News: Cloudsat Status

CloudSat radar status

CloudSat radar operations ceased as planned on December 20, 2023 at 11:10 UTC, bringing to an end a rich 17 year and 8 month history of science observations. The spacecraft will now conduct a sequence of orbit lowers leading up to its passivation in April 2024.

The Data Processing Center and Science Team are hard at work implementing the final reprocessing of the CloudSat data products. These R06 products will be released to the science community gradually throughout 2024 and early 2025.

For more information about the mission and its decommissioning, please see this Colorado State University press release.

UPDATE: 2 February 2022

The CloudSat Cloud Profiling Radar returned to daytime-only operations on 16 December, 2021.

After a series of innovative changes to the command loads on the spacecraft, Ball Aerospace engineers were able to use the remaining momentum wheels and torque-rods to stabilize the craft and allow the re-activation of the CPR instrument. After the long period of dormancy, the radar is performing nominally, and the mission will now operate in the same day-time-only mode that was in place prior to the momentum wheel failure on August 27th of 2020.

The new stabilization procedure is producing a harmonic offset in the “roll” and “pitch” direction of the spacecraft axis, resulting in a radar bore-sight pointing offset that varies from approximately 2-6 degrees off-nadir. Engineering data from the spacecraft has been successfully applied to the science data to correct the geolocation of each CPR profile.

After review by the CloudSat Science Team, this unique data set will be processed and released, along with roll and pitch offset parameters.

The real-time “QuickLook” images and granule specifications will continue to be available on the CloudSat DPC website.

UPDATE: 27 August 2020

CloudSat suffered a failure of one of its three remaining reaction wheels on August 27th, 2020 which automatically puts the spacecraft into standby mode. Radar data collection has ceased until the team determines if operations can continue with two wheels.

CloudSat successfully exited the A-Train. CloudSat is now in Enhanced Sun-Point-Spin (SPS) mode; in SPS the cloud radar (CPR) is NOT taking data. The team will begin studying options to resume science operations in the new orbit under the A-Train.

UPDATE: 29 APRIL 2014

Spacecraft systems are performing nominally and, with the exception of a few hours surrounding the 29 April Solar Eclipse, Daylight Only Operations (DO-Op) continued according to plan.

Two routine formation flying maneuvers were successfully exectuted last week, on 22 and 26 April, to position the satellite within its Constellation Control Box, while also maintaining ground track overlap whtith CALIPSO.

A repeated discharge of the spare Common Pressure Vessel (CPV) was successfully performed last week. This time the discharge activity went nominally and voltages remained close to zero after the discharge. The spare CPV will remain discharged for approximately one week, before being recharged again. Recharge operations are scheduled to resume early next week.

CloudSat was commanded to the Standby Mode for several orbits in the early morning of 29 April, interrupting science data collection, in order to shed load during a solar eclipse. The spacecraft performed nominally and remained power positive during the eclipse. Nominal DO-Op operations resumed just after 11am PDT.

Future Events in the next 4 weeks:
• Monthly Battery Health Checks
• Annual Operations Review: 20-22 May, Ft Collins, CO - tbc

UPDATE: 16 APRIL 2014

Spacecraft systems are nominal and Daylight Only Operations (DO-Op) continue.

The second of two planned Inclination Adjust Manevuers was successfully exectuted last night. This completes CloudSat's maneuvering for the Annual Inclination Adjust Maneuver Campaign.

The longer charge period applied to the spare Common Pressure Vessel (CPV) last week was ineffective in bringing the spare CPV up to a nominal charge. The spare CPV will be fully discharged this week and will remain fully discharged for approximately one week before being recharged again. It is hoped that this additional reconditioning will resolve the issue.

Future Events in the next 4 weeks:
Upcoming Maneuver Forecast:
* 22 April - Orbit Lower (0.65 m/s tbd)
* 30 April - Orbit Raise (0.15 m/s tbd)
Solar Eclipse: 29 April
Monthly Battery Health Checks

UPDATE: 18 MARCH 2014

Daylight Only Operations (DO-Op) continue nominally.

