[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

SOHO Maintains Contact With Ground Control

European Space Agency
Press Release Nr 29-98
Paris, France				6 August 1998

SOHO maintains contact with ground control

Having succeeded in receiving a response from the SOHO spacecraft late on
Monday night (3 August 1998), controllers at NASA's Goddard Space Flight
Center (GSFC) in Greenbelt, Maryland, USA have continued to coax information
from the spacecraft concerning its on-board status.

The spacecraft has responded so far to the attempts to activate the on-board
telemetry data system only by sending a simple carrier signal with bursts of
10 second duration. This signal has been tracked consistently since the
satellite was contacted on Monday night and has been received at ESA ground
stations in Perth, Australia and Redu, Belgium, as well as by NASA Deep
Space Network stations worldwide.

For the time being, the bursts of carrier signal are too short to allow the
sensitive ground station receivers to 'lock-on' to the signal and ESA
engineers are currently assessing the steps necessary to obtain a more
continuous signal from the spacecraft. The intermittent nature of the signal
is caused by the cyclic variation of the on-board power supply as the solar
arrays are shadowed due to the spacecraft's unintentional spin motion.
Attempts will be made to charge the on-board batteries sufficiently to
ensure that more continuous power availability to the spacecraft transmitter
system.

"Recovery will be a slow and careful operation" said ESA's Head of Science
Projects, John Credland, "The main thing is that the spacecraft is now
responding to us and we will take one step at a time to bring the spacecraft
into a more favourable attitude before assessing any damage which may have
been caused by its six-week unforeseen hibernation".

Radio contact with SOHO, a joint mission of the European Space Agency and
NASA, was interrupted on 25 June 1998. The delicate recovery activities are
being directed by the ESA SOHO project team from the NASA Operations Centre
at GSFC.

More information on SOHO, including mission status reports is available on
the Internet at http://sohowww.estec.esa.nl or via the new ESA science
website: http://sci.esa.int

For further information, please contact:

Franco Bonacina
European Space Agency, Headquarters
Paris, France
Tel:+33.(0)1.5369.7713

Don Savage
NASA Headquarters
Washington D.C.
Tel:+1.202.358.1727

Bill Steigerwald
NASA Goddard Spaceflight Center
Greenbelt, MD
Tel:+1.301.286.50.17

----------
List Archives are located at http://www.meteoritecentral.com/list_best.html
For other help, FAQ's and subscription info and other resources,
visit  http://www.meteoritecentral.com/mailing_list.html
----------