A SpaceX space station

SpaceX's BFS servicing the ISS

The International Space Station has cost the world -- wait for it -- $150 billion.   We've learnt much from it, but still, that's a fricking lot of money.

Each space shuttle flight to lift materials and people to the ISS cost $1.4 billion (back in the day: in today's money it's a lot more).  Musk has stated that the cost per launch of the BFR/BFS combo will be less than the cost of the Falcon 1, which is roughly $7-$10 million in today's money.  The big fall in costs is because the booster and the spaceship are reusable, which means that the cost of constructing the BFR/BFS and the cost of development will be spread over many flights.  The space shuttle was theoretically re-usable, but it turned out that so much work had to be done between launches to refurbish it, plus the fact that it had un-reusable boosters, that the cost per launch was very high.

I've talked about the cost of the BFR/BFS system here and here.  If a single launch of the BFR/BFS costs $10 million (because they're reusable) this means that a new space station could be built for much less than the ISS.  At its simplest, we could use a BFS as the core of a new space station.  Of course, it would eventually make more sense to build a customised rotating (to provide pseudo-gravity) space station.  But in the meantime, while we're waiting, we could have one as soon as a few BFSs have been built.

Let's be conservative and say that the cost of a BFS will be greater than the list price of an Airbus A380 which is $375 million ( Of course, the reason that flights on an A380 are so cheap is precisely because it is reused)  Let's assume that even though a BFS will be just 55 metres long compared with the Airbus's 73 metres that because of life support, development costs etc, the capital cost of the BFS will be $500 million.  (My previous estimate was $150 million for a slightly smaller BFS, ignoring amortised development costs.)

The BFR is about as big as the ISS, ignoring the solar panels.  We could join together two BFSs in orbit and we would have a space station twice as large as the ISS, which would cost just $1 billion compared to the ISS's $150 billion.  And could in theory hold 200 people.   It would still have to be serviced but that cost will also be an order of magnitude cheaper than it is with the ISS.  And it could be expanded, by for example attaching Bigelow Aerospace's inflatable habitats, made of  multi-layered Kevlar fabric. Or by bolt-on modular shells constructed by SpaceX themselves, which could be lifted into orbit by the cargo version of the BFS.

Once we start, our space stations will just get bigger, and become a permanent feature of our lives.

The point is that the BFR/BFS will be so cheap (relatively) that we will be able to use it to build space stations or to be space stations.  And SpaceX will have a whole new business and a new revenue source to fund the Mars expedition and settlement: space tourism.   Already, a moon fly-by is planned for 2023.

Compare this to the competition: the Space Launch System (SLS) being planned by NASA will cost an estimated $1.5 to $2.5 billion per launch, vs $10 million for the BFS--or even $100 million, to cover development costs.  Incidentally, Musk estimates the development costs of the BFR at between $2 and $10 billion with a central estimate of $5 billion.  The SLS's development costs are expected to reach at least $20 billion.   Both the BFR and BFS  will lift similar tonnage into LEO, 100 tonnes for the BFR, 130 by the SLS.

Of course, the BFR might not work.  Maybe the new technology will fail.  Maybe it's just too big.  Maybe it won't be re-usable for as many times as SpaceX hopes.  Yet, every time I look at Musk's achievements I am astounded at how much he has done.  He has single-handedly made EVs  cool and sexy.  Today the Tesla Model 3 is the 4th best-selling car in the USA.   He has slashed the cost of batteries, which mean that green energy has moved much closer: wind and solar can now be "firmed" affordably.    He started a space company from scratch, slashed costs, then introduced re-usable boosters, which will cut costs even further.  The consensus of the "experts" was that neither Tesla nor SpaceX would survive, and that reusing space craft was impossible.  Yet, here we are.

Now he plans to build a giant rocket, which will be cheaper per launch than SpaceX's own Falcon 1, a rocket which will make getting to and staying in LEO easy, let alone getting to the Moon and Mars.  He plans to set up a satellite network, Starlink, which will provide high-speed (1 gigabyte per second) internet to every place on Earth including the deserts, the seas, and the poles. He plans to introduce a Tesla semi truck and a pick-up truck.  And I believe he will do them all, and change the world.