CloudSat executed its first Inclination Adjust Maneuver (IAM) last week. An Inclination decrease was successfully performed on 11 March. The next Inclination decrease is currently scheduled for 10 April. During this time frame, coordinated flying maneuvers (orbit raise and orbit lower) are being conducted as necessary to maintain the ground track overlap with CALIPSO.

Charging of the Spare Common Pressure Vessel (CPV) began on 17 March. Charging operations will continue for the next three to four weeks, per the nominal battery management procedures.

Future Events in the next 4 weeks:
* Upcoming Maneuver Forecast: 10 April - Inclination Decrease (tbd)
* Weekly Battery Health Checks (Sundays)
* Mission Operations Working Group (MOWG): 8-11 April

UPDATE: 4 MARCH 2014

Daylight Only Operations (DO-Op) continue nominally.

CloudSat is scheduled to execute an orbit lower maneuver on 5 March. This is a routine coordinated flying maneuver to maintain good ground track alignment with CALIPSO. Next week the Annual Inclination Maneuver campaign, with the rest of the Afternoon Constellation Missions, will begin.

Future Events in the next 4 weeks:
Upcoming Maneuver Forecast:
* 11 Mar - Inclination Decrease
* 21 Mar - Orbit Raise (tbd)
* 9 April - Inclination Decrease (tbd)

UPDATE: 22 JANUARY 2014

Satellite systems are performing nominally and Daylight Only Operations (DO-Op) continue.

Two week DO-Op sequences are now being implemented for nominal mission operations. Uploading two week long sequences provides additional margin for DO-Op Operations in the event that an unexpected, lengthy ground system outage hampers uplink capability.

Multi-Mission Satellite Operations Center (MMSOC) Verification and Validation testing with the spacecraft resumed on 20 January. The MMSOC system will be configured as prime, with Legacy in Shadow, during the V&V activities. MMSOC V&V will be conducted Monday through Friday, during prime shift operations, through January 31. Initial operations have been successful in confirming that the work around for flight software table loads has effectively increased the bandwidth to enable successful file uploads.

Future Events in the next 4 weeks:
* Revised Maneuver Blocks: Late January

UPDATE: 9 JANUARY 2014

Satellite systems are performing nominally and Daylight Only Operations (DO-Op) continue according to plan.

An Orbit Raise Maneuver was conducted on 7 January, as part of the normal orbit maintenance and ground track overlap alignment with CALIPSO. The next maintenance maneuver is projected to be in the late January/early February timeframe.

The Spare Common Pressure Vessel (CPV) was completely discharged yesterday, as the first step in a planned partial reconditioning effort. A sequence of commands has been uploaded to the spacecraft to begin re-charging the Spare CPV today. The team will ccontinue to monitor the progress of the charging effort, which is expected to last for a period of 21 days.

Future Events in the next 4 weeks:
* Two Week Sequence Implementation: Early January
* MMSOC Discrepancy Report Review / Assessment: Mid January
* Revised Trim Maneuver Blocks (for improved accuracy): Late January

UPDATE: 11 DECEMBER 2013

Daylight Only Operations (DO-Op) continue nominally.

CloudSat successfully exectued an Orbit Lower Maneuver on 6 December. The spacecraft is well positioned in it's constellation control box and is in good ground track alignment with CALIPSO. It is expected that this was the last maneuver of 2013, baring any unexpected atmospheric behavior.

Charging of the Spare Common Pressure Vessel (CPV) started this week and is expected to continue until just prior to the Christmas Holiday. This will ensure an adequate charge level until early next year, when it has been proposed to do a Spare CPV Reconditioning.

Future Events in the next 4 weeks:
* Two Week Sequence Implementation: Early January

UPDATE: 21 NOVEMBER 2013

Mission Operations continue nominally in Daylight Only Operations (DO-Op) mode.

