Ho appena ricevuto un post dalla CNN che dice che MGS è ko. Per capira cosa le è successo si userà la telecamera di un’altra sonda appena arrivata in orbita marziana. Passerà a circa una novantina di miglia da MGS. Inoltre si useranno le radio dei due rover ancora su Marte per ottenere ulteriori informazioni.
Sbaglio o è la prima volta che una sonda spaziale fotograferà un’altra sonda?
Speriamo bene.
Le difficoltà alla vetusta ma produttivissima sonda erano state segnalate in occasione del suo decimo compleanno (!)
Sbaglio o è la prima volta che una sonda spaziale fotograferà un'altra sonda?
Proprio Mars Globl Surveyor aveva fotografato sia Mars Odissey che Mars Express
Sbaglio o è la prima volta che una sonda spaziale fotograferà un'altra sonda?Proprio Mars Globl Surveyor aveva fotografato sia Mars Odissey che Mars Express
Ho paura che si avvicini il capolinea…
Nov. 21, 2006Erica Hupp/Dwayne Brown
Headquarters, Washington
202-358-1237/1726Guy Webster
Jet Propulsion Laboratory, Pasadena, Calif.
818-354-6278RELEASE: 06-357
NASA’S MARS GLOBAL SURVEYOR MAY BE AT MISSION’S END
Pasadena, Calif. – NASA’s Mars Global Surveyor has likely finished
its operating career. The spacecraft has served the longest and been
the most productive of any mission ever sent to the red planet.“Mars Global Surveyor has surpassed all expectations,” said Michael
Meyer, NASA’s lead scientist for Mars exploration at NASA
Headquarters, Washington. “It has already been the most productive
science mission to Mars, and it will yield more discoveries as the
treasury of observations it has made continues to be analyzed for
years to come.” Its camera has returned more than 240,000 images to
Earth.The orbiter has not communicated with Earth since Nov. 2. Preliminary
indications are that a solar panel became difficult to pivot, raising
the possibility that the spacecraft may no longer be able to generate
enough power to communicate. Engineers are also exploring other
possible explanations for the radio silence.“Realistically, we have run through the most likely possibilities for
re-establishing communication, and we are facing the likelihood that
the amazing flow of scientific observations from Mars Global Surveyor
is over,” said Fuk Li, Mars Exploration Program manager at NASA’s Jet
Propulsion Laboratory (JPL), Pasadena, Calif. “We are not giving up
hope, though.”Efforts to regain contact with the spacecraft and determine what has
happened to it will continue. NASA’s newest Mars spacecraft, the Mars
Reconnaissance Orbiter, pointed its cameras towards Mars Global
Surveyor on Monday. “We have looked for Mars Global Surveyor with the
star tracker, the context camera and the high-resolution camera on
Mars Reconnaissance Orbiter,” said Doug McCuistion, Mars Exploration
Program director at NASA Headquarters. “Preliminary analysis of the
images did not show any definitive sightings of a spacecraft.”The next possibility for learning more about Mars Global Surveyor’s
status is a plan to send it a command to use a transmitter that could
be heard by one of NASA’s Mars Exploration Rovers later this week.Mars Global Surveyor launched on Nov. 7, 1996, and began orbiting Mars
on Sept. 11, 1997. It pioneered the use of aerobraking at Mars, using
careful dips into the atmosphere for friction to shrink a long
elliptical orbit into a nearly circular one. The mission then started
its primary mapping phase in April 1999. The original plan was to
examine the planet for one Mars year, nearly two Earth years. Based
on the value of the science returned by the spacecraft, NASA extended
its mission four times.“It is an extraordinary machine that has done things the designers
never envisioned despite a broken wing, a failed gyro and a worn-out
reaction wheel. The builders and operating staff can be proud of
their legacy of scientific discoveries and key support for subsequent
missions,” said Tom Thorpe, project manager for Mars Global Surveyor
at JPL.The spacecraft evaluated landing sites for the twin NASA rovers that
landed in 2004 and sites for future landings of the Phoenix and Mars
Science Laboratory missions. It monitored atmospheric conditions
during aerobraking by newer orbiters. It served as a relay link for
the rovers and provided mapping information about their surroundings.“When we watched the launch 10 years ago, we wondered if we would make
the specified mission length. We certainly were not thinking of a
10-year operating life,” said JPL retiree Glenn Cunningham, who
managed the Global Surveyor project through development and launch.A few of the mission’s many important discoveries about Mars include:
– The spacecraft’s camera found gullies cut into many slopes that
have few, if any, impact craters. This indicates the gullies are
geologically young. Scientists interpret this as evidence of action
by liquid water, essentially in modern times.– The mineral-mapping infrared spectrometer found concentrations of a
mineral that often forms under wet conditions, fine-grained hematite.
