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#220 by a_langwich on 11 Apr, 2013 02:03
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You can frame just about any initiative to look ridiculous.
A standard debate point, used by people who do not care to discuss TRL levels of technology, poor cost estimating, and other details of sketchy analysis.
John, you are living up to your signature.
The TRL levels of the hardware mentioned in the paper are said to be at TRL 6 or better. Which specific parts are you concerned about? If you mention anything relating to SLS, I am going to mock you mercilessly. The riskiest portion of the ACR mission, IMO, is the capture. As the paper points out, it's not "capture" so much as attachment to a ~500 tonne spinning object. But as far as I can tell, you are swinging your rhetorical sword at random other phantoms, some of which have no basis in reality.
You obvious have a big burr in your shorts about SLS. I can't help you much with that, it's a personal problem. But blaming this mission for the costs of SLS, or claiming that the robotic capture mission should somehow incorporate the costs of SLS, is not an intelligent argument. It is ludicrous to claim that not doing so is poor cost estimating.
There already were on record ideas and tentative plans for EM-1, EM-2, etc. It's like claiming the entire Apollo program up to Apollo 8 should be treated as a cost to read Genesis on a trip around the moon, or arguing early in the Apollo program that looping around the moon should not be done because it represented an abdication of all future goals. WTF? Detailed planning for the manned portion of the concept has not apparently been done yet. Is that a surprise? We are talking the 2021-2025 time frame...how many events in 2021 have you planned out in detail?
Edit: the one criticism you've made with which I might agree is that there's a good chance the timing for the robotic capture mission will not line up well with the timing for EM-2, or whichever mission they planned to use. The example asteroid used in the report, one of the few known, would actually I think produce a lunar capture time of 2026 (and it's unknown whether it is a C-type asteroid). They may find a whole range of candidates for a variety of time frames, or not. And relatively small "surprises" at the asteroid itself could translate into an extra year of travel time. Similarly, on the SLS side, there is significant uncertainty about the timeline, especially out in the 2021-2025 time frame. It is certain there will be restructuring in the program before then, and it's conceivable SLS will be cancelled/replaced entirely.
However, these don't seem like showstoppers to me. The early work done to find a candidate will pay off in much-needed knowledge, no matter what. An asteroid brought into lunar orbit before SLS is ready, or even if no SLS is available, would be still be enormously useful. Lunar X-NASA-asteroid Prize, anyone? It still is relevant, no matter if you are looking at the moon, Mars, or an asteroid as a longer term destination. Similarly, if SLS progresses faster but Two Men and a Truck runs into snags, it is still useful for later visits. For example, you could test the DSH you keep mentioning, if you've run later in the development program where you had time and money to develop DSH. -
#221 by ChileVerde on 11 Apr, 2013 02:19
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OK some questions that I have that are probably a bit funny:
1. So once NASA's spacecraft caught the asteroid, does it mean that a certain United States authority would have the ownership of the asteroid. Suppose that before/after EM-2, someone else (China/private organization etc.) want to visit the asteroid too - can the US denies the right to do so (even when, of course, there's no way to do that physically!)?
This is why beneficent Providence has created lawyers and diplomats. I suspect that the proper approach would be for the US to encourage creation of a cooperative regime to exploit the asteroid. The fact that the rock, per today's excellent video, would remain attached to and indeed enveloped by US property would probably give the US some legal leverage.Quote2. Since the asteroid is put in a high lunar orbit, it will eventually spiral down and collide with the Moon some many years later. Who should be responsible from preventing (or leading, depending on the reason) this happening, and when?
Interesting point. Again per the video, the SEP unit would remain attached and so potentially provide some options for future maneuvering of the asteroid. Or a new propulsion unit could be provided when the time came.
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#222 by a_langwich on 11 Apr, 2013 02:27
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Unless I've missed it, have they mentioned what LV will be used for the retrieval craft?
Dare I say this could be the mystery SLS Cargo mission in 2019, or is this in the realm of a medium launcher?
The Keck study said Atlas V, and a spacecraft mass of 18,000 kilos. If the retrieval craft ends up weighing in at less than 20 tonnes, I don't think this can justify an SLS cargo mission.
Of course, if this would be an SLS cargo launch, then why not scale up the design? Three times the IMLEO, three times the asteroid mass, square-cube law makes that almost half-again as wide.
Excellent, thanks!
Robotbeat posted this earlier, but look at pg 14 mentions an Atlas 551 as baseline
http://www.kiss.caltech.edu/study/asteroid/asteroid_final_report.pdf
And the concept is using SEP to move the asteroid, a process which necessarily involves years (5-8 years for various missions shown in the report). You might be able to scale up the SEP to move it faster, but I'm not sure the math closes on that (more SEPs chained also means more solar arrays and more fuel). However, the extra time also allows a much longer time to hunt for candidates, which might (cross your fingers) produce a better candidate which helps close the numbers.
