Author Topic: Asteroid Retrieval Mission Concept  (Read 264633 times)

Offline Burninate

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Re: Asteroid Retrieval Mission Concept
« Reply #180 on: 12/28/2014 02:03 pm »
I seriously don't understand the reasoning behind the ARM mission concept; why move the tiny asteroid to lunar orbit, just to send a crew to grab a few samples? If sampling it is the goal, surely it'd be far simpler and more cost-effective to take the samples roboticlly and return then to earth or LEO. (I'd bet you could get larger samples doing it that way).

As it stands, the proposed ARM seems to me to be little more than a make-work mission for SLS/Orion, because with Orion's 21 day endurance, you can't actually send a crew to a NEO in situ (even assuming SLS/Orion had the needed Delta/V). The only possibly-useful aspect of the mission that I see is the SEP system needed for the retrieval probe, but that'd still be needed if the destination is changed from Lunar orbit to LEO (the original JPL study of asteroid retrieval assumed LEO/ISS as the destination, so it's not that far-fetched to think LEO is a viable destination to consider). 
I was totally subscribed to your incredulous POV until I read/listened to some of the literature.  The thing is - you're 100% right, you're not being hyperbolic.  This is basically acknowledged by the proponents of the ARM mission at this point, when they say things like 'this is going through the ops program instead of the science program' during the last telecon. 

SLS/Orion needs something to do, something to train a generation of engineers in BLEO manned operations, something that would not put astronauts at risk on a 3-year mission, something that fit within NASA's existing budgetary outlook.

This was the first thing they came up with.  It really is that simple.  Any science that gets done is an afterthought to this training mission.  The technology developed, like a monster SEP system, will not be particularly difficult, but under the patronage of the SLS/Orion initiative with the intention of an actual mission, there will be somebody to pay for it to be integrated into an actual spacecraft.  We've had ion thrusters and we've been developing lightweight solar panels for years, but without a mission, the tech dev budgets will pay for nothing that actually flies to space, so what's the point of implementing them in megawatt-scale designs?

I have graduated from puzzled frustration to educated depression.  It's pathetic groping through the constraints of program funding conditions that prohibit actual ambition.

Money spent on this sort of thing has a logarithmic return - you might get 100x as much scientific/exploration result, out of 10x as much funding.  What Congress have done is cut funding to the bone, to the point where we can barely afford to have a space program at all anymore, and then meddle with how that funding is used, swinging around statutory instructions that change with every election, to the point that there's no money for anything that *doesn't* use SLS/Orion, and there's no money for more than one mission, and that mission starts out as an initial  training mission without much scientific or ops merit, because that's all we can afford.
« Last Edit: 12/28/2014 02:13 pm by Burninate »

Offline RonM

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Re: Asteroid Retrieval Mission Concept
« Reply #181 on: 12/28/2014 02:14 pm »
I seriously don't understand the reasoning behind the ARM mission concept; why move the tiny asteroid to lunar orbit, just to send a crew to grab a few samples? If sampling it is the goal, surely it'd be far simpler and more cost-effective to take the samples roboticlly and return then to earth or LEO. (I'd bet you could get larger samples doing it that way).

As it stands, the proposed ARM seems to me to be little more than a make-work mission for SLS/Orion, because with Orion's 21 day endurance, you can't actually send a crew to a NEO in situ (even assuming SLS/Orion had the needed Delta/V). The only possibly-useful aspect of the mission that I see is the SEP system needed for the retrieval probe, but that'd still be needed if the destination is changed from Lunar orbit to LEO (the original JPL study of asteroid retrieval assumed LEO/ISS as the destination, so it's not that far-fetched to think LEO is a viable destination to consider). 
I was totally subscribed to your incredulous POV until I read/listened to some of the literature.  The thing is - you're 100% right, you're not being hyperbolic.  This is basically acknowledged by the proponents of the ARM mission at this point, when they say things like 'this is going through the ops program instead of the science program' during the last telecon. 

SLS/Orion needs something to do, something to train a generation of engineers in BLEO manned operations, something that would not put astronauts at risk on a 3-year mission, something that fit within NASA's existing budgetary outlook.

