ARLA/CLUSTER: O CubeSat LightSail-1 deixa de transmitir.

[João Costa > CT1FBF]

 LightSail-1 CubeSat stops transmitting

JoAnne Maenpaa K9JKM AMSAT Vice-President User Services reports that
LightSail-1 has stopped transmitting on 437.435 MHz.

She says: Just read on-line at http://planet.ly/0gVop (Planetary
Society) that the LightSail satellite stopped transmitting. The team
is attempting a reboot.The telemetry data is sent on a downlink of
437.435 MHz, AX.25, 9600 bps FSK.

Excerpt from their page ...
As of late Friday afternoon, LightSail was continuing to operate
normally. The spacecraft's ground stations at Cal Poly San Luis Obispo
and Georgia Tech were receiving data on each pass. Power and
temperature readings were trending stably, and the spacecraft was in
good health.

But inside the spacecraft's Linux-based flight software, a problem was
brewing. Every 15 seconds, LightSail transmits a telemetry beacon
packet. The software controlling the main system board writes
corresponding information to a file called beacon.csv. If you're not
familiar with CSV files, you can think of them as simplified
spreadsheets-in fact, most can be opened with Microsoft Excel.

As more beacons are transmitted, the file grows in size. When it
reaches 32 megabytes-roughly the size of ten compressed music files-it
can crash the flight system. The manufacturer of the avionics board
corrected this glitch in later software revisions. But alas,
LightSail's software version doesn't include the update.

Late Friday, the LightSail team received a heads-up warning them of
the vulnerability. A fix was quickly devised to prevent the spacecraft
from crashing, and it was scheduled to be uploaded during the next
ground station pass. But before that happened, LightSail's automated
chirps fell silent. The last data packet received from the spacecraft
was May 22 at 21:31 UTC (5:31 p.m. EDT).

A LightSail map tracking application is at:
http://sail.planetary.org/missioncontrol

73 de
JoAnne K9JKM
AMSAT VP User Services

LightSail-1 and other CubeSats Launch with X-37B
http://amsat-uk.org/2015/05/20/lightsail-1-launch/