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29-09-08 & 01-10-08: Preparation to receive Chandrayaan-1

• New requirements imposed due to the sensitivity of payloads. Measurements are done and found to be meeting the specifications. These include
  • Particle Fall Out measurement (PFO)
  • Environment pollution (SO2&HydroCarbon) control in clean rooms  
  • Providing high purity Nitrogen purging with stringent quality control and other safety issues 
• The facility for the satellite checked for cleanliness, temperature and humidity requirements of the spacecraft.

We are ready to receive Chandrayan-1 in all respects.

02-10-08: Seven transport containers are received from ISAC Bangalore, unloadedand the following are kept ready:

• The checkout equipments
• Mechanical ground support equipments
• Special fixtures
• Handling equipments 
• Alignment fixtures 

03.10.08: As per the agreed Interface Control Document (ICD) thefollowing is done:

• Unpacking of checkout equipments
• Setting up the checkout system,
• Positioning of fixtures at relevant locations

Spacecraft received in the evening, unloaded in the transit area and moved to Airlock room after thorough cleaning.It is removed carefully from its container and put over the fixtures for further operations.

04.10.08 to 06.10.08: 

• Moon Impact Probe (MIP) is dismantled from main orbiter and is moved to another preparation facility which is equipped to handle explosive operations.
• 'De-boost' of the solid motor assembly, 'spin and de-spin' of the motor assembly done with great care.

07.10.08 to 09.10.08: 

• Readiness of spacecraft propellant filling facility for filling propellant like MON3/MMH, propellant analysis, gaseous He for the propulsion system were made ready.
• One of the important activities is the measurement of Spacecraft dry mass and mass of spacecraft after filling. This calls for high accuracy weighing balance which was calibrated and kept ready.

10.10.08

• Spacecraft preparation at SP1 completed and packed in a rainproof container and moved to SP2. The necessary ground support equipments were pre positioned in SP2. 
• Spacecraft unpacked and MIP assembly completed. 
• Spacecraft dry mass was measured. 
• Gas bottle of the propulsion system was charged up to 250 bar and it around 6hrs.
• To keep up the schedule, round the clock operations are planned.

11.10.08

• Periodical clean room measurements like temperature, RH, PFO are carried out. 
• Preparation of propellant tanks, filling carts and sampling are done. 
• MON3 propellant filling as per the requirement are completed. The slow filling takes around 14hrs . 
• On line pollution monitoring is done. 
• The spacecraft is kept powered on during filling to monitor the propulsion parameters.
• After propellant filling decontamination to remove the propellant remaining in the filling lines, and "safing" of spacecraft propellant tanks are done. 
• The facility and spacecraft is cleared for MMH filling.

12-10-2008

• Preparation of propellant tanks, filling carts and sampling are done. 
• MMH propellants filling as per the requirement are completed. The slow filling takes around 16hrs. 
• On line pollution monitoring is done. 
• After propellant filling decontamination of filling lines and "safing" of spacecraft propellant tanks are done.
• The pressure hold test to detect even minute leaks carried out
• After subsequent thermal work, weighing the spacecraft is completed. 
• The Spacecraft in the container is moved to Vehicle Assembly Building (VAB) for integration with the Launch Vehicle, PSLV-C11.

From the diary of 
K.B. Anantha Rama Sarma,
Associate Project Director and Operational in-charge
Chandrayaan-1 Project

After successful completion of satellite rigorous testing in vacuum chamber andsubjecting satellite for the launch vibration and acoustic environment,Chandrayaan-1 satellite was cleared for shipment to Sriharikota for furtheractivities on 1-10-2008.

01-10-2008

• Entire satellite checkout station; all the mechanical fixtures, stands and platforms; and other ground support equipments were flagged off at 10AM from ISRO Satellite Centre (ISAC), Bangalore and the convoy reached Sriharikota during the night of 1-10-2008
• Meanwhile at ISAC the satellite was put in air conditioned container and was kept ready for it's journey to the launch site.

02-10-08

• Satellite was flagged off at 5-45AM at ISAC, Bangalore.