This was the first thing they came up with.  It really is that simple.  Any science that gets done is an afterthought to this training mission.  The technology developed, like a monster SEP system, will not be particularly difficult, but under the patronage of the SLS/Orion initiative with the intention of an actual mission, there will be somebody to pay for it to be integrated into an actual spacecraft.  We've had ion thrusters and we've been developing lightweight solar panels for years, but without a mission, the tech dev budgets will pay for nothing that actually flies to space, so what's the point of implementing them in megawatt-scale designs?

I have graduated from puzzled frustration to educated depression.  It's pathetic groping through the constraints of program funding conditions that prohibit actual ambition.

ARM would be a technology demonstration mission. The technology has to be tested before NASA sends astronauts to Mars. Look at all the Apollo missions before Apollo 11. Of course, maybe there is a better way to do the testing than ARM.


Offline jongoff

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Re: Asteroid Retrieval Mission Concept
« Reply #182 on: 12/28/2014 03:33 pm »
I seriously don't understand the reasoning behind the ARM mission concept; why move the tiny asteroid to lunar orbit, just to send a crew to grab a few samples? If sampling it is the goal, surely it'd be far simpler and more cost-effective to take the samples roboticlly and return then to earth or LEO. (I'd bet you could get larger samples doing it that way).

As it stands, the proposed ARM seems to me to be little more than a make-work mission for SLS/Orion, because with Orion's 21 day endurance, you can't actually send a crew to a NEO in situ (even assuming SLS/Orion had the needed Delta/V). The only possibly-useful aspect of the mission that I see is the SEP system needed for the retrieval probe, but that'd still be needed if the destination is changed from Lunar orbit to LEO (the original JPL study of asteroid retrieval assumed LEO/ISS as the destination, so it's not that far-fetched to think LEO is a viable destination to consider). 
I was totally subscribed to your incredulous POV until I read/listened to some of the literature.  The thing is - you're 100% right, you're not being hyperbolic.  This is basically acknowledged by the proponents of the ARM mission at this point, when they say things like 'this is going through the ops program instead of the science program' during the last telecon. 

SLS/Orion needs something to do, something to train a generation of engineers in BLEO manned operations, something that would not put astronauts at risk on a 3-year mission, something that fit within NASA's existing budgetary outlook.

I used to be this cynical as well--I even came up with a mean nickname for the whole scheme. I've never been a huge fan of SLS or Orion, and it seemed like a desperate attempt to give them some sort of mission beyond a cislunar figure-8. I don't doubt that there's at least *some* truth to that cynicism, but I've grown a lot more interested in the mission the more I've gotten to know it. Yes, as I've said before, the fact that I'm getting paid to work on a study for this contract does make me biased, but it also has made me more familiar with what they're doing, and with what they (or others) could do with things if this mission were to happen.

I still think the key points to me are:

1- This will bring a new moon (somewhere between 90-1000mT worth) into the Earth-Moon system. Regardless of how many samples the Orion mission gathers, most of that mass will still be there available for either future NASA missions, or better yet commercial or international missions.

2- From a science perspective this is only so interesting, but from an ISRU standpoint it is fascinating. Sure, for about 2-3x the cost of the Osiris-Rex mission we'll bring back 2M-20Mx as much mass. And the samples we take can be investigated in the context of their surroundings way better than could be done via a purely robotic mission. But the biggest boon is just having a huge asteroid rock that can be of a sort that would have a hard time surviving reentry available for testing all sorts of asteroid processing schemes. I think most asteroid mining schemes suffer from "too many AeroE's and too few ChemE's" and this would be a way to start getting real experience.

3- The approaches I've been closest involved with have a lot of potential for commercial follow-on.

