Latest news from the BeppoSAX project

30 April 2003 

BeppoSAX reenters the Earth Atmosphere seven years after launch
According to the American Space Surveillance Network the BeppoSAX spacecraft reentered the atmosphere over the Pacific ocean on April 29 2003 at 22:06 UTC, almost exactly seven years after launch.

2 May 2002 

End of BeppoSAX operational phase
As planned, on April 30th at 13:38 GMT the BeppoSAX spacecraft has been permanently switched off terminating all in-orbit operations. During its six years of active life BeppoSAX went through 30720 contacts with the Malindi ground station and performed nearly 1500 observations of most types of cosmic sources discovering over 50 Gamma Ray Bursts. BeppoSAX will continue orbiting the Earth without active control until it will re-enter the atmosphere in about one year from now.

11 April 2002 

End of BeppoSAX Operations
Due to the poor and degrading spacecraft conditions and to the rapid orbital decay ASI has decided to terminate all in-orbit operations of the BeppoSAX mission at the end of April 2002. This date approximately agrees with the end of AO5 and (sadly) coincides with the 6th anniversary of the BeppoSAX launch. On April 30th the spacecraft will therefore be deactivated and put into its final configuration in preparation for re-entry accordingly to the existing international safety regulations. All BeppoSAX ground segment activities will then stop except for FOT production in order to ensure the completion and final validation of the data archive which will be hosted and supported at the ASI Science Data Center for the foreseeable future.

11 March 2002 

BeppoSAX LECS and MECS coordinates estimation improvement
Following recent work that has led to the removal of a 20'' systematic uncertainty in LECS and MECS source positions, the FITS headers of all BeppoSAX event files in the SSDC archive have been modified. All files will be available on-line as of March 12 2002. If you are interested in obtaining the best source position from LECS or MECS images please follow the instructions given in the dedicated BeppoSAX web pages or retrieve the corrected LECS or MECS events files from the SSDC on-line archive.

26 February 2002 

BeppoSAX Status
Since January 23 2002, BeppoSAX has progressively lost 4 of the 32 cells of Battery 1. This evolution was somehow expected since October 2001 when Battery 1 first displayed clear signs of irreversible ageing. The loss of these four cells (23,24,29,30) has severely degraded the battery performance with important consequences on the electrical and thermal stability of the spacecraft. Up to Febraury 13 a reduced instrument configuration was anyway supported (PDS, MECS, WFC1, WFC2) in an attempt to continue the AO5 programme as much as possible. However, after that date no scientific activities could be carried out since all the efforts at the Control Center had to be reserved to the rescue of BeppoSAX from a progressive thermal and electrical degrade. Strategies devised by the ground control to support Battery 1 ranged from the increase of the Battery K factor to the switch off of one Battery Discharge Regulator for as much as 15 minutes during the sun eclipse. The net outcome of these activities was the shift of a part of the power load on Battery 2 which is in a healthier condition than Battery 1. Since the loss of the fourth cell (February 23 2002) the spacecraft has not reached thermo-electrical stability yet, while also Battery 2 has started displaying fatigue signals at the end of the discharging phase. Work is still in progress at the OCC in order to re-establish the nominal temperature of 5 thermal loops. The case of a possible restart of some reduced scientific activity will be examined after the nominal thermo-elecrical values are attained. Battery 2 alone has not been designed to support the mission even in a minimal payload configuration. After the loss of Battery 1, Battery 2 will probably only allow the OCC to switch BeppoSAX definitevely off before collapse. At this time the general situation of the Electric Power System is to be considered critical with the possibility of further degradation that could easily lead to a sudden end of the mission.

7 November 2001 

BeppoSAX image quality unchanged in gyroless mode
An accurate analysis of the data from the first BeppoSAX observation in ESM2, gyroless mode, shows that the image quality of the MECS and LECS telescopes has remained unchanged compared to previous observations.

29 October 2001 

BeppoSAX in ESM2 'gyroless'
The in orbit commissioning of the ESM2 'gyroless' has been successfully completed on schedule today. All features have been positively tested including the recovery after a control performed only by the sun sensor (QSS) and the magnetometer (MGM). The ESM2 has proven to be robust and reliable enough to control BeppoSAX till the end of the in orbit operations. The Mission Director has authorised the resumption of scientific operations in the ESM2 scenario with the goal of completing the AO5 programme within the end of April 2002. The first source to be pointed shall be IRAS20051-1117. In order to perform a smooth restart of operations no TOO shall be accepted before 05/11/01. ASI thanks ALS and TPZ for the support during the 'gyroless' mode commissioning.

