Block 1 Lesson 5

Space Probes

What are the space probes we have learned about

• Fly-by

• Orbiter

• Impactor

• Lander

What is a fly-by

Flies by (without entering orbit or landing) a celestial body to collect data.

Advantages of fly-by

• Take measurements of temperature and atmospheric conditions

• Use the gravity of planets and satellites to propel themselves and gain speed

• Can take images of multiple planets/objects, allowing for more efficient trips

Disadvantages of fly-by

• Can never return to previous position

• The encounter happens very quickly, so not all asteroids and planets can be captured in images

• Fly-by’s can’t gather very detailed analysis of object features, meaning that scientists may not find out as much as they want

Example of fly-by

New Horizons:

• Launch date - January 19, 2006

• Destination - Pluto, Kuiper Belt

• Achievements - Mapped Pluto’s surface and its moons

What is an orbiter

Designed to enter and remain in orbit around a celestial object, stays for extended periods of time

Advantages of an orbiter

• Can study a planet or moor for a long period of time, collecting continuous data

• Provides a global view of the celestial body, allowing for detailed mapping

• Can relay signals from landers or rovers, acting as a communication hub

Disadvantages of an orbiter

• Requires a lot of fuel and/or precise measuring to maintain orbit

• Can’t analyse surface features as closely as a lander or rover

• If an orbiter fails, it may become space debris and remain in orbit indefinitely

Example of orbiter

Dawn:

• Launch date - September 27, 2007

• Destination - Vesta and Ceres (Asteroid Belt)

• Achievements - First spacecraft to orbit two extraterrestrial bodies, provided detailed images and data on their composition and confirmed the presence of water ice on Ceres

What is an impactor

Designed to crash into a celestial body. Analyses material kicked up from the impact or studies the impact itself

Advantages of impactor

• Can provide direct measurements of surface composition

• Can reveal subsurface material that is not visible from orbit

• Generates valuable data on impact effects and planet geology

Example of impactor

Deep Impact:

• Launch date - January 12, 2005

• Destination - Comet Temple

• Achievements - Revealed subsurface material and analysed comet’s composition, structure and behaviour

What is a lander

Lands on a celestial body and stays there. Interacts with surface, allowing for detailed, up-close scientific study

Advantages of lander

• Can conduct detailed analysis of the surface, including soil and atmospheric tests

• Provides close-up images and high-resolution data

• Can deploy scientific instruments such as drills and spectrometers for in-depth research

Disadvantages of lander

• Requires precise landing, making it risky to deploy

• Limited mobility compared to rovers, as it stays in one place

• Harsh planetary conditions can damage the lander, limiting its lifespan

Methods of landing

• Parachutes

• Retro-rockets

• Air bags

• Sky crane system

Example of lander

Philae:

• Launch date - March 2, 2004

• Destination - Comet 67P

• Achievements - First lander to land on a comet, provided data on the comet’s surface composition and structure

Manned missions advantages (3)

• Humans can cope with difficult conditions and carry out movements that no robot would be capable of

• A human does not need programming and can be flexible and intelligent enough to carry out different tasks

• Humans can adapt to problems and opportunities

Manned missions disadvantages (4)

• When astronauts are in space for a long time, they suffer from muscle fatigue, deterioration and mineral problems

• Resources such as air, water and food are needed for astronauts to survive

• If an unmanned probe is destroyed, a space organisation loses money from equipment and expertise, but if a manned spacecraft is destroyed, human lives are lost

• It takes time and money to train astronauts

What is escape velocity

Escape velocity is the minimum speed an object must reach to break free from a planet’s gravitational pull without further propulsion

What is Earth’s escape velocity

11.2 km/s

How is this speed reached

By using powerful rocket propulsion. Multistage rockets gradually shed wight as they ascend, allowing them to efficiently accelerate beyond escape velocity.

Gravity assists from planetary bodies can also help in achieving higher speeds.