03-10-08

• By 12 noon checkout lab was fully established and was certified by QA (Quality Assurance) team for connecting to the satellite. All the mechanical fixtures in clean room were made ready to receive satellite. Once this was done the entire team started looking impatiently for the arrival of the Chandrayaan-1 satellite.
• By 3-45 PM, satellite entered the main gate of Sriharikota range and by 3-50 PM reached the first destination at the launch site, called SP-1B. It was a relief for the entire team who traveled along with the satellite; remember the satellite traveled at a speed of about 20 kmph for about 350 kms!
• On the same day some more members from ISAC, many payload teams from India and abroad reached. SHAR.
• From the arrival of the satellite it was a marathon for the entire team. Every activity to be executed on the satellite was already finalized to the minutest detail and the activity scheduling was already done few weeks back. Now the time has come for the execution of the plan. All teams were told in advance when they are required.
• From the time the satellite arrived all activities went on continuously, round the clock. The defined teams were ready as per their shift timings.
• The first activity was to switch ON the satellite, verify that the health of the satellite was normal. This was through and the next activity of conducting a detailed test of Moon Impact Probe (MIP) was completed. 
• Detailed checkout of various payload instruments and the satellite platform (also called bus) systems started.

04-10-08

• MIP payload employs solid motors, which are classified as hazardous elements for carrying out de-boost and spin/despin functions. For this purpose MIP was removed from Chandrayaan-1 and was handed over to the SHAR team.
• Propulsion system integrity verification was initiated by pressurizing all the propellant tanks and feed lines and holding the pressure for a period of 60 hours.
• Propulsion system is used to take the satellite from the initial transfer orbit to the moon orbit.

05-10-08 to 06-10-08

• During the pressure hold period, all the bus systems comprising of power system, control system, telemetry-telecommanding and communication system, Thermal elements, Payload data handling/recording system and all the ten payloads were extensively tested

07-10-08

• Propulsion system performance tests completed and pressures of tanks and feed lines were brought down to the nominal values.
• Chandrayaan-1 carries one solar panel and the panel deployment test was conducted during the night. All the solar cells and their circuits were tested by illuminating the solar cells with flash guns. 
• This was followed by pyro events' test, satellite launch sequence test.

08-10-08 to 09-10-08

• Solar panel was stowed back as this was the configuration at the time of launch.
• Chandrayaan-1 payload instrument data is received through a 0.7mtr dish antenna which is driven by azimuth and elevation motors. The entire mechanical and electrical functions of the antenna were tested.
• All the RF systems of the satellite were power ON in radiated mode, and were evaluated.
• Alignment of various control elements like sensors, gyros, control engines; antennae and payload cameras and detectors are reverified.
• Last six months we were knowing only calendar dates, but no days or holidays. This time we were told that Dasara festivals are in progress and Mahanavami is on October 9th. 
• All of us joined together in celebrating the Dasara and praying for the success of Chandrayaan-1 PSLV C-11 mission.

10-10-08

• Thermal activity on satellite is very critical as every hardware sitting in the satellite -- both mechanical and electrical -- demands temperature regime of a small band. At the launch site, as the final preparation satellite will be completely covered by thermal blankets. Blanketing work is a time consuming and tedious job and this activity was spread over four days and during the night of October 10th the thermal activity was completed.
• All payload cameras, detectors, control system sensors, control system miniature rockets (thrusters) demand specific Field Of View (FOV). Any obstruction to FOV or multiple reflections will result in malfunction of these vital parts and cripples the mission objective. These aspects were addressed and FOV was ensured for every vital element.

In less than eight days all the planned activities were completed. Theearlier record for any previous satellite at SP-1 was thirteen days and we havedone it in eight days! This was due to the dedicated efforts of more thanhundred scientists, engineers and technicians belonging to various ISRO centres(ISAC, LEOS, SAC, VSSC, IISU, SDSC-SHAR, LPSC, PRL, SPL) and payload instrumentrepresentatives from different laboratories/space centres. (APL and BrownUniversity-JPL of NASA; IRF, Sweden; RAL, UK; MPAE, Germany)

11-10-08

• By 7-30AM satellite was put on the low bed trailer and by 8AM the journey to SP-2 started. 
• By 9-30 AM the satellite was positioned in the clean room at SP-2.
• While satellite was critically tested at SP-1 MIP was ready in all aspects and was waiting for the satellite. MIP was re-assembled to Chandrayaan-1 and satellite was weighed. 
• Loading of propellants began.

ISRO again proves that nothing is impossible. I always wonder what is thedriving force behind us? Money? No. Power? No. Fame? No.

It is self-motivation and dedication.

I cannot wait anymore, AND I AM EAGERLY WAITING FOR THE launch of PSLV-C11.