[FPSPACE] Dual Orion capsules studied for manned asteroid missions
Jens Kieffer-Olsen
dstdba at post4.tele.dk
Mon Aug 24 01:12:03 EDT 2009
Hi David,
There are many more ways to utilize an asteroid in GEO than as an anchor
point for a space elevator. In any case you would probably want to mine it
to
some extent, create radiation-safe quarters inside it, and so on.
Since it is truly science fiction to imagine a world government any time
soon,
all the great powers will need their own asteroid. The US may place one
over
the Pacific Ocean, the EU may choose South America, Russia will pick a
location over Africa, and China a position in the archipelago north of
Australia.
Now which country wants to be first, and who wants to be the last in the
game?
--
Jens Kieffer-Olsen
Slagelse, Denmark
-----Original Message-----
From: David Portree [mailto:dsfportree at hotmail.com]
Sent: Saturday, August 22, 2009 2:59 AM
To: dstdba at post4.tele.dk; fpspace at friends-partners.org
Subject: Re: [FPSPACE] Dual Orion capsules studied for manned asteroid
missions
Jens:
We won't go after a space elevator anchor point until we need a space
elevator. We won't grab an asteroid and park it on the off-chance that we'll
decide someday to build one. Will we need a space elevator any time soon?
I'm sorry, I just don't see it, as cool as it would be.
Before we can think about using any asteroid as such an anchor point - which
might not be necessary anyway - we need to learn more about it. What if
Apophis is a rubble pile that squirms around as we try to push it?
I've heard how VASIMR is right around the corner and is going to be test
flown in space for a decade or two now, so pardon me if I'm a little
skeptical. In any case, if you're going to use rockets, why not electric
thrusters? We know they work.
And, don't you think it would be a bit tricky politically to nudge an
asteroid into GEO? I mean, given all the hype that has been tossed around
about the threat from asteroids, who is going to support actually pushing
one toward the Earth?
I don't mean to be a party pooper, and I don't doubt that some version of
your scenario will be plausible at some point. Twenty years or so ago I
wrote in an article that "soon" no asteroid would dare come near to Earth
because the cislunar industrial infrastructure would snap it up. Maybe your
scenario will play out someday. But not by 2029. That is, after all, only 20
years in the future.
In the meantime, we have a lot of other spadework to do.
David S. F. Portree
dsfportree at hotmail.com
dportree at usgs.gov
http://robotexplorers.blogspot.com/
http://beyondapollo.blogspot.com/
http://astrogeology.usgs.gov/About/People/DavidPortree/
_____
From: dstdba at post4.tele.dk
To: fpspace at friends-partners.org
Date: Fri, 21 Aug 2009 21:58:17 +0200
Subject: Re: [FPSPACE] Dual Orion capsules studied for manned asteroid
missions
Well, well, well, David.
I'll try to be a bit more detailed with respect to the ACSEP ( Apophis
Capture and
Space Elevator Project ).
As you know Rusty Schewickart has asked that a transponder mission be
launched
by NASA in order to ascertain the asteroid's precise characteristics.
Although his
concern is solely to obviate a hypothetical collision with Earth, the same
transponder
mission is also the first part of ACSEP. 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.
A manned mission to Apophis to install a VASIMR ion engine is the second
part of
ACSEP. As you must be aware NASA's Charles Bolden is very excited about
Franklin
Chang-Diaz' and his Ad Astra company's new engine, having agreed to test it
for ISS
use around 2013. So, there is plenty of time to attach one or more VASIMR
engines
to Apophis prior to 2029.
The eventual capture of Apophis into GEO could presumably take place later
this
century, taking us into the third part of ACSEP.
And yes, the details of the space elevator itself may be a bit tenous right
now. However,
there is no expiry date attached to Apophis once it's in GEO. When the
elevator concept
is doable, Apophis is ready as anchor point.
The 2029 close pass of Apophis offers a once-in-a-century chance of
capturing a valuable
asteroid into GEO. There is no good reason at all for NASA to pussy-foot or
dismiss
ACSEP as science fiction.
--
Jens Kieffer-Olsen
Slagelse, Denmark
-----Original Message-----
From: David Portree [mailto:dsfportree at hotmail.com]
Sent: Thursday, August 20, 2009 10:09 AM
To: dstdba at post4.tele.dk; fpspace at friends-partners.org
Subject: Re: [FPSPACE] Dual Orion capsules studied for manned asteroid
missions
Jens:
Leaving aside your proposed plot for a science fiction movie (which has no
where near enough sex in it to sell, by the way) - the piloted L point
mission concept gained prominence first during the Decadal Planning Team
exercise begun in 1999. They were desperately straining to come up with
reasons to launch humans beyond LEO, but without breaking the bank (that is,
without a moon landing). With the HST servicing missions in mind, they came
up with deployment and servicing of large L point telescopes as a possible
justification. It's not an entirely silly notion, though after all the
scaredy-cat hemming and hawing and "rescue" preparations for the last HST
servicing mission, it's hard to see how an even riskier mission to service a
telescope at an L point could be justified.
David S. F. Portree
dsfportree at hotmail.com
dportree at usgs.gov
http://robotexplorers.blogspot.com/
http://beyondapollo.blogspot.com/
http://astrogeology.usgs.gov/About/People/DavidPortree/
> From: dstdba at post4.tele.dk
> To: fpspace at friends-partners.org
> Date: Thu, 20 Aug 2009 02:57:23 +0200
> Subject: Re: [FPSPACE] Dual Orion capsules studied for manned asteroid
missions
>
>
> -----Original Message-----
> From: David Portree [mailto:dsfportree at hotmail.com]
> Sent: Wednesday, August 19, 2009 3:31 PM
>
> > Just because an asteroid passes one million kilometers from
> > Earth doesn't mean one could reach it as easily or as quickly
> > as an L point. Furthermore, not all asteroids are worth
> > reaching, and this mission would focus on which are accessible
> > by straining the Orion system, not on the value of the targets;
> > basically, it'd be a stunt. Finally, for the cost of this stunt
> > mission, we could send robot explorers to a dozen more interesting
> > asteroids.
>
> Yes indeed, a mission without a concrete purpose is a stunt!
>
> Travelling to the Sun-Earth L2 point 1.5 million km away will not
> be justified until a permanent base is planned. The only resource
> there is sunlight. Hell, to paraphrase Robert Zubrin, it's a case
> of 'living off the void'.
>
> It would make more sense to first practice one's station-keeping
> skills at the Earth-Moon L2 point just 440,000 km away from home.
> In fact, EML2 was recently proposed a potential staging node
> for 'Back-to-the-Moon' missions.
>
> As for asteroids I could envisage a bold mission in 2029 to try
> to capture Apophis! That year it's passing Earth closer than the
> orbits of geostationary satellites, so if it were nudged slightly
> beforehand, the slingshot effect of the pass could be tailored
> to bring Apophis into Earth orbit as a captured moon on a future
> encounter.
>
> Having not run this through a computer program, it's quite possible
> that we would have to nudge the orbit of Apophis on several passes
> in order to effectuate a capture, but the point remains that the
> first nudge is asking to be carried out before 2029.
>
> Allow me to suggest that NASA right away spend a fair sum of
> taxpayers' dollars on a feasibility study! And maybe some
> environmental group could be persuaded to launch a 'No Asteroid
> in my Backyard' campaign to attract publicity to the scheme!
>
> If Apophis could become the anchor point for the world's first
> space elevator, it's time to act NOW!
>
> --
> Jens Kieffer-Olsen
> Slagelse, Denmark
>
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