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#200
by
CriX
on 19 Apr, 2010 04:27
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What a depressing mess! I love what the President has suggested; it is practical, affordable, and challenging. The infighting is just infuriating. The politics and lack of any interest in arriving at a compromise is just so saddening.
I hope some form of this mission is implemented. The question of Moon vs Asteroid as a destination I don't think anyone could say for certain which would pan out in the United States' best interest over, say, the next 20 years. There are compelling arguments for both trajectories, but the negative press and endless questioning is so frustrating.
The good thing is that I believe whatever NASA's path, there will be funding on the side for Elon and Bigelow and the gang, independent of who's in office.
My 2 cents!
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#201
by
vt_hokie
on 19 Apr, 2010 04:33
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The good thing is that I believe whatever NASA's path, there will be funding on the side for Elon and Bigelow and the gang, independent of who's in office.
Yes, capsules going in circles in Low Earth Orbit for the foreseeable future, with no resumption of real exploration for another 15 years under this plan's best case scenario. That's downright depressing.
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#202
by
Rabidpanda
on 19 Apr, 2010 05:01
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The good thing is that I believe whatever NASA's path, there will be funding on the side for Elon and Bigelow and the gang, independent of who's in office.
Yes, capsules going in circles in Low Earth Orbit for the foreseeable future, with no resumption of real exploration for another 15 years under this plan's best case scenario. That's downright depressing.
Not really. Real meaningful BEO exploration takes time to set up. It's not something you can just throw together in a few years. 15 years for an expedition to a NEO is a realistic goal.
As for 'capsules going in circles in Low Earth Orbit for the forseeable future', I would agree that the technology itself is not new and exciting, but the fact that commercial, not government, entities are operating these capsules is certainly new and exciting.
FY2011 is not a perfect plan, I would like it better if work on an HLV started before 2015 and if said HLV was EELV or shuttle derived. However, I think that overall, FY11 does an excellent job of opening up LEO to commerial activity and having an achievable BEO exploration goal. It's certainly not 'downright depressing'.
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#203
by
vt_hokie
on 19 Apr, 2010 05:38
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Well, wake me in 2025 if it looks like we might actually achieve something worthwhile. In the meantime, I've pretty much lost interest and lost hope for our manned space program. Maybe ISS will produce some worthwhile research, if we can make up for the logistics shortfall following shuttle retirement. But I'm not holding my breath.
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#204
by
Garrett
on 19 Apr, 2010 12:07
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For those who haven't been following JAXA's Hayabusa asteroid probe, here is the update thread:
http://forum.nasaspaceflight.com/index.php?topic=7382.0This mission has probably gained more significance for the future of the US space program in light of Obama's speech which stated that the first Beyond Earth Orbit destination for US astronauts will likely be an asteroid.
Chris's article that forms the basis of this thread states:
In NASA’s outline of the mission [to 1999 AO10]
requirements, this target – and likely the case for other NEOs – would require the automated vehicle to arrive at the asteroid several years prior to the human expedition. Such a robotic mission wouldn’t pose a problem for NASA engineers, who would follow a roadmap laid by the Hayabusa robotic mission, led by the Japan Aerospace Exploration Agency (JAXA) to return a sample of material from a small near-Earth asteroid named 25143 Itokawa.(bold emphasis by me)
A nice article on the JAXA mission:
http://spectrum.ieee.org/aerospace/robotic-exploration/bringing-back-a-piece-of-heaven
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#205
by
Cinder
on 19 Apr, 2010 12:41
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The good thing is that I believe whatever NASA's path, there will be funding on the side for Elon and Bigelow and the gang, independent of who's in office.
Yes, capsules going in circles in Low Earth Orbit for the foreseeable future, with no resumption of real exploration for another 15 years under this plan's best case scenario. That's downright depressing.
Pretty sure both Bigelow and Musk said they want to go to Mars. Musk explicitly said and keeps saying that he means to colonize other worlds asap; if in different words.
