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 ; Sun, 1 Jul 1990 02:17:10 -0400 (EDT) Message-ID: Precedence: junk Reply-To: space+@Andrew.CMU.EDU From: space-request+@Andrew.CMU.EDU To: space+@Andrew.CMU.EDU Date: Sun, 1 Jul 1990 02:16:37 -0400 (EDT) Subject: SPACE Digest V11 #595 SPACE Digest Volume 11 : Issue 595 Today's Topics: Re: HST focus problem Re: HST Focus problem Re: HST focus problem Re: public image of HST gravity and the hubble lens Re: Physiology in microgravity Re: RE Hubble Space Telescope Update - 06/28/90 Re: NSS protests Chinese launch pricing (The Letter) 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: 29 Jun 90 20:59:40 GMT From: cs.utexas.edu!varvel@tut.cis.ohio-state.edu (Donald A. Varvel) Subject: Re: HST focus problem I have a simple request for information here. Earth-bound telescopes are pointed in a variety of directions, from horizontal to vertical. The optics do not deform significantly. I have difficulty believing that a mirror that holds the same figure whether on edge or pointing straight up would have a significantly different figure in microgravity. Now, these are optics designed for working that way. Presumably the HST optics were not designed to be useful on the earth's surface. Are the mirror substrates thinner than usual? I can easily believe they would be, to save weight and because thicker glass is not necessary in microgravity. Still, I would be interested in confirmation. This is _not_ to suggest that the usual earthbound mountings would be appropriate for space. It is only to say that the optics would work there. -- Don Varvel (varvel@cs.utexas.edu) ------------------------------ Date: 29 Jun 90 23:53:38 GMT From: uvaarpa!murdoch!astsun8.astro.Virginia.EDU!gsh7w@mcnc.org (Greg S. Hennessy) Subject: Re: HST Focus problem Robert Dempsey #Greg Hennesy commented that the spectral resolution will be lower. I #presume he was referring to WFPC as the high res spectrograph should #not suffer losses in resolution, just throughput. However, if one #wants to look at faint objects lower res will need to be used. No, what I was thinking is that the rule of thumb is that the spectral resolution gets better as you make the slit smaller, untill the slit is the seeing disk. Thus the better the seeing, the better the spectral resolution. I think that for stars the spectral resolution would not be degraded, but I think (but am not positive) that the spectral resolution would be degraded. -- -Greg Hennessy, University of Virginia USPS Mail: Astronomy Department, Charlottesville, VA 22903-2475 USA Internet: gsh7w@virginia.edu UUCP: ...!uunet!virginia!gsh7w ------------------------------ Date: 30 Jun 90 02:26:15 GMT From: uoft02.utoledo.edu!fax0112@tut.cis.ohio-state.edu Subject: Re: HST focus problem In article <9542@cs.utexas.edu>, varvel@cs.utexas.edu (Donald A. Varvel) writes: > I have a simple request for information here. > > Earth-bound telescopes are pointed in a variety of directions, from > horizontal to vertical. The optics do not deform significantly. > I have difficulty believing that a mirror that holds the same > figure whether on edge or pointing straight up would have a significantly > different figure in microgravity. Now, these are optics designed > for working that way. > > This not correct. Telescope and instrument flexure can be significant on ground based telescopes. However, this can be countered by throwing stronger and heavier materials in, a luxury you don't have when launching with payload restrictions. Even if there are changes they may be lost in the seeing which are then serious when you are trying to observe at the diffraction limit. The larger the telescope the more massive the structure. Robert Dempsey Ritter Observatory ------------------------------ Date: 29 Jun 90 15:55:02 GMT From: dinl!carnahan%inljeff.den.mmc.com@handies.ucar.edu Subject: Re: public image of HST In article <1990Jun29.002601.15539@hayes.fai.alaska.edu>, ftdjt@acad3.fai.alaska.edu (THOMAS DAVID J) writes: > > I must agree that the general public will probably react to the current events > in the manner Mr. Palfreyman describes. However, as Ron Baalke at JPL has > pointed out, the mechanisms of the HST are too sensitive to be tested in > Earth-normal gravity. > > Our space program, as old as it is, is still quite experimental. With > investments (scientific and financial) as large as the HST, there are bound > to be risks. However, I believe that the potential benefits are well worth the > risks. I generally agree; however, risks must be mitigated by sound NASA and contractor management. =================================================================== --------------> rich <-------------- (carnahan@inljeff.den.mmc.com) Martin Marietta Information Systems Group | Accept AI for what it can Box 1260 | do, just as we accept MS XL8058 | the 747 because it can Denver, Colorado 80201-1260 | fly fast and carry lots | of people; don't criticize (303) 971-7981 | the plane because it | doesn't sing or perch well | on branches. ------------------------------ Date: 29 Jun 90 11:18:11 GMT From: voder!dtg.nsc.com!andrew@ucbvax.Berkeley.EDU (Lord Snooty @ The Giant Poisoned Electric Head ) Subject: gravity and the hubble lens if the problem is really microgravity (rather than a defective spec) i would have thought that, given accurate surface profile measurements and six years of computer time, the effects of gravity changes on the performance would be well understood. after all, the bulk modulus of the material is known... if it's a design flaw, one can equally well point the finger. i am not happy. -- ........................................................................... Andrew Palfreyman that asteroid has our names on it andrew@dtg.nsc.com " 'course, the 'addock's very nice " ------------------------------ Date: Fri, 29 Jun 90 15:07:08 CDT From: John Nordlie Subject: Re: Physiology in microgravity The effects on humans of living in a microgravity environment are begin intensively studied, but has anyone heard of any research being done on so-called "atrificial gravity" produced by spining a spacecraft? A group of engineering students here at the University of North Dakota came up with the idea of using a space station module, a space shuttle external tank, and some kevlar ropes to construct a "Variable Gravity Research Facility", which would investigate atrificial gravity's effects on people and things. In their plan, the module was connected to the ET (external tank) by kevlar ropes. The assembly was then spun up to 3 rpm, and the intensity of the artificial gravity varied by changing the lengths of the ropes. The idea was presented to NASA and the aerospace community at a conference last summer at Huntsville, Alabamma. (All the engineering students had graduated, so I was handed the paper and told to present it. Ever see a comp. sci. student lecture professional engineers about space hardware?) It seemed a good idea, but have heard no more about it. What are your opinions about the effectiveness of "artificial gravity" and the need to build a research facility to study it? PS A fellow from Martin Marietta told me they had done some tests that show people can be spun up to 6 rpm without getting motion sickness. ======================================================================= John Nordlie | I tried to think of something intelligent to say. | " Urgh..", I managed. | - Harry Harrison 'A Stainless Steel Rat | is Born' ======================================================================= ------------------------------ Date: 30 Jun 90 03:32:14 GMT From: ogicse!plains!overby@uunet.uu.net (Glen Overby) Subject: Re: RE Hubble Space Telescope Update - 06/28/90 In article <00938EED.5338EF60@KING.ENG.UMD.EDU> sysmgr@KING.ENG.UMD.EDU (Doug Mohney) writes: >If Hubble was run on a shoe-string budget, instead of big bucks...well... >I can't help but think the thing would have A) Gotten off the ground about >4 years sooner and B) Given us more than we bargained for. HST was trundled across the country for launch two previous times, but was delayed both times by shuttle problems. Complaint "A" above isn't the HST project's fault (except that they should have chosen a different booster). As for "B", we'll have to wait and see what we DO get out of HST. We won't get as many initial "pretty picures", but the information content could be just as good. -- Glen Overby uunet!plains!overby (UUCP) overby@plains (Bitnet) ------------------------------ Date: 30 Jun 90 03:27:00 GMT From: usc!venera.isi.edu!cew@ucsd.edu (Craig E. Ward) Subject: Re: NSS protests Chinese launch pricing (The Letter) /* * Here is the letter the NSS sent to the USTR. We've been arguing about * it enough that I thought it reasonable to get an online copy. It outlines * why the protest and why the USTR should do something about it. While it * emphasizes the US industry, -- it is to the *US*TR-- its logic applies to * every other country that has a private launch industry. * * This is courtesy of Glenn Reynolds, Chair of the NSS Legislative Committee. * * cew */ June 15, 1990 The Honorable Carla Hills United States Trade Representative Executive Office of the President Washington, DC 20500 Dear Ambassador Hills: I am writing in order to direct your attention to a serious problem facing a new and strategic industry. I refer to the problem of unfair trade practices on the part of the People's Republic of China in the area of commercial launch services. The commercial launch services industry is a strategic industry, providing an essential input to virtually all space- related goods and services: satellite hardware, space manufacturing, remote sensing, communications, etc. The civilian space industry accounted for nearly $25 billion in sales and 210,000 employees in 1987. According to Norman Augustine, CEO of Martin Marietta, each commercial Titan launch offsets the import of 10,000 Toyotas. That is why the commercial launch industry has been identified as a vital national priority by both the Executive branch and Congress. Moreover, the United States is truly a technology leader in this vital area, with a number of established competitive firms including General Dynamics, Martin Marietta, and McDonnell Douglas, as well as numerous "start up" companies such as the American Rocket Company, Orbital Sciences, and Space Services, Incorporated. No industry can flourish, however, in the face of government-sponsored competition. Unfortunately, that appears to be precisely the kind of competition that the Chinese are offering. Beginning over two years ago, the Chinese government has offered launches on its Long March vehicle at prices of $20- 30 million dollars -- about half the price of a comparable commercial launch on a U.S. or European vehicle. Such pricing is below cost, and constitutes an unreasonable, unjustifiable burden on United States commerce. Continuation of this practice also constitutes the violation of a trade agreement. After many complaints from the United States launch industry in 1988, U.S.T.R. arrived at an agreement with the Chinese government under which the Chinese were to limit the number of launches offered to no more than nine over a six year period, during which the launches would be spread evenly, and to price those launches on terms "on par with those. . . prevailing in the international market for comparable commercial launch services." It appears, however, that the Chinese are not abiding by this agreement. Published reports suggest that the recent Chinese bid to launch for the Arabsat consortium is again in the $20-30 million range, the same kind of price charged by the Chinese before the agreement was signed and well below the commercial rate in the United States or Europe. Arianespace officials have complained that the price is 50% below normal and amounts to dumping. Gerald Musarra of the Office of Commercial Space Transportation is quoted as saying, "That certainly seems to be totally at odds with the terms of the agreement with the Chinese." As is hardly necessary for the National Space Society to point out, these circumstances seem to support (indeed, to mandate) action on a petition under Section 301 of the Trade Act of 1974, for violation of a trade agreement. NSS is seriously considering the possibility of filing such a petition concerning the Chinese practices. However, we encourage you to make such a petition unnecessary by taking prompt action on your own initiative in response to the Chinese practices. It is worth stressing that NSS does not want to limit fair competition in the launch services industry; in fact, NSS strongly favors such competition as a means of promoting new technology and lowering costs in the launch field. The Chinese, however, are not offering fair competition. If China were to abide by its international commitments on fair pricing and number of launches, NSS would not be concerned. If China refuses to abide by those commitments, however, the impact will be severe not only for the U.S. launch industry, but ultimately for the payload sector -- and the future of the entire U.S. commercial space industry -- as well. The United States must act promptly to prevent such an outcome. Such action must be firm, and (given the apparent failure of the 1988 agreement to end the Chinese practices) may require the imposition of sanctions as a means of persuading the Chinese government that the United States is serious about this matter. NSS also urges USTR to consult closely with European interests, who are equally concerned about unfair Chinese pricing. We are prepared to meet with you at your earliest convenience to discuss these matters further, and to offer whatever assistance NSS may provide in bringing this matter to a swift conclusion in favor of the United States launch industry and fair competition. NSS is a nationwide pro-space organization made up of tens of thousands of members who support the creation of a spacefaring civilization, a goal also endorsed by President Bush. NSS has repeatedly spoken and acted in favor of the development of a truly competitive commercial space launch industry, another goal we share with the President. For such an industry to develop, however, competition must be on the basis of prices that reflect efficiency, reliability, and technical quality. Government subsidies and "dumping" distort such competition, since in a government-subsidized pricing regime the "price" charged is purely arbitrary and may reflect no more than the desire of the government in question for hard currency, national prestige, or technological development for national economic or military purposes. Competition distorted by dumping and government subsidies will not provide the incentives for efficiency, technology development, and real cost reduction that a truly free market will provide. Given the vital role of the commercial space launch industry for our nation's future, we cannot afford to allow the American companies involved to be extinguished by unfair foreign competition. NSS asks that you act to end the Chinese practices immediately. Sincerely, Lori Garver Executive Director, National Space Society -- Craig E. Ward Slogan: "nemo me impune lacessit" USPS: USC/Information Sciences Institute 4676 Admiralty Way, Suite 1100 Marina del Rey, CA 90292 ------------------------------ End of SPACE Digest V11 #595 *******************