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Chemical Elements

Chemical symbol English name Notes
Ar argon A noble gas, non-reactive, but toxic in high concentrations. About 1% of Earth’s atmosphere and 2% of Mars’s. Used in welding.
C carbon One of the most useful and abundant of all elements. Definitive element of organic molecules. Found in wood, plastic, steel, diamond, nanotubes and many other materials.
H hydrogen The lightest and most abundant element in the Universe. The main element in stars, commonly found in water and hydrocarbons.
N nitrogen An essential element for life, found in all living things. Comprises about 80% of Earth’s atmosphere.
O oxygen An essential element for life, and extremely abundant. Most often found in water, air, and in rocks as metal oxides.
Pu plutonium A radioactive metal sometimes used as power source in mobile robots and spacecraft.

Chemical Compounds

Chemical formula English name Notes
CH4 methane Simplest hydrocarbon, non-toxic, major constituent of natural gas, great fuel.
CH3OH methanol The simplest alcohol. A light, volatile, colourless, flammable liquid that can be used as a fuel or to make other chemicals.
CO carbon monoxide Toxic gas found in car exhausts. Can be used in fuel cells and iron refining.
CO2 carbon dioxide Non-toxic in small concentrations, exhaled by animals and consumed by plants (photosynthesis). Comprises about 96% of the atmospheres of both Mars and Venus.
H2 hydrogen The most abundant and lightest gas in the Universe.
H2O water Essential for life, extremely abundant in the Universe, an excellent solvent, we’re mostly made of it, Earth is mostly covered in it, you can swim in it, wash with it, throw it on people during Thai New Year, even drink it.
N2 nitrogen Non-toxic and a good buffer gas. Comprises about 78% of Earth’s atmosphere, 2% of Mars’s, 3.5% of Venus’s, and 95% of Titan’s.
NH3 ammonia A metabolism product and important component of fertiliser.
NO nitric oxide Important biological regulator relevant to neurology, physiology and immunology. Non-toxic, but rapidly oxidises to toxic NO2 in the atmosphere.
NO2 nitrogen dioxide A brown toxic gas and major air pollutant, commonly produced by internal combustion engines.
O2 oxygen Inhaled by animals, exhaled by plants. Extremely abundant in the Universe, comprising about 20% of Earth’s atmosphere. Most common oxidiser used in rocket propellant.
O3 ozone A toxic form of oxygen that absorbs ultra-violet radiation. Found in the upper atmosphere.

Acronyms and Initialisms

Numerous acronyms and initialisms appear in this document; all are listed below for easy reference. They are drawn from several domains, including space, technology, business and military. Several have been newly invented for this document.

To mitigate acronym overload, and reduce time spent flicking back and forth to this page, acronyms are expanded on first usage.