Well, wake me in 2025 if it looks like we might actually achieve something worthwhile. In the meantime, I've pretty much lost interest and lost hope for our manned space program. Maybe ISS will produce some worthwhile research, if we can make up for the logistics shortfall following shuttle retirement. But I'm not holding my breath.
Writing was on the wall with ridiculously unrealistic Constellation.
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#206
by
SpacexULA
on 19 Apr, 2010 16:06
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The good thing is that I believe whatever NASA's path, there will be funding on the side for Elon and Bigelow and the gang, independent of who's in office.
Yes, capsules going in circles in Low Earth Orbit for the foreseeable future, with no resumption of real exploration for another 15 years under this plan's best case scenario. That's downright depressing.
No other plan offers the REMOTE possibility of BEO development in the next 15 years without MASSIVE budget increases.
Anything but flexible will stall again in 5 years when we shocking have 5 MORE YEARS of basically flat budget. At least with flexible, in 5 years we will have new tech, and some form of limited orbital services market.
Your right, Flexible path can't compare to other "alternatives" that don't take 5 minutes to wonder "Who's going to pay for it".
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#207
by
MP99
on 19 Apr, 2010 17:16
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IIRC, the 2025 DRM mission that Chris referred to in the article related to this thread called for an extreme high-dV hyperbolic transfer orbit and then to follow the NEO to Earth before dropping off in an Orion for a quick descent. I'm sure that I'll be corrected if I've got anything wrong.
See
http://www.nasa.gov/pdf/373449main_09-07_SpaceOps.pdf (copy of page 13 attached). TNI is only 3.3 km/s (cf 3.1 km/s for TLI & 4.2 km/s for TMI). However, rendezvous & TEI adds another 3.9 km/s, which makes the overall mission pretty demanding.
If using hypergolics, nearly 75% of the mass pushed through TNI would be propellant for rendezvous & TEI.
If using hydrolox, 60% of the injected mass would be prop, but then you need zero boiloff for three months, which is pretty challenging and adds it's own mass penalty.
Could VASIMR be ready for the big time by then???
I wonder whether the approach to go to a NEO first and then many years later to Phobos or Deimos is the right thing to do. Personally, I think considering the limited funds NASA does have and the preparation required, Mars orbit should be the primary and most important goal and be focused on for mid-2020s. A NEO mission can be done as a separate mission if funds are available, but shouldn't be done as a priority.
I believe a mid-2020s date for a 4-crew Mars orbital mission would be the goal that NASA needs and which would help it to focus and invest in the right technology.
1999AO10 is about 1/4 the duration & lower delta-V (155 days & 7.2 km/s) then a manned Phobos / Deimos mission, so it is a sensible intermediate step.
(Back to Ben's post...)
That said, am I the only one who has noticed that targets suitable for this mission profile tend to be smaller than the likely mission spacecraft (in the 10-20m long axis bracket)? There is probably a good reason for this - Earth and the Moon have likely already 'swept up' any significant-sized objects in their vicinity. The big boys like the Amors, Apollos and the like (including Eros) are further away and would likely need a specialised MTV design to access rather than the proposed dual-Orion.
If I were asked to name a target, it would be the Earth-Moon co-orbital asteroids that have recently been discovered in 'crescent moon' oscilating positions relative to Earth.
You can't do one NEO mission, then wait another 10 years before attempting moons-of-Mars.
You could visit progressively smaller NEO's, but that will only work a couple of times before Congress gets fidgety.
If more tempting targets need a lot more delta-V, then they're going to be as expensive and difficult as moons-of-Mars. It's going to be a juggling act.
cheers, Martin
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#208
by
simonth
on 19 Apr, 2010 17:34
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1999AO10 is about 1/4 the duration & lower delta-V (155 days & 7.2 km/s) then a manned Phobos / Deimos mission, so it is a sensible intermediate step.
It depends on the cost comparison between a 1999AO10 mission vs. a Deimos or Phobos mission. If the costs aren't that much larger for a Mars orbital mission but using 1999AO10 as an intermediate step delays a Deimos/Phobos mission for 7-10 years would mean that a concious decision could be made to "skip" an asteroid mission.
