Thread: Re: Cheap spacelift

2 posts.

One detail about a reuseable platform, is that once bought you only have to amortize the cost of the purchase, plus per-launch costs (fuel, access, maintenance before and after, etc).  If this cost can be brought below the price of expendable rockets, then the reuseable platform will be preferred.
As an example, for the Space Shuttle part of the cost was making sure all the tiles were in good shape (and properly attached) before each launch.  Instead of using tiles, what if the bottom of the shuttle was made of wood?  The wood burns on re-entry, but the ablating means the shuttle survives.  After the shuttle lands, the wooden outside is removed (and used for a BBQ party), and a new wood surface is attached.  The nice part is you can have several of them in storage, instead of each time needing to take the shuttle out of service to get the tiles hand inspected for problems.

It is another fiction story, but check out the novel "The Rocket Company".
In it a fictional group of billionaires decide to make cheap space access.  They get a design team to develop it and go with:1) Cheap fuel, and plenty of it.  Instead of using liquid hydrogen or other current rocket fuels, they go with methane, with is less than 1/10 the cost of similar fuels.2) Reliable engine, but larger.  They base the engine off the RL-10, and make it larger.  (The RL-10 was one of the most reliable engines made)3) Reliable engine, but simple.  The RL-10 version they use has no turbopumps, and instead just uses a geared system.4) Big dumb booster.  Fuel is cheaper, so burning more of it to put the same tonnage into orbit will still cost less.  This is the first stage.5) Light upper stage.  This is where you spend money, as a kilo saved here is another kilo into orbit.
6) Vertical takeoff.  This allows them to be launched from anywhere in the world, and the first stage can land on the same square mile as it was launched from.  So Switzerland can have a space program.
7) Vertical landing.  No more worrying about mass shifts from vertical takeoff to horizontal landing, and with the fuel expended the bottom of the crafts are much heavier, making them much more stable.8) Both stages manned.  So if something goes wrong with the first stage, there is a pilot to make a decision about where to steer it, instead of a range safety officer having to decide if they should blow it up.

Also, they billionaires recognized that there was not enough market for them to make money selling cheap space access.  So instead they sell the launch platform to other countries, and let the other countries decide what to use it for.
I like the idea of air launch. Aerodynamics gains you quite a bit in
allowing you to convert lower thrust to altitude compared to brute-forcing
straight up, and air is free. And it gives you a lot of flexibility in
launch geometry. The Stratolaunch Roc is scheduled to fly next year; I'd
like to see them make a success of that.

McD-D and Pete Conrad built that Delta Clipper SSTO concept while GDW was
around. It was successful in what it set out to do (it was never going to
make it to orbit) but ran afoul of NIH politics at NASA. However, it lives
on at Blue Origin.

Elon Musk is also doing some promising work on soft pinpoint landing of
expended boosters. The first one failed to land on the barge at the last
moment, but they're also learning a lot about aerodynamics of tail-first
landings at very high speeds.

> One detail about a reuseable platform, is that once bought you only have
> to amortize the cost of the purchase, plus per-launch costs (fuel, access,
> maintenance before and after, etc).  If this cost can be brought below
> the price of expendable rockets, then the reuseable platform will be
> preferred.
> As an example, for the Space Shuttle part of the cost was making sure all
> the tiles were in good shape (and properly attached) before each launch. 
> Instead of using tiles, what if the bottom of the shuttle was made of
> wood?  The wood burns on re-entry, but the ablating means the shuttle
> survives.  After the shuttle lands, the wooden outside is removed (and
> used for a BBQ party), and a new wood surface is attached.  The nice part
> is you can have several of them in storage, instead of each time needing
> to take the shuttle out of service to get the tiles hand inspected for
> problems.
>
> It is another fiction story, but check out the novel "The Rocket Company".
> In it a fictional group of billionaires decide to make cheap space
> access.  They get a design team to develop it and go with:1) Cheap fuel,
> and plenty of it.  Instead of using liquid hydrogen or other current
> rocket fuels, they go with methane, with is less than 1/10 the cost of
> similar fuels.2) Reliable engine, but larger.  They base the engine off
> the RL-10, and make it larger.  (The RL-10 was one of the most reliable
> engines made)3) Reliable engine, but simple.  The RL-10 version they use
> has no turbopumps, and instead just uses a geared system.4) Big dumb
> booster.  Fuel is cheaper, so burning more of it to put the same tonnage
> into orbit will still cost less.  This is the first stage.5) Light upper
> stage.  This is where you spend money, as a kilo saved here is another
> kilo into orbit.
> 6) Vertical takeoff.  This allows them to be launched from anywhere in
> the world, and the first stage can land on the same square mile as it was
> launched from.  So Switzerland can have a space program.
> 7) Vertical landing.  No more worrying about mass shifts from vertical
> takeoff to horizontal landing, and with the fuel expended the bottom of
> the crafts are much heavier, making them much more stable.8) Both stages
> manned.  So if something goes wrong with the first stage, there is a
> pilot to make a decision about where to steer it, instead of a range
> safety officer having to decide if they should blow it up.
>
> Also, they billionaires recognized that there was not enough market for
> them to make money selling cheap space access.  So instead they sell the
> launch platform to other countries, and let the other countries decide
> what to use it for.
>