An orbit lower maneuver was executed successfully on 19 November, to maintain the 4km ground track overlap with the CALIPSO mission. An Orbit Raise is scheduled for next week to maintain CloudSat's position within its Constellation Control Box. Both maneuvers are part of routine orbit maintenance for coordinated flying within the Afternoon Constellation (A-Train).

Future Events in the next 4 weeks:
* Battery Health Check: Weekly
* Star Catlog Rotation: 21 November
* Autonomous Command Block Memory Update: mid-November
* Orbit Raise Maneuver: 26 November
* Two Week Sequence Implementation: mid-late November

UPDATE: 16 OCTOBER 2013

The spacecraft systems are nominal and Daylight Only Operations (DO-Op) continue according to plan. Mission operations continue on the Legacy Ground System, while issue resolution with the Multi-Mission Space Operations Center (MMSOC) system continues.

Spare Common Pressure Vessel (CPV) charging began on 6 October and continues nominally. Charging is expected to continue charging until 16:00 UTC on 25 October. Spare CPV Charging is part of the nominal battery management activities.

Future Events in the next 4 weeks:
* Orbit Lower Maneuver: 31 October / 1 November
* Solar Eclipse: 3 November
* Orbit Raise Maneuver: Mid-November
* MMSOC Prime / Legacy System Shadow: exact date tbd (due to above)

UPDATE: 2 OCTOBER 2013

Daylight Only Operations (DO-Op) continue nominally.

Routine mission operations continue on the Legacy Ground System, while testing continues to resolve issues with the new Multi-Mission Space Operations Center (MMSOC) system. Access to the Automatic Data Distribution System (ADDS) for CloudSat Operations at Kirtland AFB was restored after the 19 September outage, but no root cause is yet determined. An orbit raise maneuver was successfully done on 27 September, keeping CloudSat in tight formation with the CALIPSO satellite.

Future Events in the next 4 weeks:
* MMSOC Prime / Legacy System Shadow: exact date tbd
* MMSOC Operational Readness Review #1: tbd
* MMSOC SOAK Operations: tbd
* MMSOC Operational Readiness Review #2: tbd

UPDATE: 18 SEPTEMBER 2013

Spacecraft systems are performing nominally and Daylight Only Operations (DO-Op) continue according to plan.

The ADDS data distribution system for CloudSat Operations at Kirtland AFB was restored late Sunday 15 September. Root cause anaysis remains under investigation, however the service interruption is suspected to be due to upgrades and configuration changes within the Air Force secure computer network. Satellite state of health and science data were manually delivered to a CloudSat FTP site during the outage.

A detailed technical walk through of the issue with flight software table uploads from the the new Multi-Mission Space Operations Center (MMSOC) system was conducted at Kirtland Air Force Base on Wednesday 18 September. Shadow Operations with MMSOC were suspended last month upon discovering the upload issue and the team is working to develop a way forward for the return to shadow operations.

Future Events in the next 4 weeks:
* Orbit Raise Maneuver: Week of 23 September
* MMSOC Prime / Legacy System Shadow: exact date tbd (due to above)
* MMSOC Operational Readness Review #1: tbd (due to above)
* MMSOC SOAK Operations: tbd (due to above)
* MMSOC Operational Readiness Review #2: tbd (due to above)

UPDATE: 8 AUGUST 2013

The flight system is performing well and Daylight Only Operations (DO-Op) continue nominally.

CloudSat successfully executed a coordinated flying maneuver on 1 August. The spacecraft is positioned well in its Constallation Control Box and is in good ground track overlap alignment with CALIPSO. The next maneuver is projected to be in early October.

The new Multi-Mission Space Operations Center (MMSOC) system was configured to shadow the Legacy ground system on Tuesday 6 August. Operators are conducting mission operations from both systems, simultaneously, this week while the operations team compares uplink and downlink products for consistency.

