305:. The opacity of the atmosphere was such that almost all sunlight was blocked and the rover's solar panels were unable to recharge its batteries even for minimal maintenance and communications. It was hoped it would reboot once the atmosphere cleared in October, but it did not, suggesting either a catastrophic failure or that a layer of dust has covered its solar panels. On February 13, 2019, NASA officials declared that the
58:, involves a number of immediate physical actions taken to prevent damage or complete loss. Power is removed from non-essential subsystems. Regaining attitude control, if lost, is the highest priority because it is necessary to maintain thermal balance and proper illumination of the solar panels. A tumbling or cartwheeling spacecraft can quickly roast, freeze or exhaust its battery power and be lost forever.
86:
Recovery from safe mode involves reestablishing communication between the spacecraft and mission control, downloading any diagnostic data and sequencing power back on to the various subsystems to resume the mission. The recovery time can be anywhere from a few hours to days or weeks depending on the
37:
Safe mode is entered automatically upon the detection of a predefined operating condition or event that may indicate loss of control or damage to the spacecraft. Usually the trigger event is a system failure or detection of operating conditions considered dangerously out of the normal range.
46:
are especially prone to such events. Another trigger is the lack of a received command within a given time window. Lack of received commands can be caused by hardware failures or mis-programming of the spacecraft, as in the case of the
66:
While in safe mode the preservation of the spacecraft is the highest priority. Typically all non-essential systems, such as science instruments, are shut down. The spacecraft attempts to maintain orientation with respect to the
283:
using its main engine to lower its orbit. The spacecraft's on-board computer was rebooted, and subsequent check-out of its scientific research systems showed no major malfunctions. The exact cause remains under
110:), during which – if a critical failure were to occur – most, if not all, of the mission objectives would be lost anyway. On occasion, a spacecraft is placed in safe mode deliberately by mission control, as the
320:
failed. The failing gyro had been exhibiting end-of-life behavior for approximately a year, and its failure was not unexpected. Hubble had six new gyros installed during
Servicing Mission 4 in 2009 (
334:
NASA announced that the Hubble Space
Telescope went into safe mode after experiencing synchronization issues with internal spacecraft communications. Science observations were temporarily suspended.
192:(MRO) entered safe mode on August 26, 2009 for the second incident in a month, the fourth in 2009 and the eighth since launch in 2005. The spacecraft was kept in safe mode until December 8, 2009.
374:
was lost on
September 16, 2014, during a civilian reboot effort. It is believed that the 36-year-old spacecraft entered safe mode due to a drop in power from its solar panels. The
95:
Normal safe mode operation can sometimes be overridden. A spacecraft's ability to enter safe mode may be suppressed during crucial spacecraft operations (such as the
820:
241:
entered safe mode on 15 November 2014, after its batteries ran down due to reduced sunlight and an off-nominal spacecraft orientation at its unplanned landing site.
1071:
663:
638:
474:
443:"Planning for the Un-plannable: Redundancy, Fault Protection, Contingency Planning and Anomaly Response for the Mars Reconnaissance Orbiter Mission"
1128:
87:
difficulty in reestablishing communications, conditions found on the spacecraft, distance to the spacecraft and the nature of the mission.
591:
566:
541:
738:
368:
entered safe mode and was lost when its batteries were overheated and destroyed by incorrect solar orientation on
November 2, 2006.
166:
entered safe mode March 19, 2007 due to an uncorrectable memory error in the primary
Command and Data Handling (C&DH) computer.
27:
371:
347:
entered safe mode and was nearly lost on June 25, 1998. Normal operations were eventually restored after a gap of four months.
971:
1197:
713:
944:
302:
792:
688:
517:
189:
31:
324:). The spacecraft usually uses three gyros at a time, but can continue to make scientific observations with just one.
42:
penetrating spacecraft electrical systems can create false signals or commands and thus cause a trigger event. The
852:
200:
entered safe mode on June 15 and again on July 3, 2009. Both cases were triggered by an on-board processor reset.
