Return-path: X-Andrew-Authenticated-as: 7997;andrew.cmu.edu;Ted Anderson Received: from beak.andrew.cmu.edu via trymail for +dist+/afs/andrew.cmu.edu/usr11/tm2b/space/space.dl@andrew.cmu.edu (->+dist+/afs/andrew.cmu.edu/usr11/tm2b/space/space.dl) (->ota+space.digests) ID ; Sat, 13 Oct 1990 02:19:26 -0400 (EDT) Message-ID: Precedence: junk Reply-To: space+@Andrew.CMU.EDU From: space-request+@Andrew.CMU.EDU To: space+@Andrew.CMU.EDU Date: Sat, 13 Oct 1990 02:18:53 -0400 (EDT) Subject: SPACE Digest V12 #454 SPACE Digest Volume 12 : Issue 454 Today's Topics: Re: ulysses and galileo questions Re: Deep Space Network use (Was: Ulysses Update - 10/06/90) NASA Headline News for 10/12/90 (Forwarded) Re: Cost comparison: Apollo/Saturn vs. Shuttle Re: ulysses and galileo questions Re: Voyager Update - 10/11/90 Please include me in this news group Re: Disposal of N-waste into the Sun Re: disposal of N-waste into sun Re: Ulysses Update - 10/06/90 Re: Nerva rockets... Administrivia: Submissions to the SPACE Digest/sci.space should be mailed to space+@andrew.cmu.edu. Other mail, esp. [un]subscription notices, should be sent to space-request+@andrew.cmu.edu, or, if urgent, to tm2b+@andrew.cmu.edu ---------------------------------------------------------------------- Date: 12 Oct 90 21:14:23 GMT From: sdd.hp.com!elroy.jpl.nasa.gov!jato!mars!baalke@ucsd.edu (Ron Baalke) Subject: Re: ulysses and galileo questions In article dlbres10@pc.usl.edu (Fraering Philip) writes: >In article <5756@mace.cc.purdue.edu> dil@mace.cc.purdue.edu (Perry G Ramsey) writes: > >PR>In a sense, both spacecraft do use a three stage upper >PR>stage, but Galileo needs to save its third stage until it gets to Jupiter. > >Does anyone know if the Galileo insertion stage was bought >off-the-shelf, and if it will have a high acceleration >(decelleration?) factor the same way the Magellan prode did? > Galileo will fire a 400 Newton retro engine for an hour, and use a gravity assist from Io to get itself in Jupiter orbit. ___ _____ ___ /_ /| /____/ \ /_ /| | | | | __ \ /| | | | Ron Baalke | baalke@mars.jpl.nasa.gov ___| | | | |__) |/ | | |___ Jet Propulsion Lab | baalke@jems.jpl.nasa.gov /___| | | | ___/ | |/__ /| M/S 301-355 | |_____|/ |_|/ |_____|/ Pasadena, CA 91109 | ------------------------------ Date: 12 Oct 90 15:35:50 GMT From: sdd.hp.com!wuarchive!cs.utexas.edu!news-server.csri.toronto.edu!utgpu!utzoo!henry@ucsd.edu (Henry Spencer) Subject: Re: Deep Space Network use (Was: Ulysses Update - 10/06/90) In article <10045@xenna.Xylogics.COM> barnes@Xylogics.COM (Jim Barnes) writes: >If Ulysses needs 8 hours per day of coverage, Magellan is returning radar >images several times a day, and Galileo is doing some interesting things >at the same time, are there enough minutes in the day? ... Yes, although things are definitely going to be busy. Bear in mind that these birds are in different parts of the sky, so they are not competing for the same antennas all the time. Bear in mind also that DSN has several sets of antennas; they've only got one set of real biggies, but there are (I think) two sets of smaller ones. My recollection is that the smaller ones are quite adequate for Magellan work, which is just as well because "several times a day" is a major understatement. :-) (Magellan pours data back on *each orbit*.) The Voyagers and Pioneers are definitely not going to get a lot of DSN coverage, but then they no longer need that much. -- "...the i860 is a wonderful source | Henry Spencer at U of Toronto Zoology of thesis topics." --Preston Briggs | henry@zoo.toronto.edu utzoo!henry ------------------------------ Date: 12 Oct 90 23:44:31 GMT From: trident.arc.nasa.gov!yee@ames.arc.nasa.gov (Peter E. Yee) Subject: NASA Headline News for 10/12/90 (Forwarded) Headline News Internal Communications Branch (POC) NASA HQ Friday, October 12, 1990 Audio Service: 