conversion of solar energy via new aerospace technology

7/28/2019 Conversion of Solar Energy via New Aerospace Technology

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CONVERSION OF SOLAR ENERGY VIA NEW AEROSPACE

TECHNOLOGY

by

J. H. Bloomer., DISCRAFT Corp., Portland, OR 97233

Presented 1994 to IECEC: AIAA/IEEE/ASME/SAE/AIChE/ACS/ANS

(Intersociety Energy Conversion Engineering Conference)

Aerospace technology today would access solar energy in space in any practical desired quantity, and beam

it down to earth for unlimited use in manufacturing, agriculture, housing, education, recreation, science

astronautics.

Questions are, though: How access solar energy in space? Satellite mirrors driving heat turbogenerators?

Satellite solar cells? Sunpumped lasers? And how deliver the energy to earths vicinity? By microwave beam?

By laser beam? How transport the energy down through the atmosphere? Microwave beam? Laser beam?

Power cable? And how pick the energy up on the ground? Rectenna farm? Collector mirror? Cable downlink?

At what cost? Cost to whom? And when available?

This author respectfully submits that a mixture of new and old technologies can satisfactorily solve alproblems, and provide all answers.

For one, lasers, because providing immensely tighter, narrower, longer range beams, must be preferred in

the long run to masers, as most authors agree(1)

. But laser diffraction-limited transmitter-antenna optics (jus

maximum-quality astronomical primaries in large size) have heretofore been very difficult, expensive or

impossible to build particularly for space. Since 66, though, there appears to have been a solution

(declassified in 65(2)

), based essentially on introducing very shallow, static, capillary-boundary-constrained

reflective, liquid-metal-plated, liquid-plastic pools onto interior surfaces of rigidized balloons erected(inflated) in orbit

(3,4,5)somewhat in the fashion of Echo

(6)(Figs. 1,2,3). These pools in capillary (zero-g

fashion, pull themselves their own surfaces- into precision optical mirrors (as retouched by deliberately

introduced static masses providing self-gravitation(7,8)

(Fig. 4). Cost-saving ofthis hands-off approach to

retouching, is expected to be immensely superior to that of the essentially real-time adaptive optics

method much in the news of late(9)

.


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Fig. 1. Liquid Surface in Lowered Gravity

INFINITELY LONG TROUGH

N = 1

N = 0.5

N = 0.05

N = 0.0

N

(WATER)

Z-AXIS

Fig. 2. Liquid Optic in Zero - Gravity

N = VERTICAL LOAD IN GS

= CONTACT ANGLE


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Fig. 4. Liquid Optics Technology Satellite

C = CHARACTERISTIC = /lv

R3 = RADIUS OF MIRROR

F = FOCAL LENGTH = R3/2

D = APERTURE

= F/D

N = LOAD IN g0S

= (c,R3,N,D) = ERROR = 1+2

3

0

10

2

1 DCNg

Ng0

21

R3

Fig. 3. Error Due to Finite Load

Secondly, no one wants to send even low-intensity

maserbeams down through the atmosphere let alone

high-intensity laserbeams(10,11,12)

. Everyone is quick to

point out that, the narrower and more powerful such

beams are, the more potentially destructive they are

to the environment, to fauna and flora, man and beast.

But narrow beams are required for efficiency in

transmission over interplanetary distances, and that

evidently is required. To add to the problem,

narrowness of coherent beams from diffraction-

limited primary (maser or laser) optics, is inversely

proportional to the diameter of these optics, while

cost of visible-band (laser) such optics is proportional

to the fourth power of the diameter on earth.

(g0=


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The author would like to suggest, though, that there appears to be a solution. This solution would permit us

to transmit energy in space by as narrow, and tight and powerful a laserbeam even, as we please, but halts

that beam cold at the top of the atmosphere (above the clouds).

Balloon-Borne Sea of Solar Cells at 80,000 Ft.

