GP-B Processing Notes

NASA’s Gravity Probe B was launched successfully from Space Launch Complex 2 at Vandenberg Air Force Base on April 20 at 9:57:24 a.m. PDT. The solar arrays had a nominal deployment while still attached to the Boeing Delta II second stage. Once acquired by the tracking station in Kiruna, Sweden, onboard cameras confirmed that deployment of the four arrays had been completed 72 minutes after launch, followed by live video of spacecraft separation from the Delta II launch vehicle 75 minutes after liftoff. Gravity Probe B was launched into a 400-nautical-mile-high polar orbit for a 16-month mission.

All four gyro systems have been activated and are undergoing checkout. The full Initialization & Orbit Checkout phase of the Gravity Probe B mission is planned to last 45 to 60 days, after which the science data collection will begin.

The Gravity Probe B mission is a relativity experiment developed by NASA’s Marshall Space Flight Center, Stanford University and Lockheed Martin. The spacecraft will test two extraordinary predictions of Albert Einstein’s general theory of relativity that he advanced in 1916: the geodetic effect (how space and time are warped by the presence of the Earth) and frame dragging (how Earth’s rotation drags space and time around with it). The spacecraft consists of four sophisticated gyroscopes that will provide an almost perfect space-time reference system. The mission will look in a precise manner for tiny changes in the spin axis direction. (April 15, 2004 - status report)

The launch of the Gravity Probe B spacecraft has been postponed to no earlier than Monday, April 19. The additional time is necessary to allow engineers to troubleshoot an apparent short in launch pad ground support equipment. It is associated with a spacecraft battery monitoring circuit. Without this circuit, the battery voltage on the spacecraft cannot be remotely monitored from the pad during certain essential operations. The launch time for Monday, April 19 is 10:01:20 PDT. Should the launch be postponed 24 hours for any reason, the launch time is 9:57:24 a.m. PDT.

The spacecraft was moved from the payload processing facility to Space Launch Complex 2 on Thursday, April 1 and mated to the Boeing Delta II rocket. A spacecraft state-of-health check was successfully performed. The next major test is the Flight Program Verification to be conducted on Friday, April 9. This is an integrated test of the Delta II vehicle and the Gravity Probe B spacecraft. The two-day operation to install the two halves of the payload fairing around the spacecraft will follow on April 12 and is the final major spacecraft associated activity to be performed before launch.

Two days of major activities remain to be performed. On April 16, the loading of the second stage with its complement of hypergolic propellants is scheduled. On April 17, Flight Slews, which are launch vehicle engine steering checks, will be performed. Also, the final Range Safety beacon checks are scheduled.

Retraction of the mobile service tower, the gantry surrounding the Delta II, is scheduled to occur at 11:30 p.m. on Sunday, April 18. Loading of RP-1, a highly refined kerosene fuel, aboard the first stage, is scheduled to begin at approximately 7:30 a.m. on Monday, April 19. Loading of the cryogenic liquid oxygen into the first stage will begin approximately an hour later.

The Gravity Probe B mission is a relativity experiment developed by NASA’s Marshall Space Flight Center, Stanford University and Lockheed Martin. The spacecraft will test two extraordinary predictions of Albert Einstein’s general theory of relativity that he advanced in 1916: the geodetic effect (how space and time are warped by the presence of the Earth) and frame dragging (how Earth’s rotation drags space and time around with it).

Gravity Probe B consists of four sophisticated gyroscopes that will provide an almost perfect space-time reference system. The mission will look in a precise manner for tiny changes in the spin axis direction. Gravity Probe B will be launched into a 400-nautical-mile-high polar orbit for a 16-month mission.

Government oversight of launch preparations and the countdown management on launch day is the responsibility of the NASA Launch Services Program based at John F. Kennedy Space Center. The launch service is provided to NASA by Boeing Launch Services. (April 8, 2004 - status report)

The Gravity Probe B spacecraft is in NASA’s Payload Processing Facility 1610 on North Vandenberg Air Force Base in California, and preparations are on schedule for a launch on April 17.

The spacecraft was mated to the payload attach fitting (PAF) on March 25. Closeouts to Gravity Probe B in preparation for going to the launch pad have been completed. Today the spacecraft is being installed into the transportation canister in preparation for being moved to Space Launch Complex 2 on Thursday, April 1 and mated to the Boeing Delta II rocket.

At the pad, the rocket is enclosed within the gantry-like mobile service tower and is powered up. A Simulated Flight test, which is a plus count, has been completed successfully. This test activated the electrical and mechanical flight systems on the vehicle as they will occur from liftoff through spacecraft separation. A countdown test with the first stage loaded with liquid oxygen was successfully completed on March 18.

The next major test is the Flight Program Verification to be conducted on April 5. This is an integrated test of the Delta II vehicle and the Gravity Probe B spacecraft. Installation of the fairing around the spacecraft is scheduled for April 8.