1078:
617:
874:
309:
mission was complete, after the spacecraft had failed to respond to over 1,000 signals sent since August 2018.
667:
642:
80:
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313:
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in a command sequence. Some scientific data was lost, but with only minimal impact on mission objectives.
848:"Juno Spacecraft in Safe Mode for Latest Jupiter Flyby; Scientists Intrigued by Data from First Flyby"
1035:
412:
365:
1048:
493:
150:
100:
295:
235:
115:
898:
83:. Exactly what happens while in safe mode is dependent on the spacecraft design and its mission.
920:
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entered safe mode, tumbled out of control and was nearly lost during the first attempt of
344:
96:
26:
during which all non-essential systems are shut down and only essential functions such as
1039:
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111:
72:
1129:"Space, the financial frontier – how citizen scientists took control of a probe"
442:
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and for thermal management. The spacecraft then awaits radio commands from its
1077:. Final Report of the NEAR Anomaly Review Board. November 1999. Archived from
888:
717:
43:
39:
23:
1182:
692:
317:
216:
256:
entered safe mode on July 4, 2015, ten days before its closest approach to
739:"MESSENGER Gains Critical Gravity Assist for Mercury Orbital Observations"
208:
entered safe mode due to a programming error during its
February 17, 2009
1020:
355:
48:
321:
793:"NASA's New Horizons Plans July 7 Return to Normal Science Operations"
401:"Recovery of a Spacecraft from Sun-Safe Mode Using a Fanbeam Antenna"
107:
1057:
520:. NASA/Johns Hopkins University/APL/New Horizons Mission. 2007-03-26
494:"SOHO Mission Interruption Preliminary Status and Background Report"
316:
entered safe mode on
October 5, 2018, after one of its three active
424:
257:
972:"Oct. 8, 2018 - Hubble in Safe Mode as Gyro Issues are Diagnosed"
1106:
893:
797:
209:
158:
flyby data was interrupted by a safing event
September 10, 2007.
821:"Juno spacecraft slips into safe mode, putting science on hold"
769:
279:
entered safe mode on 18 October 2016, just prior to a planned
68:
765:"On a comet 10 years away, Philae conks out, maybe for good"
741:. MESSENGER Mission News. September 30, 2009. Archived from
54:
The process of entering safe mode, sometimes referred to as
921:"Mars Exploration Rover Mission: All Opportunity Updates"
889:"Mars Dust Storm News - Teleconference - audio (065:22)"
399:
Bokulic, R. S.; Jensen, J. R. (November–December 2000).
945:"NASA's Opportunity Rover Mission on Mars Comes to End"
763:
Brumfield, Ben; Carter, Chelsea J. (18 November 2014).
1103:"Report Reveals Likely Causes of Mars Spacecraft Loss"
798:
1072:"The NEAR Rendezvous Burn Anomaly of December 1998"
639:"Orbiter in Safe Mode Increases Communication Rate"
618:"Powerful Mars Orbiter Switches to Backup Computer"
339:
Incidents resulting in spacecraft loss or near loss
378:project has been unable to re-establish contact.
970:Chou, Felicia (2018-10-08). Garner, Rob (ed.).
174:has broken the communications link between the
1021:"The Role of Software in Spacecraft Accidents"
178:and Earth during several sudden safing events.
301:entered safe mode on 13 June 2018 during the
8:
666:. NASA/JPL. December 8, 2009. Archived from
512:
510:
220:entered safe mode during its third flyby of
641:. NASA/JPL. August 28, 2009. Archived from
447:AIAA SPACE 2007 Conference & Exposition
875:Opportunity Hunkers Down During Dust Storm
536:
534:
436:
434:
22:is an operating mode of a modern uncrewed
1047:
467:
465:
463:
394:
392:
714:"Dawn Receives Gravity Assist from Mars"
441:Bayer, Todd J. (18–20 September 2007).
388:
79:monitoring for signals on its low-gain
716:. NASA/JPL. 2009-02-28. Archived from
488:
486:
139:had several incidents with safe mode.