This discovery led to selection of a hematite-rich region as the
landing site for NASA’s Mars Exploration Rover Opportunity.– Laser altimeter measurements have produced an unprecedented global
topographic map of Mars. The instrument revealed a multitude of
highly eroded or buried craters too subtle for previous observation,
and mapped canyons within the polar ice caps.– The magnetometer found localized remnant magnetic fields,
indicating that Mars once had a global magnetic field like Earth’s,
shielding the surface from deadly cosmic rays.– The camera found a fan-shaped area of interweaving, curved ridges
interpreted as evidence of an ancient river delta resulting from
persistent flow of water over an extended period in the planet’s
ancient past.– A long life allowed Global Surveyor to track changes through
repeated annual cycles. For three Martian summers in a row, deposits
of carbon-dioxide ice near Mars’ South Pole shrunk from the previous
year’s size, suggesting a climate change in progress.JPL manages Mars Global Surveyor for the NASA Science Mission
Directorate, Washington.For more information on the mission, visit the Internet at:
http://www.nasa.gov/mission_pages/mgs/index.html
-end-
In tal caso addio MGS! Il piu’ longevo e piu’ produttivo di tutti gli orbiter marziani.
Una rapida ricerchina bibliografica sullo Smithsonian/NAS Abstract Service mi ha fruttato oltre 1300 titoli di pubblicazioni scientifiche. Non so se mi spiego…
Un minuto di silenzio in memoria della più longeva e produttiva sonda inviata attorno a Marte…
Una rapida ricerchina bibliografica sullo Smithsonian/NAS Abstract Service mi ha fruttato oltre 1300 titoli di pubblicazioni scientifiche. Non so se mi spiego...
Orpolina!
Dal prossimo numero del Jonathan’s Space Report, una cronologia dei orbiter e lander marziani
Probe Mars arrival End of ops. Duration at Mars
Mariner 9 1971 Nov 1972 Oct 0.9 yr
Mars-2 1971 Nov 1972 Aug 0.6 yr
Mars-3 1971 Dec 1972 Aug? 0.6 yr?
Mars-5 1974 Feb 1974 Mar 0.0 yr
Viking Orbiter 1 1976 Jun 1980 Aug 4.1 yr
Viking Lander 2 1976 Jul 1982 Nov 6.3 yr
Viking Orbiter 2 1976 Aug 1978 Jul 1.9 yr
Viking Lander 2 1976 Sep 1980 Apr 3.6 yr
Fobos-2 1989 Jan 1989 Mar 0.2 yr
Mars Pathfinder 1997 Jul 1997 Oct 0.2 yr
MGS 1997 Sep 2006 Nov 9.1 yr
Mars Odyssey 2001 Oct Active 5.1 yr
Mars Express 2003 Dec Active 3.0 yr
Spirit 2004 Jan Active 2.9 yr
Opportunity 2004 Jan Active 2.8 yr
MRO 2006 Mar Active 0.8 yr
Mia aggiunta: con la perdita di MGS, queste sono le cinque sonde piu’ anziane attualmente operative (con l’anno di lancio tra parentesi):
Voyager 2 (1977), Voyager 1 (1977), Ulysses (1990), Cassini (1997), Mars Odissey (2001).
ICE (1978) e Stardust (1999) sono ancora funzionanti ma attualmente in ibernazione. Anche Pioneer 6 (1965!) dovrebbe essere funzionante ma non piu’ seguita dalle antenne.
Il rapporto preliminare sulla perdita del MGS e’ stato pubblicato oggi
… e qui l’annuncio ufficiale.
April 13, 2007
Dwayne Brown
Headquarters, Washington
202-358-1726
Guy Webster
Jet Propulsion Laboratory, Pasadena, Calif.
818-354-6278
RELEASE: 07-88
REPORT REVEALS LIKELY CAUSES OF MARS SPACECRAFT LOSS
WASHINGTON - After studying Mars four times as long as originally
planned, NASA’s Mars Global Surveyor orbiter appears to have
succumbed to battery failure caused by a complex sequence of events
involving the onboard computer memory and ground commands.
