How hard is orbital bombardment

[Anaraxes]

Orbits would be those paths which don't intersect the ground; hence the word "suborbital" for those that do.

[teviet]

Originally Posted by Anaraxes

Orbits would be those paths which don't intersect the ground; hence the word "suborbital" for those that do.

Yeah, that would make it nice and simple... Unfortunately, the way I typically see it used (and the way I typically use it) is for "ballistic motion in nonuniform gravity"; i.e. where the trajectory has to be treated as (a segment of) an ellipse or hyperbola, rather than simple parabolic motion. Earth-intersecting orbits are included, if the object starts far enough away.

TeV

[Apache]

Originally Posted by lexington

Impossible, in practice. The sheath of plasma around the rod blinds it to the outside world.

Well, yeah. To radio, anyway. I think the in-game 'explanation' (ie, handwave) was that they used meson comms or some such thing. We're talking about a game with grav tanks, gauss cannons, and Romans In Space, after all.

[Fred Brackin]

Originally Posted by Apache

Well, yeah. To radio, anyway. I think the in-game 'explanation' (ie, handwave) was that they used meson comms or some such thing. We're talking about a game with grav tanks, gauss cannons, and Romans In Space, after all.

Yeah, Romans in space always requires Superscience.

[Anaraxes]

"Impossible" seems like a rather absolute word. Consider that the Space Shuttle doesn't lose radio comms during reentry. It's designed to create a radio window at the top/rear of the orbiter, and talks to satellites through that window.

Self-guidance is trickier yet, since you'd normally think of that as requiring a receiver on the "nose" of the crowbar, where it's much harder to create a low-plasma region.

There have been real-world proposals on ways to mitigate the plasma interference, including electrostatic or magnetic systems to open windows in the plasma, and injection of liquid or solid "quenchants" to neutralize and reduce the density of free electrons that cause the problem.

One reference I saw cited 285 MHz to 285 GHz as roughly the problem region. Most of our favorite communications systems lie in this frequency range, but that doesn't preclude the use of frequencies outside that range.

Thor weapons wouldn't be a dumb steel crowbar (or telephone pole). But they don't necessarily need superscience, either.

[Fred Brackin]

Originally Posted by Anaraxes

"Impossible" seems like a rather absolute word. Consider that the Space Shuttle doesn't lose radio comms during reentry. It's designed to create a radio window at the top/rear of the orbiter, and talks to satellites through that window.

Perhaps it would be theoretically possible to maintain contact but under normnal conditions the Shuttle does lose downlink durign re-entry. Columbia did for example.

[Anaraxes]

Columbia pre-dated the TDRSS system. (Actually, they had one of the satellites in orbit before it was lost, but the system didn't really get established until 1988.)

[Langy]

Originally Posted by Anaraxes

Columbia pre-dated the TDRSS system. (Actually, they had one of the satellites in orbit before it was lost, but the system didn't really get established until 1988.)

Columbia was the shuttle that burned up in re-entry in 2003. Challenger was the one that blew up on launch in 1986.

[Anaraxes]

Quite right. I don't know how I could type "Columbia" and think "1986".

A few references that might help serve as the basis for justifying a Thor system in a game:

An extremely lightweight article, as SciAm usually contains these days. Mostly useful as an overview which can be perhaps summed up in just one paragraph.

The 2006 conference revealed no lack of possible solutions. Ideas include designing the configuration of the craft so as to minimize the resulting plasmasonic sheath; building an “air spike” at the front of the leading edge that would protrude outside the plasma; finding frequency bands that might not be affected by the ionization; simply bullying through it with an enormously powerful transmitter; and using electrophilic injection, which means dispersing a deionizing substance, most likely water, into the plasma sheath to disrupt it. More exotic ideas involve employing high-powered lasers or ejecting a series of tiny relay devices, akin to messages in a bottle.

http://www.scientificamerican.com/ar...ing-the-plasma

A more in-depth survey article, which also presents the author's own idea for solid particle injection to disrupt the plasma sheath:
http://gltrs.grc.nasa.gov/reports/20...010-216220.pdf

An abstract only at this link suggesting the use of optical (laser) wavelengths to avoid the problems with radio:
http://oai.dtic.mil/oai/oai?verb=get...fier=AD0856535

[Kale]

Originally Posted by Anaraxes

A few references that might help serve as the basis for justifying a Thor system in a game:
An extremely lightweight article, as SciAm usually contains these days. Mostly useful as an overview which can be perhaps summed up in just one paragraph.
http://www.scientificamerican.com/ar...ing-the-plasma

A Russian group has found a way to use the plasma around a re-entering object as an antenna, allowing communication with hypersonic objects. This would allow you to guide a hypersonic projectile onto target.

http://www.technologyreview.com/blog/arxiv/26222/

http://arxiv.org/abs/0704.3103

Bring on the GUIDED rods from God.