Basics of Satellites
What is a satellite?
A natural or artificial object in space that orbits the Earth.
What is a space probe?
A satellite that flies by, orbits, or lands on a body other than Earth.
Which satellite series measures radiant energy and helps monitor agricultural conditions?
LANDSAT.
What subsystem collects solar energy and converts it to electrical power?
The power system (solar cells).
What is the name of the theory that placed Earth at the center of the universe, proposed by Ptolemy?
The geocentric theory.
What is the name of Earth’s only natural satellite?
The Moon.
Which probe series first took close-up photos of the Moon for Apollo planning?
The Ranger probes.
What type of satellite provides images used in weather forecasting, such as cloud patterns?
GOES (Geostationary Operational Environmental Satellites).
What is the job of a satellite’s structure?
To support all components and survive launch while remaining lightweight.
Which scientist developed the laws of motion explaining how satellites stay in orbit?
Sir Isaac Newton.
What do apogee and perigee describe?
The highest (apogee) and lowest (perigee) points of an orbit.
Which probes flew by Venus and Mercury, giving us images of Venus’ clouds and Mercury’s surface?
The Mariner probes.
What was the first U.S. satellite series, whose first mission discovered the Van Allen radiation belts?
Explorer.
What environmental hazard damaged the Space Shuttle Challenger’s window when a tiny paint chip struck it?
Space debris (micrometeoroids or man-made debris).
What law states that an object in motion stays in motion unless acted on by an unbalanced force?
Newton’s First Law (Law of Inertia).
Which country launched Sputnik, the first artificial satellite, in 1957?
The Soviet Union (Russia).
Which missions in the late 1970s provided greatly improved pictures of Jupiter and Saturn?
Voyagers 1 and 2.
Which network of deep-space antennas supports planetary missions and space observation?
NASA’s Deep Space Network (DSN).
What subsystem controls the direction a satellite points?
The attitude control system.
What are satellites battling when in low Earth orbit that causes them to eventually fall toward Earth?
Atmospheric drag and gravity.
What mathematical shape do most orbital paths follow, according to orbital mechanics?
An ellipse.
What is the term for a spacecraft's final speed needed to permanently leave the Sun’s gravitational influence?
Solar system escape velocity.
What is the term for the boundary where solar wind pressure balances with interstellar space, reached by Voyager 1?
The heliopause.
What phenomenon causes satellites in low Earth orbit to slowly lose altitude over time?
Atmospheric drag.
What is the approximate orbital velocity needed to maintain low Earth orbit?
About 7.8 km/s (17,500 mph).