202/755-1788 This is NASA Headline News for Friday, October 12, 1990 U.S. and Soviet space and aeronautics officials will hold three separate meetings next week. Adm. Richard Truly will lead a U.S. Government delegation to the Soviet Union for general discussions on the U.S. - U.S.S.R. civil space programs and for visits to Soviet space facilities. The visit will occur Oct. 15 through 19. In addition, the fourth U.S.J- U.S.S.R. Solar System Exploration Joint Working Group meeting will be held Oct. 15 through 22 in Crystal City, Va. A Soviet aeronautical group will also visit NASA aeronautical centers to be briefed on our program from Oct. 15 through 22. * * * * * * * * * * * * * * * * * * * * * * * * * * Atlantis remains in the Vehicle Assembly Building. It was not rolled out to launch pad 39-A this morning, as planned, due to severe weather associated with Tropical Storm Marco. The storm caused considerable heavy rain in the pad vicinity and that, plus the threat of lightning, caused the launch team to re-plan Atlantis' roll out for tonight at 9 pm EDT. Columbia's roll out to launch pad 39-B is scheduled for 9 pm EDT Saturday. Servicing of the Astro-1 Broad Band X-ray Telescope, inside Columbia's payload bay, is still set for Monday. Discovery is expected to begin its flight back to the Kennedy Space Center aboard the 747 Shuttle Carrier Aircraft on Monday. The trip includes a scheduled refueling stop at Kelly Air Force Base in San Antonio, and, weather permitting, should conclude with Discovery's arrival at Kennedy Monday evening. KSC and NASA Shuttle management are currently examining late October dates for fuel tanking tests for both Atlantis and Columbia. No specific date has been decided upon. * * * * * * * * * * * * * * * * * * * * * * * * * * Ulysses is now more than three million miles from Earth and moving away from the Sun at an ever-increasing velocity. It's current speed, relative to the Sun, is over 91,000 miles per hour. Jet Propulsion Laboratory Ulysses engineers have been tracking the spacecraft continuously since its release from Discovery to determine a precise trajectory. This trajectory information will be used in final determinations of the correction maneuver now set for Monday and Tuesday, Oct. 15 and 16. Following the course correction maneuver, Ulysses' nine instruments will be commanded individually during the subsequent six week period. JPL reports all onboard systems are operating normally. * * * * * * * * * * * * * * * * * * * * * * * * * * NASA announced yesterday that preliminary observational data over the Antarctic indicate the level of stratospheric ozone depletion matches the level observed in 1987. The 1987 depletion was the maximum level of ozone depletion which had been observed to date. Observational data come from the NASA Goddard NIMBUS-7 spacecraft, which has been monitoring stratospheric ozone since 1979. The data also show that ozone levels in the Southern Hemisphere are as low as any which have been previously measured. The implications of the hemispheric data are uncertain, due to variability in ozone levels related to both atmospheric chemistry and meteorological conditions. Here's the broadcast schedule for Public Affairs events on NASA Select TV. All times are Eastern. **indicates a live program. Tuesday, 10/16/90 12:00 pm NASA programs, continues through 2:00 pm. 6:00 pm NASA programs repeats, through 8:00 pm. Thursday, 10/18/90 11:30 am NASA Update is transmitted. 