 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
Pioneer 10 Misses Orbital Correction Maneuver
Moffett Field - June 5, 2000 Some 10 light hours out, an aging pioneer that keeps on trucking like an aging '70s pop star, is slowly slipping away as its plutonium battery trickles down. A recent attempt to re-orient Pioneer 10 now appears to have failed, leaving the distant probe perilously close to the point where all contact may finally be lost. It appears that a pointing maneuver conducted July 8 and previously reported as successful did, in fact, not take place. With Pioneer 10 seeing a decrease in signal strength. Ric Campo, Pioneer Operations Supervisor says a new attempt will be made. "We are looking for an appropriate time to re-command the maneuver." "Until that time we will continue to track the spacecraft one or two times a month. As Earth swings back into the spacecraft field of view, the signal level will improve until mid November when the spacecraft will once again be at a small Earth Look Angle," reported Campo. The Radioisotope Thermoelectric Generators (RTGs) continue to provide sufficient power to support the current spacecraft load of transmitter, receiver, command and data handling as well as the Geiger Tube Telescope (GTT) science instrument. The RTGs are currently providing approximately 65 Watts of power (about 42% of the 155 Watts launch value). The science and transmitter are turned off to provide enough power to fire the attitude control engines for the biannual spacecraft pointing maneuvers towards the Sun (the latest maneuver was executed on 2/11-12/00). The battery voltage is often discharged and charged. However, the battery does not support any of the load, being charged to only about 1 volt at its peak, down from its nominal value of 9 volts. The Bus Voltage is at a steady 27 Volts with a Bus Current of about 1.3 Amps. The platform temperature is still within acceptable limits at -41 degrees F (the nominal range is between -63 F to 180 F). The Deep Space Network (DSN) continues to provide good data with the received signal strength of -178 dBm (only a few dBm from the receiver threshold of -180 dBm). Although powerwise Pioneer 10 is operating OK with one science instrument on, the DSN may not be able to get good telemetry lock as the signal-to-noise ratio (SNR) continues to decrease. Even though in a year the DSN may still be able to get good telemetry lock, being this close to the receiver threshold and losing about 0.3 dBm/yr due to range, maintaining contact will be a challenge.
From a typical tracking report of late:
Deep Space Station (DSS): 63 Madrid, Spain
CommunitySpacecraft: 23 [Pioneer 10] Date of track: 3/21/00 Day of Year (DOY)=081 Beginning of Track (BOT) = 21:15 (Universal Coordinated Time) End of Track (EOT) = 23:50 Spacecraft Health: Thermal, Power, RF, Science all nominal. Email This Article Comment On This Article Related Links Pioneer Operations SpaceDaily Search SpaceDaily Subscribe To SpaceDaily Express Space Tourism, Space Transport and Space Exploration News
Spicing Up Space Meals
Los Angeles CA (SPX) Jan 04, 2006Since its launch a year and half ago, Minimus.biz has quickly become the place to go for individual and travel size items. Last week, NASA came to Minimus.biz and purchased several different travel size condiments to send with the astronauts to the International Space Station. |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| The content herein, unless otherwise known to be public domain, are Copyright 1995-2006 - SpaceDaily.AFP and UPI Wire Stories are copyright Agence France-Presse and United Press International. ESA PortalReports are copyright European Space Agency. All NASA sourced material is public domain. Additionalcopyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement,agreement or approval of any opinions, statements or information provided by SpaceDaily on any Web page published or hosted by SpaceDaily. Privacy Statement |