AEB Agência Espacial Brasileira Brazilian Space Agency.
AG Artificial Gravity Sensation of gravity, usually produced by centripetal force.
ASRG Advanced Stirling Radioisotope Generator Stirling engine powered by a large radioisotope heater unit.
ATV All Terrain Vehicle Quad bike suited for driving on rough terrain, such as on Mars.
AWESOM Autonomous Water Extraction from the Surface Of Mars Method proposed for extracting water from the Martian regolith using a mobile robot.
BP Bundle Protocol Internet protocol designed for DTNs.
CAMPER Crewed Adaptable Multipurpose Pressurised Exploration Rover A pressurised rover for multi-sol excursions on Mars, featuring robotic arms and attachments such as a drill and excavator bucket.
CCD Charge-Coupled Device Component used in digital cameras for detecting light.
CEO Chief Executive Officer Senior executive position in a company.
CIGS Copper Indium Gallium Selenide Semi-conductor material used as a substrate on flexible, thin-film solar cells.
CME Coronal Mass Ejection Massive burst of electrons, ions and atoms from the Sun’s corona into space. Also known as a solar flare.
CNSA China National Space Administration Space agency of China.
COSPAR Committee for Space Research Committee that promotes international collaboration with respect to scientific research in space.
COTS Commercial Off The Shelf Component that can be purchased from a commercial vendor, rather than custom-designed and built from scratch.
CRISM Compact Reconnaissance Imaging Spectrometer for Mars A visible-infrared spectrometer aboard the Mars Reconnaissance Orbiter searching for mineralogic indications of past and present water on Mars.
CRS Communications Relay Satellite A satellite that receives and retransmits communication signals.
CSA Canadian Space Agency Space agency of Canada.
DCS Decompression Sickness Illness caused by dissolved gases (usually nitrogen) forming bubbles in the blood upon depressurisation.
DRA Design Reference Architecture NASA’s fundamental architecture and assumptions for sending humans to Mars.
DSN Deep Space Network Worldwide network of large antennas and communication facilities located in California, Spain and Australia, used for tracking interplanetary spacecraft.
DTN Delay or Disruption Tolerant Networking Approach to computer network architecture where the network may be subject to delays or disruption, such as in space.
ECLSS Environment Control and Life Support System System for maintaining a vehicle or habitat’s environment at the right conditions to support human life.
EDC Earth Descent Capsule Crew Dragon launched from Earth at the end of the mission, which the crew use to land on Earth. Also known as Newton.
EDL Entry Descent and Landing Process of landing a spacecraft on a planet with an atmosphere.
EDRS European Data Relay System Also known as “SpaceDataHighway”. Collection of satellites in GEO providing high bandwidth laser communications between satellites, spacecraft and ground stations.
EELV Evolved Expendable Launch Vehicle Expendable launch system program designed to assure access to space for US government launches, and make them more affordable and reliable.
EMC Earth-Mars Capsule Crew Dragon that carries the crew from Earth surface to Earth orbit, then from Mars orbit to Mars surface. Also known as Einstein.
EMPP Expendable Methalox Propellant Pod Passively-cooled cryogenic tank of methane and LOX, for fuelling the MTV.
EOI Earth Orbit Insertion Orbital manoeuvre that moves a spacecraft into Earth orbit.
EOR Earth Orbit Rendezvous When two spacecraft meet and dock in Earth orbit.
EP Electric Propulsion Propulsion method that uses electricity to produce positive ions, which are then expelled using magnetic forces to create thrust.
ERV Earth Return Vehicle Vehicle to carry humans from Mars to Earth.
ESA European Space Agency Space agency of Europe, comprised of 20 member nations.
EVA Extra-Vehicular Activity When an astronaut goes outside a vehicle (e.g. spacecraft or rover) or habitat wearing a spacesuit.
FMARS Flashline Mars Arctic Research Station MARS at Haughton Crater on Devon Island in the Canadian Arctic.
G-FOLD Guidance for Fuel Optimal Large Diverts Navigation system that calculates optimised trajectory corrections in real time.
GNC Guidance, Navigation and Control Spacecraft subsystem responsible for controlling its position and velocity.
GPS Global Positioning System Navigation system that can pinpoint your location anywhere on Earth.
GRS Gamma Ray Spectrometer An instrument on Mars Odyssey.
GTO Geostationary Transfer Orbit A Hohmann transfer orbit used to reach geostationary orbit.
HD High Definition Camera, image or video with high resolution.
HEEO Highly Elliptical Earth Orbit An equatorial orbit around Earth with a low perigee (~1000 km) and a high apogee (geostationary altitude or higher).
HEMO Highly Elliptical Mars Orbit An equatorial orbit around Mars with a low periareon and a high apoareon.
