115 Flashcards
115.1 Describe the following Space mission areas
ENHANCMENT
SUPPORT
APPLICATION
Space force enhancement: Multiplies joint force effectiveness by increasing the combat potential, operational awareness, and providing needed joint force support. There are five force enhancement missions: ISR, missile warning, environmental monitoring, satellite communications, and PNT
Space Support: The space support mission area includes space lift operations (launching and deploying satellites), satellite operations (maintaining, sustaining, and rendezvous and proximity operations), and reconstitution of space forces (replenishing lost or diminished satellites)
Space control provides freedom of action in space for friendly forces, and when directed, denies it to an adversary. It consists of offensive space control (OSC), defensive space control (DSC), and SSA
Space Force Application: DOD policy defines space force application as combat operations in, through, and from space to influence the course and outcome of conflict by holding terrestrial targets at risk
115.2 Describe the following entities in the Space environment and how they affect communications SUN SOLAR WIND SOLAR CYCLE VAN ALLEN
The Sun:
The sun has the biggest effect on the space environment. Fueled by nuclear fusion, the sun combines or “fuses” 600 million tons of hydrogen each second. Two by-products of the fusion process that impact space systems are electromagnetic radiation and electrically charged particles
Solar Wind:
The solar wind is a stream of charged particles ejected from the upper atmosphere of the Sun. It mostly consists of electrons and protons with energies usually between 10 and 100 keV. These particles can escape the Sun’s gravity because of their high kinetic energy and the high temperature of the corona
Solar Cycle:
Solar activity is cyclic in nature, following an 11-year cycle which is called the Solar Cycle. Generally there is a 4-year rise to a solar maximum, followed by a gradual 7-year decline to solar minimum
Van Allen Radiation Belts:
The Outer and Inner Van Allen Radiation Belts are two concentric, donut-shaped regions of stable, trapped charged particles. The Inner Belt has a maximum proton density approximately 5,000 km above the Earth’s surface and contains mostly high-energy protons The Outer Belt has a maximum proton density at an altitude ranging from 16,000 to 20,000 km and contains low to medium energy electrons and protons
Energy deposited in the Earth’s upper atmosphere by charged particle bombardment heats the atmosphere, causing it to expand outward over a period of time
115.3 Identify the following orbits LEO MEO HEO GEOSYNCH POLAR
Low Earth Orbit (LEO) - 150 to 800 Miles with a period of 90 minutes
Medium Earth Orbit (MEO) - Altitude below 22,300 miles (Geostationary Orbit) and above the Low Earth. Covers more than LEO but requires more Satellites than Geostationary Orbit.
Highly Earth Orbit - Elliptic orbits of low-altitude perigee and high-altitude apogee (over 35,786 km) are of high earth orbits. These extremely elongated orbits have the advantage of long dwell times at a point in the sky during the approach to and descent from apogee. Visibility near apogee can exceed twelve hours of dwell at apogee with a much shorter and faster-moving perigee phase
Geosynchronous Orbit - A satellite placed in orbit with an average altitude of approximately 19,300 nautical miles (nm) will have an average angular velocity exactly equal to that of the Earth’s. Stated more simply, the satellite would have a period approximately equal to one day (limitations of approximately 70° North and South of the equator)
Polar Orbit - A polar orbit passes over the entire surface of the Earth. A polar orbit has an inclination of 90° and is usually circular. Due to the ability to pass over the entire surface of the earth throughout the course of several days, the polar orbit is used extensively by imagery satellites
115.4 Define the following
APOGEE
PERIGREE
Apogee: The point in the orbit of an object (as a satellite) orbiting the earth that is at the greatest distance from the center of the earth
Perigee: The point in the orbit of an object (as a satellite) orbiting the earth that is nearest to the center of the earth
