Exploring the Unknown - NASA's History Office

furnishes the basic information required to anticipate forthcoming pressures on resources
and to indicate appropriate steps to be taken.
4. ACCOMPLISHMENTS TO DATE
With the assistance of disciplinary groups in several Federal agencies and institutions,
program definition activities have been initiated in the four disciplinary areas. Many of the
phenomena which each natural resource discipline wishes to observe and record from
space have been identified (Figure 1). The instruments and their frequencies needed to
gather these data have also been [550] identified as closely as possible (Figure 1).
The coordinated requirements of the several natural resource disciplines for photography
and radar on initial flights have been compiled in document form. A document of
infrared instrument requirements is being prepared. Albums of imagery acquired by this
aircraft program together with spacecraft-acquired imagery (from Gemini, Nimbus, etc.)
of value to natural resource scientists are being compiled. An atlas which analyzes the
potential of this data for natural resource scientists is in preparation.
One of the principal tasks of this Program is the determination of the best combination
of instruments and the best resolutions for observing natural resource phenomena.
These are currently being identified. However, until several generations of instruments
have been flown in space and the data analyzed, it will be impossible to be completely precise
on such instrument specifications.
The various remote sensing instruments recommended by the disciplinary groups are
being flown over carefully selected test sites with aircraft. The data obtained from such test
site overflights are then studied to determine the best combination of instruments for
spaceflight and the best analytical processes for acquiring the maximum amount of information
from the data. Accomplishments in these areas are described in detail below.
4.1 AIRCRAFT DATA GATHERING SYSTEM
The Natural Resources Program together with the MSC [Manned Space Center]
Engineering and Development Directorate is presently engaged in gathering data over
test sites with a number of airborne electronic and electro-optical remote sensors for a
number of user agencies and cooperating scientists.
This program has been set up to obtain precursor data for the calibration of instruments
over known features and for the development of the best observational and interpretive
techniques in the period 1965–1968 preceding the earliest (1968) natural
resource spaceflight missions. Further, the costs of developing such a data gathering system
initially with airborne instruments is substantially less than proceeding directly to a
spaceborne system. The experience gained in this aircraft phase (1965–1968) is already
providing a solid basis for planning of the spaceflight testing phase.
It is expected that aircraft-acquired data will also be obtained over a number of key
test sites simultaneously with the initial spaceflight data in order that the spaceflight
instruments may be calibrated and in order that the aircraft and spacecraft data may complement
each other to the maximum extent.
4.2 STATUS OF THE AIRCRAFT PROGRAM
EXPLORING THE UNKNOWN 229
It can be seen from Figure 1 that each sensor has multiple uses, and in most cases a
combination of sensors is desirable to provide complete data on any particular observed
feature.
To carry out the remote sensing program in a satisfactory manner, it is necessary to
conduct aircraft testing from several altitudes (low, intermediate, and high) over a period