wing large area as it gains speed, so it works more efficiently. Small amount of moving parts on wings. Wings move from straight to swept back into delta-like configuration for most efficient, aerodynamic flight. |
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3. Magnetostrictive or piezoelectric materials to sense speed and air pressure, direction (materials are strained and magnetic or electric energy is recorded). |
Addition and maintenance of sensors may be expensive and labor-intensive. May be difficult to distinguish between forces on sensors (like rain versus wind). Lightening could negatively affect magnetostrictive material sensors. |
Smart materials could help pilots predict and compensate for turbulence, change in wind speed and direction, making flight more efficient. Active sensing and compensation by computer could make flight simpler for pilot (like auto pilot). |
|
4. Sail and parachutes for steering and landing |
Not likely to be reusable. |
Slow vehicle significantly. Take advantage of reusable, environmental-friendly resources to slow and steer vehicle. |
|
5. No wings - fins only |
Fins are small- will not generate much lift (need to have larger area). |
Fins add stability, and potentially provide lift and steering. Fuselage is very aerodynamic. |
|
6. Smooth-wing steering with Piezoelectric Actuators |
Contact with electricity (electrical storms) could cause failure or unpredictable behavior of the wings, which are activated by electricity. Electricity must be focused to very small areas, in order to change with a high degree of accuracy. |
Less moving parts Lighter and less bulky than traditional wings. No risk of hydraulics leaking. Wing is flexible and has better structural integrity. Wing is multifunctional and can alter its shape to increase surface area, cant, and location of leading and trailing edges. Steering components could be present only when needed; hidden to make vehicle more aerodynamic when not in use. |
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C. DOCKING |
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1. MR Fluids to dampen contact- fluid would be in liquid state during cruising and docking, then become solid after docking, to create a rigid seal with dock. |
Electric/Magnetic fields at docking stations would need to be controlled to prevent failure of MR Fluid. Electric/Magnetic fields would need to be focussed to prevent negative interaction with magnetized data like that on computers. |
Fluid would soften impact on otherwise breakable, bendable parts. Fluid could allow for good seal with docking ports of different shapes and sizes (Fluid molds to proper size). Docking portion of vehicle would be difficult to damage due to its flexibility during flight. Displacement from dock is safe and convenient. |
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2. Ionic or Conductive Polymers for locking ship to dock. Vehicle docks in a stable manner, then water floods the seam of this docking. Water and electricity activates the polymers at both ends of the dock, to cause them to change configuration to lock into each other tightly. |
Not useful on docks not previously designed for this locking. Electricity required may drain energy resources; there are more efficient mechanical means. Electricity and water may cause significant threat to electrocution. |
Water leakage indicates lack of success of locking (serves as a vital component for locking and as a testing variable). Polymer binding is very strong and tight. |
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3. Piezoelectric Materials for sensing position, subtle changes |
Piezoelectric Materials do not tend to be very mechanically durable, and there is some difficulty coupling piezoelectric material to other structures. |
As pressure against piezoelectric sensor occurs, current is generated that fuels subtle changes by engine/ steering to alter position. Vehicle can dock with high precision while on "auto pilot." Piezoelectric Materials can be made easily for any purpose, with any composition and shape. |
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D. OTHER TRAITS |
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1. Shape-Memory Alloys for heat defense; alloys would alter shapes to create for reflective or effective boundary from heat. |
Alloy sheets will need to be bound to vehicle in a way so they don't move / fall off, making heat damage due to exposure more of a risk. |
Heat from reentry into atmosphere can be harnessed to help prevent heat-damage inside vehicle. Shape-Memory Alloys can tolerate strain 3 to 25 times higher than piezoelectrics can. |
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2. Magnetostrictive Materials for new tank / cargo space design (collapsible empty space) |
A mechanism for changing the entire region's magnetism would need to be designed, without interfering with computers and other magnetic-dependent structures. Regions near joints would have to be flexible, to tolerate the compression / expansion of the walls of the vehicle. Magnetostrictive Materials are not easily embedded in control structures. |
Areas containing empty space could collapse and expand appropriately, making vehicle the ideal size to increase wing area: weight ratio. Magnetostrictive materials can undergo a larger range of temperature, strain, and input voltages than electroactive polymers can. If the walls of the vehicle are strained, they will create current, which can be used to either alter the walls with respect to the strain, or alter the course of the ship (see Docking #3 above). |
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3. Streamlined and smart airplane skin, with de-icing capability (shape memory alloys) |
Addition and maintenance of sensors may be expensive and labor-intensive. |
Deicing is efficient and easy to monitor, without human labor being exhausted. State of airplane surfaces can be continuously monitored, so maintenance can be made efficiently Airplane surfaces will be streamlined and in optimal performing status at all times. Shape-Memory Alloys can tolerate strain 3 to 25 times higher than piezoelectrics can. See Wings #4 above. |
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4. Shape memory alloys for brakes |
Brake heat can be used to expand the surface area of the braking pad, making braking more efficient. Brake heat is harnessed, rather than allowed to expand and dissipate, possibly causing damage. Shape-Memory Alloys can tolerate strain 3 to 25 times higher than piezoelectrics can. |
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5. MR Fluids for Noise and vibration Control |
MR Fluids provide flexibility in plasticity and elasticity that could help alleviate stress and friction between joints. MR Fluids could be made more solid at times when structural integrity is important. Vehicle would be more quiet and comfortable during high vibration period of flight, like take-off. |
