SPACE SCIENCE AND APPLICATIONS

BY DR. HOMER E. NEWELL, ASSOCIATE ADMINISTRATOR FOR SPACE SCIENCE AND APPLICATIONS, NASA

INTRODUCTION

This history of mankind has demonstrated that knowledge is fundamental to human advancement, as, for example, in the use of X-rays in medicine and industry, in modern electronics, new materials, modern fabrics, aeronautics, and in nuclear weaponry and power. In the exploration of space, scientific knowledge is both the key and the quest. The space science and applications program uses space vehicles and space technology made possible by knowledge from earlier basic research to attack a variety of important problems. The space science portion of the program seeks to advance knowledge about:

The space environment.

Sun-Earth relations.

Geodetic properties of the Earth.

The fundamental physical nature of the universe.
Physical properties of the Moon.

Properties of the planets.

The presence and behavior of life in space.

Projects in the first four of these areas are pursued under the heading of "Geophysics and Astronomy"; projects in the next two areas, under the heading of "Lunar and Planetary Exploration"; and in the last mentioned science area, under the "Biosciences Program." Each of these areas has important practical applications, and the knowledge to be obtained will be essential for the advancement of our national space capabilities.

The applications portion of the program seeks to apply space knowledge and technology to specific practical uses in such areas as: Meteorology.

Communications.
Navigation.

Technical applications.

The first mentioned application area gives rise to the meteorological satellite projects; the next two areas, to communications satellites projects; and the last mentioned application area, to the advanced technological satellite project. In addition, a continuing objective of the applications program is to search for potential practical benefits so that our national investment in space research may yield the

maximum in returns.

One of the important practical applications of advancing space knowledge and technology is the development of more powerful launch vehicles and improved spacecraft (fig. 109), and the continuing development of these necessary space tools is an important part of the NASA program of space science and applications.

Both the launch vehicle development program and the supporting university program, with its emphasis on training, research, and special facilities, are means to the programmatic ends. The team to carry out this program is national in scope. The largest portion of this team resides in industry, particularly in the development and production aspects of the program. Scientists and engineers from over a hundred universities participate in space and space-related research. Both the science and application efforts profit by the participation of foreign scientists and engineers in our international cooperative program.

The next chart (fig. 110) shows our flight program during 1963. It will be seen that we were able to continue a high percentage of successes, as in 1962. This is the result of thorough advance testing, as well as increased experience with the moderate size spacecraft involved.

Now we are in the development stages in the large observatory satellite, and the lunar and planetary spacecraft programs, with all the vicissitudes that those early phases involve. Nevertheless, the successes of the EXPLORER, TIROS, and communications satellites lend assurance that in more complicated spacecraft also, high success rates will ultimately be achieved. This assurance was further strengthened by the November 1963 launching and orbiting of the CENTAUR. The CENTAUR, the first launch vehicle to use the high energy liquid hydrogen-liquid oxygen propellant combination, is most significant for our lunar and planetary programs.

One of the major objectives of the Space Science portion of the program is to obtain information about the spatial and temporal properties and phenomena of space as needed for the understanding and utilization of space. Properties of greatest interest are:

In the upper atmosphere and ionosphere.-Pressure, temperature, density, and composition of neutral and ionized components;

In the magnetosphere.-Density and energy of trapped radiation, both natural and artificial, and the Earth's magnetic field;

Interplanetary space and the magnetosphere boundary.-Particle density and energy of radiation and the interplanetary magnetic field.

Such information is required for the design of high altitude vehicles and spacecraft, the development of space applications and manned space flight, and the conduct of operations in space. Also, the environment of interplanetary space directly influences our atmosphere; hence, space environment data are needed to fully understand weather, climate, and general atmospheric behavior.

Progress

The following list gives some of the space environment results obtained during the past year:

1. The existence of an appreciable number of protons in the outer Van Allen belts was established.

2. The lifetimes in the belt of artificially injected electrons was determined. At this time of low sunspot activity, the half-life is as long as several years in the heart of the "Starfish" radiation belt (L=1.2), and a few weeks or shorter at most other altitudes.

3. Trapping lifetimes and rates of enhancement of electrons of varying energies in the outer radiation zone have been correlated with magnetic storms.

4. Large low energy electron fluxes have been found on lines of magnetic force which appear to trail off to immense distances out into deep space.

5. Contours of constant counting rate near the magnetic equator were found to draw closer to the Earth on the night side of the Earth than on the day side.

6. Repeated observations were made of simultaneous VLF (very low frequency) electromagnetic emission, auroral optical emission, and particle precipitation into the atmosphere.

7. It was discovered that the Earth's magnetic tail in the antisolar direction extends at least half way to the Moon's orbit.

8. Direct observations were made of the way in which solar plasma on the sunward side of the Earth piles up outside the boundary of the Earth's magnetic field, and in so doing appreciably compresses the geomagnetic field.

9. Direct extended observations were made of the particle density and velocity of solar interplanetary plasma. These densities and velocities were found to have direct correlations with magnetic activity on the Earth and calcium plage activity regions on the Sun. 10. Extended measurements were made of the interplanetary magnetic field and solar and galactic cosmic ray intensities.

11. The true energy spectrum possessed by solar cosmic rays at their source on the Sun was deduced from the observational data by making corrections for the varying velocities of the different particles.

12. First simultaneous measurements were made of electron temperature, positive ion density, and neutral atmospheric constituents in the Earth's high atmosphere.

13. A new theory was developed to account for the types of ions found in the ionosphere, specifically the ratio of helium to hydrogen. 14. Sounding rockets furnished important information on the ionospheric D region from 35 miles to 55 miles and the origin of the sporadic effects in the E region of the ionosphere at about 75 miles. 15. Diurnal and seasonal variations in the ionosphere were established.

16. Sounding rockets launched simultaneously with an overhead pass of the satellite ALOUETTE reached within a few miles of the satellite, thereby connecting up ionospheric measurements in the lower atmosphere with those being made by the satellite.

By way of illustration of these results, let us consider in some detail what has been learned during the past year about the magnetospheric boundary, which at the present time is one of the most exciting areas of investigation of the space environment.

Magnetospheric boundary.-This boundary marks the edge of the region of influence in space of the Earth's magnetic field. Inside the boundary the Earth's magnetic field dominates the movement of charged particles and fields. Outside, the interplanetary space is