[Federal Register Volume 60, Number 214 (Monday, November 6, 1995)]
[Notices]
[Pages 56066-56068]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 95-27449]



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NATIONAL AERONAUTICS AND SPACE ADMINISTRATION

[Notice 95-099]


National Environmental Policy Act; Shuttle Laser Altimeter

AGENCY: National Aeronautics and Space Administration (NASA).

ACTION: Finding of no significant impact.

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SUMMARY: Pursuant to the National Environmental Policy Act (NEPA) of 
1969, as amended (42 U.S.C. 4321 et seq.), the Council on Environmental 
Quality Regulations for Implementing the Procedural Provisions of NEPA 
(40 CFR Parts 1500-1508), and NASA policy and procedures (14 CFR Part 
1216 Subpart 3), NASA has made a finding of no significant impact 
(FONSI) with respect to the proposed Shuttle Laser Altimeter (SLA) to 
be constructed at the Goddard Space Flight Center, in Greenbelt, 
Maryland. SLA involves the precise global measurement of the topography 
of the distance from the Earth's surface with respect to the Space 
Shuttle.

DATES: Comments in response to this notice must be provided in writing 
to NASA on or before December 6, 1995.

ADDRESSES: Comments should be addressed to Dr. Jack L. Bufton, 
Associate Chief for Sensor Physics, Laboratory for Terrestrial Physics, 
Code 920, NASA Goddard Space Flight Center, Greenbelt, MD 20771. The 
Environmental Assessment (EA) prepared for the proposed SLA which 
supports this FONSI may be reviewed at:


[[Page 56067]]

(a) Prince George's County Memorial Library System--Bowie Branch, 15210 
Annapolis Rd., Bowie, Maryland.
(b) NASA Headquarters Information Center, Room 1H23, 300 E. Street 
S.W., Washington, DC.
(c) NASA, Ames Research Center, Moffet Field, CA 94035 (415-604-4191).
(d) NASA, Dryden Flight Research Center, Edwards, CA 93523 (805-258-
3047).
(e) NASA, Goddard Space Flight Center, Greenbelt, MD 20771 (301-286-
7216).
(f) Jet Propulsion Laboratory, Visitors Lobby, Building 49, 4800 Oak 
Grove Drive, Pasadena, CA 91109 (818-354-5011).
(g) NASA, Johnson Space Center, Houston, TX 77058 (713-483-8612).
(h) NASA, Langley Research Center, Hampton, VA 23665 (804-864-6125).
(i) NASA, Kennedy Space Center, FL 32899 (407-867-2622).
(j) NASA, Lewis Research Center, 21000 Brookpark Road, Cleveland, OH 
44135 (215-433-2902).
(k) NASA, Marshall Space Flight Center, AL 35812 (205-544-5252).
(l) NASA, Stennis Space Center, MS 39529 (601-688-2164).

    A limited number of copies of the EA are available by contacting 
Jack L. Bufton, NASA Goddard Space Flight Center, Greenbelt, MD 20771, 
telephone 301-286-8591.

FOR FURTHER INFORMATION CONTACT:
Dr. Jack L. Bufton, 301-286-8591.

