Return-path: X-Andrew-Authenticated-as: 7997;andrew.cmu.edu;Ted Anderson Received: from holmes.andrew.cmu.edu via trymail for +dist+/afs/andrew.cmu.edu/usr1/ota/space/space.dl@andrew.cmu.edu (->+dist+/afs/andrew.cmu.edu/usr1/ota/space/space.dl) (->ota+space.digests) ID ; Fri, 24 Feb 89 05:17:19 -0500 (EST) Message-ID: Reply-To: space+@Andrew.CMU.EDU From: space-request+@Andrew.CMU.EDU To: space+@Andrew.CMU.EDU Date: Fri, 24 Feb 89 05:17:10 -0500 (EST) Subject: SPACE Digest V9 #258 SPACE Digest Volume 9 : Issue 258 Today's Topics: Re: MARS the Movie Re: NSS and space settlement Re: NSS and space settlement Photography Re: 1992 moon base Orbital debris study completed (Forwarded) Re: question.shuttles ---------------------------------------------------------------------- Date: 20 Feb 89 23:19:18 GMT From: mike@ames.arc.nasa.gov (Mike Smithwick) Subject: Re: MARS the Movie In article <890217103638.a75@VLSI.JPL.NASA.GOV> tencati%jplgp.span@VLSI.JPL.NASA.GOV writes: < < >> Henry Spencer the Movie <<< :-) > -- *** mike (cerbral GURU, insert M&Ms to restart) smithwick*** "The great thing about standards is that there are so many of them!" [disclaimer : nope, I don't work for NASA, I take full blame for my ideas] ------------------------------ Date: 20 Feb 89 22:56:53 GMT From: mailrus!jarvis.csri.toronto.edu!utgpu!utzoo!henry@tut.cis.ohio-state.edu (Henry Spencer) Subject: Re: NSS and space settlement In article <129@beaver.cs.washington.edu> szabonj@minke.UUCP (Nick Szabo) writes: >>please name a date, or cite specific criteria that would indicate >>that the time is at hand. > >Criteria: A manned mission or base is desirable when >1) It can return discoveries and/or resources, unrelated to further manned >spaceflight, that are equivalent or better than what can be done by spending >the same money on unmanned missions. >OR >2) It cannot quite meet criteria (1), but the costs are borne by the >mission promoters, not taxpayers or stockholders. On the whole I agree with this, but with a couple of important reservations. First, I don't understand the mention of stockholders in (2) -- stockholders can always take their money elsewhere if they don't like what the company is doing. Their *purpose* is to provide capital for the company; it is silly to say that they shouldn't bear the costs of a speculative venture. Second, more important, the "unrelated to further manned spaceflight" part of (1) basically gives us the same situation that is ruining North American industry: only immediate returns are of interest; long-term planning and investment in the future is forbidden. Not a promising policy. -- The Earth is our mother; | Henry Spencer at U of Toronto Zoology our nine months are up. | uunet!attcan!utzoo!henry henry@zoo.toronto.edu ------------------------------ Date: 21 Feb 89 03:51:36 GMT From: right!szabonj@beaver.cs.washington.edu (Nick Szabo) Subject: Re: NSS and space settlement In article <1989Feb20.225653.14386@utzoo.uucp> henry@utzoo.uucp (Henry Spencer) writes: >In article <129@beaver.cs.washington.edu> szabonj@minke.UUCP (Nick Szabo) writes: >>Criteria: A manned mission or base is desirable when >>1) It can return discoveries and/or resources, unrelated to further manned >>spaceflight, that are equivalent or better than what can be done by spending >>the same money on unmanned missions. >>OR >>2) It cannot quite meet criteria (1), but the costs are borne by the >>mission promoters, not taxpayers or stockholders. >On the whole I agree with this, but with a couple of important reservations. >First, I don't understand the mention of stockholders in (2) Stockholders expect a return on their investment. If a company promises such a return, but does not come through, the stockholders are cheated and future investors will be reluctant to invest in that industry. (2) applies to those people ready and willing to sacrifice their own resources; this excludes normal stock-market investors. >Second, more important, the "unrelated to further manned spaceflight" part >of (1) basically gives us the same situation that is ruining North American >industry: only immediate returns are of interest; long-term planning and >investment in the future is forbidden. Not a promising policy. The reference is to "further manned spaceflight", not the future. I specifically included that phrase because the argument, "we should do manned spaceflight now for the sake of manned spaceflight in the future", is self-referencing and self-absorbed. (And wrong anyway, because as I have pointed out the best thing we can do for manned spaceflight in the future is unmanned spaceflight and basic R&D now). The space program cannot endure as a welfare case. Nick Szabo szabonj@fred.cs.washington.edu ------------------------------ Date: 19 Feb 89 21:19:51 GMT From: bgsuvax!sbrown@tut.cis.ohio-state.edu (Scott F. Brown) Subject: Photography Hello. In the near future, I will be using our university's 1/2 meter for photography. I will be using Tri-x film for starters. What I would like to know is recommended exposure and F-stop settings for the following objects: 1 : The moon 2 : Brighter planets (Jupiter / Venus) 3 : Dimmer planets (Mars, Mercury, Saturn) 4 : Remaining planets 5 : Bright deepsky objects (M42, M31) 6 : Faint deep sky (M81, M33) 7 : Meteor storms (no telescope) 8 : Milky wat (no telescope) An additional note: Anything taken through the telescope has the misfortune of the campus lighting. The sky in Bowling