Quote from: Lobo on 07/21/2009 05:42 pmCould a rover be sent to Phobos first to scout it out? Or would it drift off because of low gravity? Phobos has about 1/1000 the gravity of Earth, so if you had a 1000lbm rover it'd weight 1 lbf on Phobos, not much but it seems like it should stay on the surface as long as it didn't drive too fast. A solar powered rover could explore a lot about Phobos ahead of any potential manned mission there. I'd think. There's a plotline in Heinlein's Space Family Stone where someone performs a (partial, IIRC) orbit of Phobos after taking a running jump.Always wondered how realistic that was.cheers, Martin
Could a rover be sent to Phobos first to scout it out? Or would it drift off because of low gravity? Phobos has about 1/1000 the gravity of Earth, so if you had a 1000lbm rover it'd weight 1 lbf on Phobos, not much but it seems like it should stay on the surface as long as it didn't drive too fast. A solar powered rover could explore a lot about Phobos ahead of any potential manned mission there. I'd think.
The scale of *some* (certainly not all) of the missions which SMD wants to do today is pushing the limits of current ELV/EELV launch assets to their breaking point -- or at the very least to the point where it results in significantly higher overall costs in order to squeeze a payload into a vehicle which just isn't the right size.
I would estimate that this doesn't affect 80% of planed missions at all. But the other 20% (I'm only talking one mission every 2-5 years or so) -- typically the larger, more expensive ones to start with -- could benefit from greater capabilities as long as they don't break the bank.
I'm certain something could be sent to scout the area.There are some unique design challenges for operating in such low gravity, but I'm sure that its nothing which a skilled team couldn't tackle with some innovative new thinking. And the chances are that some of the technology which they invent to tackle those problems would translate into applicable capabilities which a human team could also use later.Sounds to me like a perfect mission for a Jupiter-130/DHCUS to loft...Ross.
Re: WikiAnd can someone PLEASE get rid of those frakkin' Ares images, would ya? Let them "advertise" those launchers on their own pages, not ours Ross.
Re: WikiCan I also ask those good people who are editing the wiki to use the full "Jupiter-xxx" naming convention instead of the truncated "J-xxx" one please?
Quote from: kraisee on 07/21/2009 06:35 pmRe: WikiAnd can someone PLEASE get rid of those frakkin' Ares images, would ya? Let them "advertise" those launchers on their own pages, not ours Ross."Ares V has a low LOM risk factor"Huh, really?
We had no flagship since Cassini in 1997. MSL may be one (kinda), but it is far from the EELV limit. This leaves JWST, 24 years after HST.This is the timescale we are talking: Less than once per decade. As I said, even the rare expensive missions avoid Delta IVH. And you won't be cheaper than Delta IVH, considering you need an upper stage. I don't believe in your cost numbers, sorry.Analyst
Re: WikiJust uploaded this file to possibly replace the "Family" image.http://commons.wikimedia.org/wiki/File:DIRECT_Jupiter_Config_Options.jpgR.
NASA administrator optimistic about manned space flight reviews; confident gap between shuttle and replacement will not be drawn out. http://www.cbsnews.com/network/news/space/current.html
"I don't want anyone to think I have any doubts whatsoever that the Augustine committee is going to bring in a group of options that will include something that is incredibly attractive. I would not be surprised if they brought in an option that was incredibly incredibly attractive, but we couldn't do for one reason or another.
So my guess ... is the options he's going to bring in are going to be options that don't prolong the gap. I don't want to second guess, but I would be surprised if he brought in an option that said OK, it's worth waiting 10 years for."
4) JIMO was outright canceled because the cost of nuclear propulsion were and are astronomical, fitting Delta IVH or not. No launcher can help here.
That's excellent! There's your 3 minute direct presentation! Very clear about what's being done.
For those individuals interested in the manned exploration of Phobos & Deimos, they should study the PHD mission of Dr. Fred Singer & Dr. Brian O'Leary,Etc. In addition, the Russians are planning to launch the Phobos-Grunt Sample Return Mission in Oct,2009. http://www.geoffreylandis.com/Footsteps.pdf http://www.astronautix.com/craft/phdposal.htm http://www.lpi.usra.edu/meetings/phobosdeimos2007/pdf/7021.pdf http://articles.adsabs.harvard.edu/cgi-bin/nph-iarticle_query?1985lbsa.conf..801O&data_type=PDF_HIGH&whole_paper=YES&type=PRINTER&filetype=.pdf http://en.wikipedia.org/wiki/Phobos-Grunt
Ross, I understand you are pushing your booster, but there are serveral problems with your post:1) I am not sure the planned probes to Mars in the late 1960ies ("Voyager", not the outer planets Voyager launched in 1977), would have fit a Titan. But anyway, probably they were smaller than the Saturn V maximum capacity because even back then, with nearly "unlimited" budgets, they could not afford them being big.2) Surveyor never used Titan but Atlas Centaur.3) The MSL trouble hasn't much to do with launch mass, they don't even use the heaviest Atlas (551), nor the even bigger Delta IVH. They would have real trouble with anything larger (size and mass) than the MSL aeroshell during EDL. Whis is the limiting factor, and not because of fairing size, but because of EDL aerodynamics.4) JIMO was outright canceled because the cost of nuclear propulsion were and are astronomical, fitting Delta IVH or not. No launcher can help here.5) JWST: I don't know exactly what their problems are. Likely very special and demanding instruments, extremely tight tolerances etc. Comparing the total overrun to the launch vehicle cost and suggesting a larger launcher would result in no overrun is not valid. Mass does not solve anything. This is a common myth. If it were true, every simple satellite would use Delta IVH, and Pegasus et al. would be out of business.6) MSR: What is the problem with two launches? You need several independent vehicles anyway (lander, return vehicle, maybe an extra rover with the lander or seperate), why not diversify the risk?QuoteThe scale of *some* (certainly not all) of the missions which SMD wants to do today is pushing the limits of current ELV/EELV launch assets to their breaking point -- or at the very least to the point where it results in significantly higher overall costs in order to squeeze a payload into a vehicle which just isn't the right size.If this were true, at least some projects would be using Delta IVH, the current maximum. Only they don't, not even missions in their planning stage (Outer planet flagship). SMD can't afford these. Both Atlas 551 launches are high energy (NH in 2006 and Juno in 2011, look how rare they are).QuoteI would estimate that this doesn't affect 80% of planed missions at all. But the other 20% (I'm only talking one mission every 2-5 years or so) -- typically the larger, more expensive ones to start with -- could benefit from greater capabilities as long as they don't break the bank.We had no flagship since Cassini in 1997. MSL may be one (kinda), but it is far from the EELV limit. This leaves JWST, 24 years after HST.This is the timescale we are talking: Less than once per decade. As I said, even the rare expensive missions avoid Delta IVH. And you won't be cheaper than Delta IVH, considering you need an upper stage. I don't believe in your cost numbers, sorry.Analyst