Future Events in the next 4 weeks:
* Legacy System Prime / MMSOC Shadow: 6-13 August
* MMSOC Prime / Legacy System Shadow: 14-27 August
* MMSOC Operational Readness Review #1: 30 August
* MMSOC Operational Readiness Review #2: 27 September

Daylight Only Operations (DO-Op) continue nominally.

Charging of the Spare Common Pressure Vessel (CPV) charging resumed on 14 June. This is performed approximately every six months to keep the Spare CPV charged as part of routine battery charge management.

Future Events in the next 4 weeks:
* Multi-Mission Space Operations Center (MMSOC) software Sprint 3 completion - Late June/Early July
* MMSOC Sprint 3 Confidence Building Demonstration - 16 July
* MMSOC Joint Configuration Control Board (JCCB) - 16 July
* MMSOC software installation for Shadow Operations - Mid/Late July

Spacecraft systems are performing nominally and Daylight Only Operations (DO-Op) continue.

The third and final Inclination Adjust Maneuver will be exectuted on the spacecraft tonight. The planned 1.07m/sec inclination decrease maneuver will complete the annual inclination adjust maneuver campaign for CloudSat.

The team conducted an annual operations review this week. Spacecraft subystem and instrument performance were addressed as were scenarios for simplifying and streamline mission operations. These scenarios will be further vetted in the upcoming months. Lastly, the team performed a detailed walk through of the A-Train Exit procedure.

Future Events in the next 4 weeks:
* Orbit Raise Maneuver - 12 June 2013 (tbc)

Nominal Daylight Only Operations (DO-Op) continue.

A 8.6 cm/sec Orbit Raise Maneuver will be executed tonight. This maneuver is part of the routine maneuvering necessary to maintain ground track alignment with CALIPSO.

The spacecraft will be commanded to Standby Mode for one orbit and two Cloud Profiling Radar (CPR) heaters will be temporarily powered off due to a brief solar eclipse event on 10 May 2013. This will interrupt nominal DO-Op science data collection for three orbits.

Future Events in the next 4 weeks:
* Annual Operations Review: 20-21 May 2013
* Inclination Adjust Maneuver #3: 23 May 2013

Spacecraft systems are nominal and Daylight Only Operations (DO-Op) continue.

CloudSat will execute an Orbit Lower maneuver on 25 April. This maneuver will mitigate the risk of a potential conjunction, as well as improve ground track overlap with CALIPSO. Execution of this, previously unplanned maneuver, will result in an Orbit Raise maneuver on 9 May and delays the third and final inclination adjust maneuver to 23 May 2013.

Future Events in the next 4 weeks:
* A-Train Inclination Adjust Maneuver Campaign: Apr-May 2013
* Annual Operations Review

Daylight Only Operations (DO-Op) continue nominally.

Daylight Only Operations (DO-Op) continue nominally.

CloudSat will execute the first of three inclination adjust maneuvers on 5 April as part of the A-Train Inclination Adjust Maneuver campaign. The second and third maneuvers are planned for 12 April and 7 May.

The flight system is performing nominally and Daylight Only Operations (DO-Op)continue.

Charging of the Spare Common Pressure Vessel (CPV) began on 6 March and continues nominally. CPV charging is performed as part of the nominal battery management activites and will continue until approximately 27 March.

A no-burn demonstration of the Inclination Decrease robust maneuver sequence will be executed on the spacecraft tonight. The demonstration is being performed to validate the new sequence onboard the vehicle, in preparation for the A-Train Inclination Adjust Maneuver campaign.

Daylight Only Operations (DO-Op) continue nominally.

A demonstration of the Multi-Mission Satellite Operations Center (MMSOC) Sprint 2 software capabilities was conducted on 20 February 2013 at Kirtland Air Force Base. Mission planning, contact scheduling, commanding, post pass product generation and daylight only limit checking functions were demonstrated. Development has now started on Sprint 3, the last Sprint in the MMSOC development effort.