HiRISE High Resolution Imaging Science Experiment Camera in Mars orbit sending back beautiful high resolution colour images of Mars.
HI-SEAS Hawaii Space Exploration Analog and Simulation A MARS on the slopes of the Mauna Loa volcano in Hawaii.
HLCRS Heliocentric Laser Communications Relay Satellite An LCRS in orbit around the Sun.
HLLV Heavy Lift Launch Vehicle Rocket capable of lifting between 20 and 50 tonnes to LEO.
HMM Human Mars Mission Space mission that sends humans to Mars.
HSF Human Space Flight Any activities involving humans in space.
IMLEO Initial Mass in Low Earth Orbit How much mass needs to be launched to LEO at the start of a mission. Correlates with mission cost.
IMRS International Mars Research Station Mars base to be developed by the world’s leading space agencies and made available to all nations for science and engineering research.
IP Internet Protocol Communications protocol developed for the Internet.
ISAP In Situ Air Production Producing breathable air from local resources.
ISECG International Space Exploration Coordinating Group International consortium of space agencies collaborating on global space exploration policies and strategies.
ISEP In Situ Electricity Production Producing electrical energy from local resources.
ISFP In Situ Food Production Producing food from local resources.
ISPP In Situ Propellant Production Producing rocket propellant from local resources.
ISRO Indian Space Research Organisation Space agency of India.
ISRU In Situ Resource Utilisation Making use of local resources.
ISS International Space Station Space station built by international partners.
ISWP In Situ Water Production Producing potable water from local resources.
IT Information Technology Software, hardware and networking.
ITN Interplanetary Transport Network A collection of gravitationally-determined pathways through the Solar System that require minimum energy for a spacecraft to follow.
IVA Intra-Vehicular Activity Activity inside a vehicle (e.g. spacecraft or rover) or habitat.
JAXA Japan Aerospace Exploration Agency Space agency of Japan.
JSA Job Safety Analysis A process of optimising safety for a work task (such as an EVA) by going through the steps involved, identifying possible hazards, and developing strategies for mitigating these.
KARI Korea Aerospace Research Institute Space agency of South Korea.
LCRD Laser Communications Relay Demonstration Mission to demonstrate laser communications between satellites, ground stations and spacecraft, throughout Solar System.
LCH4 Liquid Methane Versatile and inexpensive rocket fuel.
LCRS Laser Communications Relay Satellite A CRS utilising laser communications.
LED Light-Emitting Diode Diode that produces coloured light when current is flowing through it, commonly used in consumer electronics.
LEO Low Earth Orbit Orbit around Earth that is low (e.g. the ISS is in LEO at about 300 km up).
LH2 Liquid Hydrogen Hydrogen in liquid form, as used in rocket propellant.
LION Landing with Inertial and Optical Navigation GNC technology that uses landmark recognition to facilitate pinpoint landings on worlds without positioning satellites.
LLCD Lunar Laser Communication Demonstration Experiment in laser communications between a satellite in lunar orbit (Lunar Atmosphere and Dust Environment Explorer) and a ground station on Earth.
LNG Liquid Natural Gas Mined gaseous hydrocarbon fossil fuel, comprised mainly of methane.
LMO Low Mars Orbit Orbit around Mars that is low (e.g. 200 km).
LOC Loss Of Crew When one or more astronauts die on a mission.
LOM Loss Of Mission When a space mission fails.
LOX Liquid Oxygen Oxygen in liquid form, as used in rocket propellant.
LPS Local Positioning System A navigation system that covers only a small area of land (c.f. GPS), usually defined by three or more signalling beacons.
LZ Landing Zone Patch of open ground where an aerial or space vehicle can land.
MAC Mars Ascent Capsule Crew Dragon which forms the topmost section of the MAV. Also known as Kepler.
MARS Mars Analogue Research Station Base in a Mars analogue environment on Earth where simulated Mars missions are conducted.
MAV Mars Ascent Vehicle Vehicle to carry people from Mars surface to Mars orbit.
MCC Mission Control Centre Team and facility on Earth that manage a Mars mission and communicate with the crew.
MCOS Mars Communication and Observation Satellite Satellite in aerostationary orbit with the same longitude as the IMRS, for maintaining communications link with Earth and watching the base.
MCP Mechanical Counter-Pressure Type of spacesuit that uses elasticised material instead of gas to provide pressure to an astronaut’s body.
MCT Mars Colonial Transporter A new SHLLV being developed by SpaceX, capable of delivering up to 100 tonnes to the surface of Mars.
MDRS Mars Desert Research Station MARS near Hanksville in Utah, USA.
MER Mars Exploration Rover Twin rovers Spirit and Opportunity that have spent many years exploring Mars.