4- I'm of the opinion that Phobos and Deimos have the potential of being key enablers for future Mars missions (via ISRU propellants delivered to LMO). The same hardware designed for Option B could be used to return a sample from those Moons. If the particular Option B scenarios I've been involved with were selected, this could be done at less marginal cost beyond the initial ARM mission (at least to get the sample back to the Moon) than a traditional robotic sample mission. Getting material back from Phobos or Deimos could really help in understanding if they are realistic ISRU sources, and if so, debugging the tools so that the first manned mission to Phobos/Deimos could have a good chance of setting up and debugging a serious ISRU facility. A source of fuel in Mars orbit could make a Mars missions cheaper for everyone.

5- I can't remember where I saw it publicly, but apparently one of the potential uses for the commercial-derived Hab module that NASA's studying under the NextSTEP BAA was to provide a hab module at the ARM asteroid sample to enable longer-duration exploration and study of the asteroid sample, and to demonstrate long-duration habitation at some place close enough you could safely make it home if something goes wrong. This would basically create a tiny man-tended NEO-lab in lunar orbit (that could also serve as a lunar gateway).

I just think that so many of the naysayers have such a limited view of what's going on. Admittedly NASA hasn't provided a ton of clarity on exactly what they're trying to do, probably since they're trading two so very different options, but I hope that will continue to change in the 1st quarter of this new year.

~Jon

Offline savuporo

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Re: Asteroid Retrieval Mission Concept
« Reply #183 on: 12/28/2014 04:33 pm »
For those of you that like reading conference proceedings, here is everything about ARM from SpaceOps2014

Extravehicular Activity Asteroid Exploration and Sample Collection Capability (AIAA 2014-1605) PDF link
Integrated Attitude Control Strategy for the Asteroid Redirect Mission (AIAA 2014-1675) PDF link
Asteroid Redirect Crewed Mission Nominal Design and Performance (AIAA 2014-1696) PDF link
Contingency Trajectory Planning for the Asteroid Redirect Crewed Mission (AIAA 2014-1697) PDF link
Asteroid Crewed Segment Mission Lean Development (AIAA 2014-1698) PDF link
Extensibility of Human Asteroid Mission to Mars and Other Destinations (AIAA 2014-1699) PDF link
Asteroid Redirect Crewed Mission Space Suit and EVA System Architecture Trade Study (AIAA 2014-1717) PDF link
Rendezvous and Docking Strategy for Crewed Segment of the Asteroid Redirect Mission (AIAA 2014-1796) PDF link

I was disappointed to see there is not much discussion about the robotic key component of the mission. But then ...

Here are abstracts from AIAA SPACE 2014 in August, San Diego

Technologies Enabling Colonization of Near-Earth Asteroids (AIAA 2014-4372) Abstract page PDF
Asteroid Redirect Robotic Mission: Robotic Boulder Capture Option Overview (AIAA 2014-4432) Abstract page PDF
Proximity Operations for the Robotic Boulder Capture Option for the Asteroid Redirect Mission (AIAA 2014-4433) Abstract page PDF
Boulder Capture System Design Options for the Asteroid Robotic Redirect Mission Alternate Approach Trade Study (AIAA 2014-4434) Abstract page PDF
Near-Earth Asteroid (NEA) Scout (AIAA 2014-4435) Abstract page PDF

Um, oh ok there is alot more at
http://arc.aiaa.org/doi/book/10.2514/MAST14
http://arc.aiaa.org/doi/book/10.2514/MJPC14
« Last Edit: 12/28/2014 04:39 pm by savuporo »
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Offline Vultur

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Re: Asteroid Retrieval Mission Concept
« Reply #184 on: 12/29/2014 02:19 am »
It certainly could be a quite valuable mission.

I'd much prefer a trip to an asteroid in its normal orbit, though. ARM sort of strikes me as an excuse to delay long-duration BEO human spaceflight, and I'm not convinced that developing a hab would be more expensive than developing the unmanned asteroid-catcher craft. (Especially since you could modify a Bigelow one rather than design something really new.)

Offline jongoff

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Re: Asteroid Retrieval Mission Concept
« Reply #185 on: 12/29/2014 04:09 am »
It certainly could be a quite valuable mission.

I'd much prefer a trip to an asteroid in its normal orbit, though. ARM sort of strikes me as an excuse to delay long-duration BEO human spaceflight, and I'm not convinced that developing a hab would be more expensive than developing the unmanned asteroid-catcher craft. (Especially since you could modify a Bigelow one rather than design something really new.)

