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and propellant loadings for the individual stages for each mission, as well as the mass and composition of the cargo. Some indication of the amount of calculation, book keeping, and selection which are ́required is provided by the fact that there are nine planets,-32-moons, 670 charted comets, āñd 1700 charted asteroids in the solar system. Although the calculations are far from complete, they are adequate for setting up planning schedules.
Two conclusions emerge. One is that that the reference rocket for manned visits to Venus and Mars also has about the right capability for all the missions we can hope to accomplish by means of existing engineering knowledge, including all of them, and being · grossly oversized for none of them. The other is that any serious space program must be based on frequently repeated mission opportunities. "One-shot" projects standing alone have no advantage, and would lead to disappointment.
By using Jupiter swingby trajectories, the reference rocket could be sent low over either pole of the sun, or even retrograde over the equator, the altitude above the sun being limited only by the intense solar radiation. It could also be sent on relatively short duration missions to plot the boundaries of the solar wind in any direction, at distances much greater than the distance to the orbit of Pluto, if desired. A special case would be the use of a propulsive kick during perihelion passage, which would result in a fifteen-fold multiplication of the speed increment when applied to the hyperbolic excess speed. Such a maneuver would send the spacecraft three times as far as the aphelion of Pluto's orbit within eight years, including the time required for the preliminary Jupiter flyby. The equivalent specific impulse of the propellant would be 6600 seconds, twice that expected of the ORION rocket, thrice that expected of the gas-core nuclear rocket, and well beyond that expected of nuclear-electric rockets. Unfortunately, a nuclear rocket stage shows little or no advantage over a chemical rocket stage for the perihelion maneuver. Just to answer the inevitable question before it is asked, a sample calculation gave 16000 years for a one-way trip to Alpha Centauri.
4 CHECK LIST OF MISSIONS
A summary of missions and flights is given in Table 4.1. list is expanded into a detailed check list in Table 4.2-a, 4.2-b, and 4.2-c. The list is predicated upon a large, single-stage-toorbit launch rocket. It should be revised as to the number of launches if the recoverable first stage, 8-cyliner rocket is chosen.
The annual average, of course, would never be correct for any particular year, either in number or composition. Moreover, the list will be altered, both during initial planning, and afterward, as a result of experience. Nevertheless, the list serves as a shopping list, and can be used to provide identifiable assumptions for planning.
5 INFORMATION MANAGEMENT
Two aspects of information management can be planned, namely, mechanization and asking questions.
A relevant model for the mechanization of information management is the telephone system, which is organized around switching centers. A suggestive diagram of a suitable mechanical system is shown in Figure 5.1. The key to switching center operation is reprogramming, whereby (in the telephone system) one dials sets of -electrical impulses to establish connections. A single system could be made to accommodate scientific, flight, and housekeeping information, and should be planned accordingly.
The use of the system in simulation and checkout is shown in the diagram. The system should be built soon enough also to be used in planning, both to facilitate planning, and to reveal any faults.. in the information management system.
This section is intended to forestall an "information explosion" in space research. The search for information is for one or the other of two reasons:
• In addition to the three-stage spacecraft itemized, there are
also 56 spacecraft, not itemized, in which the one-millionpounds-thrust first stage 18 omitted.
CHECK LIST OF MISSIONS
OPERATIONS (REQUIRING TEAMS)
FIRST OF THREE PAGES
1. CHECKOUT FLIGHTS, at the launch site
2. PRACTICE FLIGHTS, vertical and retrothrust return to launch structure
3. GLOBAL TRANSPORT, vertical and retrothrust return, detached orbiter
4. COMMERCIAL COMMUNICATIONS,
geosynchronous, equatorial, and 30° apart
5. HELIOCENTRIC SPACE LABORATORIES AND OBSERVATORIES
Inclined heliocentric. Physics, Chemistry, Biology, Medicine, Ecology Astronomy, and space and commercial technology Freight, extended baselines for radio and optical interferometry, relativity, propulsion
6. SOLAR PHYSICS
Time-lapse motion pictures of sun, and interplanetary communications Sun grazers, via Jupiter. One over each pole, two at lower latitudes Solar wind boundary plotters, via Jupiter, and sometimes via the sun Comets. Rendezvous with nucleus or fly through tail. Make artificial
Earth magnetosphere plotters, in various directions to the boundaries Moon wake plotters, cislunar (and also pickaback on translunar relay) Jupiter magnetosphere plotters--
Atomic waste disposal, to interstellar space, or elsewhere as desire Contingencies, replace losses, duplications, unexpected opportunities
OPERATIONS (REQUIRING TEAMS)
CHECK LIST OF MISSIONS
SECOND OF THREE PAGES
7. TIME-LAPSE MOTION PICTURES OF CLOUD MOVEMENTS-
geosynchronous, equatorial, 120° apart, for the low latitudes displaced heliocentric, one above each polar region-----
one preceding, one following, earth in its heliocentric orbit cis-earth, above the subsolar point, photographing in visible trans-earth, in the earth's shadow, photographing in infrared displaced heliocentric----
Uranus, trials to determine what is possible and desirable--‒‒‒‒
Contingencies, replace losses, duplications, unexpected opportunities
8. TERRAIN SCAMMERS, geology, vegetation, ice, oceans, and installations
Earth, sun-synchronous, cross equator at 10:00 AM, with ten-day cycle
" polar, cross equator at noon on solstices, cover polar regions Moon, polar----
Pluto, trials to determine what is possible and desirable--------28 satellites of Jupiter, Saturn, Uranus, and Neptune--------- trials Contingencies, replace losses, duplications, unexpected opportunities
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