The Voltage to Temperature (VT) level on the spacecraft battery was permanently lowered from VT 5.5 to VT 5.0 after a series of tests validated there was plenty of margin for reducing the amount of overcharge. Charging at VT 5.0 will reduce battery temperatures and pressures, with the goal of prolonging battery life.

Normal Daylight-Only Operations (DO-Op) continued as planned.

A 24 hour test to lower the VT level from 5.5. To 5.0 was successfully conducted on Thursday 14 February. This was the last in a series of tests and results indicated that there was very little difference between the 12hr and 24 hr tests. The testing confirmed that the minimum battery voltage remained above the success criteria of 29.5 volts, following a reduction in the VT level. It expected that the VT level will be permamently reduced to 5.0 in the coming days.

Normal Daylight-Only Operations (DO-Op) continued as planned.

On Thursday 7 February, a no-burn demonstration of the second A-Train Exit Maneuver was successfully executed on the spacecraft. The demonstration maneuver went nominally and this now completes the on-orbit validation of the exit maneuver design. The team will now begin developing the detailed procedures and will conduct a walk through in the coming months.

The VT level reduction tests, in support of the battery overcharge reduction plan, continue to go very well. A 12 hour test conducted on Monday 11 February, confirmed that the battery pressure stabilized quickly, resulting in increased heat rather than increased state of charge. A 24 hour test will be conducted Thursday, February 14, 2013 for added confirmation. It is expected that the VT level can be permanently reduced from VT 5.5 to VT 5.0, following nominal completion of Thursday's test.

Normal Daylight-Only Operations (DO-Op) continued as planned.

A no-burn demonstration of the first of two A-Train Exit Maneuvers was successfully exectued on the spacecraft on 1 February. The demonstration was successful in validating the new robust maneuver design and the longer burn duration required for the first exit maneuver

Normal Daylight-Only Operations (DO-Op) continued as planned.

CloudSat successfully executed a Drag Make-Up Maneuver on 25 January, as part of the normal coordinated flying orbit maintenance activities. The results from the latest maneuver indicate a 10% over performance. This will cause CloudSat to approach the back of its A-Train control box in mid-February. The spacecraft is not expected to exit its control box.

Normal Daylight-Only Operations (DO-Op) continued as planned.

The maneuvers necessary to eventually exit the A-Train were uploaded and stored onboard to the vehicle this week. Both sequences have designed using the new robust maneuver scenario and have been fully validated on the spacecraft testbench. Thruster commands are nulled out in the sequences and no-burn demonstrations will be conducted within thet next few weeks.

The first in a series of tests in accordance with the Batttery Overcharge Reduction Plan was executed on 23 January. The battery VT level was reduced from VT 5.5 to VT 5.0, for one orbit, to characterize the resulting response to battery pressure minimal eclipse voltage. A review of battery performance during the past year revealed that there appears to be an opportunity to reduce the overcharge into the battery and potentially extend battery life.

Normal Daylight-Only Operations (DO-Op) continued as planned.

On January 16, a second test of a modified, robust maneuver sequence was successfully completed on the satellite during a "no-burn" orbit raise. This modified maneuver design enables both star trackers to maintainlock during maneuvers, increasing the pointing accuracy and burn precision. In the next 2-4 weeks, additional 'no-burn' demo testing, using this robust design, will be conducted for the exit burns needed to eventually exit the A-Train. Once tested, the A-train exit burns will be loaded on the spacecraft to enable rapid descent from the A-Train if an urgent scenario develops.

The spacecraft system is performing nominally and Daylight Only Operations (DO-Op) continue.

A demonstration of the new Robust Maneuver Sequence was successfullty performed on the vehicle on the evening of 8 January. This new robust maneuver design allows both star trackers to maintain lock during maneuvers, which allows for better attitude knowledge and increased the pointing accuracy.

