How to Make Use of an Asteroid on Earth

Ever since Luis Alvarez and his son Walter discovered that the KT
boundary layer which exists world-wide, was enriched with iridium,
which suggests that the KT extinction event was caused by a massive
bolide strike on Earth, people have wondered generally about
humanity's ability to alter the path asteroids before they become
missiles that strike the Earth.

The potential of using nuclear explosions to alter the course of
celestial bodies was studied secretly in the 1950s and openly studied
by MIT graduate researchers in 1963. The process is rather simple.

(1) position a nuclear explosive some stand-off distance from the
object to be moved
(2) detonate the explosive causing a massive thermal shock
(3) a portion of the object evaporates forming a plume of ejected
material
(4) the ejecta acts as a rocket moving the object slightly in the
opposite direction.

This process may be used to deflect objects that are on collision
course with Earth.
This process may also be used to deflect objects INTO a collision
course with Earth.

The benefit of the first is far outweighed by the harm of the latter.
That is, unless and until humanity gets its propensity to fight and
generally wreak havoc under control it is far more likely that this
technology will one day bring asteroids to harm Earth than save it.

The harm that may be done by an asteroid impact far outweighs the harm
that may be done by a smaller event say global thermonuclear war.

A series of 1,000 detonations of rather small atom bombs carried by a
spaceship (which itself may be propelled by tiny atom bombs) can wreak
havoc on Earth if used in anger - as detailed by this video

http://www.youtube.com/watch?v=-zvCUmeoHpw

Using gravity to cause a significant force multiplier.

A colony on Mars, or in the asteroid belt, or even the Moon, who felt
threatened by the Earth, would have the means to carry out an attack
with asteroids that would overwhelm any Earth forces. A network of
dispersed space colonies could not be similarly attacked, not being in
a gravity well and a natural target of such a counter-attack.

This must be one of the reasons military types who worry about future
force capabilities frown upon developing space colonies of any sort.

The answer of course is to address the cause of human conflict. Which
is beyond the topic of this post, but which significant progress has
been made in the last part of the 20th century by psychologist Alice
Miller. It turns out that despite appearances conflict is not a
natural human condition. Our fascination as adults with power, money,
death, all stem from common mode failure in child rearing - and that
addressing this issue resolves the problem.

click

I've got to go, and will continue this later.

William Mook wrote in news:88f8a217-b11f-4b23-9b36-
:

Ever since Luis Alvarez and his son Walter discovered that the KT
boundary layer which exists world-wide, was enriched with iridium,
which suggests that the KT extinction event was caused by a massive
bolide strike on Earth, people have wondered generally about
humanity's ability to alter the path asteroids before they become
missiles that strike the Earth.

The potential of using nuclear explosions to alter the course of
celestial bodies was studied secretly in the 1950s and openly studied
by MIT graduate researchers in 1963. The process is rather simple.

(1) position a nuclear explosive some stand-off distance from the
object to be moved
(2) detonate the explosive causing a massive thermal shock
(3) a portion of the object evaporates forming a plume of ejected
material
(4) the ejecta acts as a rocket moving the object slightly in the
opposite direction.

This assumes the object is a reasonably solid object; more recent data
suggests most asteroids are dusty accretions loosely constituted by
their own weak gravity. A large disturbance can, and has been observed,
to break up asteroids into multiple impactors. Ask the Jovians.

Procede cautiously.

--Damon

On Feb 27, 3:42*pm, Damon Hill wrote:
William Mook wrote in news:88f8a217-b11f-4b23-9b36-
:







Ever since Luis Alvarez and his son Walter discovered that the KT
boundary layer which exists world-wide, was enriched with iridium,
which suggests that the KT extinction event was caused by a massive
bolide strike on Earth, people have wondered generally about
humanity's ability to alter the path asteroids before they become
missiles that strike the Earth.

The potential of using nuclear explosions to alter the course of
celestial bodies was studied secretly in the 1950s and openly studied
by MIT graduate researchers in 1963. *The process is rather simple.

(1) position a nuclear explosive some stand-off distance from the
object to be moved
(2) detonate the explosive causing a massive thermal shock
(3) a portion of the object evaporates forming a plume of ejected
material
(4) the ejecta acts as a rocket moving the object slightly in the
opposite direction.

This assumes the object is a reasonably solid object; more recent data
suggests most asteroids are dusty accretions loosely constituted by
their own weak gravity. *A large disturbance can, and has been observed,
to break up asteroids into multiple impactors. *Ask the Jovians.

Procede cautiously.

