Speculations on Deep-space-ship designs

[Widdekind]

Speculations on Deep-Space-ship designs

 

Deep Space is strewn with dust & gas. Space-craft collision, with the same, could be catastrophic, especially at trans-luminal speeds (~c). Even with a forward-mounted deflector shield, damage & drag could accumulate, especially on cosmos-crossing inter-galactic hyper-missions, whereon millions of years of fuel, for constant counter-acceleration, seems insurmountable:

 

Fig. 1 --

deep-space-ship

Von Braun

en route to star-system Darwin

(DC

Alien Planet

DVD)

Perhaps, then, deep-space-ships would be better built in an annular shape, like a 'frisbee football':

 

Spinning such a ship could create artificial gravity. And, by carrying a current, azimuthally running around the ship's central axis, such a ship could create a magnetic deflector field, funneling (charged) particles safely through the central channel:

 

Said current could conceivably be constructed using super-conductors, exploiting the cold cosmic conditions, to perpetrate a perpetual field current, 'for free', after establishment, likely on launch. And, in order to ionize onrushing deep-space gas, forward-focused 'head lights', tuned to the (relativistically red-shifted) ionization frequencies of Hydrogen & Helium. Note that this forward-focused radiation requires a rear-ward directed, compensating thrust, but the latter is allot less than dealing with direct dust & debris impacts, calculated below.

 

 

Comparison of "forward-focused 'head-lights'" strategy vs. absorbing direct debris impacts upon deflector shield

 

In the rest-frame of the deep-space-ship, traveling at trans-luminal velocity [math]v \approx c[/math], an positive mass-flux [math]\dot{m}[/math] of onrushing deep-space debris would supposedly strike the ship. That mass-flux would impart a backwards momentum-flux (i.e., Force) of [math]F = dp/dt = \gamma(v) \dot{m} v[/math]. To compensate, with futuristic laser-thrusters (E = c p), would require a negative energy-flux (energy expenditure) of [math]\dot{E} = c \dot{p} = \gamma(v) \dot{m} v c \approx \gamma \dot{m} c^2[/math], where [math]\gamma \gg 1[/math].

 

By comparison, the negative energy-flux, for the futuristic forward-focused 'head-lights', tuned to the ionization frequency of hydrogen, would be [math]\dot{E} = \dot{n} \times E'_{ion} = \dot{m} \, E'_{ion} / m_H[/math], where the hydrogen ionization energy is relativistically red-shifted, for the onrushing atoms.

 

Comparing the costs requires reckoning the former against the latter, [math]\gamma c^2[/math] vs. [math]E'_{ion} / m_H[/math]. So, since [math]\gamma m_H c^2 \gg E'_{ion}[/math], especially at such speeds, the energetic costs, of countering collisions (deflector shield) radically exceed that of ionizing incident atoms ('head-lights'). Detection of dust or debris, much more massive, and with dramatically different ionization characteristics, could potentially pose problems. However, on inter-galactic space hyper-missions, the ultra-pristine, quasi-primordial chemical composition, of the comparatively un-enriched IGM, would be a boon, in that regards.

 

What about the 'deflection force', for slightly shifting the incident gases trajectories, through the center of the ship? Surely such is allot less, than fully and face-on absorbing the same, in a head-on collision??

Edited January 16, 2011 by Widdekind

[granpa]

if the engineers that designed this universe intended that

we should be able to travel through space near light speed then

they will have made neutronium armour possible.

(and other things as well)

 

otherwise we are probably just screwed