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, 28 Mar 91 01:50:38 -0500 (EST) Message-ID: <0bwN8tC00WBw86I057@andrew.cmu.edu> Precedence: junk Reply-To: space+@Andrew.CMU.EDU From: space-request+@Andrew.CMU.EDU To: space+@Andrew.CMU.EDU Date: Thu, 28 Mar 91 01:50:33 -0500 (EST) Subject: SPACE Digest V13 #310 SPACE Digest Volume 13 : Issue 310 Today's Topics: Shuttle Status for 03/21/91 (Forwarded) Ion Propulsion Re: Rifles Re: Hi-G devices (arrows) GEOMAGNETIC STORM INFORMATION UPDATE #1 - 24 MARCH Magellan Update - 03/20/91 Soviet space tour request 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: 22 Mar 91 07:36:13 GMT From: mips!swrinde!elroy.jpl.nasa.gov!jato!mars.jpl.nasa.gov!baalke@apple.com (Ron Baalke) Subject: Shuttle Status for 03/21/91 (Forwarded) KSC SHUTTLE STATUS REPORT - THURSDAY, MAR. 21, 1991 - 10 a.m. STS-37/GAMMA RAY OBSERVATORY - ATLANTIS (OV 104) - PAD 39-B LAUNCH - APRIL WORK IN PROGRESS: - Interface verification tests between the orbiter and the Gamma Ray Observatory payload. - Inspections of orbiter components in the aft compartment due to water intrusion. - Preparations for loading hypergolic propellants into the or- biter. - Launch Readiness Review. WORK COMPLETED: - Countdown Demonstration Test. WORK SCHEDULED: - Loading hypergolic propellants into the orbiter beginning late tomorrow. - Flight Readiness Review March 26-27. STS-39/DoD - DISCOVERY (OV 103) - OPF BAY 2 LAUNCH - LATE APRIL, EARLY MAY WORK IN PROGRESS: - Rigging of the right hand external tank door hinge housings and cycling of the doors to retest. - Thermal protection system operations. - Functional tests of the external tank doors. WORK SCHEDULED: - Roll to the Vehicle Assembly Building Monday. STS-40/SPACELAB LIFE SCIENCES 1 - COLUMBIA (OV 102) - OPF BAY 1 LAUNCH - MAY WORK IN PROGRESS: - Testing connections for the payload. - Electrical connections of space shuttle main engines. - Preparations to service the ammonia boilers. - Orbital maneuvering system pod functional tests. - Thermal protection system operations. - Preparations to replace the S-band antenna. WORK SCHEDULED: - Installation of the Spacelab Life Sciences payload into the or- biter this weekend. WORK COMPLETED: - Installation of the three main engines. STS-40 SOLID ROCKET BOOSTERS - VAB Optical alignment of the hold down posts on the mobile launcher platform is in progress. The left and right aft skirts have been removed from the mobile launcher platform. Earlier this week, gauges attached to the aft skirts and hold down posts gave readings about the loads that are not understood. The concern is that the posts are not aligned properly. The aft skirts are scheduled to be restacked on Saturday. Schedule impacts are cur- rently being assessed. ___ _____ ___ /_ /| /____/ \ /_ /| Ron Baalke | baalke@mars.jpl.nasa.gov | | | | __ \ /| | | | Jet Propulsion Lab | ___| | | | |__) |/ | | |___ M/S 301-355 | Change is constant. /___| | | | ___/ | |/__ /| Pasadena, CA 91109 | |_____|/ |_|/ |_____|/ | ------------------------------ Date: Wed, 20 Mar 91 13:12:08 EST From: Babe Magnet Subject: Ion Propulsion Greetings from the Great White North! I am a final year undergrad in physics. In one of my courses, we were assigned seminar topics relating to charged particle dynamics--I got ion propulsion of space flight. I was wondering if anyone would be able to suggest to me some good references for this subject? Possibly something downloadable from somewhere. I figured someone subscribing to this list would be able to direct me to some fab-o info and that I could really shine on D-Day because of it. Please write to me directly. My address is: DFOSSUM@UOTTAWA.BITNET. Thanks Muchly, Daniel Fossum. ------------------------------ Date: Fri, 22 Mar 91 15:08:30 EST From: John Roberts Disclaimer: Opinions expressed are those of the sender and do not reflect NIST policy or agreement. Subject: Re: Rifles >From: henry@zoo.toronto.edu (Henry Spencer) >Subject: Re: railguns and electro-magnetic launchers >In article <1991Mar21.080855.27560@leland.Stanford.EDU> zowie@leland.Stanford.EDU (Craig DeForest) writes: >>Lesse: the bullet of a `typical' hunting rifle comes out at the >>speed of sound, after accelerating from rest inside the (1m) barrel. >Actually, Mach 1 is a pretty slow bullet, more typical of pistols than >modern rifles. 