Date: Wed, 11 Nov 92 05:00:08 From: Space Digest maintainer Reply-To: Space-request@isu.isunet.edu Subject: Space Digest V15 #406 To: Space Digest Readers Precedence: bulk Space Digest Wed, 11 Nov 92 Volume 15 : Issue 406 Today's Topics: Asteroid impact simulation Automated space station construction (2 msgs) Comet Collision Coverup - gravity doesn't exist? First Saturn 5 Launch - 25 Years Ago Today Galileo HGA: Hypothesis gloves in space Hubble's mirror (3 msgs) Low-Pressure O2 Atmosphere Lunar "colony" reality check Mascons Metric again More lunar gravity questions NASA Coverup (3 msgs) reality check Republican Calendar Russian Engines for DC-Y? what about toutatis? Welcome to the Space Digest!! Please send your messages to "space@isu.isunet.edu", and (un)subscription requests of the form "Subscribe Space " to one of these addresses: listserv@uga (BITNET), rice::boyle (SPAN/NSInet), utadnx::utspan::rice::boyle (THENET), or space-REQUEST@isu.isunet.edu (Internet). ---------------------------------------------------------------------- Date: Tue, 10 Nov 92 15:28:18 GMT From: Doug Mohney Subject: Asteroid impact simulation Newsgroups: sci.space In article , roberts@cmr.ncsl.nist.gov (John Roberts) writes: > >-From: sysmgr@king.eng.umd.edu (Doug Mohney) >-In article , amon@elegabalus.cs.qub.ac.uk writes: > >->With objects sized on the order of Barringer I can well imagine the >->mushroom cloud occuring: the energy is released very rapidly and in a >->very small area. Although at a certain size the explosion simply >->blows a hole in the atmosphere, ie it is a circular curtain rather >->than a mushroom cloud. > >-I wonder how much trouble it would be to try to recreate one of those events >-under controlled and monitoried conditions. > >-All we need is an asteroid, a vacant plot of land, and a lot of confidence >-in our aiming. > >One of the episodes of "Space Age" showed an early V-2 launch where the >rocket was allowed to land ballistically. I believe the crater it made >was 80 feet across and 40 feet deep, with virtually none of the rocket >remaining recognizable. (Thus the incentive to develop in-flight radio >contact for collection of scientific data. :-) Naw, we need to measure the atmospheric effects of a large dense body as it reenters. Holes in the ground are easy to make; the military has perfected it to a fine science. Referring to the original question: Do we get a circular curtain or a mushroom cloud? Of course, the experiment would have to repeated for different circumstances of temperature and humidity. :-) Play in the intelluctual sandbox of Usenet -- > SYSMGR@CADLAB.ENG.UMD.EDU < -- ------------------------------ Date: 9 Nov 92 23:38:00 GMT From: Lee Matheson Subject: Automated space station construction Newsgroups: sci.space To: kcarroll@zoo.toronto.edu (Kieran A. Carroll) From: lee.matheson@syanpse.org (Lee Matheson) Kieran, I saw your e-mail reply, and felt compelled to add to it. Hope you don't mind. I've recently started work on the Space Station program, ... but while I have added some more detailed notes, I am far from an expert. Anyway, comments are added below: KAC>>Is anyone looking into robots with very limited autonomy? That is, KAC>>under direction from a human, but able to execute instructions on KAC>>their own for periods of, say, ten seconds? KAC>> Frank Crary KAC>> CU Boulder KAC>Yes. The Canadian Space Agency (who are developing the Mobile KAC>Servicing System for SSF) are spending about CDN$50M per year KAC>on research into automating various aspects of MSS .... KAC> ..... The idea is that KAC>the baseline MSS will use control technologies very similar to KAC>those used in the Canadarm, in order to expedite development. KAC>Then, improvements will be added over the life of SSF as part of KAC>the ``Evolutionary MSS'' program (funding still TBC). The work being KAC>done now is more in the nature of up-front research and development, KAC>so that the technologies that currently look interesting will have KAC>been tested out prior to setting the requirements for the next KAC>MSS increment. Actually, CDR for the Space Station Remote Manipulator System (SSRMS), which is the name for the Space Station robotic arm, is scheduled for December of this year. Hence its design is pretty far advanced. In addition CSA is actively planning on a second robotic device, smaller but more dexterous than the large Space Station arm. This smaller