At the end, I just hope NASA gets its act together and tries to reduce costs of deep space missions. Does it really make sense to expense 20 billion for a HSF asteroid mission with a 15 year lead time? Can't we do that sooner or at least for less money?
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#209
by
Ben the Space Brit
on 19 Apr, 2010 17:47
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If using hypergolics, nearly 75% of the mass pushed through TNI would be propellant for rendezvous & TEI.
If using hydrolox, 60% of the injected mass would be prop, but then you need zero boiloff for three months, which is pretty challenging and adds it's own mass penalty.
Could VASIMR be ready for the big time by then???
Remember: VASMIR is a low-thrust, high Isp engine. It would be best utilised from an EML staging point. Not unthinkable but a significant modification to the mission plan.
As for chemical propulsion, the obvious option is to overload the EDS with much more propellent than it needs for the rendezvous burn and
let it boil off, knowing that you have the margin. There would be penalties, of course - more mass to send through TOI. However, I doubt that it is unsurmountable. Remember, the TEI mass would be only marginally different as the extra mass of propellent would have boiled off. That is probably why the Phobos DRM has so many engine stages - to mitigate the boil-off during trans-Mars cruise and Martian parking orbit.
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#210
by
mike robel
on 19 Apr, 2010 18:27
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bleh. The Moon is a NEO. It's just regular. And big.
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#211
by
MP99
on 19 Apr, 2010 20:50
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1999AO10 is about 1/4 the duration& lower delta-V (155 days & 7.2 km/s) then a manned Phobos / Deimos mission, so it is a sensible intermediate step.
It depends on the cost comparison between a 1999AO10 mission vs. a Deimos or Phobos mission. If the costs aren't that much larger for a Mars orbital mission but using 1999AO10 as an intermediate step delays a Deimos/Phobos mission for 7-10 years would mean that a concious decision could be made to "skip" an asteroid mission.
At the end, I just hope NASA gets its act together and tries to reduce costs of deep space missions. Does it really make sense to expense 20 billion for a HSF asteroid mission with a 15 year lead time? Can't we do that sooner or at least for less money?
AFAICT, the issue is the length of the Mars mission, not that it's either / or with NEO.
CLLS needs to be more efficient for 4x the duration.
Total radiation dose will build up over the longer mission.
As impatient as I am I don't think that 2030+ is over-cautious for a two-year Mars-moon mission. There
is a lot to learn before this can happen.
NEO mission is intended to be undertaken as soon as it becomes feasible, and will teach lessons that feed into the Mars transit.
Indeed, this will be the culmination of a series of less ambitious test missions. Part of my problem with FY2011 is that it doesn't seem to begin BLEO test flights early enough (ie this decade) for NEO 2025 to be feasible.
cheers, Martin
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#212
by
MP99
on 19 Apr, 2010 20:56
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bleh. The Moon is a NEO. It's just regular. And big.
Regardless of whether it delays Mars a bit, I'm still firmly of the opinion that the Moon is the only destination which can be delivered quickly enough (DIRECT-style, ULA-style) to avoid Congress reclaiming NASA's budget for something else. Even if it has to start as missions of a few days and build up from there.
cheers, Martin
Edit: ie trade 6-month life support / radiation shielding (NEO) for a larger delta-V (Lunar descent/ascent), which is ultimately a matter of brute-force mass-into-orbit, or propellant depots.
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#213
by
robertross
on 19 Apr, 2010 21:43
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bleh. The Moon is a NEO. It's just regular. And big.
Regardless of whether it delays Mars a bit, I'm still firmly of the opinion that the Moon is the only destination which can be delivered quickly enough (DIRECT-style, ULA-style) to avoid Congress reclaiming NASA's budget for something else. Even if it has to start as missions of a few days and build up from there.
