John, maybe I'm too low on the totem pole to know the secret schemes of the
powers that be, but I suspect non-chemical launch techniques aren't getting
serious attention because they're either
1. Technically dubious (Ascender style ion balloons, no one knows how to
build a power positive fusion reactor at the moment, Project Orion for
launch would render several states uninhabitable, space elevators require
as-of-yet non-manufacturable materials)
2. Capital intensive (tethers, cannons, lunar based rail launch, etc)
or
3. Some combination of both (especially space elevators)
Launch is a pretty well served industry at the moment, and nobody has made
a compelling case yet for the elasticity of the launch market (if anything,
SpaceX has raised some doubts here). This makes dropping a few dozen
billion on R&D followed by a few hundred billion on towing an asteroid to
anchor a space elevator and manufacturing some hundred thousand kilometers
of carbon nanotube reinforced cable an unlucrative idea to both governments
and private entities.
As an aside, would torch-ship style fusion powered engines have the same
radiation concerns that Project Orion or NERVA would? Fusion produces
mostly non-radioactive products, would neutron irradiation still cause
problems?
On Wed, Dec 25, 2019 at 12:49 PM John Dom <johndom@xxxxxxxxx> wrote:
Skylon, Space X, NASA, India, China, Japan: what am I missing is why
non-chemical propulsion gets no priority (in order to make it real). Like
fission or fusion propulsion or space elevators.
As for an energy source on the surface, I'd but my bets on lava streams
below heat exchangers like Iceland does. Not windmills, nor powersats.
John D.
-----Original Message-----
From: arocket-bounce@xxxxxxxxxxxxx [mailto:arocket-bounce@xxxxxxxxxxxxx]
On Behalf Of Keith Henson
Sent: woensdag 25 december 2019 17:32
To: arocket@xxxxxxxxxxxxx
Subject: [AR] Re: Flying to Orbit with Hydrogen?
On Tue, Dec 24, 2019 at 10:09 PM Rand Simberg <simberg@xxxxxxxxxxxxxxx>
wrote:
Superheavy/Starship should be able to get to that cost, or lower, and
requires no new propulsion technology.
True, though it is not obvious that Musk will let SpaceX rockets be
used for power satellites.
The two problems are the launch rate for a serious power satellite
project is high, and the other problem is how much damage hydrocarbon
rockets do to the ozone?
Keith