robotic device is referred to as the "Special Purpose Dexterous Manipulator", or "SPDM" for short. SPDM has two very small arms, and it is currently conceptually planned to operate on the end of the Space Station Remote Manipulator System, or possibly operate on its own on special "power data grapple fixtures" that are located throughout the Space Station. I think the Japanese Experimental Module will also have its own robotic arm, but I don't know anything about that. KAC>Actually, some of that work looks likely to see KAC>earlier use, perhaps even incorporation into the baseline MSS: KAC>the CSA is looking into adding ground-control capability into baseline KAC>MSS, largely to provide a means for dealing with the predicted KAC>external maintenance task backlog (the existence of this backlog KAC>was the main conclusion of the ``Fisher/Price'' KAC>report a couple of years ago; this report was probably the straw KAC>that broke the back of the previous SSF configuration, and led to the KAC>1991 re-design). With ground control, MSS could be operated almost KAC>full-time during the period between flight 3 (when MSS is launched) KAC>and PMC (when SSF will be permanently inhabited); without ground control, KAC>it could be operated during this period only when a shuttle was docked, KAC>which will be for something like 2 weeks out of every 3 months. Operating from the ground would be a real challenge. I believe that there are several technical, and schedule related hurdles to over come before ground operation is possible, ... one of which, I believe, is that the Space Station video system may not be up and running until around flight 5. Without video it is pretty hard to operate the SSRMS from the ground. I believe there are other technical hurdles to over come as well, but the video could be a real show stopper, until flights 5/6 (around when MTC, "man tended capability" starts). However if the ground system is in place, between MTC (flight-6) and PMC (around flight 11, and please pardon the acronymns), it may be feasible to operate the SSRMS from the ground when the Shuttle is on the ground (and hence no astronauts) are in the station. Lee Matheson, Ottawa --- . OLX 2.1 TD . Apathy Error: Don't bother striking any key. ------------------------------ Date: 10 Nov 92 13:35:46 GMT From: Charles Frank Radley <3001crad@ucsbuxa.ucsb.edu> Subject: Automated space station construction Newsgroups: sci.space Space Station Freedom is Apollo type technology ? Really ? Using ADA and 386 / 586 processors and Nickel Hydrogen batteries, - It isd a pretty conservative design, but a lot of new stuff has become available since Apollo ------------------------------ Date: 27 Oct 92 01:46:50 GMT From: Phil Karn Subject: Comet Collision Newsgroups: sci.space In article <92300.101858RFLOOD@ESOC.BITNET>, writes: |> I caught the end of a newsclip on SKY TV this a.m. which said that |> NASA "scientists" (probably the techs. that actually do the real work) |> had tracked a comet on collision course with the earth - I think it |> was due to hit us in 2016. Anyone else hear this, or was I just fantasising |> it ! This showed up as a Reuters story in the afternoon paper in San Diego. The year is 2116 (August 14, to be exact), and the comet is Smith-Tuttle. Caveats were added about the currently imprecise estimate of the comet's orbit. Phil ------------------------------ Date: Tue, 10 Nov 1992 16:38:36 GMT From: Nick Haines Subject: Coverup - gravity doesn't exist? Newsgroups: sci.space In article <1992Nov10.013657.7436@ee.ubc.ca> davem@ee.ubc.ca (david michelson) writes: There are (were?) a couple of "Newtonian" apple trees planted outside the Triumf Meson Facility (world's largest cyclotrom) at the University of British Columbia in Vancouver, too. I gather that Cambridge University makes apple tree seeds which are direct descendants of the trees from the orchard where Newton pondered available to deserving institutions.... If it were anyone, it would be Trinity College. But they don't. No such orchard. I _have_ been to an orchard claimed as such a thing, near where Newton used to live before (?) his Cambridge days: it's near Grantham. There are apple trees there. But the people who run the place (it's owned by the National Trust (? National Heritage? Some such charity)) frankly admit that the whole apple thing is cobblers and only useful to attract tourists. Nick Haines nickh@cmu.edu ------------------------------ Date: 9 Nov 92 21:26:44 GMT From: Bruce Watson Subject: First Saturn 5 Launch - 25 Years Ago Today Newsgroups: sci.space Twenty five years ago, 1967 November 9, the first launch, of the Saturn V, designated Apollo 4 ,took place from Merrit Island, Florida early in the morning. The dummy payload went into a nearly circular orbit of 300 km with an inclination of 32.6 degrees. Decay occurred the same day. I got up before dawn to watch the TV coverage. The old TV had a vertical control problem and I had to turn it off and back on repeatly to get a picture--I felt like I had been part of the effort to get it into space. With this first successful launch, the stage was set for the spectacular feats to occur in the next few years. -- Bruce Watson (wats@scicom) Tumbra, Zorkovick; Sparkula zoom krackadomando. ------------------------------ Date: 10 Nov 92 14:06:20 GMT From: Michel Dignard Subject: Galileo HGA: Hypothesis Newsgroups: sci.space I imported the newly released GIF of Galileo High Gain Antenna (HGA) photographed during its assembly [ames.arc.nasa.gov: /pub/SPACE/GIF/gllhga.gif]. It inspired me the two probably naive following hypothesis, and I wonder if they have been eliminated. Could the HGA be stucked because of: 1) One or more rib bent/compressed during encapsulation/decapsulation? One can observe the curvature at the base of each rib. I imagine the whole antenna has been encapsulated for launch and ascent, and the more "external" part of the ribs was probably close enough to the capsule to be accidentally compressed, either during assembly on ground, during ascent due to vibrations, or during the release of the capsule. [Or the capsule itself has been deformed at some point due to thermal effects.] 2) The transparent "celluloid" kind of dust protection envelope around the HGA during its preparation could have been accidentally torn when removed, and a piece has remained caught at the top of a rib and prevent it to be released, thereby exercising a retaining force on the whole assembly? ------------------------------ Date: 9 Nov 92 18:43:00 GMT From: Bruce Watson Subject: gloves in space Newsgroups: sci.space In article Subject: Hubble's mirror Newsgroups: sci.astro,sci.space From article <1992Nov10.160238.6523@hal.com>, by bobp@hal.com (Bob Pendleton): > From article <69203@cup.portal.com>, by BrianT@cup.portal.com (Brian Stuart Thorn): >> If there is a perfect mirror presumably sitting at Kodak, why doesn't NASA >> simply return Hubble to Earth and replace the faulty mirror? > >> Doesn't bringing Hubble home for repairs make more sense than jerry-rigging >> and dangerous EVAs on orbit? >> >> -Brian > > Depending on whose figures you believe a shuttle launch costs some > where between $100,000,000 US and $250,000,000 US. > > Repair on orbit requires 1 launch. Repair on the the ground requires 2 > launches. > > Thus, repair on orbit, saves somewhere between $100 and $250 million > dollars. As the US is rapidly approaching it's legal debt limit of > roughly $4,100,000,000,000 dollars (your share, if you are a US > citizen, is roughly $16,000) we really can afford to piss away ^^^ That's supposed to be "CAN'T" > $250,000,000 for the convenience of some astronauts and astronomers. > Especially when we are borrowing the money to fix it. > > As much as I value the information that we can get from Hubble. I'm > not willing to go $0.01 US more than is needed to fix it. > > I think it is time to face the simple fact that as long as we are > paying $300,000,000,000 US in interest on the Debt we (US) are not > going to be spending money on large, long term, space programs. > > The interest on the Debt is the single largest item in the US Federal > budget. > > Bob P. > > P.S. > > What we pay in interest on the Debt, if spent on education, would just > about double what we spend per student in the K-12 grades. > > > P.P.S > > Do we need nuclear weopons anymore? Or can we destroy the worlds > economy by just defaulting on the our loans? > -- > Bob Pendleton | As an engineer I hate to hear: > bobp@hal.com | 1) You've earned an "I told you so." > Speaking only for myself. | 2) Our customers don't do that. > <<< Odin, after the well of Mimir. >>> -- Bob Pendleton | As an engineer I hate to hear: bobp@hal.com | 1) You've earned an "I told you so." Speaking only for myself. | 2) Our customers don't do that. <<< Odin, after the well of