The main reason why I prefer ARM to a visit to a free-range asteroid is that you're only going to get a short visit to a free-range asteroid, then you'll have to wait years and years for follow-ons, since synodic periods for most readily accessible asteroids are so crappy. It may be a cooler stunt, and may test long-duration spaceflight more, but I'm really in it for the ISRU, where repeat visits whenever you want to the same object might be worth more than the novelty of going to a bigger asteroid in deep space.

~Jon

Offline QuantumG

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Re: Asteroid Retrieval Mission Concept
« Reply #186 on: 12/29/2014 04:14 am »
Why not do an asteroid redirect mission then? As in, redirect the asteroid into a more agreeable synodic period? If your goal is to restructure the solar system to the benefit of humankind, get on with it.
Human spaceflight is basically just LARPing now.

Offline A_M_Swallow

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Re: Asteroid Retrieval Mission Concept
« Reply #187 on: 12/29/2014 07:55 am »
Why not do an asteroid redirect mission then? As in, redirect the asteroid into a more agreeable synodic period? If your goal is to restructure the solar system to the benefit of humankind, get on with it.


More complexity.  Lets test the Orion's 21 day mission ability first.

Offline A_M_Swallow

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Re: Asteroid Retrieval Mission Concept
« Reply #188 on: 12/29/2014 08:15 am »
{snip}
5- I can't remember where I saw it publicly, but apparently one of the potential uses for the commercial-derived Hab module that NASA's studying under the NextSTEP BAA was to provide a hab module at the ARM asteroid sample to enable longer-duration exploration and study of the asteroid sample, and to demonstrate long-duration habitation at some place close enough you could safely make it home if something goes wrong. This would basically create a tiny man-tended NEO-lab in lunar orbit (that could also serve as a lunar gateway).

I just think that so many of the naysayers have such a limited view of what's going on. Admittedly NASA hasn't provided a ton of clarity on exactly what they're trying to do, probably since they're trading two so very different options, but I hope that will continue to change in the 1st quarter of this new year.

~Jon

The request for proposals for the hab module is in Appendix B of the Next Space Technologies for Exploration Partnerships (NextSTEP) Broad Agency Announcement NNH15ZCQ001K, which mentions using it as a node.
http://prod.nais.nasa.gov/eps/eps_data/163051-AMEND-001-001.pdf
« Last Edit: 12/29/2014 08:18 am by A_M_Swallow »

Offline Nilof

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Re: Asteroid Retrieval Mission Concept
« Reply #189 on: 12/29/2014 01:03 pm »
Why not do an asteroid redirect mission then? As in, redirect the asteroid into a more agreeable synodic period? If your goal is to restructure the solar system to the benefit of humankind, get on with it.

As I understand it, that could easily be incorporated into the plan for option B, which includes changing the orbit of a big asteroid by acting as a gravity tug. The hardware would lend itself fairly well to changing the orbit of a bigger NEO to a 1:1 resonant orbit. Furthermore, you get a large sample of the asteroid back to lunar orbit, which can be used to test the ISRU equipment at any time before you send it to the asteroid.
« Last Edit: 12/29/2014 08:40 pm by Nilof »
For a variable Isp spacecraft running at constant power and constant acceleration, the mass ratio is linear in delta-v.   Δv = ve0(MR-1). Or equivalently: Δv = vef PMF. Also, this is energy-optimal for a fixed delta-v and mass ratio.

Offline Hop_David

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Re: Asteroid Retrieval Mission Concept
« Reply #190 on: 12/29/2014 02:53 pm »
It certainly could be a quite valuable mission.

I'd much prefer a trip to an asteroid in its normal orbit, though. ARM sort of strikes me as an excuse to delay long-duration BEO human spaceflight, and I'm not convinced that developing a hab would be more expensive than developing the unmanned asteroid-catcher craft. (Especially since you could modify a Bigelow one rather than design something really new.)

The more accessible an asteroid, the rarer the launch windows.

