S.H.A.R.P

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					                  S.H.A.R.P.




Slender Hypervelocity Aerothermodynamic Research Probe
   SHARP genesis
• development of new UHTC’s,
  ultra high temperature ceramics
   – shingles on shuttle
       • max temp- 3000 F
   – new UHTC
       • max temp- 5000 F
• result- sharp leading edge
  profiles are now possible
  SHARP profile
• advantages
  – more efficient atmospheric exit and re-entry
  – better cross-range capability
     • (wider range of re-entry angles)
  – minimized radio blackout during re-entry
• disadvantages
  – generates extremely high temperature at the
    sharp edge/tip
  SHARP future
• Next generation space shuttles-   X-33
• nosecones
   – re-entry vehicles
   – launch vehicles
     (rockets & boosters)
  SHARP PROJECTS
• B-series
   – sharp nosecones
   – B1 re-entry vehicle already launched (B2 near launch)
• S-series
   – university & small business partnership
   – test a knife edge geometry
   – 4 launches
• L-series
   – full size
   – 2 launches
   – UHTC test
  SHARP S-series
• Atmospheric re-entry
  vehicles with knife edge
  profiles
   – reaches Mach 3.5              S4
   – UHTC not required
• prototype sounding rocket
  launch vehicle
   – halfway to near earth orbit
   S1 launch schedule
• Orion class rocket launches
    – 4,000 lb thrust, 5g vibrations
• S1 deploys at apogee
    – 270,000 ft
    – data acquisition begins
• fin-tube stabilizer jettisoned
    – 150,000 ft
    – primary data capture
         • temperature, pressure, accelerations
• S1 re-enters atmosphere
• S1 parachute deployed
    – 20,000 ft
• rocket and S1 recovery via helicopter
  SHARP S-series goals
• Create working relationships
  between NASA, universities and
  small businesses
• gather aero & thermodynamic data
  on the SHARP-S profile
   – compare with computer simulations
• Provide data for the L-series
   – S-series serve as prototypes
   – same geometry, ~ 2x size
   – UHTC equipped (mach 20 vs. 3.5)
SHARP-S program timeline
SHARP S-series GROUPS
NASA Ames Research Center
project co-ordinator, aero/thermodynamics


Montana State University
re-entry vehicle structure


Stanford University
re-entry vehicle avionics


Wickman Spacecraft & Propulsion
launch vehicle & site
MSU SHARP TEAM
PI:    Dr. Doug Cairns
MSGC:  Dr. Bill Hiscock

manager: Aaron Sears
consultant: Will Ritter
students: Mike Hornemann
            Kevin Amende
            Cindy Heath
            Crystal Colliflower
            Dustin Cram
 MSU research groups
• Montana Space Grant Consortium
  – federally funded program which disperses
    grant money to space oriented projects


• Composites Research Group
  – co-directors: Dr. Cairns, Dr. Mandell
  – material characterization, structures &
    manufacturing
  – wind energy, aerospace
  NASA designated responsibilities
• Design and build the S1-4 re-entry vehicles using
  composite materials
• integrate the structure with:
   – avionics (Stanford)
   – sounding rocket (Wickman Spacecraft)
• low operating budget
   – faster, better, cheaper motto
   – $ 50k/year budget
       S1 shape

                              17”


4.4”


                  39.5”
                                        6.6”


                                    o
                             11.3




 • S1 dimensions supplied by NASA
design                           manufacturing

• 4 part design                   • mold
• ProE design                     • peripherals
• FEM analysis                    • assembly




           * all design, analysis and manufacturing performed
           in-house at MSU
    S1 design constraints                        results
• Withstand high temperatures
    – 600 F in shell (one use)                 - epoxy matrix
    – 1000+ F at tip                           - metal tip (aluminum/steel)
• lightweight                                  - composite shell w solid tip
• CG in front of center of pressure
                                               - carbon/epoxy
• smooth aerodynamic surface
• withstand dynamic pressures of 10 psi with
  minor deflections
• unlimited systems integrations
• provide locations & mounting for
    – pressure and temperature sensors
    – avionics components
  S1 design
• 4 part design
   – shell
   – component mounting frame
       • parachute
   – tip
   – base
• peripheral & equipment
   – shell mold
   – fin-tube
      S1 design


                  fin-tube

      shell                                           base plate sensor arrangement
      (mounting frame internal)
tip

        S1 with fin-tube drag stabilizer

                          cutaway view of internal mounting frame
                                                     (spar system)
  shell design
• Provides the aerodynamic surface and
  serves as a main structural member
   – only surface interruptions are 6, ~1/16” holes
     for pressure and temperature sensors
• One piece
   – only joint along aero-surface at tip interface
   – pressure bladder manufactured
• IM7/8552 carbon/epoxy laminate
   – ~ 0.10” thick
 shell/spar structure
• Integrates the component
  mounting frame into the vehicle
  structure