It is simply that we suspend vast fabric say canvas or equivalent with stiffeners- platforms at, say, 80,000 ft

altitude from balloons. We might suspend a rectangular such carpet from 4 giant weather balloons attached

one at each corner. Then the carpet upper surface could be covered with the latest and best solar cells(25)

where the latter are matched for efficiency against the wavelength of our space-based nominally

synchronous-orbiting - liquid-optical laser transmission system. Waste heat rejection at these altitudes

should be facilitated by the fact that even the very thin atmosphere still probably provides enough air for

adequate solar-cell convection cooling. Tether can be umbilical cord carrying power to ground.

Thirdly, investment costincluding life-cycle cost- of all this apparatus and these assemblages for orbit, solar

cells, powerplants, antennas, laser optics, collector-mirrors, spares, repair crews, maintenance crews, etc.- is

going to be high. Particularly for conventional boost-rocket (ex-military) vehicle technology, costs have been

estimated by many as running into the hundreds of millions, a billion or several billions of (94) dollars(13,14

per vehicle. Of course space transportation rocket launch- technology costs are expected to come down

shortly by two orders of magnitude due to such innovations as the SSTOSingle Stage to Orbit- reusable

vehicle. Additionally this authors proposed epihydrostatic (ultra-lowcost, expandable, rigidizable, self

forming) orbital macrolasers supplying solar laser power to electrical rockets all over interplanetary

space(15,16,17)

(Fig. 7) should further drastically reduce space transportation system costs while extending their

scope. Debris damage repairs in such large-cross-section satellites in chosen synchronous orbit, will be

minimized by running in advance a broad-viewfield, electro-optical/lasergun, variable-orbit, sweeping

satellite, to reduce all significant debris-objects encountered to harmless space dust then electrostatically

remove same (permitted by including large sweeper onboard nuclear power(18)

.)

Ultimate Boon to Solar Energy Conversion: Free Enterprise

But to reduce the government subsidy in space to zero, and put space developments both transportation

and utilities- in private hands where they belong, this author suggests we (privately) develop another system

the VTOL, 5,000-passenger, circular-planform, aerospace SUPERSHUTTLE vehicle (see Fig. 5). Capable o

hauling sightseeing tourists to synchronous orbit and return at a suggested price of $200 per seat

SUPERSHUTTLE both VTOL aircraft and beam-climbing spacecraft rolled into one- would operate in the


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atmosphere on BLASTWAVE(19)

(Fig. 6), LPG-burning jet engines, producing only water vapor as exhaust

Likewise as spacecraft, SUPERSHUTTLE would accept energy from a synchronous-orbiting, liquid-mirror

macrolaser system, tightened beam(20)

(Fig. 7), driving its (SUPERSHUTTLEs) electric rockets, which would

exhaust water vapor again as sole expellant (steamrockets).

Predicated on six excursions per day at 3 hours each (reaching Geosynchronous Earth Orbit GEO- a

approximately 1 g continuous acceleration/braking while leading the target sufficiently, might require

about 1 hour, as would of course the return SUPERSHUTTLE if fully loaded at 5,000 passengers pe

excursion- would earn about $1 million gross profit per jaunt to GEO. Presuming net profit of one-half afte

expenses, salaries, spares, repairs, maintenance, life-cycle costs, etc., are accounted for and that perhaps

half the people on the planet might end up as customers each SUPERSHUTTLE should earn about $1.2

billion per year, net, indefinitely.

Putting SUPERSHUTTLE gross annual revenue of $2.4 billion in perspective, one-quarter this much would be

gained just by selling 747-airplane-proportional, required MACROLASER power at $.05 per kilowatt-hour

yearlong.

SUPERSHUTTLE powerplant, if proportional to 747s, would need 10 times the power to haul the (500-seat

747 payload in air and space. This power would be delivered by a 1%-efficient solar MACROLASER system of

seven miles overall diameter. However 10 that amount might be a safe margin, requiring a solar

MACROLASER system of22 miles overall diameter.

Passengers would experience very brief periods of very gradually advancing low or zero-glike fighter-pilots

once between earth and GEO and once in boarding the (centrifugal, 1 g, rotating) GEO Station (mechanically

independent of the associatedstatic- MACROLASER).

