Date: Mon, 8 Jan 1990 17:51-EST From: space-tech-request@CS.CMU.EDU To: ~/st/lists/stdigest Subject: Space-tech Digest #42 Sender: mnr@DAISY.LEARNING.CS.CMU.EDU Contents: Pete Thomas Building a space station--how big and how-to? Pete Thomas Summaries Richard Schroeppel Optimality of Galileo trajectory? Allan Wechsler Two miscellaneous queries Paul Dietz How to despin an asteroid Lou Adornato Reference needed Ray Collins ISECCo PROJECT UPDATE #9: 1989 Newsletter ------------------------------------------------------------ Date: Tue, 28 Nov 1989 17:02-EST From: Marc.Ringuette@DAISY.LEARNING.CS.CMU.EDU To: space-tech@cs.cmu.edu Subject: Building a space station--how big and how-to? This is from sci.space, and could be an interesting topic. The author has joined our list. From: ce202a2@prism.gatech.EDU (THOMAS, PETE (TEACHING ASSISTANT)) Subject: Building a space station--how big and how-to? Keywords: Space Station Orbital Manufacturing Research Date: 28 Nov 89 20:51:26 GMT Well, I expect the opinions on this one are going to vary vastly. At age nine I decided that I was going to build a space station. Now that I am at Georgia Tech and embarking on my aerospace education, it is time to start researching and building this dream into a reality. So, I'm going to start out with a question to the net: If the goals of this space station are to: a) provide real manufacturing capabilities in orbit b) give a stable base for research efforts c) be a "dry-dock" for construction or re-assembly of other orbital structures, interplanetary missions, etc. d) be a permament, and comfortable residence for its inhabitants What do I need to do to fully develop this station? Time, money, people, resources--the whole process. Let's put this out as a thought experiment for the group here to toy with--I consider this as the brainstorming step in an effort to begin the design process early. When I am in a position to start this thing, I do not intend to do it cold. I would appreciate either discussion on this newsgroup or email responses (regular summaries will be provided). Why not a manned city in space? To do the real work I envision would take upwards from 400, as far as I can estimate. Go to it. -- Peter L. Thomas (E GR 1170Z{1,2}, UTA) "Figures never lie, but liars always figure." Georgia Institute of Technology, Atlanta Georgia, 30332 Internet: {gt5139c,ce202a2}@prism.gatech.edu ------------------------------ Date: Thu, 30 Nov 89 15:13:07 -0500 From: "THOMAS, PETE (TEACHING ASSISTANT" To: space-tech@CS.CMU.EDU Subject: Summaries I am about to start my final exams for this quarter; expect my first summary sometime after Friday of next week; so far the feed-back has been excellent; however, I have to actually take time to read through the pages of text and assimilate them, myself. Keep the ideas coming, in the meanwhile; I'm keeping them all in a digest mailbox, so that it might be appended (in whole or in part) with the space-tech mailing list digest file at some later date. --Pete ------------------------------ Date: Fri, 15 Dec 89 15:06:50 PST From: Richard Schroeppel To: space-tech@CS.CMU.EDU Subject: Optimality of Galileo trajectory? Cc: acw@yukon.scrc.symbolics.com, r@la.tis.com ---Forwarded Message Follows--- I am cross-posting these queries from the astronomy mailing list, since they seem relevant. I suggest that replies to Query 1a go directly to Mr. Wechsler at acw@yukon.scrc.symbolics.com, since we may assume that readers of this list either already know the answer or know where to look, and that he is probably not on this list. I myself am curious about Query 1b: Does JPL make its down-to-the-meter ephemeris available? Query 2 is of general interest, especially to a group that wants to use a low energy trajectory to survey asteroids, or to return an asteroid to Earth orbit. Forwarded by Rich Schroeppel, rcs@la.tis.com. ------------------------------ Date: Fri, 15 Dec 89 15:02 EST From: "Allan C. Wechsler" Subject: Two miscellaneous queries To: Astronomy@BBN.COM 1. Can somebody post a brief primer on the meaning of the six orbital elements? Also, is there an on-line source for ephemeris data? I would like to try my hand at writing a software ephemeris. 2. Was anyone on this list close to the planning process for the Galileo trajectory? What a trick! Was the possibility of this trajectory (Earth/Earth/Venus/Earth/Jupiter) discovered by chance, or was it the result of a systematic search? Is it known that this trajectory is optimal in Jupiter arrival-time, given Galileo's unfortunate departure constraints? (I only ask because 1995 seems so far away.) ------------------------------ Date: Tue, 26 Dec 89 15:48:17 EST From: dietz@cs.rochester.edu To: space-tech@CS.CMU.EDU Subject: How to despin an asteroid The question arose, either here or in sci.space, of how to despin an asteroid. It seems to me the following method could be useful. (1) Split the asteroid into nearly equal mass chunks (while it is still spinning). (2) Separate the chunks. If the asteroid is, say, 1 km in diameter, and has a density of 4 grams/cc, the energy required to overcome their gravitational attraction is on the order of 2e11 joules, or about 50 tons of explosive (some of which can come from the rotational energy of the asteroid). (3) Once widely separated, maneuver the chunks so that they collide. Arrange the geometry of the collision so that the angular momentum sums to zero. The collision will occur at about escape velocity. For the example asteroid, this is a bit less than one meter per second. The trick here is that the two pieces are maneuvered while far apart, so the velocity changes act on a very long moment arm and can cause large changes in the angular momentum of the system. One would also have to consider the effects of solar tides while the two pieces are separated. It perhaps offers another way to remove angular momentum from the system. Paul F. Dietz dietz@cs.rochester.edu ------------------------------ Date: Thu, 4 Jan 90 08:58:52 CST From: Lou Adornato To: space-tech@CS.CMU.EDU Subject: reference needed Hello space techies, I'm looking for a reference on spacecraft guidance, navigation, and control. I know that there are classes taught in this at Florida Institute of Tech, Stanford, and the Air Force Academy, but I haven't been able to get in touch with any of the people who teach these classes. If anyone out there knows of a good reference in this area, please send me mail, either through this mailing list, or directly to me at lfa@cray.com Alternatively, you could post the information on the sci.space newsgroup. Thanks in advance, and sorry to take up your time. Lou Adornato | Statements herein do not represent the opinions or attitudes Cray Research | of Cray Research, Inc. or its subsidiaries. lfa@cray.com | (...yet) ------------------------------ Date: Thu, 04 Jan 90 09:51:41 -0900 To: SPACE-TECH%CS.CMU.EDU@vma.CC.CMU.EDU Sender: FSRRC%ALASKA.BITNET@vma.CC.CMU.EDU From: FSRRC%ALASKA.BITNET@vma.CC.CMU.EDU January 1. 