Re: 2004 MN4 Asteroid Possibilities

From: Matthew Hagston (otts1_at_earthlink.net)
Date: 12/31/04 

Date: Fri, 31 Dec 2004 14:15:45 GMT

> Hop David wrote:
> >
> > The major point of my reply to Edward Ruden was that delta vee for
> MN4's
> > capture could be less than 5.9 km/sec.
> >
> Granted. I was proposing something that might possibly be done for 10's
> of billions, not 100's or 1000's. That means meters per second (m/s)
> delta V from propulsion, not km/sec. Any number of km/sec isn't
> realistically going to fly by 2029. Even at m/s, for something a big as
> 2004 MN4, nuclear devices will likely be needed. The *real* delta V
> necessary for trapping will have to come from "cosmic billiards", as
> I've heard it called.
>
> The first goal in my senerio is to reduce MN4's present V_inf of 5.8
> km/s to much less than 1 km/s, where an earth-moon-MN4 3-body capture
> to the L4 or L5 Lagrange point is possible. I am assuming the final
> capture is possible with only an arbitrarily small but finite final
> delta V braking near L4/5 to set it into stable orbit about L4/5. Can
> someone verify or refute this assumption? In respond to Brian Jacobson,
> Venus certainly could provide a big delta V by aerobraking or
> sling-shot(elastic gravitational "scattering" off a moving object to
> change speed), but it's in the wrong place. V_inf is measured relative
> to earth. That means MN4 would have to approach a 1 AU radius circular
> orbit before final trapping. Any orbit passing by Venus doesn't do
> that. Scattering (not aerobraking!) MN4 off Earth may be useful for
> changing it's orbit as required, but it doesn't change MN4's V_inf. For
> that, you need the moon. Moon moves at about V_moon=1.0 km/s relative
> to earth, and has an escape velocity of V_escape=2.4 km/s. I haven't
> done the orbital calculation, but given these numbers, one can only
> alter V_inf=5.8 km/s by a fraction of 1 km/s per pass. It gets better
> later as V_inf drops, though, as the scattering angle can be increased.
> That means making sure MN4 comes by several times before people get
> bored. It's fortunate that MN4's orbital period is so close to 8/9
> year(.8853). This means we only need to change it's orbit ever so
> slightly by 2029 to get our first lunar encounter in 2037 (2029 + 8).
> The subsequent lunar encounters can then, over the rest of the century,
> increase the orbital peroid (in years) to, for example, 9/10, then
> 10/11, then 12/13, then 15/16, etc, as the orbit is circularized and
> final capture is readied.
>
> Ed
>

    Well whatever the actual cost, whether it's 100mil (yeah right) or 10bil
(more probable). Compare that cost (not just the capture cost, but the
additional costs to make it usefull as well) and compare that to how much it
would cost to bring that amount of minerals and materials up their in the
first place. If it's cheaper...just off this 1 roid, then it's worth while
due to the fact that additional roids could be obtained for 'proccessing'
quite easily.

btw, Got me a telescope for christmas!!! woot! celestron 114eq.

-Matthew Hagston.

Relevant Pages

  • Re: DIRECT HIT
    ... satellite was launched into POLAR orbit (much more costly than a lower ... I'm pretty sure it was a high-inclination orbit, I want to say 50+ degrees, but not polar. ... changes with temp and the the nuke wont work). ... the cost of a nuke warhead remains high by comparison. ...
    (sci.military.naval)
  • Re: Improved lunar landing architecture
    ... hydrogen with you, instead using what can already be obtained from Mars, then you produce a fuel that is not very efficient anyway. ... I suspect even for someone who knew how to figure ion engine ... to exploit the Oberth effect and increased delta vee. ... destination planet was Mars geosynchronous orbit altitude and Deimos ...
    (sci.space.policy)
  • Re: Space Exploitation
    ... Perhaps that's one way to help defray the cost of launches. ... asteroids then we don't have to spend money orbiting them from earth. ... > and such in orbit, but if electric power grows in price to justify the cost ...
    (sci.space.policy)
  • Re: Viability of volatile imports to Mars?
    ... Applying a sudden 2.4 km/s periapsis burn to slow a mountain sized object is a lot harder than a 1 km/sec deceleration. ... But you weren't counting it at all since you were ignoring the need to circularize the orbit for final impact. ... I then compared delta vee required for such capture between cargo ...
    (rec.arts.sf.science)
  • Re: Fictional Apollo 18(+) Missions
    ... The usual mental model of the situation -- spacecraft zooms out to ... highly elliptical transfer orbit, being overtaken by the fast-moving Moon. ... LOI burn gives a polar orbit), or something in between, is a matter of ... quite carefully do modest cost differences appear. ...
    (sci.space.history)