22 October 2001 

2nd ESM2 installation update
On Friday 19 Oct 2001 at 17:10:52 BeppoSAX has successfully acquired the first scientific target using the new ESM2 'gyroless' pointing system: X1822-371. This pointing is controlled only by STRs troughout the orbit. After several hours of stable control the MECS, PDS and WFCs have been activated and started producing nominal scientific data. Preliminary analysis of the MECS images indicate a full compliance with the mission requirements.

1 October 2001 

ESM2 installation update
The ESM2 commissioning activities have officially started today. The interruption of AO5 observations is scheduled for Thursday 4th 2001 at noon time. The spacecraft will then be prepared for the loading of the new control mode and for the commissioning. Scientific activities are foreseen to restart on October 30 within the ESM2 scenario, pending the reliability and robustness of the new mode. As of today no AO5 TOO requests can be accepted. Only 'fast GRB repointings' will be considered up to next Thursday.

19 September 2001 

ESM2 (gyroless) attitude control mode installation schedule
After the clear signs of degradation recently shown by the last surviving BeppoSAX GYRO, ASI has decided to speed up operations to install the ESM2 'gyroless' attitude control mode. The current schedule foresees a 3 week period of operative commissioning and ground segment reconfiguration. The planned AO5 scientific activity will be interrupted at the end of the first week of October to be resumed after October 29, pending the positive conclusion of the commissioning and the reliability of the ESM2 mode.

13 September 2001 

BeppoSAX scientific operation resumed
Following a period of close monitoring of the GYRO6 behaviour BeppoSAX has resumed its scientific program. Preparations for the installation of the ESM2 "gyroless" pointing system are however ongoing. The plan of the ESM2 installation activities will be available shortly.

4 September 2001 

BeppoSAX Gyro6 update
On 21 and 28 August 2001 BeppoSAX suffered two losses of attitude which triggered a 'safe' mode (GSM). In both cases this was due to a sudden increase of the output from the last surviving gyro (GYRO6) with a dramatic change in the drift estimate. This is normally interpreted as a sign of the gyro degradation which leaves a slim residual lifetime.
Since August 28 BeppoSAX has been put out of service in a safe configuration and the GYRO6 behaviour is monitored carefully.
No recurrences of the gyro output increase has been since detected.
Pending the stabilization of the gyro BeppoSAX will resume the planned scientific activity today however with an increased level of alert on the gyro measurements and operation in general.

20 Apr 2001 

BeppoSAX AO5 issued today
The fifth Announcement of Opportunity (AO5) for observations with the BeppoSAX satellite has been issued today. The deadline for proposals submission is May 21 2001. This AO is 100% open to projects led by PIs from any country worldwide.

11 Apr 2001 

AO5 approved! We are pleased to announce that ASI has decided to extend the BeppoSAX mission for another 12 months. AO5 is expected to be issued on April 20 2001.

26 Feb 2001 

ESM2 commissioning postponed On Feb 19 2001 the BeppoSAX Programme Executive Committee (SPEC) has decided to give priority to AO4 observations over the ESM2 'Gyroless' commissioning (pending the healthy status of the last surviving gyroscope GYR6). The mission director has therefore cancelled the commissioning activities foreseen for 05/03/2001.
The AO4 observation program shall continue normally until completion. A decision about the ESM2 will be taken if GYR6 fails before the end of AO4.

07 Feb 2001 

ESM2 commissioning. ASI has scheduled for the month of March 2001 the commissioning on board BeppoSAX of the Extended Scientific Mode 2 'Gyroless' (ESM2). This mode has been designed and tested on ground by ASI and Alenia Spazio with the goal of controlling the attitude of BeppoSAX without using the gyroscopes' output however respecting all the pointing and safety requirements of the mission. BeppoSAX is currently controlled by the Extended Scientific Mode 1 'Single Gyro' (ESM1) which uses the output of the last surviving Gyroscope (Gyro6). BeppoSAX scientific activity will be stopped on March 5th 2001 in order to configure the S/C and the ground segment for the commissioning. Current scheduling of activity foresees three weeks of on board uplink and tests. At the end of the commissioning the scientific activity shall be resumed using the ESM2 control mode provided the successfull completion of the test plan and the robustness of the mode. All details about commissioning will be dispatched in this web page.

10 Nov 2000 

End of SDC difficulties. Over the past weeks new SDC and SOC staff has been recruited. As of November 15 a total of 6 new people will be working at the SDC (4) and SOC (2). We expect the SDC to be fully operational in December 2000. In addition 24 h operations at the SOC will be resumed very shortly.