Daylight Only Operations (DO-Op) continue nominally.

Spare Common Pressure Vessel (CPV) charging is proceeding nominally. Charging started on 14 November and is expected to continue for three weeks.

The spacecraft experienced a brief solar eclipse by the moon yesterday. The power system performed nominally, as it experienced a brief draw on the batteries during the 10 minute eclipse in the middle of the sunlit portion of the orbit. The battery state of charge returned to nominal following the eclipse and nominal Daylight Only Operations (DO-Op) continue.

Nominal Daylight Only Operations (DO-Op) continue.

A fix to the Solid State Recorder (SSR) hang issue, that has been plaguing the mission since the implementation fo DO-Op Mode, has been implemented on the spacecraft. There have been zero hangs since this fix was implemented and the project has declared success in fixing the issue.

Nominal Daylight Only Operations (DO-Op) continue.

Nominal Daylight Only Operations (DO-Op) continue.

Nominal Daylight Only Operations (DO-Op) continue.

A small 5.1 cm/sec orbit raise maneuver will be executed in the early evening of 17 October. This maneuver was initially planned as debris avoidance maneuver, however the conjunction risk has since dropped below the criteria requiring a maneuver. Since the maneuver development work had been completed and because there was a nominal Drag Makeup Maneuver (DMU) maneuver required within the next two weeks, the project elected to execute this maneuver, as designed. Performing this maneuver will disrupt the return of nominal radar science data for four orbits.

Nominal Daylight Only Operations (DO-Op) continue.

Nominal Daylight Only Operations (DO-Op) continue.

Results from the monthly battery health check on Monday 1 October were nominal. The Spare Common Pressure Vessel (CPV) charge level also indicates a slower decay rate as compared to the prior charge in May. This is due to the increased charge duration in August.

Spacecraft systems are nominal and Daylight Only Operations (DO-Op) continue.

CloudSat executed an orbit lower maneuver on 21 September and is well positioned for a good period of ground track overlap with CALIPSO. Current estimates place the next maneuver in mid-November 2012.

CloudSat continues successful Daylight Only Operations (DO-Op). Plans are in place to execute a small orbit raise maneuver on 20 September at 1847 PDT. This maneuver will align the CloudSat and CALIPSO ground tracks.

CloudSat radar status

A small collision avoidance (orbit lower) maneuver was successfully executed Thursday evening, 6 September 2012 at 2039 PDT. The spacecraft returned to Daylight Only Operations (DO-Op) following the maneuver and continues to operate nominally.

UPDATE: 5 September 2012

CloudSat continues successful Daylight Only Operations (DO-Op).

A small orbit lower maneuver will be executed Thursday evening, 6 September at 2039 PDT. By performing this maneuver the spacecraft will return to its constellation control box in mid-September (after a minor excursion out of the back of the box).

UPDATE: 29 August 2012

CloudSat continues successful Daylight Only Operations (DO-Op).

CloudSat continues successful Daylight Only Operations (DO-Op).

CloudSat continues successful Daylight Only Operations (DO-Op).

Charging of the Spare Common Pressure Vessel (CPV) continued nominally this week. The voltage has peaked and charging will continue until Friday August 17.

UPDATE: 1 August 2012

CloudSat continues successful Daylight Only Operations (DO-Op).

UPDATE: 26 July 2012

CloudSat continues successful Daylight Only Operations (DO-Op).

On 19 July, commands were uplinked to the spacecraft to perform a Star Catalog Rotation. This is performed approximateley twice per year, to ensure the spacecraft maintains accurate knowledge of star locations relative to the current epoch and to account for the Earth's precession rate.

The CloudSat spacecraft successfully executed the first Drag Make-Up (DMU) Maneuver, since returning to the A-Train, on Tuesday evening, 24 July. This 12.5 cm/sec maneuver successfully adjusted the position of the spacecraft within it's control box and aligned the ground track for formation flying with Calipso.

