NIAC Fellows Meeting Atlanta, GA 9 November 1999
Hypersonic Airplane Space Tether Orbital Launch (HASTOL) System Thomas J. Bogar, Boeing - Phantom Works Robert L. Forward, Tethers Unlimited, Inc. Michal E. Bangham, Boeing - Huntsville Mark J. Lewis, University of Maryland
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Discussion Topics
• HASTOL Concept Overview • Hypersonic Vehicle Description • Trajectory Analysis Results • Tether Design Considerations
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Hypersonic Airplane – Space Tether Orbital Launch System
CardioRotovator Concept
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Tillotson Two-Tier Tether (T4) Concept
• Two-Stage Rotovator
• Reduces Ratio Of Tether System Mass To Payload Mass PHANTOM WORKS
Rotovator Tether Mass Ratios Tether Length
Orbital Radius
Orbital Velocity
Tip Velocity
L (km)
RO (km)
VO (m/s)
VT (m/s)
400 500 600 700 800 900
6878 6978 7078 7178 7278 7378
7614 7559 7506 7453 7402 7352
2494 2749 3006 3263 3522 3782
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Hypersonic Airplane Velocity VH= VO-VT-470 m/s (m/s) Mach 4650 4340 4030 3720 3410 3100
15.0 14.0 13.0 12.0 11.0 10.0
Tether to Payload Mass Ratio
Spectra ™ 10.4 16.7 27.1 44.0 71.8 117.6
MT/MP 2x
10x
2.4 4.2 5.9 8.2 11.6 16.3
0.37 0.56 0.65 0.73 0.90 1.07
CardioRotovator Tether Mass Ratios Tether Length L (km) 1000 1200 1400 1600 1800
Orbital Radius RO (km) 7478 7678 7878 8078 8278
Orbital Tip Velocity Velocity VO VT (m/s) (m/s) 7147 2076 7004 2440 6868 2789 6737 3124 6611 3445
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Tip Accel. a (m/s2) 0.43 0.50 0.56 0.61 0.66
Hypersonic Airplane Velocity VH= VO-VT-470 m/s (m/s) Mach 4601 14.8 4094 13.2 3608 11.6 3143 10.1 2695 8.7
Tether to Payload Mass Ratio MT/MP Spectra 2x 10.8 3.1 22.2 5.2 44.7 8.4 87.8 13.4 168.5 21.0
10x 0.39 0.55 0.75 0.97 1.24
High-strength Electrodynamic Force Tether (HEFT) Facility Plasma Contactors
Tether Rotation
Magnetic Field Current
Electrodynamic Force
HEFT Facility High Strength Tapered Survivable Hoytether
Solar Array Power Supply
AIAA 98-1584
Dual-Fuel DF-9 Dual Role Vehicle
JP-7 Tanks LOX (Below) SH2 Tanks
Looking Aft
AceTRs (Internal)
Crew Station Linear Rocket Payload
Ramjet/Scramjet Air Core Enhanced Turboramjets (AceTR) Ramjet/Scramjet 208.5 ft
GP81153026.cvs
Matrix Of Payload Transfer Points Analyzed 120
400,000 ❍ ft
km
❍
❍
● Achievable Points ❍ Unachievable Points
110
Altitude
350,000 ❍
100
●
❍
●
300,000 90
●
●
80
250,000 8,000 2,500
9,000
10,000 3,000
Velocity PHANTOM WORKS
●
●
11,000
12,000 3,500
ft/s m/s
Normal Load Factor Along Descent Trajectory
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Dynamic Pressure Along Descent Trajectory
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Hoytether™ Failsafe Tether Design
Primary Lines
First Level of Secondary Lines Redistributes Load to Adjacent Nodes
Secondary Lines (initially unstressed)
Effects of Damage Localized
Second Level of Secondary Lines Redistributes Load Back to Undamaged Portion of Primary Line
Severed Primary Line
0.2 to 10's of meters
0.1- 1 meter
a.
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b.
c.
High Temperature Tether Materials Tensile Strength (GPa) vs. Temperature Material Spectra 2000 Zylon (PBO) Quartz Glass (SiO2) S-glass Carbon Carbon/Ni-coated Tyranno (SiTiCO) Textron β-SiC 0.72 β-SiC/Ti-coated Altex (Al2O3/SiO2 ) Nextel (α α-Al2O3) 0.65 Nextel/Al-coated Tungsten Wire
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VC (km/s) 2.87 2.73 1.81 1.94 2.77 2.12 1.66 2.19 1.72 1.21 1.30 0.97 0.55
Density d (g/cc) 0.97 1.56 2.20 2.50 1.80 2.68 2.55 2.93 3.37 3.30 3.88 3.40 19.35
20 C 4.0 5.8 3.6 4.7 6.9 6.0 3.5 7.0 5.0 2.4 3.3 1.6 2.9
300 C 3.7 3.6 ? ? ? 3.5 6.6 4.8 2.4 ? 1.4 2.9
600 C 3.6 ? ? ? 3.5 6.0 4.3 2.4 ? ? 2.9
800 C 3.6 ? ? ? 3.5 5.6 4.0 2.4 ? ? 2.9
1000 C 3.6 ? ? ? 3.5 5.2 3.7 2.4 ? ? 2.9
1200 C ? ? ? ? 3.5 4.5 3.2 1.5 ? ? 2.9
HASTOL GRAPPLE ASSEMBLY High Temperature Tether With Embedded Conductor For Electrodynamic Tether Electric Power Generation
Tether Deployer and Retrieval Mechanism
Mounting Structure for Reaction Control System
Housing for Tether Reel, Avionics, RCS Fuel, Batteries, and Electrodynamic Tether Battery Recharging Circuits
Mounting Structure for Reaction Control System RCS Nozzles Flush with Surface to Minimize Drag and Heating PHANTOM WORKS
Grapple
Grapple to Payload Attachment Option Grapple/End mass comes down on Payload
1
Grapple stops on Payload, levers on payload are in “in-close� position
2
Payload Surface
3
Attach Levers then move radially outward toward ring; sliding on rails. Once contact with ring is made, they latch to the ring securing the payload to the grapple.
Grapple Ring
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Conclusions
• The HASTOL System provides a system to deliver payloads to space with minimal reliance on rocket propulsion • Tether designs using existing materials can provide required strength at required thermal loads • The Hoytether™ design provides a survivable tether concept for long duration operation • Issues to be addressed in future work include Grapple design refinement and payload transfer logisitics
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