Fig. 5. Supershuttle

Fig. 6. Pulse Ramjet Blastwave Jet Engine


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At the extreme left of the figure is the great solar-collecting mirror (60 miles in dia.), (1). CO2-type macrolase

is shown symbolically, although in actual fact, a free-electron-type (variable-wavelength in near-infrared and

perhaps 4-5 times more efficient) laser will be used. The great solar-collecting mirror focuses solar energy

onto the semi-silvered collar-like pumping mechanism (9). Energy trapped by multiple reflections in collar (9)

is transferred to the transparent, hollow laser cylindrical cavity (8). Rod (8) is maintained concentric with

collar (9) by strut-supports (10).The laser cavity is filled with a gas which absorbs the reflected solar energy

and lases, i.e., transmits a coherent beam normal to the rods end-surface mirrors. The end-mirror neares

the great solar mirror (1) is partially silvered, so that a portion of the coherent energy in the rod continuously

escapes. The escaping beam is diverged by secondary lens (6). The latter is rigidly attached to laser -rod

(8) and pump (9), by strut-supports (7). The diverged coherent beam (4) illuminates the large (1-mile-

diameter) liquid-surface primary mirror (3). High-precision primary (3) is bordered by a rigid plastic-foam

boundary-ring (2). Laser energy (5), focused by reflection from primary (3), passes through the empty interio

of collar (9) and emerges in the form of focused high-energy coherent beam (11). The beam (11) supplies

energy at or near its focus to disc-like craft (12), which might carry a protected payload as shown at (13).

Fig. 7. Orbital Macrolaser Tightened-Beam System

1

5

6 10

2

3

9

8

11

12

13

47


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Permanent Balloon-Borne Space Gate at 80,000 Ft

Again to exclude power beams entirely from entering the atmosphere, SUPERSHUTTLE would begin and end

each trip to GEO only at one of the 80,000-ft-high, balloon-borne, carpets. Carpet would be reachable from

anywhere on earth by SUPERSHUTTLE operating as a VTOL/amphibious/cruise conventional chemical

poweredalbeit circular-planform or disc (saucer) shaped- aircraft. The disc-shape is convenient for efficientabsorption of energy diffraction-disc (focal spot) of the cooperative macrolaser, earth-going beam

dispatched from synchronous orbit above. Main purposes of SUPERSHUTTLE might be, spectacular symbol to

popularize spaceflight (advertising), plus that of testing the entire concept of epihydrostatic macrolaser

(probably sunpumped CO2(21)

), power-beaming, cooperative satellites.

Permanent, 7-Terawatt, Space-Based, Solar Orbital Utility

A self-boosted orbital solar (probably sunpumped CO2(21)) macrolaser utility-power system boosted

exponentially in stages under its own (collected solar) power and circumferentially assembled(17

(continuously via astronauts and robots) in orbit (Fig. 8) would reach 500 miles (collector) diameter in

about 310 days from 200,000-lb LEO seed at starting (collector) diameter of 1 mile (if its exponentia

growth rate is 1/80th

per day).

Delivery of this power level continuously for one year at a standard rate of $.05 per kilowatt-hour, would

earn about $3 trillion gross profit.

Fig. 8. Orbital Macrolaser

System Construction

Such a (500-mi.-diameter)

system, at characteristic 1%

efficiency, would deliver on

the ground about 7

terawatts of power. This is

perhaps comparable to

earths total present power

consumption from all

sources combined coal, oil,

hydro, nuclear.


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The Solar Power Satellite

The (microwave) Solar Power Satellite concept(10,11,12)

has since 68 fired the worlds imagination as perhaps

no other space project since Apollo. However, the cost context of the (microwave -beaming) SPS is truly

discouraging in prospect. For example, launch vehicles in the West are characterized by yearly operating

costs from $1-$5 billion (fixed & recurring) and operational costs from $60-$1000 million per flight (14). SPACE

SHUTTLE missions today cost about $1/2 billion each and weigh about 200,000 lb, whereas SPS will for a 5

gigawatt system- weigh 1,000 times as much as SPACE SHUTTLE or at least 100,000 tons. Thus at the same

per-pound value, a single 5-GW SPS will be worth at least $1/2 trillion. Actually, infrastructure costs for SPS

will drive this figure much higher(14)

