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Author
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Topic: Manned asteroid mission with Apollo hardware
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Proponent
Member Posts: 59
From: London
Registered: Oct 2008
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posted 11-04-2008 04:16 AM
  
I've come across references to proposals in the Apollo era for a manned mission to a near-earth asteroid. A non-Hohmann transfer would have been utilized to keep transit times down to several weeks. Step 1: escape from earth in a direction more or less outward from the sun. Step 2: intercept the asteroid, burn the LM descent stage dry, discard it, and then burn the ascent stage to match velocity with the asteroid. Spend a week or two exploring the asteroid. Step 3: as the asteroid passes nearest earth, use the service propulsion system for a TEI burn.The LM could have been stripped down quite a bit to save weight. I suppose that to stretch consumables, one might go with a two-man crew. The whole thing would have been quite marginal, but it's a fascinating possibility. Does anyone know where I could find any hard information on this? The best I've been able to do is turn up a 1966 paper by Eugene Smith of Northrop entitled "A Manned Flyby Mission to Eros." It discusses the use of Apollo-based hardware, rather than Apollo hardware itself, for a much more extensive mission. |
Obviousman
Member Posts: 438
From: NSW, Australia
Registered: May 2005
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posted 11-07-2008 01:03 AM
I presume I am telling you how to suck eggs, but have you checked the NTRS? A goldmine, that is.
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1202 Alarm
Member Posts: 445
From: Switzerland & France
Registered: Nov 2003
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posted 11-07-2008 02:10 AM
quote:
Originally posted by Proponent:
The LM could have been stripped down quite a bit to save weight.
REALLY? Hello? Yeah, right, that fat LM was sooo heavy in the first place... |
Proponent
Member Posts: 59
From: London
Registered: Oct 2008
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posted 11-07-2008 07:06 AM
quote:
Originally posted by Obviousman:
I presume I am telling you how to suck eggs, but have you checked the NTRS? A goldmine, that is.
NTRS is great, but I've found nothing on this particular topic. |
Proponent
Member Posts: 59
From: London
Registered: Oct 2008
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posted 11-07-2008 07:16 AM
quote:
Originally posted by 1202 Alarm:
REALLY? Hello? Yeah, right, that fat LM was sooo heavy in the first place...
Think of all of the things you wouldn't need for an asteroid mission: legs, ladder, porch, radar, guidance, rendezvous lights, RCS (unless maybe you want that for back-up). The docking probe could be jettisoned after docking with the LM, since there would be no need to re-dock. |
cspg
Member Posts: 6222
From: Geneva, Switzerland
Registered: May 2006
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posted 11-07-2008 08:31 AM
Less fuel (descent/ascent stages) due to "lack" of gravity?Chris. |
ilbasso
Member Posts: 1522
From: Greensboro, NC USA
Registered: Feb 2006
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posted 11-07-2008 11:39 PM
They used the RCS thrusters to supplement the boost of the ascent engine in taking off from the moon. I'm sure that the RCS thrusters would give far more impulse than you'd need to take off or land on an asteroid - hence no need for a descent or ascent engine and associated fuel. |
Max Q
Member Posts: 399
From: Whyalla South Australia
Registered: Mar 2007
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posted 11-08-2008 12:28 AM
NTRS? |
cspg
Member Posts: 6222
From: Geneva, Switzerland
Registered: May 2006
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posted 11-08-2008 12:32 AM
NASA Technical Reports Server (NTRS)Chris. |
Proponent
Member Posts: 59
From: London
Registered: Oct 2008
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posted 11-08-2008 06:24 AM
quote:
Originally posted by ilbasso:
I'm sure that the RCS thrusters would give far more impulse than you'd need to take off or land on an asteroid - hence no need for a descent or ascent engine and associated fuel.
"Landing" on a small asteroid is going to be more of a docking maneuver than a landing. Suppose the asteroid has the same density as earth (5 g/cm3) and is 13 km in size (1/1000th of earth). Then the acceleration of gravity at the surface is going to be about 1/1000th that on earth, i.e., about 1 cm/s2. Circular velocity in a low orbit will be about 7 m/s. The LM isn't used for landing operations at all; it's just used for propulsion, because we need a lot of delta-V to get rendezvous with the asteroid in the first place. So the point is, we're going to need a full fuel load in the LM. If anything, we'd probably want to increase its fuel capacity. By the time we've rendezvoused with the asteroid, we've already used up the descent stage and probably the ascent stage as well. We set the CSM itself gently down on the surface of the asteroid. I guess we fit some small landing pads on the side of the SM to make sure that the SM isn't damaged as it touches down and to make sure that it is stable. Or maybe the CSM doesn't land. It just goes into orbit, and then an astronaut "lands" with an extravehicular mobility unit (thrusters on his backpack). |
Proponent
Member Posts: 59
From: London
Registered: Oct 2008
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posted 11-08-2008 06:26 AM
quote:
Originally posted by cspg:
NASA Technical Reports Server
Better make sure you've got lots of time before you visit the NTRS website. It can easily suck you in for hours and hours. 
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Duke Of URL
Member Posts: 1316
From: Syracuse, NY
Registered: Jan 2005
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posted 01-04-2009 12:16 PM
How would you keep a crew from going nuts in an Apollo capsule on a trip of that duration?One reason Orion is wrong for Mars missions is that people would lose their minds in that cramped space. |
Robert Pearlman
Editor Posts: 43576
From: Houston, TX
Registered: Nov 1999
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posted 01-04-2009 12:18 PM
quote:
Originally posted by Duke Of URL:
One reason Orion is wrong for Mars missions is that people would lose their minds in that cramped space.
Orion is not intended to be the crew cabin for a Mars mission: it is only meant to serve as the Earth reenty module. |
Duke Of URL
Member Posts: 1316
From: Syracuse, NY
Registered: Jan 2005
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posted 01-07-2009 07:41 PM
See? You shoot off your mouth without watching your step and see what happens? |
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