Common questions about colonizing Mars

Mars can be as warm as the hottest beaches on Earth and colder than the coldest arctic winter. In the same location on Mars it can be as warm as 95 degrees Fahrenheit, and is typically more than a hundred and fifty degrees colder at night. The Mars Spirit rover tracked its daily hottest and coldest temperature on the chart below and you can see how much it varies throughout the year. This means people will probably want to spend their night times and winters indoors, either in a well insulated house or partially or fully underground.

Just like on Earth, the climate does vary depending on where on the planet you are, but the extreme difference in day time and night time temperature are pretty common due to the low atmospheric pressure compared to Earth. Mars has a wide range of atmospheric pressure due to its extreme variation in altitude. Compared to sea level on Earth, the highest mountain has 3000x less air density, and the lowest point is much more dense but still 100x less dense. Even the densest air on the surface of Mars is still 30x less dense than at the top of Mount Everest.

So, when you go for a walk on Mars, you will want to wear a heated and pressurized space suit. But this won't be your grandparent's space suite. It will likely be a slimmer, more flexible and comfortable than the spacesuits of the astronauts who landed on the Moon.

The fastest way we know how to communicate is using light in its many forms (Radio Frequency as in a radio, or optical as in a laser). The time it takes light to travel from Earth to Mars, known as the light-time delay, varies considerably due to the changing positions of the two planets in their orbits around the Sun. Here's a breakdown of the range:

1. Minimum delay:

- When Mars is at its closest approach to Earth (known as opposition), the light-time delay is about 3 minutes and 2 seconds each way.

- This occurs when Mars is about 54.6 million kilometers from Earth.

2. Maximum delay:

- When Mars is at its furthest point from Earth (known as conjunction), the light-time delay can be up to about 22 minutes and 16 seconds each way.

- This occurs when Mars is about 401 million kilometers from Earth.

3. Average delay:

- On average, the light-time delay is around 12 minutes and 30 seconds each way.

4. Round-trip communication:

- For a message sent from Earth to Mars and back, you would need to double these times.

- At minimum: about 6 minutes and 4 seconds

- At maximum: about 44 minutes and 32 seconds

- On average: about 25 minutes

These delays pose significant challenges for real-time communication and remote operation of equipment on Mars. Any Mars mission would need to account for these delays in its communication protocols and operational procedures. It means it is impossible to have a live phone call or video call with loved ones back home. Pre-recorded messages can be sent back and forth but it will not be the same and this is an important contributor to the isolation colonists may feel on Mars.

Mars is seen as a good candidate for terraforming (turning the planet into a planet which resembles Earth in terms of temperature, pressure and climate) because of its many similarities to Earth.

• Similar day length: Mars has a day (sol) of about 24 hours and 37 minutes, very close to Earth's 24-hour day.

• Tilted axis: Mars has a similar axial tilt to Earth (25.2° vs Earth's 23.5°), resulting in seasonal changes.

• Presence of water: Mars has water ice at its poles and likely has subsurface water ice in various locations.

• Potential for atmospheric thickening: Mars' CO2 ice caps and regolith could potentially be converted to atmosphere.

• Gravity: While only 38% of Earth's, Mars has enough gravity to potentially hold an atmosphere long-term.

• Available resources: Mars has minerals and elements necessary for life.

• Temperature range: Though cold, Mars' temperature extremes are less severe than other planets.

• No need to reduce atmospheric pressure: Unlike Venus, Mars wouldn't require reducing atmospheric pressure.

• Potential for in-situ resource utilization: Mars' resources could be used in the terraforming process.

• Proximity to Earth: Mars is relatively close, making it more feasible for human missions and resource transport.

However, we don't have to terraform Mars to live there. We only have to terraform Mars if we want to live there without space suits.

Astronauts on Mars will eat a combination of pre-packaged meals sent from Earth and, potentially, some locally grown produce:

1. Pre-packaged meals:

- Freeze-dried and dehydrated foods that can be rehydrated with water

- Thermostabilized (heat-processed) meals in pouches

- Nutrient-dense bars and pastes with a long shelf life

2. Locally grown foods (in controlled environments):

- Leafy greens like lettuce, spinach, and kale

- Vegetables such as tomatoes, peppers, and radishes

- Possibly some fruits like strawberries

The sun periodically belches out a mass of high energy particles. If it belches it towards Earth we can get large solar storms and Aurora Borealis and Aurora Australis at much lower latitudes than is typical. If astronauts are unlucky enough to have a coronal mass ejection shot their way as they are in transit to Mars, they could experience a potentially life threatening radiation dose. Therefore it is important to protect astronauts from radiation during the journey to Mars.