--Damon

The acceleration applied to a celestial body must be less than the
surface gravity on any world that's held together by surface gravity
regardless of size. The Earth would tear apart if accelerated at
rates higher than one gee.

A small hydrogen bomb blast in a vacuum ejects material heated by the
shock wave at speeds averaging 50 km/sec. One-third the energy in the
bomblet is deposited in the material, which comes from the body.

A UV laser pulse achieves the same levels of performance, two-thirds
of the energy in the laser pulse finds its way into the ejected
material.

This is sufficient for us to estimate the performance of an asteroid
conveyance system using powerful lasers or a series of small atomic
bombs.

http://www.npl.washington.edu/av/altvw21.html

So, let's take an asteroid like 253 Mathilde which is a main belt
asteroid 52.8 km in diameter. It masses 1e+17 kg and has a surface
gravity of 0.0025 m/s2. It has an orbit that allows us to have it
intersect Earth's orbit by adding 0.5 km/sec at orbit and make by
adding another 6.0 km/sec at perihelion near Earth, it becomes another
Moon around Earth.

Total delta-vee for a bombing run at Earth is 0.5 km/sec while
bringing it into Earth orbit for processing requires 6.5 km/sec total
delta vee.

With an exhaust speed of 50 km/sec 12.2% of the planetoid's mass must
be ejected to carry out this 6.5 km/sec maneuver. With a total mass 1e
+17 kg this requires that 1.22e+16 kg are ejected. 9.95e+14 kg over a
2.3 day period to slow the asteroid to fall to Earth. 1.125e+16 kg
ejected over a 30.2 day period to bring the asteroid into a stable
orbit around Earth. The acceleration limit is given by the surface
gravity of 0.0025 m/s2 of the asteroid itself.

Each ton of ejected material contains 1,250 GJ of kinetic energy.
This means each ton of material requires 3,750 GJ of bomb energy or
1,875 GJ of laser energy.

This requires 8.2 trillion giga-watts of laser energy incident on the
asteroid over a 32.5 day period - combined with about 2 years wait
time between propulsive pulses.

A 32 km diameter solar pumped laser array orbiting at 2 million km
from the Sun, produces a beam of this magnitude. At 200 um wavelength
this size emitter can form a spot 4 km in diameter in the asteroid
belt from this orbit. This means that 175 discrete spots on the
surface of the asteroid may be illuminated by the sun orbiting power
satellite providing a means of finely controlling the acceleration
across the surface.

I have described how to place a sun orbiting power satellite into an
orbit close to the sun in another post. A laser light sail deployed
at the sun may be flown to the asteroid in a few days and allow the
satellite to see the far side of the asteroid from its position near
the sun. The mirror also allows the sun orbiting satellite to
illuminate all sides of the asteroid with the laser beam - providing
complete control. The laser light sail itself may be navigated with
the beam, and by gravitationally binding to the asteroid allowing both
to accelerate together as they maneuver toward Earth.

The 1e17 kg asteroid contains enough material to provide every single
one of Earth's 6.8 billion people to have 14.7 tonnes of material from
the asteroid.

This single power satellite can deliver a dozen such asteroids to
Earth orbit every year! This is 176 tons of materials for every man
woman a child on Earth - every year the satellite is in operation!

This is far more than required for even US consumption (US population
is 4.5% of the world's population and consumes 40% of all resources)
which totals 3 tons per person per year, and even more than
millionaires - which totals 15 tons per person per year, and even more
than billionaires - which totals 75 tons per person per year (mostly
for fuels and stone and metals)

With energy being delivered by laser beam from orbit, these figures
are cut by one third.

World Average $10,000/person/year 0.2 tons/year
US Average $ 50,000/person/year 1.0 tons/year
Millionaire $250,000/person/year 5.0 tons/year
Ultra-rich $1,250,000/person/year 15.0 tons/year

We have the means to provide a very high standard of living for every
man woman and child on Earth using resources from the asteroid belt
and other small bodies throughout the solar system.

Send a 32 km satellite to Jupiter, which uses gravity assist to drop
into the Sun, hovering 2 million km above the solar surface. There we
produce an 8 trillion giga-watt laser beam from the satellite to
illuminate a laser light sail 32 km across - that flies to an asteroid
of interest, and propels it toward Earth in two maneuvers.

The first propulsive boosts slows the asteroid so that it falls into
Earth orbit - which generally takes a few days of propulsion (so the
asteroid holds together) and then slow it AT Earth so that it gently
enters the Earth orbit desired for it - a few years after the first
boost. This second boost takes a month generally.

An orbiting solar powered factory - remotely operated - has already
been placed in that orbit to process the asteroid into products useful
on Earth or on the growing infrastructure on Earth orbit.

