TCM - Trajectory Correction Manuver (I'm guessing)
DSN - Deep Space Network, NASA's system of radio dishes for communicating
with beyond-earth-orbit missions.
On Wed, Dec 6, 2017 at 7:24 AM, John Dom <johndom@xxxxxxxxx> wrote:
TCM and DSN (Deep Space ???) meaning?
Is the Kepler probe still being used, in part? Years ago I read it was
crippled.
John
-----Original Message-----
From: arocket-bounce@xxxxxxxxxxxxx [mailto:arocket-bounce@xxxxxxxxxxxxx]
On
Behalf Of Henry Spencer
Sent: dinsdag 5 december 2017 22:41
To: Arocket List
Subject: [AR] Re: It still works.
On Tue, 5 Dec 2017, Monroe L. King Jr. wrote:
Just WOW! Hard to believe they can still contact it. It will be sad
day when it's out of reach.
Despite the title of the piece, in fact the Voyagers are still in active
operation and their ops teams (small, but still in existence) talk to them
and collect data from them quite regularly. The notable thing this time
was
not contact with the spacecraft, but the successful test of the long-unused
TCM thrusters.
There was originally some thought that the Voyagers' working lives might be
limited by communications range, but upgrades to DSN have more than kept
pace with the growing distances.
Barring late surprises, the real limit is the steady decline of their RTGs'
power output (mostly due to accumulating radiation damage in their
thermoelectric converters, not decay of the Pu-238 that heats them). If I
recall correctly, sometime around 2025 there will no longer be enough power
to run the spacecraft subsystems and the handful of instruments that are
still operating; another year or two can be eked out by running only one
instrument at a time. When there's no longer enough power for the
spacecraft subsystems, the Voyagers will fall silent, as Pioneers 10 and
11 did around the turn of the century.
Henry