700-1000 m/s is more typical for a high-velocity rifle. >That's also a reasonable velocity range for medium-performance artillery. >1000m/s in a 5m barrel is an average of 10000G, and the peak will be >somewhat higher. As an example of the high acceleration of chemical launchers, and of the working of mechanical devices at high accelerations: The fastest commercial load I know of is the Remington .30-06 Springfield "Accelerator". It uses a large powder load and a small (55 grain = 3.56 gram) bullet. From the promotional literature: Remington's new "Accelerator" has an incredible muzzle velocity of 4080 fps [1244 m/s]. A sub-caliber (.30-06/.224) bullet is seated in a plastic sabot and put into a standard .30-06 metallic case. The plastic sabot separates within 14 inches of the muzzle and falls to the ground.... Given that most Remington .30-06 rifles have a 22-inch (.56 m) barrel, and using the formula a = v^2 / (2 * d), this gives a minimum peak acceleration of 1.38E6 m/s^2, or about 140000 G. (I know that sounds high, but I checked the calculations several times. Correction or verification welcomed.) It's impressive that the plastic sabot holds up under that load. John Roberts roberts@cmr.ncsl.nist.gov ------------------------------ Date: Fri, 22 Mar 91 17:24:16 EST From: John Roberts Disclaimer: Opinions expressed are those of the sender and do not reflect NIST policy or agreement. Subject: Re: Hi-G devices (arrows) >From: korpela@stew.ssl.berkeley.edu (Eric J. Korpela) >Subject: Re: railguns and electro-magnetic launchers >Organization: Cal Berkeley-- Space Sciences Lab >In article <1991Mar21.080855.27560@leland.Stanford.EDU> zowie@leland.Stanford.EDU (Craig DeForest) writes: >> >> This is an interesting comment on material strength: >>arrows are typically light wood (pine?) or sheet metal or plastic, >>with flimsy plastic or real feathers at the back. All of these >>materials withstand the initial (and much stronger final) acceleration >>in the arrow! >You materials strength comment is a bit inaccurate. You've probably >never seen a wooden arrow explode when someone attempts to fire it >from a compound bow. Even a 45# compound bow has the ability to >shread wooden arrows (usually doing some damage to the arms of the >bowman.) Arrows used in high pull bows are usually hollow aluminum >shafts. > /\ korpela@ssl.berkeley.edu Internet > /__\ rioch BKYAST::KORPELA 42215::KORPELA DecNet > / \ of Chaos korpela%bkyast@ucbjade Bitnet > (_____________________ I've shot cedar arrows with a friend's 50-60 lb compound bow with no trouble. Actually, for a given transfer of kinetic energy, a compound bow will treat an arrow more gently than a recurve. (Though cedar arrows tend to be lighter than aluminum, and thus shoot faster.) Good cedar arrows are *very* hard to find nowadays. I suspect that's because they're more prone to warping than aluminum arrows. One of the big compound bow gimmicks of recent years is the "overdraw" kit. This allows you to shoot arrows several inches shorter than your natural draw length, making the arrow shorter and lighter for faster travel and a flatter trajectory. A "typical" rating for a good compound bow is 210 feet per second, or 250 feet per second with overdraw. (Standard draw lengths are usually in the range of 26-32 inches.) So a good compound bow shoots an arrow with a "typical" minimum peak acceleration of ~270 G, and if the target stops the arrow in a distance of 3 inches (typical targets are made of high-density foam plastic), then peak deceleration might be on the order of 2700 G. John Roberts roberts@cmr.ncsl.nist.gov ------------------------------ Date: Sun, 24 Mar 91 01:51:12 MST From: oler%HG.ULeth.CA@BITNET.CC.CMU.EDU (CARY OLER) Subject: GEOMAGNETIC STORM INFORMATION UPDATE #1 - 24 MARCH X-St-Vmsmail-To: st%"space+@andrew.cmu.edu" /\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\ INFORMATIONAL MAGNETIC STORM UPDATE /\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\ 08:30 UT, 24 March ------------- ATTENTION: Severe geomagnetic storming has been observed over most North American middle and high latitude stations. Boulder reported a K-index of 8 for the 03-06 UT period. Severe storming continues in progress. Intense magnetic fluctuations are occurring which are capable of producing induction effects. The interplanetary shock speed has been corrected to a value of 800 km/s. Satellite