Green is bright and causes many stars to not be visible. Thanks in advance. - Scott F. Brown ------------------------------ Date: 21 Feb 89 04:37:32 GMT From: mailrus!jarvis.csri.toronto.edu!utgpu!utzoo!henry@tut.cis.ohio-state.edu (Henry Spencer) Subject: Re: 1992 moon base In article <1989Feb19.154324.513@cs.rochester.edu> dietz@cs.rochester.edu (Paul Dietz) writes: >One additional problem with the shuttle (vs. the Saturn V) is that a >lunar vehicle launched by the shuttle must use solid or storable >propellant rockets to leave earth orbit, rather than oxygen/hydrogen, >unless you are proposing to refuel in orbit with propellants launched >by something other than the shuttle. Don't forget that the first Shuttle/Centaur launch was only a few months away when Challenger was lost. A shuttle-based plan made *today* cannot assume oxygen/hydrogen without orbital assembly or something like that, but before January 1986 oxygen/hydrogen was a reasonable choice of fuel. -- The Earth is our mother; | Henry Spencer at U of Toronto Zoology our nine months are up. | uunet!attcan!utzoo!henry henry@zoo.toronto.edu ------------------------------ Date: 21 Feb 89 06:29:01 GMT From: yee@ames.arc.nasa.gov (Peter E. Yee) Subject: Orbital debris study completed (Forwarded) Jim Cast Headquarters, Washington, D.C. February 17, 1989 Pam Alloway Johnson Space Center, Houston Lt. Col. Rick Oborn Department of Defense, Washington, D.C. RELEASE: 89-20 ORBITAL DEBRIS STUDY COMPLETED The U.S. Government today released results of a 6-month interagency study on orbital debris. The study, co-chaired by NASA and the Department of Defense, cites satellite and rocket body fragmentation as the principal source of orbital debris and concludes that, left unchecked, the growth of debris could threaten the safe and reliable operation of manned and unmanned spacecraft in the next century. A major finding concerns the limits of our knowledge about the current population of orbital debris objects. While the U.S. Space Command routinely tracks objects in space that are larger than a softball (about 10 centimeters and larger), the ability to track smaller objects is hampered by system design. The uncertainty, therefore, as to exactly how much debris is in orbit makes it difficult to assess the true risk posed to spacecraft. This, in turn, creates uncertainty as to the urgency for action and the potential effectiveness of any corrective action. The report states that the need for enhancing debris measurement capabilities "has been universally recognized." The report reviews current policies and activities designed to reduce debris or mitigate its effects and explores potential opportunities for further action. International efforts, legal issues and commercial regulation also are examined. Along with NASA and DOD, other federal organizations participating in the orbital debris study included the Departments of State, Commerce, Transportation and Treasury as well as the Office of Management and Budget, Federal Communications Commission and the Intelligence Community Staff. A fact sheet concerning the orbital debris study follows. Limited quantities of the report itself are available in the newsrooms of NASA Headquarters, Johnson and Kennedy Space Centers and at the Office of Secretary of Defense/ Public Affairs. ------------------------------------------------------ February 17, 1989 ORBITAL DEBRIS STUDY The U.S. government today released the Interagency Group (Space) Report on Orbital Debris. The report is the culmination of an intensive 6-month study, which was initiated in response to a directive contained within the National Space policy approved by President Reagan in February 1988. The directive stated that "all space sectors will seek to minimize the creation of space debris. Design and operations of space tests, experiments and systems will strive to minimize or reduce accumulation of space debris consistent with mission requirements and cost effectiveness." An interagency working group was tasked last July by the National Security Council to review the extent of the orbital debris problem, identify options for minimizing or reducing the accumulation of orbital debris and its impact on future space activities and recommend courses of action. The group was co- chaired by senior officials from NASA and DOD and included representatives from the departments of State, Commerce, Transportation and Treasury, as well as the Office of Management and Budget, the Federal Communications Commission and the Intelligence Community Staff. The report is written in concise, non-technical language. It begins with a description of the current space environment, a discussion about the major sources of debris, and an assessment of the implications of current debris growth trends. It then reviews current policies and activities designed to reduce debris or mitigate its effects and explores potential opportunities for further action. International efforts, legal issues and commercial regulation also are examined. According to the report, the principal source of orbital debris has been fragmentation of satellites and rocket bodies. Other sources include inactive satellites and objects discarded during satellite delivery or operations, such as lens caps, packing devices or empty propellant tanks. The report concludes that, left unchecked, the growth of debris could threaten the safe and reliable operation of manned and unmanned spacecraft