115.5 Identify the two main space launch facilities in the U.S.
Vandenberg Air Force Base, approximately 9 miles northwest of Lompoc, California
Kennedy Space Center/Cape Canaveral Air Force Station, Florida
115.6 Discuss the following Military Satellite Communication Systems
UHF Follow on
GBS
WGS
Navy UHF Follow-on: A new constellation of satellites the Navy has procured to replace the aging FLTSAT system. The UFO features higher power transmitters designed to improve service, reliability, and dependability
A high capacity, SHF satellite based subsystem of the Defense Communications System (DCS). Currently all active and reserve satellites are DSCS III, first launched in 1982. DSCS III provides global coverage 70N to 70S with a primary constellation consisting of five satellites
GBS: The Global Broadcast Service (GBS) is derived from commercial direct broadcast technology and uses high-powered transponders to provide High Dynamic Range (HDR) wideband simplex broadcast signals into 1meter or smaller antennas and sophisticated receiver suites
WGS: The Wideband Gap filler System satellites will be the DOD’s most capable and powerful communication satellite. The WGS will provide near-term continuation and augmentation of the services that are currently provided by the DSCS and GB
115.7 Describe the Global Positioning System
The Global Positioning System (GPS) is a space-based global navigation satellite system that provides reliable location and time information in all weather and at all times and anywhere on or near the Earth when and where there is an unobstructed line of sight to four or more GPS satellites
GPS was created and realized by the U.S. Department of Defense (DOD) and was originally run with 24 satellites. It was established in 1973 to overcome the limitations of previous navigation systems
115.8 Describe the advantages and disadvantages of Space-based ISR
Advantages:
The prime advantage of space-based ISR capabilities is their potential to provide systematic and focused coverage of AOIs, sometimes without detection, from sanction
Often, the product of a space or terrestrial capability can enhance accuracy and shorten reaction times to the user by cueing another space system to survey an AOI
ISR systems also enhance planning capabilities by providing updated information regarding terrain and adversary force dispositions
Disadvantages:
systems may be affected by a variety of atmospheric disturbances such as fog, smoke, electrical storms, and precipitation and clouds, which affect the ability of imaging systems to detect adversary activity, missile launches, and battle damage
115.9 Discuss the importance of space situational awareness
It is fundamental to conducting space operations. The requisite current and predictive knowledge of the space environment and the operational environment upon which space operations depend including physical, virtual, and human domains as well as all factors, activities, and events of friendly and adversary space forces across the spectrum of conflict.
SSA supports the following key objectives: Ensure space operations and spaceflight safety, Implement international treaties and agreements, Protect space capabilities, and Protect military operations and national interests.
Components of space situational awareness: Intelligence, Surveillance, Reconnaissance, Environmental Monitoring, and Space Common Operational Picture.
115.10 Define the following
ASTROMETRY
EARTH ORIENTATION PARAM
Astrometry: The branch of astronomy that relates to precise measurements and explanations of the positions and movements of stars and other celestial bodies
Earth Orientation Parameters: The Earth’s rotation is not even. Any motion in/on the Earth causes a slowdown or speedup of the rotation, or a change of rotation axis. Most of them can be ignored, but movements of very large mass, like sea current or tide can produce discernible changes and cause error to very precise astronomical observations
Components: Universal time, Coordinates of the pole, and Celestial pole offsets
115.11 Discuss the role of precise time in the following
GPS
GEO LOCATION
NETWORK SYNCH
Global Positioning system (GPS)
GPS is a radio navigation system that allows land, sea, and airborne users to determine their exact location, velocity, and time 24 hours a day, in all weather conditions, anywhere in the world
24 GPS satellites (21 active, 3 spare) are in orbit at 10,600 miles above the earth. The satellites are spaced so that from any point on earth, four satellites will be above the horizon
Geo Location
Geo-location is the wireless detection of the physical location of a remote device
Network Synchronization
GPS is transmitted in the GPS Signal in space and utilized globally. It keeps the computer networks on the exact time and is automatically updated