protons (at geosynchronous altitudes) shot up by 11,000 particle flux units (p.f.u.) to 43,000 p.f.u. at greater than 10 MeV on 24 March at 03:50 UT. The shock arrived at 03:42 UT with a vengeance. Boulder recorded a magnetic SSC with an amplitude of 183 gammas. Local measurements have been more closely examined and show a rapid rise-time SSC measured at 180 gammas. Severe storming began shortly thereafter. The Polar Cap Absorption event has reached an absorption intensity of 46.5 dB's. The protons at greater than 100 MeV are now measured at 16 p.f.u.. Southerly middle latitude locations have observed auroral activity. Low latitude auroral activity is believed to be visible, although no confirming reports have been received yet. Most of the activity to 08:30 UT confirms the presence of bright red auroral patterns mixed with greyish arcs. Auroral oval expansion has occurred. Further southward migration is possible. It is difficult to say whether or not North American observers will be able to spot auroral activity tommorrow after dark. The storm could begin detensifying at that time. For interested observers, make the effort to check. The activity could still be present. It all depends on the duration of the storm, and that is very difficult to predict. Significant HF disruptions have occurred. Middle latitudes are experiencing significant levels of absorption, fading, flutter, distortion and noise. Near blackout conditions exist over many middle latitude locations (particularly the more northerly middle latitudes). Very poor to near blackout conditions are expected to continue throughout the next 12 to 24 hours. Some improvements can probably be expected thereafter (25/26 March). PLEASE REPORT AURORAL OBSERVATIONS, SIGNIFICANT HF SIGNAL ANOMALIES OR DEGRADATION, VHF BACKSCATTER COMMUNICATIONS, OR OTHER UNUSUAL PHENOMENA TO: OLER@HG.ULETH.CA. PLEASE INCLUDE THE DATE AND TIME OF THE OBSERVATION (LOCAL AND UT TIME), LOCATION (LATITUDE/LONGITUDE), AND A BRIEF DESCRIPTION OF THE PHENOMENA OBSERVED. /\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\ ------------------------------ Date: 20 Mar 91 21:38:49 GMT From: swrinde!elroy.jpl.nasa.gov!jato!mars.jpl.nasa.gov!baalke@ucsd.edu (Ron Baalke) Subject: Magellan Update - 03/20/91 MAGELLAN STATUS REPORT March 20, 1991 The Magellan spacecraft and its radar system are performing nominally. All of the STARCALS (star calibrations) and DESATS (desaturations) yesterday were successful. Only one star reject was noted. Magellan is now in its 1260th mapping orbit. The capture rate of data on the Earth is still about 94%, which is the equivalent of 1182 orbits on the ground. This covers almost 65% of the total Venus surface area. The weekly mapping command sequence, M1079, was be sent to the spacecraft and is now executing. This upload contained a command sequence to perform Test #2 on the Flight Tape Recorder "A." Mission controllers are now uploading the final files to reload the AACS (Attitude and Articulation Control Subsystem) Memory "B". Two of the seven uplinks have been accomplished this morning. This process will restore full redundancy to the AACS memories, and includes fault detection which will quickly isolate the memory in the event of a chip failure. ___ _____ ___ /_ /| /____/ \ /_ /| Ron Baalke | baalke@mars.jpl.nasa.gov | | | | __ \ /| | | | Jet Propulsion Lab | ___| | | | |__) |/ | | |___ M/S 301-355 | Change is constant. /___| | | | ___/ | |/__ /| Pasadena, CA 91109 | |_____|/ |_|/ |_____|/ | ------------------------------ Date: 22 Mar 91 18:36:20 GMT From: hub.ucsb.edu!ucsbuxa!3001crad@ucsd.edu (Charles Frank Radley) Subject: Soviet space tour request HELP :- $ 5 K to Baikonur is more than I wanna spend right now...... But I am entering the British Airways sweepstakes, and there are a LOT of tickets being given away ! The grand prize is ANYWHERE (specified in advance). Moscow seems to be the closest BA city to Leninsk. If I win a ticket (they are awarded in pairs, anybody wanna double up ?) how much does it cost to get to Baikonur from Moscow ? Can you set up a tour like that ? How long will it take ? I wanna see a launch of course ! Outbound travel will be on April 23 rd 1991 (not negotiatble - competition rules). HELP ! Send any e-mail to charles@stb.info.com ------------------------------ End of SPACE Digest V13 #310 *******************