Hacker News Reader

Comment by benl | Hacker News Reader

The table here doesn't give cost comparisons for the other launch vehicles, but in the press conference Elon Musk said that the Delta IV Heavy costs roughly 3x the Falcon Heavy, meaning that the FH is approximately 6x cheaper in $/lb to low earth orbit.

The figures quoted on the page work out to $1,070 per lb to LEO. That's less than $200k to lift the mass of a 180lb human.

View on HN

Ahem: a Russian Orlan-M spacesuit, about the best available off the shelf today, weighs 112-120Kg (or up to 250 of your quaint imperial "pounds"). Then you need to include air, water, and food. The structural mass of the seat the astronaut sits in isn't insignificant, either. A Mercury capsule -- a can sized to hold one guy in a space suit -- weighs around 1100Kg at splash-down, minus retro-rockets, parachutes, escape tower, and most of the heat shield; the corresponding weight for a Soviet Vostok spacecraft was around 2400Kg, with the cosmonaut sitting in an ejector capsule weighing around 340Kg (they ejected before touchdown because it had no soft-landing system).

All told, I reckon 1000Kg of spacecraft deadweight plus 200-250Kg of supplies per astronaut is as low as you're going to get. So once you add your notional 85Kg astronaut, you're talking about 1500Kg at US $2300/Kg, or around US $4M per person for a ride into orbit. If you're really slick you might be able to shave that by 50%. 90%? I don't think so.

Done right, this will cut the cost of space tourism by nearly an order of magnitude and will open up the possibility of the private sector actually being able to send folks to do stuff in orbit -- like fix or upgrade comsats. But it's not a magic wand and it's not going to reduce the cost per person to orbit to the rough order of a year's salary for an engineer.

Of course, I fully agree. Please don't read any implication about space tourism into a simple FYI calculation. But a 6x cost reduction is a big deal, and this figure illustrates that very well. See the follow up comment I'd already posted here:

http://news.ycombinator.com/item?id=2412096

> That's less than $200k to lift the mass of a 180lb human.

Before anyone tries to estimate how much space tourism will cost, remember that the actual weight of humans will make up a tiny fraction of the total weight of any orbiting hotel. Probably need to multiply by an order of magnitude or two.

Yes, indeed. And even disregarding the mass of the destination and of the ferrying craft, the mass of life support systems and consumables for each individual on the way up and down are likely at least double this anyway.

But, longer term, consider what happens if/when there is existing infrastructure in LEO and highly productive and profitable work for an individual to do there. The cost of actually getting to LEO will be a relatively minor relocation cost, even at these numbers.

Longer term you'd hope for another order of magnitude reduction in launch costs. If SpaceX can make a fully reusable Falcon 9 as Elon Musk has said he really wants to:

http://www.nasaspaceflight.com/2009/01/musk-ambition-spacex-...

then we can start looking at paying ten times less.

> consider what happens if/when there is ... highly productive and profitable work for an individual to do there.

What productive work is there to do in LEO? I can hardly think of any, and NASA was scrapping the bottom of the barrel looking for worthwhile science to do on the international space station.

That's less than $200k to lift the mass of a 180lb human.

No, it's $80-$125 million to lift 650 humans, packed like intermodal containers in stacks roughly 20 bodies high. Which technically amortizes to ~$150k/sardine, but I don't think this is meaningful!

Reply on news.ycombinator.com