It's possible a Falcon Heavy might be an option in a year or two. I'm not sure the lack of a high-energy upper stage would be a problem here, since the vehicle in question is using SEP. -
#223 by RocketmanUS on 11 Apr, 2013 02:29
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If SLS or other HLV were to be used then it could be launched with an EDS to shorten then travel time to the NEA. And as we know that would add more cost.Unless I've missed it, have they mentioned what LV will be used for the retrieval craft?
Dare I say this could be the mystery SLS Cargo mission in 2019, or is this in the realm of a medium launcher?
The Keck study said Atlas V, and a spacecraft mass of 18,000 kilos. If the retrieval craft ends up weighing in at less than 20 tonnes, I don't think this can justify an SLS cargo mission.
Of course, if this would be an SLS cargo launch, then why not scale up the design? Three times the IMLEO, three times the asteroid mass, square-cube law makes that almost half-again as wide.
Hopefully a commercial company would be ready to mine the asteroid before it would crash into the moon.OK some questions that I have that are probably a bit funny:
1. So once NASA's spacecraft caught the asteroid, does it mean that a certain United States authority would have the ownership of the asteroid. Suppose that before/after EM-2, someone else (China/private organization etc.) want to visit the asteroid too - can the US denies the right to do so (even when, of course, there's no way to do that physically!)?
This is why beneficent Providence has created lawyers and diplomats. I suspect that the proper approach would be for the US to encourage creation of a cooperative regime to exploit the asteroid. The fact that the rock, per today's excellent video, would remain attached to and indeed enveloped by US property would probably give the US some legal leverage.Quote2. Since the asteroid is put in a high lunar orbit, it will eventually spiral down and collide with the Moon some many years later. Who should be responsible from preventing (or leading, depending on the reason) this happening, and when?
Interesting point. Again per the video, the SEP unit would remain attached and so potentially provide some options for future maneuvering of the asteroid. Or a new propulsion unit could be provided when the time came. -
#224 by Eric Hedman on 11 Apr, 2013 02:41
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I'm curious if the capture mechanism could also be used to remove spent upper stages from earth orbit to help mitigate orbital debris. Any comments on if that would be a good dual use of the technology developed if this goes forward?
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#225 by RocketmanUS on 11 Apr, 2013 02:45
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I'm curious if the capture mechanism could also be used to remove spent upper stages from earth orbit to help mitigate orbital debris. Any comments on if that would be a good dual use of the technology developed if this goes forward?
Good idea and commercial companies are probable already working on that. Also on how to reuse that material in space ( repurpose )
The capture part might come in in different concepts for different items.
The SEP could be refueled. -
#226 by Chris Bergin on 11 Apr, 2013 02:52
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Unless I've missed it, have they mentioned what LV will be used for the retrieval craft?
Dare I say this could be the mystery SLS Cargo mission in 2019, or is this in the realm of a medium launcher?
The Keck study said Atlas V, and a spacecraft mass of 18,000 kilos. If the retrieval craft ends up weighing in at less than 20 tonnes, I don't think this can justify an SLS cargo mission.
Of course, if this would be an SLS cargo launch, then why not scale up the design? Three times the IMLEO, three times the asteroid mass, square-cube law makes that almost half-again as wide.
Excellent, thanks!
Robotbeat posted this earlier, but look at pg 14 mentions an Atlas 551 as baseline
http://www.kiss.caltech.edu/study/asteroid/asteroid_final_report.pdf
I hate it when people don't read the entire thread before posting!
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#227 by Eric Hedman on 11 Apr, 2013 03:08
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Chris:
I hate it when people don't read the entire thread before posting!
This is the first time this has ever happened!
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#228 by arachnitect on 11 Apr, 2013 05:15
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I'm curious if the capture mechanism could also be used to remove spent upper stages from earth orbit to help mitigate orbital debris. Any comments on if that would be a good dual use of the technology developed if this goes forward?
Who else thought of that scene in You Only Live Twice where the supervillain captures a Gemini capsule in orbit?
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#229 by R7 on 11 Apr, 2013 09:19
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Who else thought of that scene in You Only Live Twice where the supervillain captures a Gemini capsule in orbit?
Spot on
The new promo video could be cut into next Bond film as is. And I bet I'm not the only one who has thought of the potential "harsh mistress" application of asteroid bagging hardware. There's your evil ploy for the film.
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#230 by Ben the Space Brit on 11 Apr, 2013 09:28
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The early work done to find a candidate will pay off in much-needed knowledge, no matter what.
