12 Reasons SpaceX Won’t Fly a Manned Mission to Mars by 2030
- Cargo Capacity — Scaling is Hard.
- Proper Maintenance — Accessibility is Important
MTBF Expectations are too high.
Jet Fuel is Corrosive and Methalox engines are a tough design proposition.
- Cosmic Radiation — Impedes human interoperability.
- Solar Panels —Mars Dust Storms impede sunlight.
- Living Module — 7 month duration for a living module.
- Microbial Realities — We rely on microbes to live.
- Parachute Design — Size vs. Thrust vs. Jettisoning Fuel
- Electronic Protection — Shielding is Resource/Weight Intensive.
- Eye Sight — Your ability to see diminishes in space and we don’t quite know how this works fully. (This one is huge)
- Muscle Loss- you lose muscle mass as you stay longer in space.
1. Cargo Capacity Increases
The trade offs between mass, volume, and cargo capacity as you scale any space-venturing vehicle are very real. The further you go in space, the more space you need to store things for long duration. The Saturn V Rocket had a lot of crazy characteristics.
As you scale, somethings become economically de-incentivized because of the nature of the Square Cube Law and proper preventative maintenance. The Square Cube Law as it applies to flight says that the area of a wing grows (mm) and its volume and weight grow cubically (mm*m). This means every new kg you add to a structure makes its build increasingly complex because you have to increase the acceleration.
2. Proper Maintenance
In most mechanical systems a few things happen that make beyond- LEO (low earth orbit) space flight very difficult:
- Sealants and Mechanical Seals eventually wear out. One of my favorite papers on seals in vacuum related environments. This is admittedly old, but illustrates the point of maintenance on seals. http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19670008177.pdf.
Most space going vehicles simply aren’t designed to have routine maintenance and aren’t accessible by astronauts during the flight.
Usually, parts have to be cleaned, replaced, and maintained. In manufacturing, we call this the 7 P’s. Space flights routinely center around resupplying the ISS(International Space Station).
Designing a ship that can go to Mars and drop a crew there with high performance and cargo while maintaining accessibility will be tough..
Prior proper planning prevents piss poor performance.
In engineering, we often think heavily about the Mean Time Between Failures(MTBF) when designing parts. The MTBF for any part on any space-going vehicle has to go well beyond the duration of the normal distribution of flight tie. It will take at least 180–300 days to get to Mars.
4. Jet Fuel
Jet Fuel is also incredibly corrosive, which means you’d want to probably dump/get rid of all fuel before you land.
Now, let’s say you use Methalox engines which is something Musk has proposed. There’s still a huge number of tradeoffs with utilizing Methalox engine fuel.
- The fuel tank must handle cryogenic conditions requiring more insulation to prevent boiling off of Methalox engine fuel.
- Cryogenic fuel temperature creates a greater chance of valves and regulators sticking.
Maybe Kerolox engines will do. Certainly, more research must be done. I have no clue how cryogenic insulation degrades over time nor its energy requirements.
5. Cosmic Radiation
As you pass the Van Allen Belts, you get more cosmic radiation…..ionizing radiation.
The Mars Science Laboratory came back with ~0.5 Sieverts of radiation after 1 round trip. (There’s many ways to measure radiation.) NASA’s career limit for Astronauts on radiation is something a bit higher, like 1 Sievert. (Keep in mind I used the word ‘career.’) Cosmic radiation presents a mission critical problem and shielding against it requires considerable weight gains to the vehicle.
6. Solar Panels
It takes months for dust from Mars storms to settle. The dust storms obfuscate/block the path of the sun’s rays to the panels. We have the technology to clear off the panels, but what about obfuscation/line of sight issues? It has definitely happened before!!
In mid-2007 a planet-wide dust storm posed a serious threat to the solar-powered Spirit and Opportunity Mars Exploration Rovers by reducing the amount of energy provided by the solar panels and necessitating the shut-down of most science experiments while waiting for the storms to clear. Following the dust storms, the rovers had significantly reduced power due to settling of dust on the arrays. Source:
7. Living Module
What type of module would the crew live in and how would they eat for 7–10 months on the way to Mars from Earth? You have to carry enough food, water, and oxygen for every person. In a single day, you need 6 to 10 pounds of water per a day per a person and I’m not even sure how much Oxygen. Water Recycling is not simple.
8. Microbial Realities
What’s the longest we’ve been unexposed to the environment’s microbes and bacteria? We don’t know how this will affect us in space. The longest any human has been in space was about 438 days, Valeri Polyakov.
Visual Impairment Proof/Data
Parachutes work differently across varying atmospheres. One of the most stressful landings was the Curiosity Rover landing on Mars. With the parachute deployed in the Mars Atmosphere, its velocity was 200MPH. The parachute was massive and the rover itself weighed 2000 pounds/900 kilograms.
With a crew of 8 people, you approach that weight pretty quickly. Now let’s suppose you only wanted to counter the landing with thrusters, then the proposition quickly becomes more expensive. The tradeoffs between options are extreme.
Electronics don’t behave the same way in deep space. Outside of the Van Allen Belts, space becomes hostile to any sort of electronics you try to take there. Mars surface exploration missions require functionality from -120°C to +20°C for many cycles. The many ways in which electronics can fail in space just for the ISS.
How does space radiation affect electronics?
Radiation effects in the interior of satellites are often grouped into three categories: total ionizing dose, displacement damage and single event effects. Total ionizing dose effects in electronics are the result of damage that usually builds up over a long period of time in an insulating region of an electronic device. This changes the device properties, which results in performance degradation and eventually can cause the device to fail completely. Displacement damage is also a cumulative effect but this occurs in the electronic device’s semiconductor material. These effects also cause the device to deteriorate at first and possibly fail if it is exposed to enough radiation. Single event effects are caused by the passage of a single particle through a sensitive region in an electronic device. There are many types of single event effects, which can be either non-destructive or destructive to the device. The severity of the effect can be so small that it can go unnoticed. At the other extreme it could cause a system in a satellite to shut down.
Space radiation can create other kinds of damage in satellites as well. For example, it can cause electric charge to build up in an insulating material to the point where a discharge can occur that damages something. This discharge is the same type of thing that would happen if you walked across a carpet, touched an object and were shocked by a static discharge. Source: http://lws-set.gsfc.nasa.gov/space_radiation.html#how
Shielding is hard, complex, and treacherous in Galactic Cosmic Ray(GCR) environments.
11. Eye Sight
You run into intercranial eye issues with vision and your skull as you stay in space. We don’t know the full effects for a duration required to get to Mars, land, and stay for all the work.
12. Muscle Loss
As you stay in space you lose muscle mass. As you stay in space you lose muscle mass. Even with VASIMR, how do you get to Mars on time, rehabilitate, and have all the supplies to be viable? Not sure how this works.