21 Jun 2000 

SDCdifficulties. Due to persisting administrative difficulties the SDC is currently experiencing a very severe staff problem. All data processing and data distribution activities are temporarily suspended. ASI is actively working toward a solution of the problem in order to resume all the SDC services in the shortest possible time.

16 Mar 2000 

As a result of the fourth BeppoSAX observing cycle (AO4), the SDC has received 212 valid proposals for a total observing time of 47.2 Ms corresponding to an oversubscription factor of 3.9.
The results of the TAC selection will be communicated aproximately the last week of April.

18 Jan 2000 

AO4 to be issued on Feb 1st 2000. Following recent ASI/SSSC meetings the SDC has received the go ahead for the fourth BeppoSAX Annoucement of Opportunity (AO4). A formal announcement will be made on February 1st; the deadline for proposal submission is anticipated to be March 6 2000.

3 Jan 2000 

Back to normal operations After the short precautionary break due to the Y2K transition BeppoSAX has restarted normal operations. No problems were encoutered.

28 Dec 1999 

BeppoSAX interrupts normal operations around 1999/2000 transition. Although all the BeppoSAX operational systems have been certified to be Y2K compliant, it has been decided to put the spacecraft in safe mode (Gyroless Safe Mode, GSM) for about 24 hours during the 1999/2000 transition. Normal operations will be resumed on January 1st 2000, approximately at noon time.

27 Dec 1999 

BeppoSAX AO4 update. Because of funding issues not completely solved at this time, the publication of the fourth BeppoSAX Announcemnet of Opportunity (AO4) has been delayed. A final decision about AO4 is expected to be made at the next meeting of the BeppoSAX Scientific Steering Committee which has been scheduled for January 17, 2000.

27 Jul 1999 

HPGSPC usage policy. In order to maximize the operational life time of the HPGSPC (which occasionally shows an anomalous behaviour) it has been decided to keep this instrument in standby mode when the target expected flux does not exceed 10 mCrab.

3 May 1999 

BeppoSAX has resumed normal science operations starting on May 1st at 06:30 UT

23 Apr 1999 

We are finishing the analysis of the accident which caused BeppoSAX to switchover its attitude control computer in 14th April. This analysis has taken us longer than we originally estimated. The cause of the switchover was a corruption in the onboard safe mode attitude control software. We are still analyzing the cause, and the methods to better monitor the onboard software status to avoid a similar problem in the future. We intend to return to the normal scientific observation program by Thursday 29th April.

16 Apr 1999 

On Wednsday 14 April at 07:30 GMT we had a switchover of the attitude control computer. We are still investigating the reason prior to returning to the scientific mission plan which we expect to do next week.

30 Mar 1999 

The TAC/SSSC review of AO3 proposals has taken place on March 8-10. The results are now public and can be accessed from the usual SDC web pages dedicated to the approved target list 

8 Dec 1998 

The BeppoSAX on-line calendar 1999 is now available at the SDC and at the HEASARC mirror (for best results use Netscape 4.0, Explorer 4 or later version)

8 Dec 1998 

The third Announcement of Opportunity for BeppoSAX observations has been issued today with deadline Feb. 1, 1999.
E-mail proposals can be sent to the SDC starting from January 1st 1999.
Data simulation and on-line analysis tools supporting BeppoSAX, XMM, AXAF and Jet-X are available from the SDC web pages. 


25 May 1998 

WFC1 status from the Mission Director. 

Wide Field Camera 1 has returned to its normal observational activity two weeks ago (12/5/98) with its full operational and scientific performance intact. On Saturday 11th April WFC1 suddenly started to show a 3% instability on the high voltage of its position sensitive proportional counter. Immediately this was realized it was switched off. In collaboration with the personnel of SRU/SRON who constructed the WFC, the subsequent investigation showed that the high voltage was unstable even at values lower than nominal. A campaign of   very small increments in voltage was started from well below the onset of the instability. This was done during the 10 minutes visibility periods in the orbits during the day when the consequences of each increment could be evaluated in real time. Occasional instability occurred but disappeared almost immediately. The last sign of instability occurred at 2960 volts from which we reached the nominal working voltage of the counter at 3727 volts  with no further incident. Single orbit tests at reduced voltage were then performed without the problem returning. It was thus decided to return WFC1 to normal operation on 12/5/98. It is difficult to reach a firm conclusion about the nature of the problem.
Now WFC1 has been functioning perfectly for about two weeks (or two hundred orbits) and its recovery looks permanent. We are all very content to be able to welcome WFC1 back to full participation in the BeppoSAX mission. 