1990 ISECCo PROJECT UPDATE #9: 1989 Newsletter. The following is an extract from our annual newsletter. We are sending it so that you can see the general outline and, hopefully, encourage your interest in space in general and us in particular! If you would like the entire newsletter but do not wish to join please send a self-addressed, stamped envelope to ISECCo: we will be happy to send you one! We of ISECCo hope you had happy holidays and that your new year is enjoyable and industrious. International Space Exploration and Colonization Company I.S.E.C.Co P.O. Box 60885 Annual Newsletter Fairbanks, Ak. 99706 Issue #3: 1989 (907)457-2674 January 1, 1990 INTRODUCTION This is the International Space Exploration and Colonization Company's third annual newsletter. There are 3 ways you can obtain these newsletters: pay $5 for a 10 year subscription to it, do 2 or more hours of volunteer work in the last year or donate $20 or more in the last year. Except as noted this newsletter was written by Ray R. Collins, the president and co-founder of ISECCo. Other people who contributed to the writing, editing and distribution of this newsletter are: Debi Wilkinson, Patrick Wilkinson and Robert Hale, and ISECCo extends it's thanks to their generous donation of time to this effort. Anyone wishing to join ISECCo can write to ISECCo, P.O. Box 60885, Fairbanks AK 99706 and request an information package and membership form. CONTENTS: Introduction................................Page 1, Column 1 Contents....................................Page 1, Column 1 Overview....................................Page 1, Column 1 Biosphere Grant Application.................Page 1, Column 2 Biosphere Land Lease........................Page 2, Column 1 Biosphere Excavation........................Page 2, Column 1 Volunteer Workers...........................Page 2, Column 1 Videos of Biosphere Project.................Page 2, Column 2 Biosphere II................................Page 2, Column 2 ISECCo Support..............................Page 2, Column 2 An ISECCo Vacation by Wilkinson.............Page 2, Column 2 1989 Successes and Setbacks.................Page 3, Column 1 Non-Profit Status...........................Page 3, Column 2 1990 Projects...............................Page 3, Column 2 Selected Project Updates....................Page 4, Column 1 #4: Hydroponics & Space Utilization....Page 4, Column 2 #6: Crop Cycling.......................Page 5, Column 1 #7: Questions & Answers................Page 5, Column 2 #8: Summer Activities..................Page 6, Column 1 The Last Line...............................Page 6, Column 2 OVERVIEW 1989 was a successful one for ISECCo. The Biosphere Project has progressed to the point where construction can proceed, some preliminary work has been done on the aero-space plane model, our office procedures are getting smoothed out, and (after more than 15 months) the IRS granted our request for non-profit status. Early in 1989 Gene and Marilyn Rowley offer to let us build the Biosphere on their land. By May we had an agreement worked out for a lease to their land. During May, when Richard Kline and Debi Wilkinson were up from Florida donating 2 weeks of labor, we got the Biosphere site cleared and ready to begin digging. In the early fall we obtained the used of some heavy equipment and managed to get a lot of dirt excavated before freeze-up. Our core membership stands slightly over 50 people right now. We have members from Alaska, California, Georgia, Florida, Michigan, Kentucky, New Jersey, Massachusetts, Ohio, Washington, Illinois, New York, Canada, and people in Belgium, New Zealand, India and Australia have also expressed interest. Our principal method of reaching these people is via the computer mail networks such as BITNET. Our progress reports, which are distributed this way, have proven to be an excellent method of informing people what we are about, where we are headed and generating interest in our activities. This is, in effect, passive advertising. In the upcoming year we plan to do a little more active advertising, for now that we have a project underway we need to develop a better support network. In this we request your help: If you know of any classified advertisers who allow free ads please send one of their coupon to us! 1990 is going to be a busy year for ISECCo. We expect to make good progress with the biosphere, getting the hole finished and the concrete slab poured. We also plan to plant a garden again, which will be used to help feed ISECCo volunteers. We are going to continue expanding our hydroponic gardens, as well as increasing our fish tank capacity. We plan to begin experimenting with several new support systems, including saprophytes (ants, earthworms), rabbits, and bacterial breakdown of plant waste products. To keep our more dedicated members better informed we plan to start bimonthly mailings of the project updates to those members contributing $10/mo or more. Ray R. Collins::President ISECCo. For more information about ISECCo you can write us at the address above or send a note to Robert Hale FNRJH@ALASKA ------------------------------ End of Space-tech Digest #42 *******************