                                    spars


• spar system is removable for
  unlimited avionics & systems
  integration
  spar system
• 2 axial, 3 lateral
   – carbon/epoxy plates
   – mechanically connected
• guided in by L-rails bonded
  into shell
   – spars mechanically attach into L’s for
     unlimited systems integration
• 4th lateral spar of aluminum
• sensor board mount on left axial
  structural design drivers
• aerodynamic pressures
   – ~ 10 psi at Mach 3.5

• launch vibrations
   – as Orion class sounding rocket
   – 6-g random vibration

• heat
   – 600 F at tip/shell interface
   – +1000 F at tip

• component space allocation
   – forward CG required advanced
     placement of heaviest components
   – governed possible placements of spars
hypersonic pressure analysis




                                                                               (inches)


(02/±45/903)s hoop = 90, axial = 0, E1 = 20 Msi (~65% Vf, 0.058 lbf/ft3), t = 0.09”
hypersonic skin pressure = 2.78 psi (Mach 3.5, 85,000 ft)
natural frequency analysis


                                                           mode 1: 56 hz
                                                           mode 2: 111 hz
                                                           mode 3 : 180 hz




(02/±45/903)s hoop = 90, axial = 0, E1 = 20 Msi (~65% Vf, 0.058 lbf/ft3), t = 0.09”
(base plate constrained boundary condition)
  tip & interface
• design drivers
   –   forward the CG location for aerodynamic stability
   –   temperature resistance
   –   pull-off (drag difference) force
   –   smooth external interface
• features
   – aluminum
        • better machining control
   – 1/2” lip for shell overhang
        •   improves transition and connection
   – steel parachute line mounts
        • better impact/fracture properties than composites
tip interface sketch
  mounting bolt                             steel mounting plate

           tip                                     link


                                                          parachute line


         lip                                          retention cup

                                                             epoxy


               epoxy gap sanded flush   shell
tip & interface
S1 sensor locations
  Pressure (8)
  Temperature (4)     •The
  parachute specifications
• manufacturer
   – Rocketman recovery parachutes
   – Ky Michaelson
• specifications
   –   R7 pro experimental
   –   2.12 lbs
   –   reinforced panels
   –   specially formed canvas deployment bag
  parachute deployment
• Deployment mechanism
   – single bay door
      • hinged
      • latched by #2 nylon bolt
   – black powder charge pushes parachute through door
• Altitude
   – 20,000 ft
shell mold




Top half of mold   Male preform plug
mold design
Constraint                       result

• Must be able to withstand       requires a metal mold
  temperatures up to 400F for
  curing of the resin
• Aerodynamic surface shape       CNC provides tightest tolerances
  requires tight tolerances
• Seam lines kept to a minimum    machined from solid blocks
• Must be able to withstand
  pressures up to 80 psi
    mold design
• Negative of S1 model
• All dimensions to .0001 inch
• ProE IGES to MasterCam for
  CNC


P   Aluminum
       - lower weight & thermal mass
       - no warpage during machining
O   Steel
        - better damage tolerance


    Equivalent commercial mold cost
                    $ 35,000
    Estimated MSU mold cost
         materials: $ 1,600
         labor:     $ 5,000
         tooling:   $ 500
plug




• CNC machined from ProE model
   – Accurate shape insures that pre-
     form will fit snugly into the mold
   – The plug is .25 inch smaller than
     real sharp in all directions
manufacturing - tip




current tip pic in HAAS
composites manufacturing




1. preforming   2. curing                    3. trim & assembly
                  (w pressure &/or vacuum)
   prototyping
• Aid troubleshooting
    – design methodology
    – details
• 2 prototypes (full scale)
    – G1
        • glass polyester/shell, wood tip
        • S1 deployment test
    – G2
        • glass polyester/shell
        • avionics mounting trouble shooting
S1 structure parts
  assembly & integration
• first full assembly at Stanford for flight
  certification tests
• total weight 44.5 lbs.
• CG: 52% of length
   flight certification tests
• mass properties *!
    – center of gravity
    – moment of inertia
• vibration loading (shake test) *!
    – sine sweep (natural frequency)
    – random vibrations (launch loading)

• deployment tests,
• altitude chamber (Stanford only)

   * performed at NASA Ames Research Center
   ! passed
moment of inertia




                                 roll


                          CA DAQ- proximity detector



                    yaw
shake testing
  yawwise shake




                           pitchwise shake

                  CA DAQ- acceloremator w FFT
  S1 status
• Launch
   – TBA
• Avionics
   – software at 90% complete
   – altitude chamber test
• Rocket
   – static fire- 10/18/00
       • weld failure at 4 seconds
       • good propellant fire

				
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