Chemistry of Rockets

Hopewell Valley Student Podcasting Network

Chemistry Connections

Chemistry of Rockets and Space Crafts

Episode #15

Welcome to Chemistry Connections, my name is Vanessa and I am your host for episode #15 called Chemistry of Rockets and Space crafts. Today I will be discussing how rockets are launched into space and how people are able to survive in the vessels. Specifically, how chemistry helps make space travel possible.

Segment 1: Introduction to Rockets and Space Crafts

What is a rocket?

First off I’m going to talk about what a rocket actually is. Usually when you think of a rocket, you probably think of a tall, thin, round vehicle. However, a rocket isn’t just the traditional spacecraft but it can also be the engine and any vehicle that uses the engine

When were rockets invented?

The first “rockets” were created in China in the 1200s. They used solid fuel and were used as fireworks. They were also used by armies. Overtime, rockets evolved and became bigger. Rocket production really picked up during the cold war, where in 1957 the Soviet’s Sputnik was launched. In 1969, the United States sent the first men to the moon with the Saturn V rocket
How rockets and spacecraft work have changed over time, especially with the types of engines used and how the engines work.

Shuttles and space capsules (apollo missions)

How do the engines work?

The engines burn fuel, which turns into hot gas which is then pushed out the back by the engine. The gas causes the rocket to propel upwards and move forwards
A rocket engine is different from a jet engine because it doesn't need air. It has everything it needs, allowing it to work in space.
There are two types of engines:
Liquid fuels (used in the space shuttles and Russian Soyuz)
First liquid fuel rocket which is used today was invented by Robert H Goddard
Solid fuels (on the side of the space shuttles)

Rockets/Space Crafts Today:

ISS (International Space Station)
NASA, Russia’s Roscosmos, Japan’s JAXA, Europe’s ESA, and Canada’s CSA
To conduct research and study space
Artemis missions
Return to the moon, long term presence on the moon, to study and better understand the lunar surface
Space X
Aims to help in the mission to colonize mars and participate in space travel and exploration

Segment 2: The Chemistry Behind Rockets and Space Crafts

What makes NASA rockets fly:

Combustion Reactions:

Newton’s Third Law states that for every action there is an equal and opposite reaction. The combustion reactions are what allow the rockets to launch and then fly.
A combustion reaction results from burning something. It releases energy which is what allows the rockets to move. The fuel is what burns when it is mixed with an oxidizer creating a propellant.
RS-25 main engines are liquid engines:
Liquid hydrogen is the fuel
Liquid oxygen is the oxidizer
The boosters use aluminum as fuel with ammonium perchlorate as the oxidizer and is mixed with a binder creating a homogeneous solid propellant.
Hydrogen: the main fuel is the lightest element as exists normally as a gas
Low density meaning a little takes up a lot of space
A really large tank would be needed for a large combustion reaction, which isn’t aerodynamically suitable
Therefore, by turning hydrogen into a liquid it makes it denser meaning it takes up less space. Hydrogen is cooled to a temp of -432 degrees Fahrenheit.
Oxygen:
Oxygen is denser than hydrogen but also needs to be compressed into a liquid in order to fit into the smaller lighter tank so it is cooled to -297 degrees Fahrenheit
LH2 and LOX
Liquid oxygen and liquid hydrogen
2H2 + O2 = 2H2O + Energy
Water
Releases a lot of energy in the form of steam
The hydrogen-oxygen reaction generates heat which causes the water vapor to expand and exit the nozzles at speeds of 10000 miles per hour. The fast moving stream allows the rocket to propel upwards.
*talk about not knowing it was steam*

Living long-term in space:

The ISS uses a method to remove CO2 from the air and allow astronauts to breath by using a sorbent, LiOH
The exothermic reaction of LiOH with CO2 creates lithium carbonate (Li2CO3)(s) and water. LiOH has a high absorption capacity for CO2 and produces a small amount of heat. It is also a very strong base.
This will also be used in future missions to Mars as well as on other long term missions that require people to be able to breath without their suits on.
CO2 and O2
2LiOH(s) + CO2 (g) → Li2CO3(s) + H2O (g)
It's an acid-base reaction. Scrubbers, which are expandable filters, containing lithium hydroxide, capture carbon dioxide. This removes carbon dioxide in the air, allowing astronauts to breathe. (originally)

For long term missions, this isn't effective so scrubbers with minerals called zeolites are instead used. They capture the CO2 and release it into space, allowing it to be reused for extended periods.

Now, scientists discovered a way to turn carbon dioxide into water.

Carbon dioxide reduction system →meanign the number of electrons associated with the atom increase. `

Combines CO2 with hydrogen gas to form water and methane. The methane gas is vented into space and the water is split into breathable oxygen and hydrogen gas using hydrolysis. The hydrogen gas is then used to make more water.

Segment 3: Personal Connections

Space has always been something that has fascinated me and I grew up obsessed with everything space and NASA related. I know a lot about the planets and stars, but not a lot about the rockets and vessels that actually allow us to get data on astronomical bodies. So I wanted to research this topic to learn how exactly rockets work on a chemistry level.
Air and Space museum in DC
NASA Houston
NASA Cape Canaveral/Kennedy Space Center
How cool it is the affect chemistry has on space

Thank you for listening to this episode of Chemistry Connections. For more student-ran podcasts and digital content, make sure that you visit www.hvspn.com.