I have to agree that an attempt to find and track 5-10m-class meteors in near-Earth orbits would justify the expenditure even if the capture mission itself does not fly. -
#231 by manboy on 11 Apr, 2013 10:14
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Animation Of Proposed Asteroid Retrieval Mission | Video
The music reminds me of the Lord of the Rings theme (which isn't a bad thing).
Published on Apr 10, 2013
NASA's 2014 budget proposes a mission to robotic-ally capture a small near-Earth asteroid and bring it into a stable lunar orbit where astronauts can visit and explore it, a 'stepping stone' to future missions to farther asteroids. -
#232 by Robert Thompson on 11 Apr, 2013 10:47
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attached … enveloped … future maneuvering
The finest metric of ownership I've seen. What OST.Lord of the Rings theme (Howard Shore)
Also James Horner in STII. -
#233 by mikes on 11 Apr, 2013 13:29
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I like the name "Asteroid Retrieval & Utilization Mission" with the acronym ARUM. During the first deployment stage (00:55 to 01:05) the canopy does look like a flower opening, though more like a water lily than an arum lily.
I think they need to relocate the HGA - as the bag is drawn back there's a lot of material waving around very close to it!
To add to the debate: once NASA has done an "official" human exploration, this would be accessible by third parties (whether private industry or Universities) using secondary payload systems such as Spaceflight's Sherpa. That could open things to a much larger field of players.
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#234 by Lar on 11 Apr, 2013 14:55
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#235 by Chris Bergin on 11 Apr, 2013 14:58
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Here's our article on this all.....
http://www.nasaspaceflight.com/2013/04/captured-asteroid-mission-redefining-em-2-challenge/
I'll set up another thread, as it covers a few areas outside of this specific mission. -
#236 by alexterrell on 11 Apr, 2013 15:16
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What propulsion system would they use and why so long. Some numbers with basic estimatons:Can anyone provide a "for example asteroid" and guess what the delta-V needed to bring it into orbit (HEO, HMO, LM1/2). Then we can guess some of the mission parameters such as thrust and power needed vs. duration of the mission.
The paper gives an example on page 16, NEA 2008HU4, which has close approaches in 2016 and 2026. On page 28, they list the delta-V required to place it in high lunar orbit as 160 m/s. Since the weight of this asteroid is not known, they give example trajectories for weights ranging from 250t to 1300t in Table 5 on page 30, with arrival C3s between 1.6-1.8 km^2/s^2. If, instead of high lunar orbit, you drop it exactly at L2, the total mass moved drops to 200t even using an 8-year travel time.
Mass 1000 tons
Delta V 160 m/s
Exhaust speed 30000 m/s
Exhaust mass 5.333333333 tons
5333.33 kg
Exhaust energy 2.4E+12 Joules
efficiency 50%
electrical energy 2.08333E-13 Joules
Power 100 KW
time 24000000 Seconds
6666.666667 Hours
277.7777778 days
Even allowing for manouvering and coasting, it seems a long mission time.
Keck Institurte proposes ion thrusters (5x10KW) but VASIMR would be good for this as you could travel out with a high Isp and back with a lower, more energy effcient Isp. -
#237 by Hop_David on 11 Apr, 2013 17:33
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No response from PR or DSI?
Haven't had a chance to read whole thread. But in case someone else hasn't, I'll post links to Lewicki's blog posts:
http://www.planetaryresources.com/2013/04/nasa-wants-to-bag-an-asteroid/
and
http://www.planetaryresources.com/2013/04/nasa-budgets-congressional-hearings-asteroids-oh-my/ -
#238 by Hop_David on 11 Apr, 2013 20:20
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#239 by JohnFornaro on 12 Apr, 2013 14:18
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You can frame just about any initiative to look ridiculous.
A standard debate point, used by people who do not care to discuss TRL levels of technology, poor cost estimating, and other details of sketchy analysis.
John, you are living up to your signature.
It's one of the more truthful ones around here.Quote from: LangwichThe TRL levels of the hardware mentioned in the paper are said to be at TRL 6 or better. Which specific parts are you concerned about?
Uhhhh.... These?It will probably come as a surprise to some that the asteroid capture mechanism itself is "assumed" to be at TRL6. As is DSH, ECLSS, 40 kW class SEP, and more.
More? "reliable robotic anchoring capability"; "Structural characterization, especially of the surface layers"; "dust levitation and settling behavior [mitigation thereof]"; "gravity tractor (GT) concept"; "Proximity operations"; "extraction and purification of water"; "autoreduction of the major mineral magnetite"; "using the released CO as a reagent for the extraction, separation, purification, and fabrication of iron and nickel products". All of these assumed to be at TRL6. No exceptions given.Quote from: LangwichIf you mention anything relating to SLS, I am going to mock you mercilessly. The riskiest portion of the ACR mission, IMO, is the capture. As the paper points out, it's not "capture" so much as attachment to a ~500 tonne spinning object. But as far as I can tell, you are swinging your rhetorical sword at random other phantoms, some of which have no basis in reality.