MGS Mars Global Surveyor NASA spacecraft in Mars orbit.
MIT Massachusetts Institute of Technology University in Massachusetts, USA, known for developing breakthrough technologies.
MLI Multi-Layer Insulation Multiple layers of thin sheets of material designed to reduce heat loss by thermal radiation.
MLLV Medium Lift Launch Vehicle Rocket capable of lifting between 2 and 20 tonnes to LEO.
MOI Mars Orbit Insertion Orbital manoeuvre that moves a spacecraft into Mars orbit.
MOLA Mars Orbiting Laser Altimeter Instrument onboard MGS that measures the topography of Mars.
MOR Mars Orbit Rendezvous When two spacecraft meet and dock in Mars orbit.
MSA Mars Society Australia Australian branch of the Mars Society.
MSC Mars Supply Capsule Cargo Dragon used to deliver supplies to the Martian surface.
MTO Mars Transfer Orbit A Hohmann transfer orbit that connects Earth’s orbit with Mars’s.
MTV Mars Transfer Vehicle Vehicle to carry humans from Earth to Mars.
NASA National Aeronautics and Space Administration Space agency of the USA.
NDS NASA Docking System Universal docking system used on the ISS, Soyuz, Dragon, B330 and other spacecraft.
NEP Nuclear Electric Propulsion Form of EP where the electricity is generated from nuclear energy.
NERVA Nuclear Engine for Rocket Vehicle Application An American program to develop a thermal nuclear propulsion system for interplanetary crewed missions.
NTR Nuclear Thermal Rocket Rocket with a propulsion system that uses nuclear fission to superheat reaction mass.
OMS Orbital Manoeuvring System System of thrusters for manoeuvring on orbit.
OPALS Optical PAyload for Lasercomm Science Experiment in laser communications between ISS and ground stations.
PLSS Personal Life Support System Part of a spacesuit that maintains a healthy environment for the occupant.
PV Photovoltaic Conversion of light into electricity.
RCS Reaction Control System System of thrusters that control a spacecraft’s orientation in space.
RH Relative Humidity Amount of water vapour in the atmosphere expressed as a degree of saturation.
RLS Reusable Launch System Rocket that can be reused multiple times.
ROI Return On Investment What you get back from an investment in a project or business.
RP-1 Rocket Propellant-1 or Refined Petroleum-1 Highly refined form of kerosene used as rocket fuel.
RTG Radioisotope Thermoelectric Generator Generator that converts heat produced by radioactive decay into electricity.
RWGS Reverse Water Gas Shift Chemical reaction that reacts CO2 with H2 to produce CO and H2O.
SEP Solar Electric Propulsion Form of EP where the electricity is generated from solar energy.
SCUBA Self-Contained Underwater Breathing Apparatus Equipment to enable breathing when diving underwater.
SHAB Mars Surface Habitat Habitat for the surface of Mars.
SHLLV Super Heavy Lift Launch Vehicle Rocket capable of lifting more than 50 tonnes to LEO.
SLS Space Launch System Space Shuttle-derived SHLLV currently in development by NASA.
SN Space Network Network of satellites and ground stations that support communications with spacecraft close to Earth.
SOEC Solid Oxide Electrolysis Cell A solid oxide fuel cell operated in regenerative mode to separate CO2 into CO and O2.
SP Special Publication Publication that is special (esp. NASA).
SSAU State Space Agency of Ukraine Space agency of Ukraine.
SSTO Single Stage To Orbit Rocket that can reach orbit with only one stage.
STEM Science, Technology, Engineering and Mathematics Educational topics related to space exploration and settlement.
TCP Transmission Control Protocol Internet protocol that ensures reliable data communication.
TDRSS Tracking and Data Relay Satellite System Network of communications satellites and ground stations used by NASA for space communications.
TEI Trans-Earth Injection Orbital manoeuvre that places a spacecraft on a trajectory towards Earth.
THAB Mars Transit Habitat Habitat for the flight from Earth to Mars and back.
TMI Trans-Mars Injection Orbital manoeuvre that places a spacecraft on a trajectory towards Mars (see MTO).
TRL Technology Readiness Level Level of maturity of a technology, and an assessment of its suitability for space applications.
TWR Thrust-to-Weight Ratio The ratio between an engine’s thrust and its weight in Earth gravity.
VASIMR Variable Specific Impulse Magnetoplasma Rocket Spacecraft propulsion technology that uses radio waves to to produce a plasma, which is then accelerate using magnetic fields.
VTOL Vertical Take-Off and Landing Refers to aircraft or spacecraft that can take-off, hover and land vertically.
WAVAR WAter Vapour Adsorption Reactor Device for extracting water from the Martian atmosphere.
WRS Water Recovery System A high-efficiency water recycling unit for a space habitat.
ZPB Zero Prebreathe When no time is required for prebreathing before EVA, usually because of the spacesuit technology.
ZPS Zero Prebreathe Spacesuit Spacesuit providing a high enough pressure that prebreathing is not required.