Return-path: X-Andrew-Authenticated-as: 7997;andrew.cmu.edu;Ted Anderson Received: from hogtown.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 ; Thu, 31 Jan 91 04:14:35 -0500 (EST) Message-ID: Precedence: junk Reply-To: space+@Andrew.CMU.EDU From: space-request+@Andrew.CMU.EDU To: space+@Andrew.CMU.EDU Date: Thu, 31 Jan 91 04:14:31 -0500 (EST) Subject: SPACE Digest V13 #093 SPACE Digest Volume 13 : Issue 93 Today's Topics: Re: Why man rate? (was: space news from Dec 17 AW&ST) Pioneer 10 Update - 01/25/91 Pioneer Venus Update - 01/25/91 Re: MAJOR SOLAR FLARE ALERT - POWERFUL EVENT (25 JANUARY) Re: Why man rate? (was: space news from Dec 17 AW&ST) MAJOR SOLAR FLARE ALERT - POWERFUL EVENT (25 JANUARY) Re: Weekly World News publishes Challenger tape transcript Administrivia: Submissions to the SPACE Digest/sci.space should be mailed to space+@andrew.cmu.edu. Other mail, esp. [un]subscription requests, should be sent to space-request+@andrew.cmu.edu, or, if urgent, to tm2b+@andrew.cmu.edu ---------------------------------------------------------------------- Date: 27 Jan 91 04:07:05 GMT From: zaphod.mps.ohio-state.edu!sdd.hp.com!cs.utexas.edu!news-server.csri.toronto.edu!utzoo!henry@tut.cis.ohio-state.edu (Henry Spencer) Subject: Re: Why man rate? (was: space news from Dec 17 AW&ST) In article <1991Jan25.200639.16712@freedom.msfc.nasa.gov> cornutt@freedom.msfc.nasa.gov (David Cornutt) writes: >>In the entire 30 year history of the Delta this is an accurate figure. >>However, their success rate over the last 13 years is 98.33%... > >You can make the probability be anything you want if you pick and choose your >data points. If you only consider the last 11 flights, the Shuttle has a >100% success rate. This of course proves nothing... Nonsense. It is entirely possible to assign some degree of statistical meaning to the shuttle's recent record. What is lacking is very much confidence that this accurately represents overall reliability, since there are not very many tests involved. Delta *does* come out ahead here, simply because it has been launched many more times. We have considerably more confidence in the Delta numbers than in the shuttle numbers. If anything, the poorer Delta reliability in its early days weakens the case for assuming the shuttle to be highly reliable! It is an observed fact, from Delta and the other expendables, that early reliability is worse than long-term reliability because the bugs are still being found and fixed. Delta has flown often enough for considerable confidence that it is past its "infant mortality" stage. The shuttle has not, especially considering its much greater complexity, which would normally be taken to require rather more debugging. It is entirely reasonable to discount Delta's early troubles while not discounting Challenger. >>Don't look now but the Shuttle *IS* being canned. > >If you are saying that there will be no more Shuttle flights, that's >news to me. Do you know something that the rest of us don't? Of course there will be more shuttle flights. But NRC, OTA, and others who have studied the matter concur that an ongoing shuttle program requires an ongoing orbiter supply. How can you plan a launch manifest for the things five years ahead when you don't even know *how many* of them will be available then? Discontinuing orbiter production amounts to abandoning the shuttle fleet, as the remaining orbiters age (nobody seriously expects them to last 100 flights each any more, but nobody has any very clear idea of how long they *will* last either) and are lost in accidents. Without replacement orbiters, the next big accident will kill the shuttle completely... because it will demonstrate the impossibility of planning fleet operations without maintaining the fleet. Or are you suggesting that there will not be another accident? >... I was opposed to building Endeavor -- as another >copy of the _current_ Shuttle design. By now, we should be working on >the next version of that vehicle... Agreed. But (a) we aren't, and (b) even if we were, that next version would not be ready for use until circa the year 2000, so what do we do until then? You are confusing development with maintaining operational capability, saying that we should abandon the latter because we ought to be doing more of the former. >...If you're saying that the Shuttle concept in >general is