On Earth our atmosphere and Earth's magnetic fields (what makes your compass needle move) protect us from much of this harmful radiation. On Mars however, there is far less atmosphere and almost no magnetic field to speak of. Therefore it is also important that pioneers on Mars are protected.

There are several well known and dependable ways to protect people from this radiation:

1. Shielding: Mass stops the radiation, so astronauts can be kept safe with thicker walls than are otherwise necessary. On Mars, habitats can be built with thick walls made of Martian dirt to provide protection.

2. Storm shelters: Astronauts can have a hiding room surrounded by water tanks where astronauts can take shelter during a particularly strong storm as they travel to Mars.

3. Health monitoring: Regular health monitoring can help detect radiation-related health issues early so that appropriate measures can be taken.

4. Mission planning: The sun has a twelve year cycle with periods of more radiation output and less (when the sun has more sunspots it is in a more active mode which means more coronal mass ejection s and therefore more radiation). Planning missions during periods of low solar activity can reduce radiation exposure risks.

5. Medication: Developing medications that can protect astronauts from the harmful effects of radiation exposure is also an area of research.

By implementing a combination of these strategies, astronauts are not expected to get any more radiation dosage than an airliner pilot (who get 2-3x more radiation dose in their lifetime on average than most people because they are just that much closer to space) (or more conservatively no more than a NASA International Space Station Astronaut).

Yes! In terms of the orbital mechanics of Mars and Earth, there will be an option to return home on a 6 month trip 1.5 years after arriving at Mars. This return trip can be made in the same Starship rocket that was used to get to Mars. It can be refueled on Mars by filling it up with propellant created from the air on Mars combined with water using two well proven chemistry processes: electrolysis and the Sabatier process.

The water can be mined from frozen sheets of ice found covering most of the northern hemisphere above 38 degrees north latitude (under a few meters of dust). Or the water can be brought from Earth (which will likely be the case for the first missions).

The air on Mars is 95% carbon dioxide. This carbon dioxide can be pulled out of the atmosphere by cooling and heating along with the day night cycle.Electrolysis of the water (using electricity to separate water into hydrogen and oxygen) can be used to make hydrogen. The hydrogen is then reacted with the carbon dioxide using the Sabatier process to make the methane rocket fuel.

There are a number of reasons that Martian spacesuits will be both more stylish and more comfortable than the space suits we have seen on spacewalks and on the Moon:

1. Pressure requirements:

   - Deep space: Must withstand full vacuum

   - Mars: Needs to compensate for low pressure, but not a complete vacuum

2. Radiation protection:

   - Deep space: Requires more robust shielding against unfiltered cosmic and solar radiation

   - Mars: Still needs radiation protection, but the planet's atmosphere, though thin, provides some shielding

3. Mobility:

   - Deep space: Often prioritizes protection over mobility

   - Mars: Can potentially offer more flexibility for surface operations with nearby access to a habitat

4. Thermal regulation:

   - Deep space: Must handle extreme temperature swings

   - Mars: Needs to handle cold temperatures, but within a narrower range

5. Weight:

   - Deep space: Weight is less of a concern in microgravity

   - Mars: Lighter suits would be preferable due to Mars' gravity (about 38% of Earth's)

Given these factors, a Mars suit could potentially be designed to be less bulky than a deep space suit. It might use:

1. Mechanical counter-pressure: Instead of gas pressurization, the suit could use tight-fitting, elastic materials to provide pressure directly to the body.

2. Hybrid designs: Combining hard and soft elements for optimal protection and mobility.

3. Advanced materials: Lighter, stronger materials for radiation shielding and environmental protection.

4. Improved joint systems: To allow for better range of motion while maintaining pressure.

5. Mars-specific life support systems: Optimized for the Martian environment rather than the more extreme conditions of deep space.

While a Mars suit would still be complex and protective, these considerations could allow for a somewhat sleeker and more comfortable design compared to current deep space suits.

A Mars mission is estimated to cost anywhere from $30 million to $100 million depending on the equipment that will be brought along. The latest estimates for a Starship-like spacecraft are $16 million for a one-way trip to Mars with no equipment onboard. Adding in equipment (power plant, life support, oxygen generator, mining equipment, hydroponics equipment for growing food, medicine, food and water, etc.) brings the cost up to the lower end estimate of $30 million. With an estimated crew of 100 people, that is a total cost per person of $300,000.

Compact nuclear power generators are the most promising large scale power sources for Mars. There is a large push to build these 'micro reactors' for use on Earth and similar designs can be applied to use on Mars.

Small outposts may also rely on solar panels. Mars is farther away from the Sun than Earth so the sun feels only 40% as strong. Therefore more area will be needed for the same amount of power than would be needed on Earth. Dust storms can also be a problem so someone may have to go brush off the panels every once and a while.