115 Flashcards
115.1 Discuss the role of Navy Space Command (NSC):
- The command was merged into Naval Network and Space Operations Command, itself part of Naval Network Warfare Command, about July 2002.
- The Naval Space Command (NSC) was the Naval component command of United States Space Command.
- Headquartered at Dahlgren, VA, NSC used space capabilities to support naval forces through the operation of reconnaissance and communications satellites, as well as representing the Navy’s space interests, both within the Navy and within U.S. Space Command.
115.2 Describe the following Space Mission areas:
a. Space Force Enhancement - Combat support operations and force-multiplying capabilities delivered from space systems to improve the effectiveness of military forces as well as support other intelligence, civil, and commercial users.
b. Space Support - Operations to deploy and sustain military and intelligence systems in space.
c. Space Control - Operations to ensure freedom of action in space for friendly forces, and when directed, denies an adversary the same.
d. Space Force Application - Combat operations in, through, and from space to influence the course and outcome of conflict by holding terrestrial targets at risk.
115.3 Describe the following entities in the Space environment and how they affect communications: [ref. a]
a. The Sun Produces highly charged electric particles and strong magnetic radiation fields which creates a strong background noise floor and will prevent locking onto significantly weaker signals when the sun is directly in front of the object being locked onto, eg. Sun in the background of a satellite will prevent lock on the satellite due to a low signal to noise ratio. It has the biggest effect on our local space environment.
b. Solar Wind: electrically charged particles of primary interest in the space environment are electrons and protons. These particles stream continuously from the sun to form what is called a “Solar Wind.” The solar wind travels at one million mph, carrying various particles from the sun.
c. Solar Cycle: Solar activity is cyclic in nature, following a 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.
d. Van Allen Radiation Belts: The Outer and Inner Van Allen Radiation Belts are two concentric, donut-shaped regions of stable, trapped charged particles that exist because the geomagnetic field near the Earth is strong and field lines are closed.
e. Atmospheric Drag: Expanding of the earth’s upper atmosphere due to heat generated by charged particle bombardment producing frictional drag on a satellite decreasing its altitude while increasing its speed causing the satellite to be below and ahead of its expected position.
115.4 Identify the following orbits:
a. Low Earth Orbit - A satellite is considered to be in a low earth orbit (LEO) at altitudes between approximately 1200 miles or less above the Earth’s surface. At an altitude of approximately 150 miles, a satellite’s period will be about 90 minutes.
b. Medium Earth Orbit – The region of space around the Earth above low Earth orbit and below geostationary orbit 1200 to 22,236 miles. The most common use for satellites in this region is for navigation, such as GPS. Communication satellites that cover the North and South Pole are also put in MEO. The orbital periods of MEO satellites range from about 2 to 24 hours.
c. Highly Elliptical Orbit - A satellite in this type of highly eccentric elliptical orbit slows down at apogee in the Northern Hemisphere (providing longer duration over its greatest field of view) and whips through perigee (smallest field of view) in the Southern Hemisphere. This provides communications in the Northern Hemisphere for nearly 75 percent of the satellite’s orbital period.
d. Geosynchronous Orbit - A satellite placed in orbit with an average altitude of approximately 22,236 miles 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.
e. Polar Orbit - 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.
115.5 Define the following:
a. Apogee - The point on the orbit farthest from the center of the Earth (apogee – “away”).
b. Perigee - The point closest to the center of the Earth will be halfway around the orbit and is called perigee.
115.6 Identify the three main space launch facilities in the U.S. [ref. b]
- To support its aggressive launch requirements, the U.S. maintains three sites for launching expendable and recoverable space vehicles. T
◦ Kennedy Space Center & Patrick AFB in Cape Canaveral, Florida
◦ Vandenberg Space Force Base in California
◦ Wallops Flight Facility in Virgina
115.7 Discuss the following Military Satellite Communications Systems: [ref. b]
a. Navy UHF Follow-on - Replaced the aging FLTSATs and features higher power transmitters designed to improve service, reliability and dependability. All UFO’s have 39 channels and UFO’s 4-9 have 11 additional EHF channels for a total of 50 available channels.
b. Defense Satellite Communications System (DSCS) - A high capacity, SHF satellite based subsystem of the Defense Communications System (DCS). The DCS provides worldwide, jam-resistant, secure voice and high data rate communications for command and control, crises management, and intelligence data transfer service between the National Command Authority, Joint Chiefs of Staff (NCA/JCS) and the Unified Commanders-in-Chief (CINC).
c. GBS - Derived from commercial direct broadcast technology and uses high-powered transponders to provide HDR wideband simplex broadcast signals into 1-meter or smaller antennas and sophisticated receiver suites.
d. WGS: The Wideband Global SATCOM program augments, and will eventually replace, the existing DSCS system which provides super high frequency (SHF) wideband communications. A single WGS spacecraft has as much bandwidth as the entire existing DSCS constellation (quoted on Spaceflight Now)
115.8 Describe the Global Positioning System.
- Space-based radio positioning systems that provide 24 hour three-dimensional position, velocity and time information to suitably equipped users anywhere on or near the surface of the Earth.
- Provides Positioning, Navigation, Timing and NUDET (Nuclear Detection).
115.9 Describe the Advantages and Disadvantages of Space-based ISR.
- Advantages: Has potential to provide systematic and focused coverage of AOIs, sometimes without detection, from sanction; enhances accuracy and planning capabilities for the user.
- Disadvantages: Access limitations and a predictable over flight schedule dictated by the satellite orbit; satellite systems may be affected by atmospheric disturbances such as fog, smoke, electrical storms, and precipitation and clouds, which affect the ability of imaging systems; priority conflicts; tasking, processing, exploitation, and dissemination limitations; and low numbers of assets.
115.10 Discuss the importance of space situational awareness.
- SSA is fundamental to conducting space operations. It is a key component for space control because it is the enabler, or foundation, for accomplishing all other space control tasks.
- Ensures that US space operators understand the conditions that could adversely impact successful space operations and spaceflight safety.
- Incorporates understanding of the space capabilities and intent of those that pose a threat to our space operations and space capabilities
- The ability of the US to monitor all space activity enables protection of space capabilities, helps deter others from initiating attacks against space and terrestrial capabilities, and assures allies of continuing US support during times of peace, crisis, and conflict.
- In short, SSA supports and enhances military operations.
115.11 Define the following:
a. Astrometry - Relates to precise measurements and explanations of the positions and movements of stars and other celestial bodies.
b. 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.
115.12 Discuss the role of GPS in the following operations:
a. Land Operations
b. Maritime Operations
c. Air Operations
d. Space Operations
e. Navigation Warfare
- All heavily utilize GPS for the purpose of Position, Navigation, and Timing (PNT) to accomplish operational goals. We seek to utilize PNT to most effectively utilize our warfighting assets and capabilities while denying the enemy effective use of theirs.