Synodic period is (P1*P2)/(P1-P2). So if an asteroid's period is 1.1 years, it's synodic period with regard to earth would be:
(1.1*1)/(1.1-1) years. That's 11 years.

We have zero experience with asteroid ISRU. Initially it will be very much a trial and error process. To build up useful infrastructure would take repeated missions. What would be the pace of infrastructure development if launch opportunities are 11 years apart?

At this stage of the game, a visit to an asteroid in heliocentric orbit would be a purely flags and footprints publicity stunt.


Offline RonM

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Re: Asteroid Retrieval Mission Concept
« Reply #191 on: 12/29/2014 03:33 pm »
At this stage of the game, a visit to an asteroid in heliocentric orbit would be a purely flags and footprints publicity stunt.

It also could be a useful test of equipment and exploration techniques before a mission to Phobos. If we are going to have a manned BEO program, we need a series missions to figure out what we are doing before landing on Mars.

Offline Vultur

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Re: Asteroid Retrieval Mission Concept
« Reply #192 on: 12/29/2014 04:39 pm »
Synodic periods - good point. I wasn't really thinking in terms of ISRU, at least for the first mission, but in terms of exploring the asteroid itself. Follow up missions wouldn't necessarily be to the same asteroid.

If ISRU is the point, then yes, moving the asteroid makes sense.

Offline ehb

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Re: Asteroid Retrieval Mission Concept
« Reply #193 on: 12/29/2014 04:49 pm »
Jon,

Thank you for your insight on this topic and I had a couple of questions perhaps you (or others) could answer.

After listening to the recent conference
I thought: I like Option B, it could be the basis for a series of missions bringing bits of the solar system back.  And quickly afterwards, I thought cynically of some future 2030's politician "we have achieved the goal of a human visit to Mars before 2040", except it is a chunk of Mars brought back to lunar orbit by MRM.

But if this is all we choose to afford, I'm still excited about any HSF BLEO.
I wonder if 'citizens' were allowed the choice of allocating a % of their tax payments to specific programs... but I digress...

To the point:

...
4- I'm of the opinion that Phobos and Deimos have the potential of being key enablers for future Mars missions (via ISRU propellants delivered to LMO). The same hardware designed for Option B could be used to return a sample from those Moons.
...
~Jon

You state the same Option B hardware could be used to return samples from Phobos and Deimos.  These are much larger than the 100m to 500m asteroids that seem to be the target of Option B. 

1. I was curious as to how much of gravity well option B hardware can handle?

We were designing for a 3.75m diameter boulder (about 90mT assuming 3.3tonne/m^3 rock) for our "Option B" ARM BAA design point. Now, I don't know if the rest of the system can handle that size with realistic destination asteroids, etc., but 1.5-2.5m is a lot smaller than what we've been focused on.
Heck, the 1G ground test prototype we're building is sized for a 1m diameter boulder...
~Jon
You state a 3.75 m ~90mT design target.

(edit: for potential subsequent missions:)

2. By what factor do you feel this could be somewhat easily scaled up?

3. What are the main hurdles to get to say 500mT or 1k mT?

TIA
-ehb.

 
« Last Edit: 12/29/2014 05:00 pm by ehb »

Offline Hop_David

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Re: Asteroid Retrieval Mission Concept
« Reply #194 on: 12/29/2014 07:02 pm »
Synodic periods - good point. I wasn't really thinking in terms of ISRU, at least for the first mission, but in terms of exploring the asteroid itself. Follow up missions wouldn't necessarily be to the same asteroid.

If ISRU is the point, then yes, moving the asteroid makes sense.

If the end goal is flags and footprints or one off scientific missions, I believe ~20 billion is too high of an annual budget for NASA. As a taxpayer I would call for the elimination of NASA.

If the end goal is use of space resources and/or human settlement of space, it's worth that investment plus much more.

So (in my view) ISRU is the point.

A rock in lunar orbit would make a great test bed for entities like Planetary Resources or Deep Space Industries. Launch windows open every two weeks from a given orbit. Trip time is about a week.