. Since its proposed to build a whole fleet of SPSs simultaneously say 6

then we could be looking at a minimum on-line cost for these six of at least $3 trillion. But MACROLASER

system above, delivering 7 TW, ifmostly membranous- materials, and crews could be provided fast enough

could fuel itself into orbit and be fully on-line at the end of a year, furnishing $3 trillion/yr worth of power. Six

SPSs would cost $3+ trillion to build, might require 10 yrs. to build, and would furnish % as much power as

one MACROLASER system.

Space experts and engineers agree that low-cost SSTO rockets operating much like conventional aircraft

would reduce the cost of transportation into space by at least 2 orders of magnitude(13)

. But of course space

transportation is only one of the costs of SPS. Too SSTO projects are undergoing tough sledding in Congress

and well perhaps they should be; perhaps they shouldnt need to be funded any longer by Congress anyway

Present proposal shows significant U.S. Government subsidy to the aerospace industry is probably obsolete,

unnecessary and retrogressive.

Critical experiments in Liquid Space Optics

Experiments are needed on: potential spacecraft outgassed monolayer effects changing liquid-metal surface

tension, variable surface tension effects on optical image or laserbeam collimation, ripple or vibration effects

on optical surfaces, attitude-control system (probably using RRC(22)

subliming propellant microrockets

effects, high-power laserbeam heating effects on optical-surface tension, quality, etc. Experience to date

evidently is only with dynamic (rotating) liquid-metal systems of (paraboloidal) astronomical optics, such as

R.W. Woods mercury experiments in 1908(23)

and Ermanno Borras electro-optical experiments of 1993 on

same type apparatus(24)

.

Elementary experiments on static liquid optics systems, might begin with ground-based simulation tests

using the experimental apparatus shown in Fig. 9, essentially meant to create and test and artificial zero-g

liquid-metal, capillary epihydrostatic, optical surface (G). Density of clear, contained liquid (E) is precisely

matched to density of reflective liquid metal (H) such as to create precision concave mirror (G), where mirror


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radius of curvature is determined by (fixed) contact angle on toroidal boundary-surface, (F). Zero-g drop tests

from a tower might be performed with equipment such as the Northrop apparatus shown in Fig. 10, drop

time was 2.2 seconds. A more elaborate drop-test is shown in Fig. 11, consisting of a capsule for balloon-drop

from 80,000 ft. Droptime was about a minute. High flying aircraft have been put in parabolic arc to provide a

certain amount of zero-g test time. Liquid space optics ultimate testbed is a Liquid Optics Technology

Satellite (LOTS) as shown in Fig. 4, provided with both reflective and refractive liquid optics and a

microwave downlink antenna. Latter vehicle, following expansion (inflation) and rigidization from rocket

payload shroud (at bottom of figure), would power internal equipment via thin-film solar cells covering its

exterior (spherical) wall(12,25)

.

Fig. 9. Optics Zero-g Simulation via Matched Liquid Density

1 FORWARD

0 REVERSE

1

5

S

L

PL

M

O

T

F

D

E

R

F

H K

B

A

A

Q

GCI

J

1 0

1 0


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Fig. 10. Optics Zero-g Short-Free-Fall Test


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Fig. 11. Optics Zero-g Long-Free-Fall Test


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REFERENCES

1. Toussaint, M., Energy Transmission in Space; An Enabler Technology, SPS 91 Power From SpaceProceedings, Paris/Gif-Sur-Yvette, France, 27-30 Aug. 1991.

2. Military Secrecy Order, implemented June 15, 1965 by USAF on Space Telescope subject-matter opatent application by J.H. Bloomer, inventor, under amended Serial Number 352,690. Filed Mar. 17,

1964.

3. Forbes, F.W., Expandable Structures, Space/Aeronautics, PG. 62 et seq., Dec. 1964.4. Forbes, F.W., ExpandableStructures for Aerospace Application, American Rocket Society 17th Annua

Meeting, Los Angeles, CA., Nov. 13-18, 1962.