UPDATE: 19 July 2012

The CloudSat spacecraft successfully executed an Inclination Increase Maneuver on Tuesday evening, 17 July. Results indicate very small underperformance, which will be corrected by a Drag Make Up (DMU) maneuver on 25 July. Last night's maneuver successfully positioned the CloudSat spacecraft 108 seconds behind CALIPSO and in alignment with the other Afternoon Constellation (A-Train) satellites. This completes the maneuver campaign to return CloudSat to the A-Train.

UPDATE: 11 July 2012

CloudSat continues to operate nominally in the A-Train. The team is preparing to implement a planned inclination increase maneuver on 13 July that will complete the overlap alignment of the CloudSat radar footprint with the CALIPSO lidar footprint.

UPDATE: 14 June 2012

CloudSat still plans to execute an inclination-decrease maneuver in mid-July. This will optimize the footprint overlap with the CALIPSO lidar in preparation for the SEAC4RS field experiment which begins on 8 August 2012. The spacecraft and cloud radar are performing nominally. Battery health checks confirm that the power system is nominal.

CloudSat continue to operate in DO-Op mode (operations during the daylight only). The team is in the process of analyzing a possible trim burn in June and an inclination increase on July 22, 2012.

On Tuesday, 15 May 2012, CloudSat successfully entered the A-Train, 394 days after the battery anomaly and 333 days after dropping out of the A-train.

In mid-July, we will perform an inclination increase burn to arrest the current spacecraft nodal precession (Mean Local Time of the Ascending Node or MLTAN); this final burn will enable the overlap of CloudSat's CPR footprint with the CALIPSO liar footprint approximately 50% of the time.

Science operations continued nominally in the Daylight-Only Operations Mode. Plans are continuing on a final maneuver that will return the satellite to the A-Train constellation behind CALIPSO on May 15.

On February 3, 2012 the CloudSat Spacecraft was scheduled to perform the first of two planned Semi Major Axis maneuver burns, beginning the return to the A-Train Constellation. During the slew to the delta-v attitude, the star trackers stopped tracking stars. Fault protection determined that there was insufficient sensor data to meet the pointing requirements for a delta-v maneuver and terminated the burn. In fact, the maneuver burn was terminated before it even started and the spacecraft returned to point mode.

The spacecraft performed exactly as designed. While this was disappointing to the team, the spacecraft continued nominal operations and was never in any danger. Power margin on the spacecraft was positive and all other subsystems performed nominally. The spacecraft continued to execute the planned post-maneuver command sequence and returned to the nominal DO-Op mode several orbits later, as expected.

The next opportunity to return to the A-Train will be in June 2012. The spacecraft continues to operate nominally in the DO-Op mode, collecting radar data.

UPDATE: 24 January 2012

CloudSat is planning on re-entering the A-Train constellation beginning February 3, 2012. The first maneuver on 3 FEB 2012 will occur at ~0212 UTC and the second maneuver will occur on 8 FEB 2012 at ~0722 UTC (these times MAY change as we approach these dates). The CloudSat team suggests radio astromony suspend operations during the DAYLIGHT hours ONLY beginning 3 FEB 2012 at 00 UTC. More information will become available after the first manuever is completed. Radio astromony during the nighttime is unaffected by these CloudSat maneuvers.

UPDATE: 23 January 2012

CloudSat continues to fully operate in the Daylight-Only Operation mode (DO-Op) and all issues with the Solid State Recorder (SSR) operation have been resolved.

CloudSat plans on rejoining the A-Train constellation orbit beginning February 3, 2012 to be completed by the end of February.

UPDATE: 3 November

On Tuesday, November 1, the spacecraft was configured for an altitude where by the CPR boresight is offset by 0.16° from Nadir (the pre-anomaly attitude configuration, to minimize clutter in the lower range bins due to surface reflection of the radar signal).

