[FPSPACE] Dual Orion capsules studied for manned asteroid missions

[Jens Kieffer-Olsen]

Although Apophis is very much more massive than Messenger
its orbit needs less change to enter Earth orbit than does that
spacecraft to enter orbit around Mercury.   
 
In both cases the bulk of the change will stem from slingshot
effects, whereas nudging is merely the mechanism to fine-tune
the slingshots.
 
The size of planets makes the difference in size between Messenger 
and Apophis unimportant. Just as Larry Ellison's yacht Rising Sun
and the world's largest container ship Emma Maersk ( with a
deadweight of 156,000 tonnes ) obey the same principles of
hydromechanics.
 
The 2029 pass of Apophis within GEO distance provides a strong,
natural slingshot effect. Just as there exists a so-called 'keyhole'
passing through which in 2029 Apophis will be able to target Earth
for a direct hit in 2036, other keyholes exist that will permit Apophis
to repeat its close encounters with Earth in later years, and thus
allow us to plan a chain of slingshots, just like Messenger goes
through a series of such.
 
Attaching ion engines to Apophis well before 2029 will enable the
desired fine-tuning of the pass, directing the asteroid through a
pre-calculated keyhole. The exercise is similar to the deflection
required, if we wanted instead to prevent Apophis from passing
through the keyhole causing a 2026 collision.
 
--
Jens Kieffer-Olsen
Slagelse, Denmark


-----Original Message-----
From: Michael K. Heney [mailto:mike at heney.net]
Sent: Sunday, August 23, 2009 4:44 PM

Take a look at J002E3 - initially thought to be a NEO when discovered in
September 2002, it turned out to be the S-IVB from Apollo 12.  The stage
entered a heliocentric orbit after sending Apollo 12 on its way to the
moon; in 2002, it was recaptured into a chaotic orbit as it passed near
the Earth-Sun L1 point; it was ejected back into heliocentric orbit in
July 2003, and may do it again sometime in the 2030-2040 timeframe...

So, nudging Apophis (an exercise left to the reader...) to interact with
the L1 (or L2 point) for capture into an unstable orbit, and then tweaking
that orbit to something more stable would do the trick.

Of course, there IS a wee difference in situations (ignoring mass) ...
The S-IVB is in an earth-grazing orbit - with an eccentricity only
slightly different than Earth's.  It approaches gently, on a tangent to
the L-1 point.  Apophis is an Earth-crossing asteroid, with an
eccentricity of about .19 - it's movin' on through as it approaches Earth.
You'd want to bump it's aphelion down from 1.1 AU to closer to 1, raise
the perihelion from .75 to something much closer to 1, and do it in such a
way so that it still ends up near the Earth so it can be captured.

That's a lot of noodging on a good-sized (350m) rock ...


On Fri, 21 Aug 2009, David R. Woods wrote:

> Jens,
>
> Do you know of any references that describe how that capture process could
take place? 
> Typically, with conservation of momentum, there is too much energy for
something to be captured
> if it comes in from beyond Earth's gravitational well.  I could see a
sling shot maneuver using
> the Moon to somehow put it into a retrograde orbit, but that seems bazaar
and dangerous if you
> did not get it exactly right.
>
> Dave
>
> -------- Original Message --------
> Subject:
> Re: [FPSPACE] Dual Orion capsules studied for manned asteroid missions
> Date:
> Fri, 21 Aug 2009 21:58:17 +0200
> From:
> Jens Kieffer-Olsen <dstdba at post4.tele.dk>
> Reply-To:
> dstdba at post4.tele.dk
> Organization:
> Indian Red
> To:
> <fpspace at friends-partners.org>
>
> <snip>
>
> Only by knowing the precise orbit of Apophis
> can the necessary combination of nudges and slingshots be calculated that
will eventually
> deliver the asteroid into GEO.
>  
> <snip>  
> Jens Kieffer-Olsen
> Slagelse, Denmark
>
>


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