a bad idea, I totally disagree. In this day and age of >recycling, why is everyone so anxious to build throwaway launchers? Because we know how to make them work fairly dependably for a development cost we are willing to pay. >... The main >problem with the Delta, as far as man-rating, is that steering >of the first stage is provided solely by gimbaling of the main >engine. If that engine fails, the vehicle has no directional >control and must be aborted... ??? The launcher world abounds in such single-point failure modes when it comes to directional control. I doubt very much that either the shuttle or Titan can survive a failed SRB nozzle gimbal. And every US manned expendable was single-engined at some point during its flight. (Redstone from launch to burnout, Atlas after dropping booster engines, Titan after staging, Saturn IB after staging, Saturn V after second staging.) -- If the Space Shuttle was the answer, | Henry Spencer at U of Toronto Zoology what was the question? | henry@zoo.toronto.edu utzoo!henry ------------------------------ Date: 25 Jan 91 23:19:26 GMT From: usc!elroy.jpl.nasa.gov!jato!mars.jpl.nasa.gov!baalke@apple.com (Ron Baalke) Subject: Pioneer 10 Update - 01/25/91 PIONEER 10 STATUS REPORT January 25, 1991 On January 14, the reference frequency used by the DSS (Deep Space Station) transmitters was lowered by 35 Hz for the Pioneer 10 spacecraft. This is done periodically to to compensate for the lower spacecraft receiver rest frequency brought about by the the changing thermal environment. On January 17, unpredicted RFI (Radio Frequency Interference) at the 70 meter antenna at Spain caused a 1 hour and 14 minute loss of telemetry data. ___ _____ ___ /_ /| /____/ \ /_ /| Ron Baalke | baalke@mars.jpl.nasa.gov | | | | __ \ /| | | | Jet Propulsion Lab | ___| | | | |__) |/ | | |___ M/S 301-355 | It's 10PM, do you know /___| | | | ___/ | |/__ /| Pasadena, CA 91109 | where your spacecraft is? |_____|/ |_|/ |_____|/ | We do! ------------------------------ Date: 25 Jan 91 23:23:14 GMT From: usc!sdd.hp.com!elroy.jpl.nasa.gov!jato!mars.jpl.nasa.gov!baalke@apple.com (Ron Baalke) Subject: Pioneer Venus Update - 01/25/91 PIONEER VENUS STATUS REPORT January 25, 1991 A 25-pulse precession maneuver was successfully executed on January 19 by the Pioneer Venus spacecraft. An HGA (High Gain Antenna) adjustment was not required because the precession moved the antenna in the desired direction. On January 18, a scheduled 34 meter track in Spain was cancelled due to station antenna problems. This prevented the loading of the spacecraft with the commands to turn the downlink on for a subsequent Goldstone 34 meter track on the same day. As a result, data from both tracks were lost, as well as the periapsis data for orbit 4427. On January 19, several antenna problems at the 70 meter station at Australia, caused a 1 hour and 30 minute loss of telemetry data, and a 2 hour and 20 minute loss of command capability. On January 20, a power failure at the same station caused a 1 hour and 30 minute loss of data. This was post-periapsis data for orbit 4429. ___ _____ ___ /_ /| /____/ \ /_ /| Ron Baalke | baalke@mars.jpl.nasa.gov | | | | __ \ /| | | | Jet Propulsion Lab | ___| | | | |__) |/ | | |___ M/S 301-355 | It's 10PM, do you know /___| | | | ___/ | |/__ /| Pasadena, CA 91109 | where your spacecraft is? |_____|/ |_|/ |_____|/ | We do! ------------------------------ Date: 27 Jan 91 02:42:12 GMT From: haven!uvaarpa!murdoch!astsun9.astro.Virginia.EDU!rws3n@ames.arc.nasa.gov (Robert W. Spiker) Subject: Re: MAJOR SOLAR FLARE ALERT - POWERFUL EVENT (25 JANUARY) std_oler@HG.ULeth.CA (Cary Oler) writes: > > A very powerful major energetic event ripped off the eastern limb of the >sun on 25 January. [...] Wow! The flares are getting so intense they're tearing the sun limb from limb! Is this what they mean by solar maximum? :-) :-) -- Robert W. Spiker, UVa Dept. of Astronomy +------------------------+ It is truly written that a man has five | rws3n@virginia.edu | times as many fingers as ears, but only | rws3n@virginia (BITNET)| twice as many ears as noses. ------------------------------ Date: 26 Jan 91 18:11:42 GMT From: world!ksr!clj%ksr.com@uunet.uu.net (Chris Jones) Subject: Re: Why man rate? (was: space news from Dec 17 AW&ST) In article <9101251307.AA23591@iti.org>, aws@ITI ("Allen W. Sherzer") writes: >In