Products are sent via MEMS laser rocket arrays from Earth orbit
directly to consumers where they execute a soft touchdown or braking
maneuver. Products are sent anywhere on Earth in minutes. Products
are sent anywhere in the solar system in a matter of days for the
inner solar system, or weeks for the outer solar system - using laser
light sails.

Matilde 253
Orbital Characteristics

Aphelion 501.334 Gm (3.35121 AU)
Perihelion 290.564 Gm (1.94230 AU)
Semi-major axis 395.949 Gm (2.64676 AU)
Eccentricity 0.266157
Orbital period 1572.787 d (4.31 yr)
Average orbital speed 17.98 km/s
Mean anomaly 111.960°
Inclination 6.738°
Longitude of ascending node 179.633°
Argument of perihelion 157.475°

Physical characteristics

Dimensions 52.8 km
(66×48×46 km)
Mass 1.033(±0.044)×10e+17 kg
Mean density 1.3 g/cm³
Equatorial surface gravity 0.0025 m/s²
Escape velocity 16.2 m/s
Rotation period 17.406±0.010 d (17 d 9 h 45 min)
Albedo 0.0436
Temperature ~174 K
Spectral type Cb
Absolute magnitude (H) 10.20

The governing equations are for energy;

F = m * a --- F = mdot * Ve --- mdot = F/Ve
E = 1/2 m Ve^2 --- W = 1/2 mdot * Ve^2 --- 2 * W = F * Ve
and for navigation

Vf = sqrt( mu * ((2/R) - (1/A)) )

and for performance

Vf = Ve * LN(1/(1-u))


Where

F = Force (Newtons)
m = mass of propellant
mu = standard gravitational parameter
a = acceleration (meters per second per second)
A = semi-major axis
R = orbital radius
mdot = mass flow rate (kg per second)
Ve = exhaust velocity (meters per second) *500,000 m/sec*
E = energy (joules)
W = power (watts)
u = propellant fraction (dimensionless)

On 28/02/2010 8:33 AM, William Mook wrote:
On Feb 27, 3:42 pm, Damon wrote:
William wrote in news:88f8a217-b11f-4b23-9b36-
:







Ever since Luis Alvarez and his son Walter discovered that the KT
boundary layer which exists world-wide, was enriched with iridium,
which suggests that the KT extinction event was caused by a massive
bolide strike on Earth, people have wondered generally about
humanity's ability to alter the path asteroids before they become
missiles that strike the Earth.

The potential of using nuclear explosions to alter the course of
celestial bodies was studied secretly in the 1950s and openly studied
by MIT graduate researchers in 1963. The process is rather simple.

(1) position a nuclear explosive some stand-off distance from the
object to be moved
(2) detonate the explosive causing a massive thermal shock
(3) a portion of the object evaporates forming a plume of ejected
material
(4) the ejecta acts as a rocket moving the object slightly in the
opposite direction.

This assumes the object is a reasonably solid object; more recent data
suggests most asteroids are dusty accretions loosely constituted by
their own weak gravity. A large disturbance can, and has been observed,
to break up asteroids into multiple impactors. Ask the Jovians.

Procede cautiously.

--Damon

The acceleration applied to a celestial body must be less than the
surface gravity on any world that's held together by surface gravity
regardless of size. The Earth would tear apart if accelerated at
rates higher than one gee.

Well, yes, but the point is that if, as is suspected, asteroids are held
together by gravity, then the force that can be applied without making
them come apart is very small. Changing the orbit of such an object
would require the application of a small force over an extended period
of time, which is going to be hard to achieve using bombs.

Sylvia.

On 2/27/2010 12:42 PM, Damon Hill wrote: A large disturbance can, and
has been observed,
to break up asteroids into multiple impactors. Ask the Jovians.

And all that took was a mild dive through Jupiter's gravity field.
Here's a whole other approach to deflecting a asteroid:
http://www.mikebrotherton.com/diamonds/?page_id=134

Pat

On 2/27/2010 9:22 PM, Sylvia Else wrote:
Well, yes, but the point is that if, as is suspected, asteroids are held
together by gravity, then the force that can be applied without making
them come apart is very small. Changing the orbit of such an object
would require the application of a small force over an extended period
of time, which is going to be hard to achieve using bombs.

That thing that hit down in Yucatan wasn't a a bolide BTW, it came down
in one big piece - although it could have been a part of a larger object
that was disrupted by either the Sun's or Jupiter's gravity before it
hit Earth: http://en.wikipedia.org/wiki/K%E2%80%93T_boundary
One small piece may even have come down here in North Dakota, as a
buried meteor crater dating from the same time period was found while
doing seismic explorations for oil in the state.