Mimir. >>> ------------------------------ Date: 10 Nov 92 16:02:38 GMT From: Bob Pendleton Subject: Hubble's mirror Newsgroups: sci.astro,sci.space From article <69203@cup.portal.com>, by BrianT@cup.portal.com (Brian Stuart Thorn): > If there is a perfect mirror presumably sitting at Kodak, why doesn't NASA > simply return Hubble to Earth and replace the faulty mirror? > Doesn't bringing Hubble home for repairs make more sense than jerry-rigging > and dangerous EVAs on orbit? > > -Brian Depending on whose figures you believe a shuttle launch costs some where between $100,000,000 US and $250,000,000 US. Repair on orbit requires 1 launch. Repair on the the ground requires 2 launches. Thus, repair on orbit, saves somewhere between $100 and $250 million dollars. As the US is rapidly approaching it's legal debt limit of roughly $4,100,000,000,000 dollars (your share, if you are a US citizen, is roughly $16,000) we really can afford to piss away $250,000,000 for the convenience of some astronauts and astronomers. Especially when we are borrowing the money to fix it. As much as I value the information that we can get from Hubble. I'm not willing to go $0.01 US more than is needed to fix it. I think it is time to face the simple fact that as long as we are paying $300,000,000,000 US in interest on the Debt we (US) are not going to be spending money on large, long term, space programs. The interest on the Debt is the single largest item in the US Federal budget. Bob P. P.S. What we pay in interest on the Debt, if spent on education, would just about double what we spend per student in the K-12 grades. P.P.S Do we need nuclear weopons anymore? Or can we destroy the worlds economy by just defaulting on the our loans? -- Bob Pendleton | As an engineer I hate to hear: bobp@hal.com | 1) You've earned an "I told you so." Speaking only for myself. | 2) Our customers don't do that. <<< Odin, after the well of Mimir. >>> ------------------------------ Date: Tue, 10 Nov 1992 16:26:03 GMT From: "Michael V. Kent" Subject: Hubble's mirror Newsgroups: sci.astro,sci.space In article <69203@cup.portal.com> BrianT@cup.portal.com (Brian Stuart Thorn) writes: >If there is a perfect mirror presumably sitting at Kodak, why doesn't NASA >simply return Hubble to Earth and replace the faulty mirror? There is no perfect mirror sitting at Kodak. The "mirror" at Kodak is a blank that would need to be ground and polished at considerable expense. >At 24,000 lbs, Hubble is well within >the Shuttle's landing cargo capacity, and since the only part of Hubble >likely to suffer damage during a 3g return is primary mirror (which >will be replace anyway) I don't understand why NASA doesn't simply swap >mirrors. NASA has already spent a fortune building COSTAR and ESA is >building replacement (no wobble) solar panels. With three spacewalks, the >Shuttle crew will be hard pressed to get all the work done. The expense of grinding and polishing a new mirror from the blank and the expense of launching two Shuttle missions (one for retrieval, another for relaunch) is far in excess of the expense of COSTAR and one Shuttle mission. It is also much more time-consuming, and time is science. Meanwhile, while Hubble is on the ground, it is doing *no* science, while considerable cutting- edge work can be done even with the faulty mirror. Add in the possibility that unforseen problems may arise during retrieval, storage, and relaunch, and the sum is that the retrieval option is costlier and riskier than the COSTAR option. At least that's NASA's opinion. If the gyro's, solar panels, and COSTAR can all be fixed, then Hubble should be back up to about 80% planned capability. It is about 15% now. Note to astronomers: I realize one number is not sufficient to decribe all of the qualities of a telescope, but if these figures are true, they give a sense of the magnitude of improvement this revisit should bring. Hopefully all will work as planned. Mike -- Michael Kent kentm@rpi.edu McDonnell Douglas Rensselaer Polytechnic Institute Tute Screwed Aero Class of '92 Apple II Forever !! ------------------------------ Date: Tue, 10 Nov 92 15:09:49 EET From: flb@flb.optiplan.fi (F.Baube x554) Subject: Low-Pressure O2 Atmosphere Carl J Lydick writes: > Subject: Lunar "colony" reality check > giglio@betsy.gsfc.nasa.gov (Louis Giglio) writes: > >The oxygen had to be diluted with something. > >They would have died otherwise. > > You would be