9 Jan 1998 

The American Astronomical Society has awarded the BeppoSAX Team with the "Bruno Rossi Prize" for the BeppoSAX results on Gamma Ray Bursts. 

7 Jan 1998 

The list of AO2 proposals approved for the Core Program is now available at BeppoSAX SDC. 

19 Dec 1997 

BeppoSAX discovers the X-ray afterglow of GRB 971214. Major details are reported in the BeppoSAX Results Page

27 Nov 1997 

In response to the second BeppoSAX Announcement of Opportunity (Core Program) the SDC has received 167 proposals. The oversubscription was a factor of 4.6. The results of the selection will be made available to the general community approximately the third week of December 1997. 

25 Sep 1997 

The second Announcement of Opportunity for BeppoSAX observations has been issued on September 15 with deadlines November 14 1997 (Core Program) and January 20 1998 (Guest Observers Program). New data simulation and on-line analysis tools supporting BeppoSAX, XMM, AXAF and Jet-X are available from the SDC web pages. 

15 Sep 1997 

On Friday 12 September scientific operations have been interrupted as a consequence of an on-board data corruption in a star sensor induced by a cosmic ray. Normal operations will restart later today. 

9 Sep 1997 

Reccommencement of TOO Activity. 

We are pleased to announce that from 9 September 1997 we are reccommencing our normal Target Of Opportunity activity. The new single gyro scientific mode software is performing very well. 

14 Aug 1997 

Science operations restarted 

The commissioning of the Single Gyro Scientific Mode software has now been succesfully completed. A first analysis of the data acquired reveals that the accuracy of the pointing is essentially the same as when three gyros where in use. Normal scientific activity has been restarted today. No Target Of Opportunity pointings can however be accepted until sufficient experience and confidence with the new system is achieved. 

11 Aug 1997 

Single Gyro Pointing software 

The commissioning of the Single Gyro Scientific Mode software has started on Aug 7th and is proceeding smoothly. A few observations using the new pointing software have already been succesfully completed. We expect to resume routine observations within a few days. 

14 Jul 1997 

BeppoSAX, satellite status

The Single Gyro Scientific Mode software is now undergoing its final testing at Alenia Spazio, Turin.

The commissioning of the new operational mode should commence on the satellite on Monday 28 July 1997. The commissioning is expected to take two weeks so that the normal scientific program of observations will restart by the 11th August. 

During the commissioning of the Single Gyro Mode, scientific observations will be performed to demonstrate the performance of the mode. The X-ray sources have been chosen from those remaining to be observed from the approved observation list, and so after verification analysis in the Science Data Center (SDC) we are expecting to distribute their data to the relevant principle investigators. 

06 Jun 1997

BeppoSAX, satellite status

On thursday, 29/05/97, gyro 2 suddenly showed a reduction in sensitivity of a factor of two (in scale factor). This situation worsened over the next two days. At this point the gyro was switched-off for safety reasons.

The loss of gyro 2 leaves us with only two healthy gyro's (no.5 and no.6)- both of which are still performing well. We would need three healthy gyro's to continue the normal scientific mission until arrival of the single gyro and gyroless on-board attitude control software, and thus until then the satellite will operate in its gyroless safe mode. 

We confirm that the single gyro software should be ready by the mid of July and the gyroless version at the beginning of October. As expected, the simulations of these modes demonstrate that the characteristics of the mission will remain very similar to those up to now.

For the period prior to the arrival of the single gyro mode we are working on a plan of scientific activity which foresees at least the following: 
1 ) Gamma Ray Burst monitoring with the monitor (GRBM) in the phoswich detector system. 
2 ) Operation of the wide field cameras (WFC) at least in the part of the orbit in sunlight where there is no danger that they could point towards the Sun or at Sco X-1 while observing. 
With this plan we should at least be able to obtain the X-ray spectra of coincident bursts (seen simultaneously by the GRBM and WFC). If there are very strong known X-Ray sources in the WFC field of view the direction of the burst may be calculable. Also known x-ray source monitoring may be possible.

We will keep you informed of all developments. 

