Bogar nov99

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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