I don't think a criteria like that would stop congress from de-funding ANYTHING. Or on the flip side: "NASA, you spent all that money, got to the moon, and now we have even more moon rocks. Sorry, nothing left for NEO or a Mars flyby mission"
Everything is open to cancellation. Everything. You just pay the exit clause penalty, that's all. That's Obama had in his budget: cancel everthing being developed for the long term, focus on the short term. Pay the people off. Pay for it all over again in another 5 years time.
Flexible path, fixed path...it doesn't matter. We should just be thankful we're getting something to keep what many of us consider our 'hobby' alive, compared to others keeping their 'livelyhood' alive, their families fed, and a roof over their heads.
But anyway, a NEO it is, so let's get with it and make it happen.
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#214
by
simonbp
on 20 Apr, 2010 00:50
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The total mass of the inner solar system asteroids (everything not a planet or moon inside of Jupiter) is just about 4% of the mass of the Moon. And half of that is in the four largest asteroids. In other words, the Moon isn't just big; it's bloody enormous.
While one or two visits to an earth-crossing asteroid could be useful, we actually quite a lot about them already (from meteorites). Otherwise, if you are going to an asteroid, go to an exciting one: Pallas, Vesta, or especially Ceres. Indeed, Ceres is not only almost certainly the most complex and least understood asteroid, it actually has the potential for extant, current life in its deep interior (much more so than Mars, in fact). Plus, it's much easier to land on or take off from than either Mars or the Moon...
And if you're not going to an asteroid, and unless someone invents warp drive tomorrow, the Moon hands-down will deliver the most science bang for the buck. But note that the Augustine Commission had no planetary scientists on it...
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#215
by
FinalFrontier
on 20 Apr, 2010 00:55
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bleh. The Moon is a NEO. It's just regular. And big.
Regardless of whether it delays Mars a bit, I'm still firmly of the opinion that the Moon is the only destination which can be delivered quickly enough (DIRECT-style, ULA-style) to avoid Congress reclaiming NASA's budget for something else. Even if it has to start as missions of a few days and build up from there.
cheers, Martin
Edit: ie trade 6-month life support / radiation shielding (NEO) for a larger delta-V (Lunar descent/ascent), which is ultimately a matter of brute-force mass-into-orbit, or propellant depots.
I agree, although I find asteroid missions particularlly interesting. Moon first to prove we still can and to test all that juicy new tech then on to asteroids.
"The moon is an NEO. Just regular. And big."
ROFLOL
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#216
by
pathfinder_01
on 20 Apr, 2010 01:13
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The total mass of the inner solar system asteroids (everything not a planet or moon inside of Jupiter) is just about 4% of the mass of the Moon. And half of that is in the four largest asteroids. In other words, the Moon isn't just big; it's bloody enormous.
Warp drive not needed. Just the ability to spend months BEO. Ability short jaunts to the moon do not require. Nor will develop because they are not required. I mean 2 weeks at the week two times a year with nothing going in LEO is NOT a space program.
No Lander needed either. This plan gets us closer to real exploration than short missions to nearby objects. This plan allows us to choose to land at a later date rather than try to develop rocket, Lander, capsule all at once. In fact the old plan couldn't even do that and put off everything but the capsule and the non moon rocket.
In terms of science depends. Just about all meteoroids on earth have fallen through the earth's atmosphere and many have been exposed to hundreds if not thousands of years of weathering. There are few fresh samples unaltered by a 3000+ degree plung. There are a wide vartity of near earth objects.
A craft desgined for NEO is a much better bais for moon missions and mars missons than one designed strickly for the moon(like Apollo and it’s short life support). You could linger in LLO longer and have a wider choice of landing spots.
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#217
by
alexw
on 20 Apr, 2010 01:38
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The total mass of the inner solar system asteroids (everything not a planet or moon inside of Jupiter) is just about 4% of the mass of the Moon. And half of that is in the four largest asteroids. In other words, the Moon isn't just big; it's bloody enormous.