article : > >++ There is no need to ask them. We HAVE sent people up on Delta's. Funny >++ how they managed to make it do something it was never intended to do :-). > >+I was under the impression that Redstones and Atlases were used for >+Mercury, and Titans were used for Gemini (and of course Saturns for >+Apollo and Skylab) -- am I missing something? > >Sorry about that. I did indeed mean to say Atlas. The point remains that >humans use tools in unintended ways all the time. > The effort to man-rate the Atlas was non-trivial. In fact, the original Atlas failed in its first flight with a Mercury on top of it, and quite a bit of effort went into beefing up its structure and adding redundancy. Human-rating either the current Deltas or Titans seems to be dicey: both have solid fuel motors with, um, interesting firing strategies. In fact, the Titan uses the exact opposite of the Shuttle's ignition strategy (check out liquid fuelled motors, and, when they're all working, fire SRBs). It takes off under solid propulsion only, and doesn't ignite its liquid fuelled engines until some time has passed. -- Chris Jones clj@ksr.com {world,uunet,harvard}!ksr!clj ------------------------------ X-Delivery-Notice: SMTP MAIL FROM does not correspond to sender. Date: Sat, 26 Jan 91 12:17:34 MST From: std_oler%HG.ULeth.CA@vma.cc.cmu.edu (Cary Oler) Subject: MAJOR SOLAR FLARE ALERT - POWERFUL EVENT (25 JANUARY) X-St-Vmsmail-To: st%"space+@andrew.cmu.edu" -- MAJOR SOLAR FLARE ALERT -- JANUARY 25, 1991 Flare Event Summary Potential Impact Forecast -------- MAJOR ENERGETIC EVENT SUMMARY A very powerful major energetic event ripped off the eastern limb of the sun on 25 January. The flare, rated a powerful class X10.8/SF flare began at 06:23 UT on 25 January. It peaked at an x-ray level of X10.8 at 06:35 UT and held at an X10 level for 17 minutes. This event ended at 09:51 (a long duration event). The flare was associated with strong Type II and Type IV sweep frequency events and was also associated with strong radio emissions. A burst of 57,000 s.f.u. was observed at 245 MHz. The burst at 10 cm was 3,500 s.f.u. The location of this flare was S16E78. The region responsible for this exceedingly powerful event is Region 6471 (near S13E61). This region is very complex and is large in area. Magnetic gradients in this regon are also high. Major flaring from this region is likely. The potential impacts of this flare are stated below. In addition to Region 6471, Regions 6466 and 6462 (now nearing the central meridian) also retain very complex parameters and high magnetic gradients. Any of these three regions could produce major energetic flares which could include proton flares. The probability for further X-class and/or proton flares from these regions has been increased, particularly with the appearance of Region 6471 on the east limb. The solar flux has responded to the enormous jump in activity and is now recorded at a level of 283. The background x-ray flux has jumped to levels in excess of class C2.0. The sunspot number has likewise jumped and is now estimated at a value between 240 to 260 (observations are not yet all in). The regions now on the disk represent a very serious increase in solar activity. The risk for major flaring, proton flaring, satellite proton activity and Polar Cap Absorption activity is high. The Space Environment Services Center is maintaining a condition YELLOW alert status for possible PCA activity. This recent flare did not produce any significant increases in solar protons, but the position of this flare was too far east for solar protons to seriously impact with the earth. As Region 6471 approaches the central meridian, and as Regions 6466 and 6462 move into the western hemisphere, the risk for proton bombardments will increase. POTENTIAL TERRESTRIAL IMPACT FORECAST The recent class X10.8/SF major flare is expected to produce a low to moderate impact with the earth sometime on 28 January. It will likely only produce active conditions, but many area's could experience minor storming. The long duration minor flare of 24 January is expected to produce some increased activity today or possibly into tommorrow. There are conflicting reports that the activity from this minor flare may have already impacted with the earth. However, at the present time, we still believe the shock (if one does indeed