SUPPLEMENTARY INFORMATION: NASA has reviewed the EA prepared for the 
proposed SLA and has determined that it represents an accurate and 
adequate analysis of the scope and level of its associated 
environmental impacts. The EA, including the ``Shuttle Laser Altimeter 
Ground Observer Eye Safety Analysis'', is incorporated by reference in 
this FONSI.
    NASA is proposing to test a low power laser altimeter instrument in 
space as a pathfinder instrument for global measurement of the 
topography of the Earth's land surface. Laser altimeter instruments 
have been in use for several decades from airborne instrument platforms 
for the purpose of terrain mapping and previous laser altimeters have 
flown in space. Research results from these earlier programs indicate 
the advantages of a spacebased global observations of Earth land 
surface topography using the high spatial resolution and vertical 
precision offered by the laser altimeter technique. Accurate 
topographic information on the Earth's landforms is essential in a wide 
variety of Earth science disciplines, agriculture, land-use studies, 
and natural disaster (e.g., floods, erosion, landslides, volcanoes, 
earth quakes, etc.) mitigation.
    The principal components of a laser altimeter system are the laser 
transmitter, optical receiver, and data system. The laser transmitter 
sends a low powered pulsed laser bean of 1064 nano meter wavelength 
radiation throughout the Earth's atmosphere toward the Earth's surface. 
Each laser pulse has a temporal duration of 10 nano seconds and forms a 
spot of approximately 100 meters (m) in diameter on the Earth's 
surface. Reflection of laser radiation from this spot is detected at 
the laser altimeter instrument by the combination of an optical 
telescope and detector that constitute the optical receiver package and 
covert the optical pulse into an electronic pulse. The laser pulse 
time-of-flight for the round-trip from the laser altimeter instrument 
to the Earth's surface and return is measured. This data then is used 
to compute distance between the instrument and the Earth's surface. The 
data system performs the computation of distance from pulse time-of-
flight and communicates the altimeter data to external systems and on-
board data recorders.
    For laser altimeter operations, the instrument must be pointed 
perpendicular to the Earth's surface in order to make accurate distance 
measurements. The optical receiver is quite sensitive, since most of 
the pulse laser radiation is scattered in the reflection of light from 
the spot on the Earth's surface or scattered and absorbed in the 
Earth's atmosphere. By using pulsed laser energy to make a series of 
distance measurements (profiles) along the ground track of a 
spacecraft, laser altimeter instrument can build up a global grid of 
accurate surface topography.
    The proposed SLA experiment will entail flying a laser altimeter 
instrument as a small attached payload on the Space Shuttle. The first 
flight is scheduled for November 1995 and will be a 9-day mission to 
gain experience in operating a laser altimeter in space environment, 
and to evaluate the sensitivity of the laser altimeter instrument for 
performing the surface elevation measurement mission. The current 
flight plan calls for seven operational periods of approximately 10 to 
15 hours duration each during which the SLA will continuously profile 
the Earth and ocean surface topography along the ground track (nadir 
track) of the Shuttle. The SLA instrument operates continuously at 10 
pulses per second (pps) during each period. This results in a 
continuous profile of 120 m diameter optical spots (i.e., altimeter 
sensor footprints) that are separated by approximately 740 m along the 
ground-track of the Space Shuttle. At least one SLA operational period 
is scheduled on each Shuttle flight day after flight day 2. The planned 
orbit for these SLA operations is a 300 kilometer (160 nautical miles) 
circular orbit at 28.5 deg. inclination. Thus the SLA measurements will 
be conducted between 28.5 deg. North latitude and 28.5 deg. South 
latitude. Among the land masses crossed will be Africa, most of Latin 
America, Southland Southeast Asia, and much of Australia. Consequently, 
no SLA operations will be conducted over the continental US north of 
Cape Canaveral, Florida.
    The proposed action and the no-action alternative were considered 
in this Environmental Assessment (EA). The no-action alternative will 
not fulfill the objective of advancing the Nation's topographic 
measurement capability. Under the No-Action alternative, it will not be 
possible to fully develop or space test the laser altimeter instrument 
technology for an operational space-based topography system. It will 
then be necessary to rely on existing photogrammetric and radar mapping 
instruments which have limitations in accuracy and in interpretation of 
topography data.
    A review by the North American Defense Command and United States 
Space Command SPADOC Laser Clearinghouse found that the SLA laser 
transmitter does not produce sufficient laser energy to exceed their 
damage threshold and, therefore, does not require clearinghouse 
screening.
    The only potential source of environmental impact from the proposed 
action is the portion of the laser pulse energy which will pass through 
the Earth's atmosphere and reach the surface. The SLA laser energy is 
negligible compared to natural sources of optical radiation. A ground 
observer safety analysis was performed for the SLA experiment and found 
no substantial risk of human eye or skin injury from operation of the 
SLA instrument within the range of possible Shuttle orbital altitudes.
    No other environmental impacts have been identified as a result of 
the EA. On the basis of the SLA EA and underlying reference documents, 
NASA has determined that the environmental impacts associated with this 
project will not individually or cumulatively have a significant effect 
on the quality of the environment. NASA will take no final action prior 
to the expiration of the 30-day comment period.


[[Page 56068]]

    Dated: November 1, 1995.
William F. Townsend,
Deputy Associate Administrator for Mission to Planet Earth.
[FR Doc. 95-27449 Filed 11-3-95; 8:45 am]
BILLING CODE 7510-01-M