The downside of which is that it's gravity well is deep, both directions, and has to be descended entirely propulsively. It's only virtue from an engineering-difficulty perspective is that it's short-duration, permitting open-loop life support.
While one or two visits to an earth-crossing asteroid could be useful, we actually quite a lot about them already (from meteorites). Otherwise, if you are going to an asteroid, go to an exciting one: Pallas, Vesta, or especially Ceres. Indeed, Ceres is not only almost certainly the most complex and least understood asteroid, it actually has the potential for extant, current life in its deep interior (much more so than Mars, in fact). Plus, it's much easier to land on or take off from than either Mars or the Moon...
Agreed that Ceres would be fascinating, but if you want science, send robots. And, as the Obama plan provides funding for, do tech development missions like SEP and ASRG.
And if you're not going to an asteroid, and unless someone invents warp drive tomorrow, the Moon hands-down will deliver the most science bang for the buck. But note that the Augustine Commission had no planetary scientists on it...
Note that the planetary scientists themselves set scientific priorities via the decadal surveys, and apart from Lunar Prospector (pocket change), the US flew no pure science missions to the moon (IIRC?) between Apollo and LRO/LCROSS (which were themselves driven by the politics of Constellation). That speaks volumes about the priorities of the planetary scientists: Mars, NEOs, outer planets, inner planets, all above Luna. If that's changing for Astro2010, do tell.
-Alex
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#218
by
beb
on 20 Apr, 2010 02:27
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I agree, although I find asteroid missions particularlly interesting. Moon first to prove we still can and to test all that juicy new tech then on to asteroids.
As far as I can tell Obama's plans does not include either a Lunar lander or a martian lander. I suspect one reason he's not interested in Return to The Moon is because of the large costs involved in building a lander. NEO only requires Orion
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#219
by
simonbp
on 20 Apr, 2010 05:11
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The downside of which is that it's gravity well is deep, both directions, and has to be descended entirely propulsively. It's only virtue from an engineering-difficulty perspective is that it's short-duration, permitting open-loop life support.
No, Earth is deep gravity well. A circa-1944 V-2 could reach Earth from the surface of the Moon. It's not that hard. And anyone who tells you different is either an unimaginative engineer or a parrot.
Agreed that Ceres would be fascinating, but if you want science, send robots. And, as the Obama plan provides funding for, do tech development missions like SEP and ASRG.
There is absolutely, positively not reason why you can't do science with a manned mission. It's just that NASA HSF is run by engineers who don't understand or care about science and just want to build big rockets and space stations and prop depots and figure out the uses later. The "Flexible Plan" is emblematic of this. It's like letting the inmates run the asylum!
And we don't need extra funding for lab-bench test of SEP or Stirling engines. We know they work; there's an SEP rocket on its way to Ceres for goodness sake! What we need is actual missions using that technology. But that's too ambitious-sounding for this administration...
Note that the planetary scientists themselves set scientific priorities via the decadal surveys, and apart from Lunar Prospector (pocket change), the US flew no pure science missions to the moon (IIRC?) between Apollo and LRO/LCROSS (which were themselves driven by the politics of Constellation). That speaks volumes about the priorities of the planetary scientists: Mars, NEOs, outer planets, inner planets, all above Luna. If that's changing for Astro2010, do tell.
No, that speaks volumes of what they thought they could get funded. Note that NASA successfully sent nothing to Mars between 1975 and 1996, a similar span of time between Apollo 17 in 1972 and Clementine in 1994. And both Clementine and Pathfinder were shoestring missions that barely made it to the pad.
I am an actual planetary scientist, a minor bodies specialist in fact, and can tell you that given the choice, the vast majority of us would never favor an unmanned mission to an asteroid over a manned one. The guaranteed return is just so much greater. However, because of the way NASA and NRC is set up, there is little opportunity to express this support. I was at several of the decadal survey meetings last fall and it was made clear that any manned missions or anything to do with CxP was beyond the scope of the survey. So don't take its lack to mean anything beyond bureaucratic baliwicks...
ROFLOL 