Welcome to the first issue of Starship

An introduction to each of the 4 main categories I'll be covering

SpaceX and Starship

As you may have heard, pressure testing of Starship SN7 on June 23 was successful. That version of the ship was built using a new alloy of stainless steel with more strength at cryogenic temperatures. Reports are that it reached 7.6 bar before developing a leak (1 bar is a little less than 1 atmosphere of pressure, or about 14.5 psi).

SN7 wasn’t a full build; it was more like a small tank. Here’s a video of the test. You can see the ice on the outside, followed by the eventual structure failure:

SN5 and SN6 are still in progress. It's possible that one or both will be used for suborbital "hopper" type tests. Before that, though, I expect to see another static fire test, along the lines of what we saw previously with SN4 on May 29. The plans for SN5 appear to include attaching 3 Raptor engines. No details have been announced yet about SN6.

The most recent Falcon 9 launch on June 30 was a success, delivering a GPS satellite into orbit. This launch was the first time a booster was recovered after launching a military satellite. The original contract was for $96.5M, but was discounted several million dollars when US Space Force agreed to allow the booster to be recovered.

There was also an F9 launch on June 13, just a few weeks before. That launch delivered another 58 Starlink satellites into orbit, along with 3 ride-sharing satellites, the first in SpaceX's SmallSat Rideshare program. This mission marked the first time SpaceX didn't perform a static fire before launch. This launch brings the total number of Starlink satellites launched by SpaceX up to 540.

Getting Ready

One of the central goals of SpaceX is to make human life interplanetary. To accomplish that , they've announced a plan to reduce the cost of space travel by a factor of 30,000. How is such a thing even possible?

Full re-usability provides the first 300x. This is launching, landing, refueling and launching again with little or no refurbishment. Falcon 9 only re-uses the first stage, and requires refurbishment each time. The second stage is still discarded after each use. Starship (and Super Heavy) fixes those issues.

Automated docking and refueling on orbit is the next 10x. Going to Mars without refueling would require a much larger rocket. Refueling also feeds into re-use, since it will take several flights to fully re-fuel a single Starship.

Using the right propellant provides 3x. This was the driver for using methane and oxygen instead of hydrogen and oxygen, for example. Liquid methane is much easier to handle and store than liquid hydrogen.

Finally, producing that propellant on Mars provides the final 3x. Methane can be produced on Mars using the Sabatier process, which combines carbon dioxide extracted from the atmosphere and hydrogen from the electrolysis of water. Electrolysis also provides oxygen, both for propellant and for life support.

If SpaceX can achieve their initial factor of 30,000 goal, that would allow them to provide travel to Mars for roughly US$500,000 per person. They have announced a long-term goal of around $200,000, which is roughly the cost of a median home in the US. My estimate is that early flights will be priced more in the $2M per person range. That would include a return trip, spacesuit, the ability to take some cargo with you, as well as food, water, air and housing while you’re away.

Another topic I'll be discussing in this section is things you can personally be doing to get ready to travel to Mars. What should you be learning and doing? What skills will be needed on the way and once you arrive?

Getting There

Mars and Earth aren't always very close to one another. Orbital alignments that make space travel between them possible in a reasonable amount of time only happen every 25 months or so. We are actually at one of those points right now, in July 2020. The next window will be in 2022, then 2024, and so on.

It will take between 3 and 7 months to fly from Earth to Mars. Although an immediate flight back may be possible in some cases, for most people and missions, you will need to stay there for between 13 and 31 months before the next window opens up. Flights back generally take a little longer, at between 4 and 7 months.

The exact travel time depends heavily on the departure date. Departure dates, in turn, depend on the mass of the cargo being carried. The minimum time-away would be about 3 years, and could be 4 or more years depending on the specific launch window and other mission requirements.

Here's a rough sketch of what the inside of Starship might look like, as provided by SpaceX some time ago. I'll cover possible ship layouts in much more detail in later issues.

Living There

Mars has 38% of Earth's gravity. That means you will be able to lift things about 2.5 times as heavy as on Earth. You will also be able to jump about twice as high, which could make for some fun-to-watch and participate in sports. Basketball on Mars will be pretty wild.

Outside, Mars has about 1% of the atmospheric pressure as Earth. That's a near-vacuum, so whenever you're outside, you will need to be in a pressure suit of some kind. Also, sound doesn't travel through a vacuum, so the only sounds you will hear while outside are those from inside your suit and from your radio. Radio communications will be extremely important for safety and other reasons.

Mars has an average low temperature of -88C, and an average high of +4C, as observed by the Curiosity Rover in Gale Crater. This means your spacesuit will need to provide thermal protection. Objects carried inside will be capable of damaging skin by freezing until they warm up. Equipment that needs to operate outside on Mars will need to be able to withstand both the cold and the vacuum.

The Martian day is 24.5 hours long. Daylight sky is red, but sunsets are blue. Mars is tilted on its axis like Earth is, so it has seasons. In the northern hemisphere, a typical spring is 7 months, summer 6 mo, fall 6 mo, and winter 4 mo. Mars has a more elliptical orbit than Earth, so it's distance from the Sun varies more, too. The Martian year is 687 days long.

I will cover each of these areas in much more detail in future issues. Stay tuned, and please consider subscribing.