correct had the vehicle been pressurized to 1 atmosphere. > However, your conclusion does not follow if the cabin pressure was .2 > atmosphere. But in pure O2 lots of things burn that "shouldn't", like asbestos fibers. This actually happened long before that Apollo capsule burned up, and should have alerted NASA. If our lunar atmosphere is pure O2, then every dust cloud kicked up by a lunar buggy creates an explosion hazard. It will have to be "diluted". Can nitrogen be generated ? What other gases would work ? Helium would leak away too quickly and incidentally create a Planet of the Ducks. /fred :: baube@optiplan.fi ------------------------------ Date: 10 Nov 92 15:21:54 GMT From: Joseph Versagg Subject: Lunar "colony" reality check Newsgroups: sci.space,alt.sci.planetary Sorry for rehashing what was posted earlier, or , even worse, what may now be common knowladge, but what is this about ice at the poles of Mercury? Since Mercury rotates, although slowly, ice would be baked off the surface, then would leak into space due to the low gravity. Also, to answer Nicks anti-lunar base stance: if you buy the theory, any of them, that the moon was part of the earth, or was formed with it in the early solar system, then there is no reason that both bodies are composed of the same elements in similar quantities. Read: it has signifigant amounts of Si, Fe, C, O etc. Is it mineable? Well we won't know until we get there(personally or through probes). C'Ya Joe ------------------------------ Date: 9 Nov 92 19:01:42 GMT From: Bruce Watson Subject: Mascons Newsgroups: sci.space In article Subject: Metric again Newsgroups: sci.space If I remember the press release correctly, NASA is now providing metric equivalents in parentheses after the standard British units. (Someone ought to tell the PR people about precision in numbers when they do the conversion.) In about a year or two, NASA will switch to providing standard metric units with the British units in parantheses. Finally, after a few years the British units will be dropped entirely. I believe, also, that all new starts after 01 Oct 93 must be in metric. As for SSF, there was considerable debate about two years back about whether to convert it to an all-metric station. The cost -- in the tens of millions of dollars -- was deemed too great. SSF is not metric. Mike -- Michael Kent kentm@rpi.edu McDonnell Douglas Rensselaer Polytechnic Institute Tute Screwed Aero Class of '92 Apple II Forever !! ------------------------------ Date: Tue, 10 Nov 1992 11:51:29 GMT From: Paul Dietz Subject: More lunar gravity questions Newsgroups: sci.space A "gal" is 1 cm/s^2. A mgal would be .001 cm/s^2, or about a microgee. Paul F. Dietz dietz@cs.rochester.edu ------------------------------ Date: Tue, 10 Nov 92 08:50:55 EST From: John Roberts Subject: Nasa coverup -From: moroney@ramblr.enet.dec.com -Subject: Re: NASA Coverup -Date: 9 Nov 92 20:01:37 GMT -Organization: Digital Equipment Corporation -In article <1992Nov9.133331.1039@cs.rochester.edu>, dietz@cs.rochester.edu (Paul Dietz) writes... ->In article <1992Nov9.031208.23856@engage.pko.dec.com> moroney@ramblr.enet.dec.com writes: -> > Wouldn't a collision with something that size totally destroyed the Earth, -> > blasting it (and the Mars-sized thing) out of existance leaving not -> > much more than an asteroid belt? If not, wouldn't the system be in a -> > rather elliptical orbit? -> ->Answered in order: (1) no, there is insufficient energy available ->(recall that the gravitational binding energy of a sphere at constant ->density goes as the 5/3 power of the mass) -I was thinking of the Voyager picture of one of the outer moons (forgot which -one) which has a comparatively huge impact crater, and it was stated that if -the impacting body was much larger the moon would have been shattered. -Typically impact craters are larger than the body itself so the radius ratio -and thus the mass ratio would have been quite large. Isn't it Miranda that's supposed to have been blown apart and then reassembled itself? If you want to permanently destroy a moon or planet, you have to hit it so hard that most or all of the mass achieves escape velocity (and in different directions :-). Watch the computer simulation on "Space Age" - the Earth is pretty much turned to mush, but it doesn't fly apart. John Roberts roberts@cmr.ncsl.nist.gov ------------------------------ Date: Tue, 10 Nov 1992 16:20:53 