Pat

On Feb 28, 12:22*am, Sylvia Else wrote:
On 28/02/2010 8:33 AM, William Mook wrote:



On Feb 27, 3:42 pm, Damon *wrote:
William *wrote in news:88f8a217-b11f-4b23-9b36-
:

Ever since Luis Alvarez and his son Walter discovered that the KT
boundary layer which exists world-wide, was enriched with iridium,
which suggests that the KT extinction event was caused by a massive
bolide strike on Earth, people have wondered generally about
humanity's ability to alter the path asteroids before they become
missiles that strike the Earth.

The potential of using nuclear explosions to alter the course of
celestial bodies was studied secretly in the 1950s and openly studied
by MIT graduate researchers in 1963. *The process is rather simple.

(1) position a nuclear explosive some stand-off distance from the
object to be moved
(2) detonate the explosive causing a massive thermal shock
(3) a portion of the object evaporates forming a plume of ejected
material
(4) the ejecta acts as a rocket moving the object slightly in the
opposite direction.

This assumes the object is a reasonably solid object; more recent data
suggests most asteroids are dusty accretions loosely constituted by
their own weak gravity. *A large disturbance can, and has been observed,
to break up asteroids into multiple impactors. *Ask the Jovians.

Procede cautiously.

--Damon

The acceleration applied to a celestial body must be less than the
surface gravity on any world that's held together by surface gravity
regardless of size. *The Earth would tear apart if accelerated at
rates higher than one gee.

Well, yes, but the point is that if, as is suspected, asteroids are held
together by gravity, then the force that can be applied without making
them come apart is very small. Changing the orbit of such an object
would require the application of a small force over an extended period
of time, which is going to be hard to achieve using bombs.

Sylvia.

Right, I mentioned elsewhere accelerations would take days to months
to impart the required delta vees. Since transit times are on the
order of years - we have plenty of time to apply gentle pressure
needed.

On Feb 28, 1:15*am, Pat Flannery wrote:
On 2/27/2010 12:42 PM, Damon Hill wrote: A large disturbance can, and
has been observed,

to break up asteroids into multiple impactors. *Ask the Jovians.

And all that took was a mild dive through Jupiter's gravity field.
Here's a whole other approach to deflecting a asteroid:http://www.mikebrotherton.com/diamonds/?page_id=134

Pat

Right! Applied pressure must accelerate less than surface gravity.
Exceed surface gravity and parts are left behind - definitely. It
will take care and planning, but it will be less difficult than say
herding sheep - that's why the ability to apply small spot sizes (or
small explosions for the micro-nukes) broadly and quickly across a
surface will be important. Absolutely.

In sci.space.policy message
, Sat, 27 Feb 2010 14:42:30, Damon Hill
posted:

The potential of using nuclear explosions to alter the course of
celestial bodies was studied secretly in the 1950s and openly studied
by MIT graduate researchers in 1963. The process is rather simple.

(1) position a nuclear explosive some stand-off distance from the
object to be moved
(2) detonate the explosive causing a massive thermal shock
(3) a portion of the object evaporates forming a plume of ejected
material
(4) the ejecta acts as a rocket moving the object slightly in the
opposite direction.

This assumes the object is a reasonably solid object; more recent data
suggests most asteroids are dusty accretions loosely constituted by
their own weak gravity. A large disturbance can, and has been observed,
to break up asteroids into multiple impactors. Ask the Jovians.

Procede cautiously.
YSCIB.

Remember that in a vacuum a nuke generates comparatively little direct
blast. The idea is not to give the whole target a massive shock, but to
dump enough energy into the surface that it boils. The ejecta will go
radially outwards from most of the illuminated hemisphere, pushing the
rest inwards. That is a comparatively favourable situation.

The necessary caution should not be exaggerated.

Assuming that by using "Jovians" you are referring to the impacts of
SL-9 (D/1993 F2) in 1994 : it was broken up in 1992 when it passed
within Jupiter's Roche limit. It felt a substantial tidal field for
some hours, pulling it apart. The analogy is weak.

Roche : URL:http://www.merlyn.demon.co.uk/gravity5.htm#Roche;
Wikipedia.

--
(c) John Stockton, nr London, UK. Turnpike v6.05 MIME.
Web URL:http://www.merlyn.demon.co.uk/ - FAQqish topics, acronyms & links;
Astro stuff via astron-1.htm, gravity0.htm ; quotings.htm, pascal.htm, etc.
No Encoding. Quotes before replies. Snip well. Write clearly. Don't Mail News.