12:00 pm NASA programs, continues through 2:00 pm. 6:00 pm NASA programs repeats, through 8:00 pm. All events and times may change without notice. This report is filed daily, Monday through Friday, at 12:00 pm, EDT. It is a service of Internal Communications Branch at NASA Headquarters. Contact: CREDMOND on NASAmail or at 202/453- 8425. NASA Select TV: Satcom F2R, Transponder 13, C-Band, 72 degrees West Longitude, Audio 6.8, Frequency 3960 MHz. ------------------------------ Date: 12 Oct 90 05:14:48 GMT From: uc!cs.umn.edu!quest!orbit!pnet51!schaper@tut.cis.ohio-state.edu (S Schaper) Subject: Re: Cost comparison: Apollo/Saturn vs. Shuttle What are the comparisons between Big Gemini/Int-20 and the shuttle stack? mass to orbit, cost to orbit per pound, mass of Big Gemini vrs. Shuttle. (might this have been a better shuttle launch stack?) What was this project, and where can we read more about it? UUCP: {amdahl!bungia, uunet!rosevax, chinet, killer}!orbit!pnet51!schaper The necktie is a device of Mordor ARPA: crash!orbit!pnet51!schaper@nosc.mil INET: schaper@pnet51.cts.com ------------------------------ Date: 12 Oct 90 15:49:30 GMT From: mentor.cc.purdue.edu!mace.cc.purdue.edu!dil@purdue.edu (Perry G Ramsey) Subject: Re: ulysses and galileo questions In article <1990Oct11.174657.8009@cbnewsc.att.com>, kca@cbnewsc.att.com (k.c.archie) writes: > Ulysses is going to get to Jupiter in about 14 months, or so I understand. > This is because of the multi-stage rocket attached. > Why couldn't this be used with Galileo? Is it too big? Galileo is a lot heavier than Ulysses. Among other things, it carries an engine to put itself into orbit around Jupiter, something Ulysses doesn't need. In a sense, both spacecraft do use a three stage upper stage, but Galileo needs to save its third stage until it gets to Jupiter. -- Perry G. Ramsey Department of Earth and Atmospheric Sciences perryr@vm.cc.purdue.edu Purdue University, W. Lafayette, IN USA dil@mace.cc.purdue.edu We've looked at clouds from ten sides now, And we REALLY don't know clouds, at all. ------------------------------ Date: 12 Oct 90 16:55:04 GMT From: mtndew!friedl@uunet.uu.net (Steve Friedl) Subject: Re: Voyager Update - 10/11/90 > Voyager Mission Status > October 11, 1990 > Voyager 1 > > There was an tracking outage of 4 hours and 55 minutes with > the 34 meter antenna in Spain on September 29 because of heavy rain. Is tracking lost because the rain messes up the signal or because the antenna has to be stowed because of wind and stuff? Steve -- Stephen J. Friedl, KA8CMY / I speak for me only / Tustin, CA / 3B2-kind-of-guy +1 714 544 6561 / friedl@mtndew.Tustin.CA.US / {uunet,attmail}!mtndew!friedl "No job is too big, no fee is too big" - Gary W. Keefe ------------------------------ Date: 12 Oct 90 21:49:23 GMT From: daniel@boulder.colorado.edu (DANIEL KEN) Subject: Please include me in this news group VEGA::Koehler.Colorado.edu ------------------------------ Date: Fri, 12 Oct 90 14:33:49 PDT From: greer%utdssa.dnet%utadnx@utspan.span.nasa.gov X-Vmsmail-To: UTADNX::UTSPAN::AMES::"space+@andrew.cmu.edu" Subject: Re: Disposal of N-waste into the Sun It seems a waste of net bandwidth to include all the discussion leading up to this, so I'll summarize briefly: First, someone asked why we couldn't dump n-waste into the sun. Then someone asked why it would be harder to send something to the sun than away from the sun? Then Henry Spencer said, >The direction is unimportant; what matters is the velocity change needed. >To get something into the Sun, you have to kill *all* of Earth's orbital >velocity (well, just about), and that's 30 km/s, a horrendous amount for >chemical rockets. Then all hell broke loose and one person showed how it takes 4/3 as much energy to go into the sun as away, then another person showed how it's really 7/4, both of which answers are way off. Now, here are the correct answers. First some useful numbers GMs=1.37e20 m^3/s^2 Gravitational constant of Sun GMe=3.99e14 m^3/2^2 Gravitational constant of Earth AU=1.5e11 m Astronomical unit (mean Earth-Sun distance) Re=6.378e6 m Radius of Earth The speed V of an object in a circular orbit of radius R is given by V^2=GM/R, where GM is the gravitational constant of the orbited