SB NEWS @ AMSAT $SPC1118 * SpaceNews 18-Nov-96 * BID: $SPC1118 ========= SpaceNews ========= MONDAY NOVEMBER 18, 1996 SpaceNews originates at KD2BD in Wall Township, New Jersey, USA. It is published every week and is made available for non-commercial use. * OSCAR-13 VERY HOT * ===================== James Miller, G3RUH, reports that AO-13's solar panels are now hitting 60C + during perigee, and this will increase still more over the next few days. If the panels are getting this hot, the antennas could be close to meltdown. There is a good chance of failure this weekend (Nov 16/17), but IF it survives to orbit 6463 then we should be able to make it to next weekend because perigee height has a "hold" at 110 km until orbit 6475 (Nov 22). Re-entry material: keps, plots, notes etc are archived in: ftp://ftp.amsat.org/amsat/satinfo/ao13/decaykep.zip (70K) which is updated daily, often twice. * GLOBAL SURVEYOR NEWS * ======================== All operations onboard Mars Global Surveyor continue to go smoothly on the spacecraft's 10-month journey to the red planet. On 10-Nov-96, the spacecraft used its star sensor to identify known stars and establish its orientation in space. Later that day, the spacecraft was placed in "array normal spin" orientation, the way in which Surveyor will fly all the way to Mars. In this configuration, Surveyor is pointed 60 degrees off the Sun, its solar panels are swept forward 30 degrees and the spacecraft rolls at a rate of one revolution every 100 minutes. This roll maintains a thermal balance on the spacecraft and allows it to constantly slew the star sensor across the sky. Surveyor's ultra-stable oscillator, one of six science instruments, has been powered on to assist in telecommunications. Communications with Earth will always occur through the low-gain antenna during Surveyor's flight to Mars, due primarily to its configuration and solar array geometry. The spacecraft's high-gain antenna will not be used until Surveyor reaches Mars because it must be pointed directly at Earth to operate, and that position currently would turn the spacecraft too directly into the sunlight. Engineers continue to evaluate telemetry from the spacecraft to understand why one of the spacecraft's two solar arrays, the - Y wing, is tilted about 20 degrees away from its expected angle relative to the main spacecraft bus structure. A variety of computer-simulated scenarios based on observed data and engineering tests involving the solar array deployment mechanisms are being examined to explore possible solutions. The array's position does not affect spaceflight operations in the near term. However, controllers at JPL and at Lockheed Martin Astronautics in Denver, CO, will decide how to position the array to compensate for the tilt during the spacecraft's first trajectory correction maneuver on 21-Nov-96. Another option presently being explored might involve positioning the array so that additional force is exerted on it during the maneuver to push the panel into its latched, fully deployed position. At this time both solar panels are receiving sunlight and converting it to electricity to operate the spacecraft, with power levels normal and batteries fully charged. Controllers also report that a minor wobble in the spacecraft's rotation was quickly corrected within 48 hours after launch. On 12-Nov-96, the Mars Global Surveyor was approximately 1.5 million kilometers (946,000 miles) from Earth, traveling at a velocity of about 119,000 kilometers per hour (about 74,000 miles per hour) with respect to the Sun. [Info via JPL] * AO-27 NEWS * ============== As of 02-Nov-96, the AO-27 schedule is as follows: TEPR 4 = 16 = 8 Minutes in Length TEPR 5 = 52 = 18 Minutes in Length TX-3 is on Mid Power during TEPR 5. This will have the TX turn on 8 Minutes after the satellite enters the sun for a duration of 18 Minutes. This is back to US latitudes operation. Controllers thank all the messages about the satellite turning on late. Michael Wyrick, N4USI, let the turn on time drift later (for about 4-5 Minutes) so stations in the southern latitudes could have a chance to work AO-27. Every few months Michael will let the turn on time drift like this to give more stations a chance to make contacts through the satellite. [Info via Michael Wyrick, N4USI, AO-27 Control-op] * STS-80 NEWS * =============== Following a launch readiness meeting Wednesday, NASA managers have decided to postpone launch of Columbia on Mission STS-80 to Tuesday, November 19th. The reason for the postponement is predicted bad weather that is expected to be in the vicinity of Kennedy Space Center for the next several days. Weather forecasters are calling for improved conditions by early next week. The STS-80 countdown will proceed to the T-11 hour mark where it will remain in an extended hold. No technical issues are currently being worked by the launch team. The STS-80 crew will remain at KSC. The launch window on November 19 opens at 1:53 p.m. Central Time (19:53 GMT) and extends for 2.5 hours. The mission duration is planned for 16 days. An on-time launch and nominal mission will have Columbia and her crew returning to KSC on December 5 at 6:37 a.m. Central Time (12:37 GMT). STS-80 will NOT carry a shuttle amateur radio experiment. The orbital inclination will be 28.5 degrees. [Info via NASA] * FEEDBACK/INPUT WELCOMED * =========================== Comments and input for SpaceNews should be directed to the editor (John, KD2BD) via any of the paths listed below: WWW : http://www.njin.net/~magliaco/ PACKET : KD2BD @ KS4HR.NJ.USA.NA INTERNET : kd2bd@amsat.org, magliaco@email.njin.net SATELLITE : AMSAT-OSCAR-16, LUSAT-OSCAR-19 <<=- SpaceNews: The first amateur newsletter read in space! -=>> /EX