You obvious have a big burr in your shorts about SLS. ...
You're simply not paying attention to what I've written, which is your choice. I have no problems with SLS in certain useful configurations.
Nice handwave about how a "capture" isn't a "capture".Quote from: LangwichWe are talking the 2021-2025 time frame...how many events in 2021 have you planned out in detail?
Nice ad hominem. Somehow my personal schedule pertains to the accomplishment of this mission?Quote from: LangwichEdit: the one criticism you've made with which I might agree is that there's a good chance the timing for the robotic capture mission will not line up well with the timing for EM-2, or whichever mission they planned to use. ...
However, these don't seem like showstoppers to me. ...
You chose to see no relationship between cost and TRL development, nor the importance to remove funding instability by accurate costing, as do the other shills for this mission, who parrot the party line.
This mission, properly costed, is probably closer to $46B than to $2.6B. Above, I've included some of the line items that have not yet been discussed, but which have been deliberately handwaved away, while deceiving policymakers about the accurate costing and feasibility of the asteroid retrieval mission.
Nothing being discussed here. Move along, move along.
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Background on another viewpoint about costing:Just to be clear: $2.6B is the cost to move the asteroid to an L point only, and doesn't include the cost of a subsequent manned mission or sample return, correct?
Yes, that is correct, to answer the question simply and in a straightforward fashion. See Figure 17.
To this cost must be added the several billion dollars per year just to keep the SLS job force employed, with no launches; several more billion for the DSH; several more billion for the actual launch itself to the rock; a few more billion for the capture mechanism; and finally, ignoring the development costs and test flights to evolve SLS to the predetermined size, because these costs have already been characterized as sunk costs.
all costs from the $2.6B Keck estimate also assume everything is TRL6...
"Assumes all technologies are at TRL Level 6 – the estimate does not include any cost for technology development up to TRL 6"
This, IMHO, is also suspect:
"Represents the most likely estimate based on cost-risk simulation results"
It's fine to present the ML, but in general cost risk estimates include the actual s-curve...why? Because almost anyone can interpret the relative risk posture of the estimate via the slope and range...Why bother telling me you did a cost risk estimate and not even include the most basic visual output of the analysis (e.g. cost s-curve)? Also, why not include even a simple statement on what was actually varied in the risk analysis and by how much (assuming this was inputs-based)
From the format, it looks like a NAFCOM estimate - which is all fine and good but makes it even more questionable why the s-curve wasn't included...that's a standard output from NAFCOM...and it would have been really easy to throw a sentence in there about how mass was varied and by how much...
And lastly, if you actually did a 'cost risk simulation' adding 30% reserves to the ML at the end is a real head scratcher. The whole point of a risk analysis (cost, schedule, joint, whatever) is to provide a probabilistic range of values so we don't have to go off and apply some 30% rule of thumb to a point estimate. Show the s-curve, highlight a point (like the ML) for budgetary purposes (or the actual budget if it's already set) and provide the confidence levels. I mean come on guys...
Sigh. Sorry, had to vent. I know studies like this don't often allow a lot (if any) time for the estimator too so perhaps I am jumping the gun here with my nits. Apologies in advance to the poor guy or gal reading this who may be thinking to themselves, "man i only got like 2 days to generate estimate". Been there.
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The chart at Figure 17 is remarkably concise, and is probably considered adequate to initiate political support in the right districts, particularly, since this estimate appears to cost only about $100M more than Curiosity.
The study is a "false flag", since there is not an iota of truth in the cost estimate, and there is no widely perceived need nor any pragmatic utility for the information that the mission would discover. They even admit that they are "following up on the ESA Don Quijote study".
My estimate is $46B. Since "delivery of 500 t of material to a high lunar orbit would cost of order $20B", it would cheaper to start launching rocks and ice ASAP.
Of course, they could save "bill-yuns" by eliminating people; their fall back position" "A mission like this even decoupled from human exploration would engage a whole new generation of space interested persons".
"It is important to place the asteroid in a location that is reasonably close to and accessible from Earth (within a few days journey from LEO)" It's nice how close the Moon is, when it suits one's purposes, but how foolish it is when it doesn't suit.
Did they mention that the asteroid is "unique"? Yeah. Here: "There are roughly a hundred million NEAs approximately 7-m diameter".
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The new promo video could be cut into next Bond film as is. And I bet I'm not the only one who has thought of the potential "harsh mistress" application of asteroid bagging hardware. There's your evil ploy for the film.