Orbits — Set 1

Correct Answer: A. 35,786 km

A satellite at this specific altitude has an orbital period equal to Earth's rotation. This allows it to appear fixed over a single point on the equator. Most communication and weather satellites are placed in this high orbit.

Correct Answer: A. Low Earth Orbit (LEO)

Low Earth Orbit typically extends from 160 km to 2,000 km above Earth's surface. It is the most accessible orbit for human spaceflight and satellite imaging. Objects in this orbit travel at very high speeds to avoid falling back into the atmosphere.

Correct Answer: C. It passes over the North and South Poles.

The correct answer is 'It passes over the North and South Poles.'. A Polar Orbit has a high inclination, allowing a satellite to scan the entire Earth as the planet rotates beneath it. This makes it ideal for global mapping and reconnaissance missions. It is often a sub-type of Low Earth Orbit.

Correct Answer: D. Polar Orbit

In an SSO, the satellite passes over any given point of the Earth's surface at the same local solar time. This ensures consistent lighting conditions for high-quality earth observation and climate monitoring. It is achieved by precisely balancing the orbit's altitude and inclination.

Correct Answer: A. Medium Earth Orbit (MEO)

The correct answer is 'Medium Earth Orbit (MEO)'. MEO is the region of space between LEO and GEO, typically around 20,200 km. It is used for navigation systems because it provides broad coverage with fewer satellites than LEO. Global systems like GPS and GLONASS operate in this altitude range.

Correct Answer: C. 24 hours

The period matches the Earth's sidereal rotation day, which is approximately 23 hours and 56 minutes. This synchronicity is what keeps the satellite stationary relative to the ground. If the period were different, the satellite would drift across the sky.

Correct Answer: A. Molniya Orbit

A Molniya orbit allows a satellite to spend a large portion of its time over high-latitude areas. It has a high inclination and an eccentricity that prevents the satellite from moving too quickly over its target. This was originally developed by the Soviet Union for northern communications.

Correct Answer: C. Storing decommissioned satellites.

A graveyard orbit is located several hundred kilometers above GEO to safely dispose of old satellites. Moving satellites here prevents collisions in the valuable active communication bands. It is a critical part of space debris management.

Correct Answer: D. Lagrange Points

Lagrange points are positions where the gravitational pull of two large masses equals the centripetal force required for a small object to move with them. There are five such points for any system of two large bodies. The James Webb Space Telescope is located at the L2 point.

Correct Answer: A. Perigee

Perigee is the specific term for the nearest approach in an Earth-centric orbit. At this point, the satellite travels at its maximum orbital velocity. The opposite point, where the satellite is farthest, is called the apogee.