Return-path: X-Andrew-Authenticated-as: 7997;andrew.cmu.edu;Ted Anderson Received: from corsica.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 ; Wed, 2 Aug 89 03:18:03 -0400 (EDT) Message-ID: <0Ype0Vm00UkV8AjE5N@andrew.cmu.edu> Reply-To: space+@Andrew.CMU.EDU From: space-request+@Andrew.CMU.EDU To: space+@Andrew.CMU.EDU Date: Wed, 2 Aug 89 03:17:54 -0400 (EDT) Subject: SPACE Digest V9 #577 SPACE Digest Volume 9 : Issue 577 Today's Topics: Re: Don't Mess with NASA (afterburners) Don't Mess with NASA (afterburners) Re: NASA Select Broadcasts New satellite of Neptune Re: S-Band Beacon on Moon Modules Re: Apollo 8, 9, and 10 Voyager rebroadcast frames deciphered (long) ---------------------------------------------------------------------- Date: 21 Jul 89 19:34:01 GMT From: mailrus!jarvis.csri.toronto.edu!utgpu!utzoo!henry@tut.cis.ohio-state.edu (Henry Spencer) Subject: Re: Don't Mess with NASA (afterburners) In article shafer@elxsi.dfrf.nasa.gov (Mary Shafer) writes: >... Just speaking personally, as a fairly >frequent flier, I'd really prefer that fighters be limited-distribution >items. There are enough things to worry about, without worrying about >some yahoo out there in an F-something with sidewinders at my 747's six. Anybody with any sense who wants to shoot down your 747 will just hang the Sidewinders on a Learjet -- less conspicuous, and perfectly adequate performance for the job. (You can hang Sidewinders on almost anything.) >...I have some real definite opinions about required >piloting skills. We require our test pilots to fly a minimum of 200 >hours per year, with specified minimums for each aircraft, to maintain >proficiency. That F-86 driver had very low total time, low jet time, >and was what I'd consider non-current... >Just because you can afford an airplane, doesn't mean you can fly it. I have no quarrel with the idea that anyone who owns his own jet fighter needs to be properly qualified to fly it. I see no reason why a civilian is incapable of acquiring the qualifications, though. >... I don't know why those posters who despise the government and all >its fruits are panting to buy those fruits. Let's see some consistancy... If a private market in such things were allowed, we wouldn't have to buy things designed by the government. Which sort of brings us back to spaceflight, since that's the big problem with space launchers too... -- 1961-1969: 8 years of Apollo. | Henry Spencer at U of Toronto Zoology 1969-1989: 20 years of nothing.| uunet!attcan!utzoo!henry henry@zoo.toronto.edu ------------------------------ Date: Thu, 20 Jul 89 06:27:34 EDT From: dsc@osteocyber.ortho.hmc.psu.edu (david s. channin) Subject: Don't Mess with NASA (afterburners) >Me too! Unfortunately the US military wants to keep jet aviation all to >itself, so even its tamer aircraft are never sold to civilians. (Both >the Starfighter and the T-38 were rebuilt from hardware that slipped out >basically by accident.) Hypothetical Question: Let's say you just happen to have hit the PA state lottery last April, and walked away with $115 Million. You will receive 5.75 M for 20 years. You save diligently for 6 -7 years. What are the laws, regulations, etc (if any) that prevent you from doing the following: 1. Walk into the Northrop offices in wherever. 2. Pull out a bank check for x million dollars. 3. Say,``I'd would like that nice T-38 that's in the showroom''. 4. Fly away with same after filling the tank. (assuming you already have a license). Why wouldn't this scenario work?? (or would it?). dsc@osteocyber.ortho.hmc.psu.edu David S. Channin Research Fellow Division of Orthopaedic Surgery Pennsylvania State University College of Medicine The Milton S. Hershey Medical Center 717 - 531 - 6698 ------------------------------ Date: 20 Jul 89 16:46:03 GMT From: leech@apple.com (Jonathan Patrick Leech) Subject: Re: NASA Select Broadcasts In article <4980@mtuxo.att.com> tee@mtuxo.att.com (54317-T.EBERSOLE) writes: >also with no luck. Has anyone been able to find NASA Select's broadcasts? >Did you need to know anything more than the data in the excerpted paragraph? >Is this bird viewable from the east coast with "standard" equipment, i.e., >is it a good quality signal or very weak? I tuned in SELECT numerous times from UNC-Chapel Hill, which has a pretty good view of F2R. While I'm no expert on satellite TV, both I and our communications director had trouble getting a good signal. Generally we had to fiddle with the skew setting of the receiver and nudge the antenna back and forth. It seemed to be best ~2 degrees further east than the claimed position, in general. -- Jon Leech (leech@apple.com) Apple Integrated Systems __@/ ------------------------------ Date: Thu, 20 Jul 89 10:17:57 PST From: Peter Scott Subject: New satellite of Neptune X-Vms-Mail-To: EXOS%"space@andrew.cmu.edu" Excerpted without permission from NASA _Voyager Bulletin_, Mission Status Report No. 88, July 12: ADD A NEW NEPTUNIAN MOON A new moon has been discovered orbiting Neptune. Temporarily designated 1989 N1, the new moon was initially seen in images transmitted to Earth by Voyager 2 in mid-June. Its existence was confirmed upon examination of other images after the moon's orbital motion had been calculated and its position could be predicted. The new Neptunian satellite could range in diameter from 200 to 600 km (about 125 to 400 miles) and oribts in a very nearly circular and equatorial orbit about 92,700 km (about 57,600 mi) from the planet's cloud tops (or about 117,500 km) (73,000 mi) from the planet's center). A permanent name will be given to the moon at a later date by the International Astronomical Union (IAU). According to Dr. Stephen P. Synnott, a Voyager imaging team scientist at JPL, the satellite appeared as a small, bright smudge in Voyager pictures due to the long (46-second) exposure. At this point, the moon is too indistinct to appear in photographic prints made from the Voyager images. Pictures taken in coming weeks will show the moon more clearly. 1989 N1 cannot be seen from Earth because the moon is so close to Neptune that the brightness of the planet itself masks the tiny point of light. Voyager 2 will continue to study the moon and will conduct searches for others on approach to the planet. [...] The moon orbits well outside the orbits of the postulated ring arcs. Its existence lessens concerns about radiation hazards to the spacecraft near the planet, since the moon probably sweeps charged particles out of the area as it orbits Neptune. Peter Scott (pjs@grouch.jpl.nasa.gov, speaking only for myself) ------------------------------ Date: 21 Jul 89 23:17:43 GMT From: vsi1!v7fs1!add@ames.arc.nasa.gov (Andrew D. Daniel) Subject: Re: S-Band Beacon on Moon In article <138@nwnexus.WA.COM> edm@nwnexus.WA.COM (Ed Morin) writes: >wjc@XN.LL.MIT.EDU (Bill Chiarchiaro) writes: >"Unix Public Access for the Masses!" Now Ed, lets enforce the consitutional separation of church and (solid) state. -- Andrew D Daniel, Video Seven, Inc. Angels fear to tread ..ames!vsi1!v7fs1!add where fools login: ------------------------------ Date: 20 Jul 89 11:08:52 GMT From: cs.utexas.edu!usc!orion.cf.uci.edu!dkrause@tut.cis.ohio-state.edu (Doug Krause) Subject: Modules I lost a couple of articles. Was Snoopy an LM or CM? If it was an LM, a historic quote would have a whole new feel. "Houston, Tranquility Base here. Snoopy has landed." :-) Douglas Krause One yuppy can ruin your whole day. --------------------------------------------------------------------- University of California, Irvine Internet: dkrause@orion.cf.uci.edu Welcome to Irvine, Yuppieland USA BITNET: DJKrause@ucivmsa ------------------------------ Date: 20 Jul 89 14:46:07 GMT From: mfci!rodman@CS.YALE.EDU (Paul Rodman) Subject: Re: Apollo 8, 9, and 10 In article <199@enuxha.eas.asu.edu> kluksdah@enuxha.eas.asu.edu (Norman C. Kluksdahl) writes: > >My memory indicates that the descent stage was cut free, and the ascent >stage was used for the rendezvouz. Again, the book "Chariots for Apollo" Mine too. And I also recall the the LEM underwent some very scary gyrations when the ascent stage was fired.....which were not worried about afterward, as this was the only time anyone planned to fire the ascent stage/jettision the descent stage in flight. pkr ------------------------------ Date: Thu, 20 Jul 89 10:27:02 PST From: Peter Scott Subject: Voyager rebroadcast frames deciphered (long) X-Vms-Mail-To: EXOS%"space@andrew.cmu.edu" Lines: 172 Extracted without permission from NASA _Voyager Bulletin_, Mission Status Report No. 88, July 12: WHAT DO THE HIEROGLYPHICS MEAN? Images and some of the other data received at JPL from the two Voyager spacecraft are sent to display devices at JPL from the computers in JPL's Multimission Image Processing System. A subset of these data, primarily images, is being broadcast on the NASA Select TV channel by the GE Satcom F2R satellite. Currently there is a one-hour broadcast every Tuesday through August 8. Broadcasts will probably be more frequent as Voyager 2 nears its closest approach to Neptune on August 25. The frames that appear on the monitors are black and white only and include basic identification information for the image being displayed, as well as information about the processing that has been applied to that image. Data from the Planetary Radio Astronomy and Plasma Wave investigations can also be displayed on video devices. The following is a brief summary of the information shown for imaging, PRA, and PWS frames. IMAGING FRAMES Each Voyager spacecraft carries two imaging cameras: a 200-mm, f/3.5 wide-angle camera using a refracting telescope and a 1500-mm f/8.5 narrow-angle (telephoto) camera using a reflecting telescope. Each camera uses a one-inch selenium-sulfur vidicon to convert an optical signal into electrical signals. Each frame consists of 640,000 pixels, each of which is expressed as a level of gray on a scale from 0 (black) to 255 (white). Color scenes are reconstructed on Earth by electronically combining images taken through different filters. The sensitivity of the filters ranges from 3460 (ultraviolet) to 6184 angstroms (red-orange). [The rest of this extract contains mostly information of interest to those people receiving the images.] The elements of the displayed imaging frames are described below: [1-5 run left-to-right across the top line of the frame] 1. MIPL Multimission Image Processing System (a JPL facility). 2. Spacecraft identifier 3. System Source: RLTM Real Time. The data is displayed from telemetry as soon as the data arrives at JPL; this data may be only 4 hours old (as long as it took for the data to travel from the spacecraft to Earth); it may have been taken earlier, recorded on the spacecraft's digital tape recorder, and played back to Earth at an optimum time; or it may have been stored at the Data Capture and Staging computer and read from there later. (See item 13, to learn when the data was received at Earth.) INTR Interactive. Image is displayed from a work station where a scientist or analyst is interactively enhancing the data. RPLA Replay, for NASA Select TV, of data received earlier. 4. Target Body (Neptune, Triton, Nereid, rings, etc). 5. FDS Count. Image identifiction in units of spacecraft clock time (the spacecraft's clock is in the spacecraft's Flight Data Subsystem computers). 6. Frame identification in units of picture number, planet, spacecraft, and days from encounter [displayed under #5]. 7. Frame. The data are displayed at half resolution. As displayed, the image area is 400 lines by 400 rows [sic] of picture elements. A full Voyager image frame is 800 lines of 800 elements, but since the display devices can display only 640x480 pixels, every other pixel of every other line is displayed. 8. Reference Gray Scale [along left edge] 9. Histogram (frequency distribution) of number of bits at each of the gray levels in the incoming image [top right]. 10. Histogram of number of bits at each of the gray levels in the image as displayed at left. [Center right]. (Note: the histograms are an aid in evaluating the quality of the displayed image; e.g., how bright was the image, how good was the exposure, etc). 11. [Text under #10] Describes processing that has been done to transform the input image to the output image, e.g., magnification factor, dark current subtraction, contrast enhancement. 