5. Osgood, Carl C., Foamed-In-Place Structures for Space Vehicles and Stations, RCA Astro-ElectronicsProducts Division, Princeton, N.J.

6. Echo II Satelloon: Worlds Largest Spacecraft, G.T. Schjeldahl Co., Information Folder, NorthfieldMinnesota, 1965.

7. Bloomer, J.H., The 300-Inch Diffraction-Limited Orbiting Eye, American Astronautical SocietyScience & Technology Series Vol. 6, New York 1965.

8. Bloomer, J.H., Liquid Space Optics,J. Society of Photo-optical Instrumentation Engineers, Jan. 1966.9. Protz, Rudolf, Active Optics forHigh Power Lasers, Messerschmitt-Bolkow-Blohm GmbH, Dynamics

Division, P.O. Box 80 11 49, D-8000 Mnchen 80, Germany, in SPIE Vol. 1024, Beam Diagnostics and

Beam Handling Systems, 1988.

10. Satellite Power System Concept Development and Evaluation Program System Definition TechnicaAssessment Report, by NASA, Washington, D.C. 20546, for DOE Ofc. of Energy Research, Solar Power

Satellite Projects Division, Washington, D.C. 20585; Dec. 1980.

11. Glaser, Peter E., An Overview of the Solar Power Satellite Option, IEEE Transactions on MicrowaveTheory and Technique, Vol. 40, No. 6, June 1992.

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13. Richardson, Robert C. III, Prospects for Inexpensive SpaceTransportation, Space Power, Vol. 10, No2, pp. 217-224, 1991.

14. Hannigan, R.J., SPS Transportation Requirements: Which Launch System?, SPS 91 Power From SpaceSecond International Symposium Proceedings, Paris/Gif-Sur-Yvette, France, 27-30 Aug. 1991.


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15. Bloomer, J.H., The Alpha Centauri Probe, International Astronautical Federation XVIIth (MadridCongress, Proceedings published 1966 in Poland; published USA by Gordon and Breach, Inc., New York,

1967; pp. 225-232.

16. Bloomer, J.H., Earthly Millennium Energy and Interstellar Shuttle Propulsion Potentials of Liquid SpaceOptics, in 28

th

Intersociety Energy Conversion Engineering Conference Proceedings, Atlanta, GA., Aug1993.

17. Bloomer, J.H., Liquid Space Optical Theory of Manned Starflight with Earthly Applications, in 23rInternational Electric Propulsion Conference Proceedings, Seattle, WA., Sept. 1993.

18. Angelo, J.A., Jr., & Albert T.E., Satellite Power System (SPS) Space Debris Management Strategies andTechnologies, in SPS 91 Power From Space Proceedings, Paris/Gif-Sur-Yvette, France, 27-30 Aug. 1991.

19. Lockwood, R.M. & Lockwood, E.M., BLASTWAVE Proprietary Valveless Pulsejet System Infopak,Lockwood & Associates, 516 Adams St., Cottage Grove, OR., 1994.

20. Townes, C.H. & Schwartz, R.N., Interstellar and Interplanetary Communication by Optical Masers, inInterstellar Communication, ed. by A.G.W. Cameron, W.A. Benjamin, Inc., 1963.

21. Brauch, U., Opower, H., Wittwer, W., Muckenschnabel, J., Solar-pumped Solid State Lasers for Spaceto-Space Power Transmission, SPS Power From Space 2

ndInternational Symposium Proceedings

Paris/Gif-Sur-Yvette, France, 27-30 Aug. 1991.

22. Subliming-Propellant Microrocket, Rocket Research Corp., Redmond, WA.; Attn: Wm. W. Smith, 1994.23. Wood, R.W., RotatingMercury Paraboloid Telescope Mirror,Astrophysics Journal, March 1909.24. Borra, Ermanno, Liquid Mirrors, in Scientific American, Feb. 1994.25. Landis, Geoffrey A., Appelbaum, Joseph, Photovoltaic Power Option for Mars, in Space Power, Vol

10, No. 2, 1991.

conversion of solar energy via new aerospace technology

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