The spacecraft systems performed as expected and the pointing offset has been initially validated. In addition, full-orbit Solid State Recorder (SSR) operations are successfully capturing CPR observations for playback during scheduled downlinks (~7 per day). The CloudSat satellite is now declared fully operational in the Daylight-Only Operations (DO-Op) mode!

On Thursday, October 27, 2011 the CloudSat team successfully turned on the GPS receiver for the first time since April, 2011. We have confirmed in telemetry that, after six months, the GPS receiver is operating nominally.

The GPS allows us to geolocate the spacecraft and timestamp the CPR data appropriately. This is the final piece and a crucial part in producing fully functional science data products.

On Monday, October 24, 2011 the CloudSat team increased the CPR transmit time per orbit from 46 to 52-minutes. The CPR has now been transmitting every orbit in the daylight for nearly two weeks and continues to perform nominally.

On Wednesday, October 26, 2011 the CloudSat team successfully turned on the Non-Essential Bus (NEB) in eclipse. Having reached this critical milestone, CloudSat can now power the GPS, Solid State Recorder (SSR) and star trackers through Earth's umbra.

The CloudSat team has successfully completed our 46 minute/orbit CPR transmit test to improve our understanding of the Flight System thermal characteristics.

The radar continues to perform nominally and all temperatures were within expected ranges.

UPDATE: 14 October

CloudSat has completed the CPR transmit test in which the radar successfully operated in the sunlight for 5 minutes/orbit over a 24 hour period.

At 8:30AM PDT this morning, we increased the operating time to 20 minutes/orbit and telemetry from the first three orbits shows that the radar continues to perform nominally. The 20 minutes/orbit test will continue through the weekend. Data from these tests are being used to study the thermal characteristics of the flight system.

Nominally, we plan to increase the operating time to 46 minutes/orbit beginning Monday, October 17, 2011.

Below is an image from CloudSat during an intentional radar activation on October 12 at approximately 1PM Pacific.

The radar performed nominally and appears to be in good health.

Teams are now working on the implementation of a CPR transmit test in which radar will operate for 5 minutes each orbit over a 24-hour period beginning tomorrow.

The CloudSat team is very excited about the state of the radar and progress made so far in our recovery from the battery anomaly experienced in April 2011.

UPDATE: 7 October

Yesterday afternoon, CloudSat successfully executed an Orbit Lowering Delta-V Maneuver. As planned, telemetry indicated a burn duration of 398.6 seconds for a Delta-V of -1.4 meters/sec. Attitude control was nominal during the burn. Following the maneuver, the spacecraft successfully transitioned back into point standby mode. Analysis of the post-maneuver orbit, indicates that the spacecraft achieved a Delta-V of 1.3965 meters/sec, lowering the semi-major axis by 2.63 km. The CloudSat team is extremely pleased that this maneuver executed as planned, demonstrating the spacecrafts ability to perform maneuvers in advance of returning to a science orbit for the remainder of the mission.

UPDATE: 21 September

The CloudSat radar has not been transmitting since April 17 after suffering a spacecraft battery anomaly. Activities are nominally scheduled to begin the week of 25 September to begin bringing the radar back to operations over the next few weeks. Because of the spacecraft battery issues, CloudSat will no longer be able to operate in eclipse, i.e. when the earth under it is in nighttime.

Although at about the same altitude, CloudSat is no longer part of the A-train of satellites, and hence no longer has the old 16-day repeating orbit. Orbital elements (the so-called TLE) may be downloaded and used as before and the NASA orbital website is still operational. Eventually, CloudSat may return to the A-Train.

The CloudSat radar will be pointed near the nadir, but its pointing may be less stable than prior to the anomaly, although the CloudSat engineers are hoping to eventually fix this and return control to the pre-anomaly level. This means that the cone of avoidance for ground-based radio astronomy is much larger than before, and NASA suggests that radio telescopes cease 94 GHz operations during the daytime until further notice.