23 May 1997

In the evening of Tuesday 20 May 1997 Gyro-1 caused a fallback from a scientific pointing. Analysis of its output during the next 2.5 days has shown that its parameters (scale factor and drift rate) have changed and are evolving. It is evident that this gyro is no longer useful for scientific operations. As a consequence we have put the satellite into its gyro-less safe mode, and interrupted the scientific program. This was a suffered decision as if it was at all realistic to have continued using this gyro we would have made all efforts to do so. 
We are now proceeding to the introduction of gyro-2 to replace gyro-1 in prospect to a return to the normal scientific program by Wednsday 28th May. 
While we are preparing to return to normal operations we are still operating the Gamma-Ray burst monitor and the two Wide Field Cameras to look for coincident events. We will not however be able to give tempestive response on direction for follow-up observations as in the gyro-less safe mode the axes of the satellite follow the Earth's magnetic field, and the Sun, when available. 

15 May 1997

A Gamma Ray Burst was observed both with the GRBM and one of the WFC on May 08 1997 UT. Scientific information about this event has been reported in the IAU Circular n.6649. Three Follow-up observations centered on the accurate position derived from WFC data have been performed. The first about 6.5 hours after the event, the second two days after and the third four days after. A fourth 60ksec long follow-up is currently on going. A relatively bright X-ray source was visible in the first follow-up observation within the WFC error box. The source intensity is slowly decreasing. Scientific information about the first follow-up observation has been reported in the IAU Circular n.6656

9 May 1997

In the afternoon of May 6 1997 the detector unit 1 of the MECS developed a fault. The investigation and on-board testing performed during the subsequent two days have localized the problem to the unit's gas cell high voltage supply. It is not currently possible to say if this unit can be recovered, but the investigation is still continuing. The other two detector units of the MECS (DU2 and DU3) are working normally. Normal scientific operations of the MECS using DU2 and DU3 is restarting today. 


The first announcement of a Symposium dedicated to the discussion of BeppoSAX and Rossi-XTE results has been issued today.
The meeting will take place in Rome on October 21-24 1997 at the Accademia Nazionale dei Lincei. 


A Gamma Ray Burst was observed both with the GRBM and one of the WFC on Apr. 02 1997 UT. Scientific information about this event has been reported in the IAU Circular n.6610. Follow-up observations centered on the accurate position derived from WFC data have been performed less than 8 hours and two days after the burst. Scientific results from these observations are going to be reported in a submitted IAUC. A relatively bright X-ray source was visible in the first follow-up observation within the WFC error box. The source disappeared two days after. 


The fourth BeppoSAX e-mail news has been issued today. 


A Gamma Ray Burst was observed both with the GRBM and one of the WFC on Feb. 28 1997 UT . Scientific information about this event has been reported in the IAU Circular n.6572. Follow-up observations centered on the accurate position derived from WFC data have been performed less than 8 hours and three days after the burst. Scientific results from these observations have been reported in the IAU Circular n.6576. A relatively bright X-ray source was visible in the first follow-up observation within the WFC error box. The source was much fainter (a factor 10 or more) three days after. These results are shown in a dedicated page at BeppoSAX SDC.
A press release was issued on March 12 1997 by ASI Public Relation Office. 


BeppoSAX Gyro Status - 

As a result of the several gyro problems which stopped the observation program from 31-Jan-1997 to 20-Feb-1997 a new series of pointing modes are in preparation. The current (nominal) pointing mode needs any three of the four gyros that are currently operational. The new modes need only one or no gyros in the control loop and are expected to retain the same scientific quality that can be achieved at present. 


Normal science operations have been resumed on Feb 20 at 10:00 GMT. 


A new version of the SAXDAS software package has been released on Feb 14 1996. Detailed description of the changes with respect to the previous version is available here 


On 31 January 1997 one of the BeppoSAX gyros started to become unstable. This is the second gyro since the start of the mission that has given problems. There are 6 gyros on board and three are needed to continue the normal observation program. In consequence of this event it has been decided to temporarily interrupt the observation program and to commission a new safe mode for the satellite, called the Gyro-less Safe Mode. This safe mode was succesfully implemented on-board the week starting 3rd February. It has been decided to use this mode as baseline for the future and all procedures are currently being revised. Normal science operations are expected to be resumed within a few days. 


First results from the follow-up observation of GRB970111 have been published in IAUC 6539. 


The BeppoSAX Gamma Ray Burst Monitor (GRBM) was triggered on Jan. 11. 9:44 UT. A Gamma Ray Burst was observed both with the GRBM and one of the WFC. Scientific information about this event has been reported in the IAU Circular n.6533. A follow-up observation centered on the accurate position derived from WFC data has been performed less then 16 hours after the burst. 

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