12. [Text, bottom left to center] Identification information: INSTR Instrument: ISSWA Imaging camera, Wide angle ISSNA Imaging camera, Narrow angle FILTER Clear, green, orange, blue, ultraviolet, methane (6910 or 5410 angstroms), or sodium. EXP Exposure time (seconds) IMODE Shutter mode: NAONLY Narrow angle only WAONLY Wide angle only BOTALT Wide and narrow angle shuttered alternately BOTSIM Both wide and narrow shuttered simultaneously BODARK Neither wide nor narrow shuttered (used to calibrate background noise (or "dark current")) NOSHUT Neithr wide nor narrow read out TMODE Spacecraft telemetry mode at which data is read out (e.g. compressed, edited, slow scan, etc). RANGE Distance from spacecraft to center of target body, in km. INA Lighting angle (incidence angle of sunlight striking target) EMA Viewing angle (emission angle of sunlight reflected from target) PHA Phase angle (angle between incoming sunlight and emitted or reflected light from target) SCALE Distance across frame (at the target body) 13. [Bottom right] Time signal was received at Earth (day of year:hour:minute) in Universal Time Coordinated (UTC). 14. [Right of #13] Calendar day (JPL local time), MIPS computer ID, display device ID. PLANETARY RADIO ASTRONOMY (PRA) The planetary radio astronomy experiment uses two 10-meter whip antennas to listen for radio emissions from the Sun, planets, and lightning in planetary atmospheres over a range from 1.2kHz to 40.5MHz. The PRA high-rate receiver gives high time resolution at two fixed frequencies that will be selected by the PRA science team when the spacecraft is a few weeks away from the planet. At Uranus the frequencies were 35.9424MHz and 1.230MHz. Data from the PRA is sometimes displayed on the video devices. The following discussion indicates information that differs from the Imaging frames: 7. Frame. A high-rate PRA frame contains 48 seconds of data formatted as 800 lines, each containing 800 8-bit samples. The total time per line is 0.06 second. Only 1/4 of the PRA data is displayed in the video convrsion of the frame. The first 24 seconds of the displayed frame represents signals at the first fixed frequency, at two antenna polarizations. The last 24 seconds show only one polarization at the second fixed frequency. "Real" signals show as horizontal white (or light) streaks running across the frame [an example is pictured showing lightning-like electrical discharges at Uranus]. The pattern observed in each line represents the "loudness" as a function of time, of an "audio" noise signal in a narrow band centered on the receiver frequency. Real data increases the "loudness" of the signal, just like extra static in a home radio. The amount and type of noise gives information about what causes it. 9. Histogram of signal intensity as received (input). 10. Histogram of signal intensity values as displayed (output). 12. Only INSTRU and TMODE have any meaning for PRA and PWS frames. PLASMA WAVES (PWS) Plasma waves are low-frequency oscillations in the plasmas in interplanetary space and in planetary magnetospheres. The plasma wave instrument detects and measures plasma wave interactions in planetary magnetospheres and detects interactions between a planetary magnetosphere and the solar wind. It can detect particles in the ring plane and measure their impact rate on the spacecraft. The PWS shares the two whip antennas with the PRA investigation to provide the equivalent of a single 7-meter antenna. PWS covers the frequency range from 10Hz to 56.2kHz. The PWS high-rate receiver is a very sensitive audio amplifier. In the display of a Fourier transform of the data, the horizontal axis is time (one 48-second frame) and the vertical axis is frequency. Plasma wave scientists interpret the signal patterns in terms of various mechanisms the interactions of charged particles and elctromagnetic waves. Steady frequencies generally are associated with interference signals from other subsystems on the spacecraft; for example, the 2.4kHz hum of the spacecraft's power supply [shows up as a horizontal line near the bottom of the sample frame]. Peter Scott (pjs@grouch.jpl.nasa.gov) Standard disclaimers. ------------------------------ End of SPACE Digest V9 #577 *******************