The causes were released today in a preliminary report by an internal
review board. The board was formed to look more in-depth into why
NASA’s Mars Global Surveyor went silent in November 2006 and
recommend any processes or procedures that could increase safety for
other spacecraft.
Mars Global Surveyor last communicated with Earth on Nov. 2, 2006.
Within 11 hours, depleted batteries likely left the spacecraft unable
to control its orientation.
“The loss of the spacecraft was the result of a series of events
linked to a computer error made five months before the likely battery
failure,” said board Chairperson Dolly Perkins, deputy
director-technical of NASA Goddard Space Flight Center, Greenbelt,
Md.
On Nov. 2, after the spacecraft was ordered to perform a routine
adjustment of its solar panels, the spacecraft reported a series of
alarms, but indicated that it had stabilized. That was its final
transmission. Subsequently, the spacecraft reoriented to an angle
that exposed one of two batteries carried on the spacecraft to direct
sunlight. This caused the battery to overheat and ultimately led to
the depletion of both batteries. Incorrect antenna pointing prevented
the orbiter from telling controllers its status, and its programmed
safety response did not include making sure the spacecraft
orientation was thermally safe.
The board also concluded that the Mars Global Surveyor team followed
existing procedures, but that procedures were insufficient to catch
the errors that occurred. The board is finalizing recommendations to
apply to other missions, such as conducting more thorough reviews of
all non-routine changes to stored data before they are uploaded and
to evaluate spacecraft contingency modes for risks of overheating.
“We are making an end-to-end review of all our missions to be sure
that we apply the lessons learned from Mars Global Surveyor to all
our ongoing missions,” said Fuk Li, Mars Exploration Program manager
at NASA’s Jet Propulsion Laboratory, Pasadena, Calif.
Mars Global Surveyor, launched in 1996, operated longer at Mars than
any other spacecraft in history, and for more than four times as long
as the prime mission originally planned. The spacecraft returned
detailed information that has overhauled understanding about Mars.
Major findings include dramatic evidence that water still flows in
short bursts down hillside gullies, and identification of deposits of
water-related minerals leading to selection of a Mars rover landing
site.
The Jet Propulsion Laboratory, Pasadena, Calif., manages Mars Global
Surveyor for NASA’s Science Mission Directorate, Washington. Lockheed
Martin Space Systems, Denver, developed and operates the spacecraft.
Information about the Mars Global Surveyor mission, including the
preliminary report from the process review board and a list of some
important discoveries by the mission, is available on the Internet
at:
http://www.nasa.gov/mission_pages/mgs
EDITORS NOTE:
NASA will hold a media teleconference today at 3 p.m. EDT, to discuss
the report.
Reporters should call 1-888-398-6118 and use the pass code “Mars” to
participate in the teleconference. International media should call
1-773-681-5826. Replays of the teleconference will be available by
calling 866-369-3645. International media may call: 203-369-0243.
Audio of the teleconference will stream live at:
-end-
Metto anche la nostra: 
Dopo una missione più lunga del preventivato di 4 volte, nel novembre scorso l'orbiter della NASA era stato definitivamente perso e non si erano più instaurati contatti con la Terra. Oggi è stato pubblicato un report che spiega la probabile causa della perdita. Sembra che il guasto sia dovuto ad un malfunzionamento delle batterie dovuto ad una serie di eventi in sequenza che riguardano il computer di bordo e i comandi inviati da terra. Il 2 Novembre scorso dopo un comando di routine per il riorientamento dei pannelli sono giunti una serie di allarmi alla stazione di controllo che comunque indicavano una situazione stabilizzata. Questa è stata l'ultima trasmissione. Successivamente la sonda si è riorientata in maniera errata esponendo entrambe le batterie direttamente al Sole e provocandone un surriscaldamento fatale. Un cattivo orientamento dell'antenna ha impedito che venisse inviata a terra la situazione di pericolo cui era posta la sonda e la procedura automatica d'emergenza installata a bordo non prevedeva la messa in sicurezza dell'equipaggiamento dagli effetti termici. Si è quindi concluso che gli operatori da terra hanno eseguito tutto quello che potevano e sempre nelle procedure, le quali erano però insufficienti per questa evenienza.