For robots, light lag latency is about 3 seconds. And since signal strength falls with inverse square of distance, bandwidth is 100s to 1000s times better than something in heliocentric orbit.

A rock parked in our neighborhood would be a very helpful test bed for developing a fledgling asteroid mining technology.

« Last Edit: 12/29/2014 07:04 pm by Hop_David »

Offline jgoldader

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Re: Asteroid Retrieval Mission Concept
« Reply #195 on: 12/29/2014 09:19 pm »


5- I can't remember where I saw it publicly, but apparently one of the potential uses for the commercial-derived Hab module that NASA's studying under the NextSTEP BAA was to provide a hab module at the ARM asteroid sample to enable longer-duration exploration and study of the asteroid sample, and to demonstrate long-duration habitation at some place close enough you could safely make it home if something goes wrong. This would basically create a tiny man-tended NEO-lab in lunar orbit (that could also serve as a lunar gateway).

I just think that so many of the naysayers have such a limited view of what's going on. Admittedly NASA hasn't provided a ton of clarity on exactly what they're trying to do, probably since they're trading two so very different options, but I hope that will continue to change in the 1st quarter of this new year.

~Jon


If we end up with the beginnings of a lunar orbit outpost, that would be more interesting than the asteroid.  If a couple modules were added, I could imagine somebody teleoperating a rover from lunar orbit.  There was a paper or two about running rovers on the lunar farside from an orbiting Orion, I believe it was, so the idea's at least been investigated a little. 

At some point, a rover with waldo-controlled hands and a decent driving or walking speed needs to happen, that would be a good way to test it. Would give good experience for operating rovers on Mars as well.  Given the list of issues with boots on Mars, running robots from Mars orbit would seem a lot simpler.
Recovering astronomer

Offline savuporo

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Re: Asteroid Retrieval Mission Concept
« Reply #196 on: 12/29/2014 09:58 pm »
  If a couple modules were added, I could imagine somebody teleoperating a rover from lunar orbit.  There was a paper or two about running rovers on the lunar farside from an orbiting Orion, I believe it was, so the idea's at least been investigated a little. 
The entire Lunokhod team is still scratching their heads about this one.
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Offline jgoldader

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Re: Asteroid Retrieval Mission Concept
« Reply #197 on: 12/30/2014 01:35 am »
  If a couple modules were added, I could imagine somebody teleoperating a rover from lunar orbit.  There was a paper or two about running rovers on the lunar farside from an orbiting Orion, I believe it was, so the idea's at least been investigated a little. 
The entire Lunokhod team is still scratching their heads about this one.

Rovers are still a difficult business.  A quickly-moving, dextrous one commanded with less than a half-second time lag would be a major advance.  The Mars rovers are fantastic, but imagine speeds of miles per day and hands that could really manipulate rocks, driven with effectively no time lag.
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Offline savuporo

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Re: Asteroid Retrieval Mission Concept
« Reply #198 on: 12/30/2014 02:16 am »
  A quickly-moving, dextrous one commanded with less than a half-second time lag would be a major advance. ..
This discussion does not really belong in this thread and has happened elsewhere before but : if someone somewhere could submit an even slightly convincing piece of research supporting this argument, i'd be very interested to see that.
Until then, Lunokhods, Yutu, Robonaut, DEXTRE, Orbital Express, DARPA DRC, myriads of ROVs and a lot more serve as an example of teleoperation doing just fine ( and improving ) with signal time lags in order of seconds.
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Offline jongoff

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Re: Asteroid Retrieval Mission Concept
« Reply #199 on: 12/30/2014 02:22 am »
Why not do an asteroid redirect mission then? As in, redirect the asteroid into a more agreeable synodic period? If your goal is to restructure the solar system to the benefit of humankind, get on with it.

I'm not sure that makes any sense. Short synodic periods typically mean higher delta-V (at both ends) to get to/from the asteroid. You'd still be stuck with revisit times >2-3yrs. Whereas with a rock back in lunar DRO you could visit it whenever you wanted (well more accurately, your windows would be like once a month or so).

~Jon

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