body. Using the numbers above we get about 30 km/s for the speed of the Earth in its orbit. For a parabola, which is the minimum escaping orbit, the speed at R is V^2=2*GM/R. This means that escape velocity at any radius is always the square root of 2 times the circular orbit velocity at that radius. To escape from the Sun at the Earth's orbit you have to be going about 42 km/s. Energy changes with the square of the velocity. To escape from the Sun from the Earth, you have to add 144 MJ/Kg, but to drop into it you have to add 900 MJ/Kg. So it takes over six times as much energy to drop into the Sun from the Earth as it does to escape, but of course, this is just the energy you're adding to the payload, and doesn't acccount for energy added to the vehicle and the fuel during acceleration. I will leave that accounting as an exercise for the reader ;-). _____________ Dale M. Greer, whose opinions are not to be confused with those of the Center for Space Sciences, U.T. at Dallas, UTSPAN::UTADNX::UTDSSA::GREER "I will continue to use my boat." -- George Bush ------------------------------ Date: 10 Oct 90 23:28:50 GMT From: edsews!teemc!fmeed1!cage@uunet.uu.net (Russ Cage) Subject: Re: disposal of N-waste into sun In article <1452@blenheim.nsc.com> alan@spitfire.nsc.com (Alan Hepburn) writes: >Picture this: a supertanker modified slightly so that the nuclear >waste starts out in the bow tank, being diluted 100:1 with sea water. >This mix is then pumped to the next tank where it is diluted 100:1 with >sea water. And so on till the last tank, which is pumped into the open >ocean. You would be unable to detect other than background radiation >in the resulting water. BZZZZZZZZZZZZZZZZZZT! Wrong, on at least two counts. First, if the background level of the radioisotopes in question is small enough, they could still be detected even after many dilutions. I-131, for example, even at 6000 atoms/liter (10^20 dilution factor), could almost certainly be detected by Cerenkov radiation. Second, you are assuming that the sea is infinite, that the waste can be diluted indefinitely. This is false; eventually, your ship will start steaming through water it took in earlier. The radwaste inventory of the sea accumulates. Third, you are implicitly assuming that dilution is permanent. Not so; there are many biological pathways which concentrate nasties such as heavy metals (which many radionuclides are). -- Russ Cage Ford Powertrain Engineering Development Department Work: itivax.iti.org!cfctech!fmeed1!cage (Business only, NO CHATTY MAIL PLS) Home: russ@m-net.ann-arbor.mi.us (Everything else) I speak for the companies I own, not for the ones I don't. ------------------------------ Date: 12 Oct 90 15:50:13 GMT From: mcsun!ukc!icdoc!syma!andy@uunet.uu.net (Andy Clews) Subject: Re: Ulysses Update - 10/06/90 From article <9830@ur-cc.UUCP>, by haake@osprey.cvs.rochester.edu (Bill Haake): > :Shome mishtake, shurely? What about when Ulysses was in the orbiter payload > :bay in orbit around Earth? Or even after deployment as it floated gently > Not if we weren't at perihelion when it was in orbit! :-) Thanks to all who corrected my own "shilly mishtake", by email and followup. I completely forgot about the perihelion factor. *blush* Andy -- Andy Clews, Computing Service, Univ. of Sussex, Brighton BN1 9QN, England JANET: andy@syma.sussex.ac.uk BITNET: andy%syma.sussex.ac.uk@uk.ac ------------------------------ Date: 12 Oct 90 18:00:26 GMT From: usc!wuarchive!rex!rouge!pc!dlbres10@ucsd.edu (Phil Fraering) Subject: Re: Nerva rockets... To the people in sci.physics discussing Nerva: Perhaps sci.space would be a more appropriate newsgroup. To people in sci.space: there is an ongoing discussion about Nerva in sci.physics. Phil Fraering dlbres10@pc.usl.edu ------------------------------ End of SPACE Digest V12 #454 *******************