| Final decision with rationale: | First Choice: | Second Choice: | Third Choice: | Fourth Choice |
|---|---|---|---|---|
1. PROPULSION |
Space Elevator and "taxis" (sail, rocket, or ionic powered vehicles) |
Smart Rotor used for take-off, wings for acquiring high speeds up to 350,000 feet, then rocket. Wings and Rotor used for landing. |
A 3-way tie: (1) Space Tethers with "smart" aircraft and ionic, sail, or rocket propulsion for small position changes in space. |
(2) & (3) The emerging technology of sails and ionic engines, both with a "smart" aircraft |
2. SMART WINGS |
Electroactive polymers to expand wing area and position with altitude and speed change |
Smooth-wing steering with piezoelectric actuators |
Magnetostrictive or piezoelectric materials to sense speed and air pressure and direction (materials are strained and magnetic or electric energy is recorded) |
|
3. DOCKING |
MR Fluids to dampen contact; fluid would be in liquid state during cruising and docking, then become solid after docking, to create a rigid seal with the dock |
Piezoelectric Materials for sensing position and subtle changes |
Ionic or Conductive Polymers for locking the ship to the dock. Vehicle docks in a stable manner, then water floods the seam of this docking. Water and electricity activates the polymers at both ends of the dock, to cause them to change configuration to lock into each other tightly. |
|
4. OTHER TRAITS |
MR Fluids for noise and vibration control |
Shape Memory Alloys for braking |
Magnetostrictive Materials for new tank / cargo space design (collapsible empty space) |
|
Reflect upon decision: |
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1. PROPULSION |
The space elevator is the most expensive option to create, but allows for efficient, low-cost use once it is developed. It requires little ground space, though it limits where the user can depart from. Departure is quiet, and small taxis at the end of the track can easily transport people to destinations desired, without worry of reentry issues or fuel weight requirements. Space propulsion means (ionic, rocket, or sail) have their own pros and cons. This is the only means of using sail technology without concern about creating the sail in space and collapsing it before reentry into the Earth's atmosphere. |
Although this vehicle will have a very high weight with high fuel needs and several mechanical parts, if built out of low-weight materials and taking advantage of innovative propulsion means in space, it could be the most efficient means of travel. It requires little space for take-off and landing and can leave from any location, which could be ideal, though travel of this vehicle may be hard to control and monitor because of its convenience. Above all, it takes advantage of the most efficient means of propulsion for different environments. Rotors and potentially wings could take advantage of biomimetic and smart material research, as tunable entities to further the efficiency of flight. A retractable rotor would solve problems having to do with aerodynamics and reentry issues. |
Space Tethers are a low-energy way to dock and launch the vehicle from positions in space. Use of tethers reduce weight and fuel requirements, while potentially providing a means to harness magnetic change as electrical energy. Use of tethers involves limited stops, slow movement, and potentially some error in destination positioning. Space propulsion means (ionic, rocket, or sail) have their own pros and cons, but would be used only minimally. Traffic would need to be monitored to prevent vehicles having to stop and wait for tether availability. |
Both of these new technologies have major faults: sails may be quick, but require obscene amounts of energy and may be complex to set up; ionic engines are feasible in terms of energy, but accelerate very slowly. Both of these technologies harness efficient, environmentally-friendly energies (solar and nuclear), and so could be very lightweight. Both technologies would be used in combination with aircraft-like propulsion when in Earth's atmosphere. This aircraft would have "smart" wings designed to change shape and self-monitor in response to flight conditions. Smart wings are described in the next category. |
2. SMART WINGS |
Smart materials allow the wing to be simple with few moving parts, while also allowing it to change dynamically. As the aircraft speed increases, the wing area can increase to work more efficiently. Wing direction would also change, to go from a straight to delta design. |
Wing steering controlled with piezoelectric actuators can reduce wing weight, simplify the wing, and improve flexibility and strength, while creating a structure with multifunctionality. The wing could be changed along its leading and trailing edges, in terms of cant and area, to more efficiently steer the vehicle. Potential issues include focussing of electricity for each actuator and coping with electric storms. |
These sensors could help the pilot and machines in the vehicle monitor effects of wind and weather on the vehicle surface, and change flight traits based upon this. Flight becomes more efficient based upon these changes, although it may be difficult to determine between different external forces and electrical storms near the vehicle could cause problems. |
|
3. DOCKING |
MR Fluids to dampen contact; fluid would be in liquid state during cruising and docking, then become solid after docking, to create a rigid seal with the dock |
Piezoelectric sensors could be used for steering situations (like docking) requiring high accuracy. The sensors could directly communicate with engines on the vehicle to subtly change position. Durability of sensors is the only concern with this design. |
Water helps to check the seal produced during locking, as well as providing stimulus (with energy) to get electroactive polymers to re-shape and seal together. However, the water/electricity interaction could be hazardous, if not monitored. This method could only be useful on docks with previously attached electroactive locking devices. |
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4. OTHER TRAITS |
MR Fluids could help reduce noise and vibration during flight, while providing some stress relief for joints of the vehicle when structural integrity is not crucial. |
Brakes can be made more efficient with the application of shape memory alloys, while dissipating brake heat to prevent damage. |
Smart materials are used to collapse empty space, in order to make the vehicle more aeronautical. The collapsing / expanding of the aircraft can be dynamic, as strain on the surfaces generates electricity that can be harnessed to make further changes. Design of a surface that can change this way wold require flexible joints and parts whose magnetism would have to be isolated. |