materialize) is still on its way and should reach the earth sometime today or early tommorrow (27 January), UT time. There is a chance that a shock from the class X10.8 flare may not have an impact with the earth. This flare occurred relatively far away on the eastern limb, and hence the probability for terrestrial impacts is much lower than it would be if the flare would have occurred nearer to the central meridian. But it's association with strong Type II and IV sweeps is indicative of a coronal mass ejection which could have an impact with the earth, depending on the trajectory of the plasma cloud. People should be on the alert for potential increases in geomagnetic activity over the next 24 hours, and again late on 27 January through to about 29 January. Impacts shouldn't be too strong (unless some other powerful flare occurs from Regions 6466 or 6462), but middle latitude minor storming is a possibility. Major flares are still possible (if not likely) over the next 24 to 48 hours. Proton flaring is possible, as is potential PCA activity. Radio communications may experience significant long-duration fadeouts on HF bands if major flares occur. Affected area's will be restricted to the sunlit hemisphere, and will include mostly the low and middle latitudes. SID's/SWF's of more minor intensity are also expected as M-class flaring increases. Night-time propagation should be mostly normal if effects from the minor M-class flare of 24 January do not materialize or are smaller than expected. Propagation on 28 January is expected to become somewhat degraded. VHF propagation via D-layer reflection is possible during periods of major flaring. Also, the MUF has increased over the past 48 to 72 hours and may provide some openings on 6 meters. Watch for possible future major flare alerts and/or possible geomagnetic storm alerts. ** End of Report ** ------------------------------ Date: 25 Jan 91 05:28:55 GMT From: bfmny0!tneff@uunet.uu.net (Tom Neff) Subject: Re: Weekly World News publishes Challenger tape transcript In article <9947@orca.wv.tek.com> bill@flutter.tv.tek.com (William K. McFadden) writes: >So, what does it say? --- WARNING --- This may make you very sad. I sure was. Nevertheless, I think it needs to be posted. Hit 'n' now if you would rather not hear... NASA's account of tapes made during the ill-fated Challenger mission ends with pilot Michael Smith saying "uh-oh" one minute, 13 seconds into the flight. Here is the rest: the suppressed transcript of the crew's last minutes, captured on Christa McAuliffe's personal cassette recorder and recovered from the shattered crew cabin. The sex of the speaker is indicated by M or F. T+1:15 (M): What happened? What happened? Oh God, no -- no! T+1:17 (F): Oh dear God. T+1:18 (M): Turn on your air pack! Turn on your air... T+1:20 (M): Can't breathe... choking... T+1:21 (M): Lift up your visor! T+1:22 (M/F): (Screams). It's hot. (sobs). I can't. Don't tell me... God! Do it now! T+1:24 (M): I told them... I told them... Dammit! Resnik don't... T+1:27 (M): Take it easy! Move (unintelligible)... T+1:28 (F): Don't let me die like this. Not now. Not here... T+1:31 (M): Your arm:... no... I (extended garble, static). T+1:36 (F): I'm... passing... out... T+1:37 (M): We're not dead yet. T+1:40 (M): If you ever wanted (unintelligible) me a miracle... (unintelligible)... (screams). T+1:41 (M): She's... she's... (garble)... Damn! T+1:50 (M): Can't breathe... T+1:51 (M/F): (Scream). Jesus Christ! No! T+1:54 (M): She's out. T+1:55 (M): Lucky... (unintelligible). T+1:56 (M): God. The water... we're dead! (Screams). T+2:00 (F): Goodbye (sobs)... I love you. I love you... T+2:03 (M): Loosen up... loosen up... T+2:07 (M): It'll be just like a ditch landing... T+2:09 (M): That's right. Think positive. T+2:11 (M): Ditch procedure... T+2:14 (M): No way! T+2:17 (M): Give me your hand... T+2:19 (M): You awake in there? I... I... T+2:29 (M): Our father... (unintelligible)... T+2:42 (M):... hallowed be Thy name... (unintelligible) T+2:57 (M): You... over there? T+2:58 (M): The Lord is my shepherd, I shall... not want. He maketh me to lie down in green pastures... though I walk through the valley of the shadow of death, I will fear no evil... I will dwell in the house... T+3:15 to end (None): Static. Silence. ------------------------------ End of SPACE Digest V13 #093 *******************