The opportunity hiding in plain sight

 

The opportunity hiding in plain sight

A deeper dive into Handmer's link, given yesterday. Looking at the chart, it shows the advantages of setting up fuel depots to refuel the Starship.

First, let's decode that chart. I highlighted the cargo mass in yellow, the supporting launches needed in green, and the mass/launch ratio in red. Thus, the triads of numbers can be easier to read and decode. For example, from Low Earth Orbit (LEO), 25 tons could be delivered to the lunar surface. It would take 13 launches of the Starship to do this, and each launch would average out at 1.9 tons per launch.

Note that with each tweek of the parameters, more cargo can arrive at the Moon per launch. It would thus behoove anybody who would want to develop the Moon to consider these possibilities. At the cost of about a hundred launches, an enormous amount of cargo could be delivered. It gets better as you go along, because once the capability is built up, the flow per launch could be increased. At any rate, a very capable base could be established in such a manner.

But NASA seems more interested in the simplest things. A few tons to the lunar surface won't accomplish nearly as much as millions of tons. Shoot, you could have a small city on the lunar surface with that much stuff.

It's hard to say what Musk would think of this, since he is more interested in Mars. Imagine parking a thousand Starships on the Moon, and then launching to Mars with most of your reaction mass coming from the lunar regolith. This would really leverage things a bit. Eighty percent of the reaction mass is oxygen, which can be obtained from mining the lunar regolith. That's eighty percent that doesn't have to come from the Earth, and that is a bunch of launches that won't be needed from the Earth.

It may not save costs, as launches from Earth could get pretty cheap. But perhaps it could speed things along a bit. It takes fewer launches to refuel from the lunar surface than from the Earth. A Starship sitting in lunar orbit could be refilled in two launches, rather than several, and it would be have less delta V to get to Mars from lunar orbit. Or more delta V to make the trip shorter in time.

If the trip could be made quickly enough, a round trip could be possible in just one launch window. That would help a lot. For example, a trip to Mars could take 7 months. If it were to be shortened, then a round trip in 7 months would get your Starships back for the next trip in two years. It takes two years for each launch window to Mars. A round trip in one launch window gets all your Starships back so that you can be ready for the next trip when it opens in two years. Otherwise, your Starship is marooned on Mars waiting to get back for the next load of passengers. It would be a slow process.

There are other possibilities on the Moon. Maybe you could BUILD Starships there. Imagine not having to launch from Earth AT ALL. Or launching from Earth a lot less.

Anyway, that's the opportunity that knocks. Who knows if anyone will answer.

Handmer's blog: "Starship is a very big deal"