GMT From: Nick Haines Subject: NASA Coverup Newsgroups: sci.space,alt.conspiracy In article gregn@coombs.anu.edu.au (Gregory Newton) writes: ObConspiracy(quite possibly true): Von Daniken wrote a lot of crap with evidence he made up in order to sell books (to the gulible) and make himself very rich. Oh, this _is_ true. I've seen him admit it to a journalist in a documentary about the crap he makes up. Nick Haines nickh@cmu.edu ------------------------------ Date: Tue, 10 Nov 1992 16:24:37 GMT From: Nick Haines Subject: NASA Coverup Newsgroups: sci.space,alt.conspiracy In article <1992Nov9.194619.28736@pixel.kodak.com> dj@ekcolor.ssd.kodak.com (Dave Jones) writes: [about Snarfy] When this all started I thought of that nonsensical 70's paperback that pushed the idea of a hollow moon as a giant starship. [...] "Somebody Else is On Our Moon". Can't remember the author; Donald Something? Very entertaining (and quite fun doing the Rorschach experiments, trying to `see' machinery in the moon pics). Nick Haines nickh@cmu.edu ------------------------------ Date: Tue, 10 Nov 92 15:33:40 GMT From: Doug Mohney Subject: reality check Newsgroups: sci.space In article , roberts@cmr.ncsl.nist.gov (John Roberts) writes: > >So ship it in the form of nylon. Plenty of hydrogen, nitrogen, and carbon, >and able to withstand high impact velocity, which should save considerably >on delta-v to land it on the moon. How difficult is it to break down nylon into useable components? Burn it or shove some ozone at it? Play in the intelluctual sandbox of Usenet -- > SYSMGR@CADLAB.ENG.UMD.EDU < -- ------------------------------ Date: Tue, 10 Nov 92 8:33:21 PST From: dkelo@pepvax.pepperdine.edu (Dan Kelo) Subject: Republican Calendar Could someone please e-mail me the French Republican Calendar Info??? Thanks, Dan P.S. To David Knapp:You may print photos, I lost your e-mail address. ____________________________________________ dkelo@pepvax.pepperdine.edu ____________________________________________ ------------------------------ Date: Mon, 9 Nov 1992 15:39:27 GMT From: "Robert B. Whitehurst" Subject: Russian Engines for DC-Y? Newsgroups: sci.space In article henry@zoo.toronto.edu (Henry Spencer) writes: >In article <1992Nov5.055945.28439@murdoch.acc.Virginia.EDU> rbw3q@helga9.acc.Virginia.EDU (Robert B. Whitehurst) writes: >> The interesting thing about this article was that it said that >>the RD-701 used only two turbopumps, with the LOX and kerosene being >>pumped by one, and the LH2 by the other. I read it quickly, so I >>might have this wrong, but that sounds rather intriguing. Is >>fuel/oxidizer premixed in other engines? ... > >I haven't seen the article yet... but almost certainly that means a >common turbine driving two separate pumps. It's fairly normal to >use a separate pump turbine for hydrogen, because a hydrogen pump is >a very different animal due to hydrogen's very low density, but a >common turbine for more normal propellants is nothing unusual. The >thought of trying to pump premixed propellants would make any sane >rocket engineer dive for cover, even disregarding the fact that you >*can't* premix LOX and kerosene due to temperature differences... >-- Gives new meaning to the term "molasses in January"! Hmmm, slush kerosene, anybody? :-) Seriously, I'll exhibit a little more ignorance here: In kerosene/LOX engines, do they vaporize the LOX, or do they inject it as a spray into the combustion chamber? We use strictly gaseous fuel in our work--just thinking about all those 2 phase sprays gives me a headache! :) -- Brad Whitehurst | Aerospace Research Lab rbw3q@Virginia.EDU | We like it hot...and fast. ------------------------------ Date: 10 Nov 92 13:16:32 GMT From: Dominique Beauchamp Subject: what about toutatis? Newsgroups: sci.astro,sci.space In article <1992Nov4.175705.2775@cbnewsc.cb.att.com> rjp1@cbnewsc.cb.att.com (be here now) writes: > >What's the latest on asteroid 4179 Toutatis? Where should I look >for it during it's close encounter on Dec 8th, 1992? > > >-- >Bob Pietkivitch | "Moon, my long lost friend, is smiling from above." >rjp1@ihspa.att.com | -- Genesis, Stagnation 1970 > Hi Bob, I refer you to Sky & Telescope, December issue. There is a long article on Toutatis with many finding charts. I think it will cross Sextans, Cancer and Leo. Dominique Beauchamp ------------------------------ End of Space Digest Volume 15 : Issue 406 ------------------------------