in the next century. A major finding of the report is that not enough is known about the extent of the problem posed by small debris in the orbital environment. Although the U.S. Space Command routinely tracks objects in space that are larger than about 10 centimeters in diameter, the limited ability (a design limitation) of current surveillance systems to detect and track the much greater number of small debris objects creates high uncertainty in the debris environment models that scientists have constructed. This makes it difficult to assess the true risk posed to spacecraft by orbiting debris, which in turn creates uncertainty as to the urgency for action and the potential effectiveness of any corrective measure. The report states that the need for enhancing debris measurement capabilities "has been universally recognized." The report's recommendations call for appropriate agencies to make debris minimization a design consideration for all future civil, military and commercial launch vehicles, upper stages, satellites, space tests and missions. This would include promulgating and implementing agency-level internal policy guidance consistent with the debris minimization directive of the National Space Policy. The report also recommends that NASA and DOD undertake a joint study to develop a comprehensive R&D plan to improve orbital debris environment monitoring, statistical modeling and data management capabilities. A second joint study, to be undertaken by NASA and DOD in consultation with the Department of Transportation and the commercial space sector, would construct a basic research plan for developing technologies and procedures for debris minimization and spacecraft survivability. The report further recommends a continuing dialog between the federal government and industry, recognizing that any imposition of requirements on the private space sector to control or prevent the proliferation of space debris will have important commercial implications. The report also includes these recommendations: -- Current agency operational practices for debris mitigation during launch and space operations should be continued and, where feasible and cost-effective, improved. -- The following activities should be emphasized and, where appropriate, accelerated: - efforts to improve debris characterization measurements and inventory through use of ground-based radars and development of an improved data base - modeling and statistical analysis of the debris characterization measurements - analysis of physical evidence returned from space - technological research directed toward improved spacecraft shielding and a better understanding of the fragmentation processes that result from hypervelocity collisions - licensing agency development of performance requirements and regulations to guide private industry activities - ongoing studies of design and operations techniques to minimize the cost of debris elimination -- Representatives of commercial licensing agencies (DOT, DOC and FCC) should continue their discussions to define the boundaries of regulatory authority among the licensing agencies over commercial activities that may produce orbital debris. -- An ad hoc interagency working group on orbital debris, chaired by NASA and DOD, should be retained as a coordinating mechanism for issues, policies and activities concerning the orbital debris problem. -- The U.S. should inform other spacefaring nations about the conclusions of this report and seek to enhance understanding about orbital debris issues. As appropriate, the U.S. should enter into discussions with other nations to coordinate debris minimization policies and practices. -- Within 18 months, an interagency working group should develop a long-term strategy for researching, developing and implementing means to minimize the accumulation of orbital debris and protect spacecraft operations (within an acceptable level of risk) from collision with debris objects. As a minimum, this strategy should include establishing long-range goals, providing a milestone plan and schedule leading to achievement of these long- term goals, and preliminary resource implications. The Interagency Group (Space) Report on Orbital Debris is being prepared for printing, and finished copies will be available for distribution by early April 1989. Meanwhile, a limited number of photocopies is now available upon request. ------------------------------ Date: 21 Feb 89 04:42:36 GMT From: mailrus!jarvis.csri.toronto.edu!utgpu!utzoo!henry@tut.cis.ohio-state.edu (Henry Spencer) Subject: Re: question.shuttles In article <224@tree.UUCP> guest@tree.UUCP (Lord Shadowhawk) writes: >I'm just curious if anybody knows whether or not two space shuttles can be >launched simultaneously.....like the Atlantis and Discovery?? There is no theoretical reason why it can't be done, since all the big hardware (VAB bays, launch platforms, pads, control rooms) is at least duplicated, but the current processing and support organization is very much keyed to one launch at a time. Also, not all of that duplicated equipment is really ready to go -- pad 39A is not up to 39B standard at present, for example, and I'd suspect that there's only one fully up-to-date control room. -- The Earth is our mother; | Henry Spencer at U of Toronto Zoology our nine months are up. | uunet!attcan!utzoo!henry henry@zoo.toronto.edu ------------------------------ End of SPACE Digest V9 #258 *******************