7:
689:"2009 July 7 Mission Manager Update"
91:Overriding normal safe mode behavior
819:Feltman, Rachel (20 October 2016).
518:"The PI's Perspective: Trip Report"
1153:Keith Kowing (25 September 2014).
691:. NASA. 2009-07-07. Archived from
14:
1127:Geraint Jones (3 October 2014).
901:from the original on 2021-12-21
791:Gipson, Lillian (6 July 2015).
616:Tariq Malik (August 8, 2009).
1:
664:"Spacecraft Out of Safe Mode"
44:central processor electronics
887:NASA Staff (13 June 2018).
190:Mars Reconnaissance Orbiter
1214:
594:. NASA/JPL. Archived from
569:. NASA/JPL. Archived from
544:. NASA/JPL. Archived from
1019:Nancy G. Leveson (2004).
472:Cassini Spacecraft Safing
1155:"ISEE-3 is in Safe Mode"
16:Uncrewed spacecraft mode
176:Mars Exploration Rovers
81:omnidirectional antenna
1028:Spacecraft and Rockets
405:Spacecraft and Rockets
314:Hubble Space Telescope
224:on September 29, 2009.
77:mission control center
30:, radio reception and
877:. NASA. 12 June 2918.
592:"Spirit Updates 2007"
567:"Spirit Updates 2006"
542:"Spirit Updates 2005"
362:on December 20, 1998.
1198:Spaceflight concepts
366:Mars Global Surveyor
303:2018 Mars dust storm
71:for illumination of
1040:2004JSpRo..41..564L
996:"Hubble on Twitter"
951:. February 13, 2019
417:2000JSpRo..37..822B
477:2009-07-09 at the
28:thermal management
1105:(Press release).
856:. 19 October 2016
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281:maneuvering burn
154:download of the
122:Modern incidents
99:maneuver of the
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1109:. 13 April 2007
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1162:. Retrieved
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1079:the original
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953:. Retrieved
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253:New Horizons
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163:New Horizons
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112:Spirit rover
101:
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73:solar panels
65:
62:In safe mode
55:
53:
36:
34:are active.
19:
18:
776:28 December
620:. SPACE.com
452:January 28,
376:crowdfunded
307:Opportunity
297:Opportunity
40:Cosmic rays
1164:15 January
1138:16 January
1113:2009-07-10
1088:2009-08-18
1005:2018-10-23
981:2018-10-23
930:2018-02-10
860:20 October
832:20 October
749:2009-09-30
724:2009-08-04
699:2009-07-08
674:2009-12-23
649:2009-08-31
624:2009-08-18
602:2009-08-18
577:2009-08-18
552:2009-08-18
524:2016-10-19
500:2006-08-17
411:(6): 822.
383:References
318:gyroscopes
260:, after a
104:spacecraft
24:spacecraft
1183:Fail-safe
1044:CiteSeerX
217:MESSENGER
20:Safe mode
1192:Category
1177:See also
899:Archived
853:NASA JPL
475:Archived
51:lander.
49:Viking 1
1036:Bibcode
1000:Twitter
905:13 June
413:Bibcode
322:STS-125
222:Mercury
171:Odyssey
156:Iapetus
114:was on
102:Cassini
1046:
804:6 July
372:ISEE-3
239:lander
237:Philae
212:flyby.
197:Kepler
135:Spirit
108:Saturn
56:safing
1082:(PDF)
1075:(PDF)
1024:(PDF)
299:rover
258:Pluto
137:rover
118:451.
1166:2016
1140:2016
1107:NASA
976:NASA
957:2019
949:NASA
907:2018
894:NASA
862:2016
834:2016
806:2015
778:2014
454:2023
356:Eros
351:NEAR
345:SOHO
329:2021
312:The
294:The
289:2018
276:Juno
269:2016
246:2015
234:The
229:2014
210:Mars
205:Dawn
188:The
183:2009
144:2007
132:The
127:2005
1054:doi
770:CNN
421:doi
116:sol
106:at
69:Sun
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