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Author
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Topic: Sending ISS's Tranquiliy Node 3 to an asteroid
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Robert Pearlman
Editor Posts: 50516
From: Houston, TX
Registered: Nov 1999
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posted 08-11-2010 10:07 AM
   
New Scientist: NASA mulls sending part of space station to an asteroid One idea is to take apart the International Space Station, which is currently set to be retired in 2020, and use one of its crew compartments to build an asteroid-bound spacecraft in orbit instead of launching a similar capsule from Earth.
Credit: NASA/New Scientist"These [asteroid] missions are going to occur at about the time that the space station is near retirement, so one has to wonder, 'Is it possible to use assets from the station as part of your mission complement?'" he said. A space station compartment called Node 3 or Tranquility, which launched to the station aboard a shuttle mission in February, is particularly attractive for recycling because it has docking ports that could be used to attach to a pair of smaller, more nimble spacecraft. After arriving at the asteroid, astronauts could enter the smaller spacecraft and detach from the main ship in order to inspect the asteroid up close. |
Robert Pearlman
Editor Posts: 50516
From: Houston, TX
Registered: Nov 1999
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posted 08-11-2010 11:38 AM
SPACE.com: Part of Space Station Could Carry Crew to an Asteroid, NASA Says ...the interior of the node could also see major makeovers.A spinning centrifuge device installed within the node might also create artificial gravity to help astronauts stave off muscle and bone loss, Wilcox said. The space station currently does not have such a device. |
Fezman92
Member Posts: 1031
From: New Jersey, USA
Registered: Mar 2010
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posted 08-11-2010 12:06 PM
Interesting, very cool. |
328KF
Member Posts: 1388
From:
Registered: Apr 2008
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posted 08-11-2010 03:20 PM
With the current orbit of the ISS, how feasible is it that an assembly such as this could be put on a trajectory toward an asteroid? |
KSCartist
Member Posts: 3047
From: Titusville, FL
Registered: Feb 2005
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posted 08-11-2010 04:49 PM
I would think they'd want to utilize Node 2 Harmony, Columbus, Kibo and Node 3 Tranquility to give the crew more living space and maybe a "storm cellar" in the event of a solar eruption. Those are the modules easiest to remove as well as being the ones with the least time on orbit.
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Robert Pearlman
Editor Posts: 50516
From: Houston, TX
Registered: Nov 1999
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posted 08-11-2010 04:59 PM
The more mass you add to this proposed spacecraft, the more thrust you need to move it out of Earth orbit, the more additional equipment you need to launch from Earth, the less attractive reusing ISS modules becomes... |
328KF
Member Posts: 1388
From:
Registered: Apr 2008
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posted 08-11-2010 10:20 PM
quote:
Originally posted by 328KF:
With the current orbit of the ISS, how feasible is it that an assembly such as this could be put on a trajectory toward an asteroid?
I should have been more specific with regard to the inclination of ISS's orbit. Walt Cunningham has long pointed out that once we got the Russians involved and increased the inclination to accommodate launches from there, we effectively ended it's usefulness as a launching point for exploration beyond LEO.Any rocket scientists here? |
Robert Pearlman
Editor Posts: 50516
From: Houston, TX
Registered: Nov 1999
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posted 08-11-2010 10:33 PM
quote:
Originally posted by 328KF:
...ended it's usefulness as a launching point for exploration beyond LEO.
I may be mistaken (and I don't claim to be a rocket scientist) but I think it's less a case of usefulness as it is advantage. The relatively high inclination of the ISS removes most of the potential advantage of departing from orbit rather than from the ground. In this proposed scenario though, the advantage is partially restored, as a major part of your spacecraft is already bought and paid for, proven and on orbit. And it's not just the shell: you also have your life support equipment (already housed in Node 3) and a cupola perfect for overlooking an asteroid. |
SpaceAholic
Member Posts: 5246
From: Sierra Vista, Arizona
Registered: Nov 1999
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posted 08-11-2010 11:28 PM
Its a good bet the high inclination will either severely constrain target options or require creative trajectories which leverage gravitational assist and narrow departure windows to go after the asteroid. The very attribute which makes the Cupola an asset is its vulnerability in deep space - radiation protection. Even the polyethylene shielding used on the nodes offers weak attenuation of environmental radiation and would not be close to sufficient outside the Earth's magnetosphere. Integrating robust shielding or baffles into the node (while on orbit - without the benefit of a shuttle) will be a challenge. |
Jay Chladek
Member Posts: 2272
From: Bellevue, NE, USA
Registered: Aug 2007
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posted 08-13-2010 12:51 PM
A trajectory could be set up to get the thing out of orbit and on its way to an asteroid easily enough. Indeeed you would lose the momentum of Earth's orbit at a lower trajectory to hit escape velocity, but it can still be done. The Soviets did lunar flybys with their Zond spacecraft and they launched into high inclination orbits, like what the ISS sits on. The N-1 had similar constraints as well (assuming one had managed to get a Soyuz lunar craft into orbit as opposed to blowing up).Where it gets sticky as I see it is the return trajectory as in order for the thing to get back onto the ISS orbit, the window would be rather narrow. The design of this craft seems to offer no return to Earth option via a CM. So the craft would HAVE to rendezvous with the ISS. |
Robert Pearlman
Editor Posts: 50516
From: Houston, TX
Registered: Nov 1999
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posted 08-13-2010 01:07 PM
quote:
Originally posted by Jay Chladek:
...so the craft would HAVE to rendezvous with the ISS.
If the intention is to return this asteroid mission to Earth orbit, then the craft could rendezvous with an Orion, Dragon or other crew-return spacecraft as well.I think by suggesting the use of Node 3, the proposal is implying that the ISS would be by then decommissioned and its other components deorbited consistent with the station's nominal end of life scenario. |
cspg
Member Posts: 6347
From: Geneva, Switzerland
Registered: May 2006
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posted 08-13-2010 11:42 PM
quote:
Originally posted by Robert Pearlman:
The relatively high inclination of the ISS removes most of the potential advantage of departing from orbit rather than from the ground.
If someone could elaborate on this, that would be nice. What difference does it make for interplanetary trajectories whether you're orbiting Earth at 28.5° or 51.6°? The disadvantage comes from launching from the ground but once you're orbiting the Earth, does it matter?. |
SpaceAholic
Member Posts: 5246
From: Sierra Vista, Arizona
Registered: Nov 1999
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posted 08-14-2010 12:48 AM
The disadvantage with departure from a high inclination orbit vs the ground/low inclination prograde orbits for interplanetary launches - the vehicle can take advantage of Earth's orbital motion to accelerate the spacecraft to escape velocity and in plane with the destination. High inclination orbits require substantial changes in velocity (delta-V) for re-vector to a trajectory/orbital plane roughly orthogonal to the earths rotational axis (proximate to the ecliptic) where the majority of planets and asteroid orbits lay (most asteroids inhabit inclinations of less then 20 degrees). |
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