Gravity Probe B consists of four sophisticated gyroscopes that will provide an almost perfect space-time reference system. The mission will look in a precise manner for tiny changes in the direction of spin. Gravity Probe B will be launched into a 400-nautical-mile-high polar orbit for a 16-month mission.

Government oversight of launch preparations and the countdown management on launch day is the responsibility of NASA’s John F. Kennedy Space Center. The launch service is provided to NASA by Boeing Launch Services. (March 31, 2004 status report)

The Gravity Probe B spacecraft is in NASA’s Payload Processing Facility 1610 on North Vandenberg Air Force Base in California, and preparations are on schedule for a launch on April 17.

All four solar arrays have been installed and were tested successfully. Powered-on testing of the spacecraft with the reworked Experiment Control Unit (ECU) reinstalled also has been successfully completed. Installation of small ordnance inside the Forward Equipment Enclosure (FEE) has been completed. The FEE surrounds the electronics of the Science Mission Dewar, which has valves that are opened on-orbit by these pyrotechnics to equalize pressure.

The spacecraft will be mated to the payload attach fitting (PAF) on March 25. Closeouts to Gravity Probe B in preparation for going to the launch pad will then be performed on March 29. The following day, it will be installed into the transportation canister. The spacecraft will be transported to Space Launch Complex 2 on April 1 and mated to the Boeing Delta II rocket.

At the pad, the rocket is enclosed within the gantry-like mobile service tower and is powered up. A Simulated Flight test, which is a plus count, is underway today. This activates the electrical and mechanical flight systems on the vehicle as they will occur from liftoff through spacecraft separation.

A countdown test with the first stage loaded with liquid oxygen was successfully completed on March 18. The Launch Site Readiness Review, an assessment of the Delta II launch vehicle’s readiness for spacecraft arrival, is scheduled for March 30.

The Gravity Probe B spacecraft is in NASA’s Payload Processing Facility 1610 on North Vandenberg Air Force Base in California and preparations are on schedule for a launch on April 17.

Three of four solar arrays have been installed and tested. The remaining array will be installed tomorrow. After each solar array is installed, a “walk-out test,” which is an unfolding, is performed to ensure that the array deploys properly. The spacecraft is then rotated for installation of the next solar array.

Powered-on testing of the spacecraft with the reworked Experiment Control Unit (ECU) reinstalled is complete. A detailed data analysis has confirmed that the ECU is performing as desired.

Installation of small ordnance inside the Forward Equipment Enclosure (FEE) has been completed. The FEE surrounds the electronics of the Science Mission Dewar, which has valves that are opened on-orbit by these pyrotechnics to equalize pressure.

The spacecraft is currently scheduled to be transported to Space Launch Complex 2 on April 1 and mated to the Boeing Delta II rocket.

At the pad, the rocket is enclosed within the gantry-like mobile service tower and is powered up. A countdown test with the first stage loaded with liquid oxygen will occur tomorrow, March 18. A Simulated Flight test, which is a plus count, will occur March 24. This activates the electrical and mechanical flight systems on the vehicle as they will occur from liftoff through spacecraft separation. The Launch Site Readiness Review, an assessment of the Delta II launch vehicle’s readiness for spacecraft arrival, is scheduled for March 30.

The Gravity Probe B spacecraft is in NASA’s Payload Processing Facility 1610 on North Vandenberg Air Force Base in California and preparations are on schedule for a launch on Saturday, April 17.

The first of four solar arrays has been installed and testing has been completed. The second solar array will be installed tomorrow, March 11. Solar array installation activities are targeted for completion on March 18.

Powered-on testing of the spacecraft with the reworked Experiment Control Unit (ECU) reinstalled is complete. A detailed data analysis is confirming that the ECU is performing as desired.

The spacecraft is currently scheduled to be transported to Space Launch Complex 2 on April 1 and mated to the Boeing Delta II rocket.

At the pad, the rocket is enclosed within the gantry-like mobile service tower and was powered up yesterday for the resumption of pre-launch testing.

The Gravity Probe B spacecraft is in NASA's Payload Processing Facility 1610 on North Vandenberg Air Force Base in California and preparations are on schedule for a launch on Saturday, April 17.

Powered-on testing of the spacecraft with the reworked Experiment Control Unit (ECU) reinstalled is complete and a detailed data analysis is now underway. The ECU appears to be performing fully as intended. Functional testing of the remainder of the spacecraft continues and is on schedule. No problems have been revealed.

In other planned spacecraft processing, the Gas Management Assembly (GMA) "rate of rise" testing has been completed satisfactorily. This testing checked leakage rates and amounts. The GMA provides the helium gas required to spin up the gyroscopes. It also performs magnetic flux reduction, or "flux flushing," to minimize noise or reduce the trapped magnetic field within each gyro's housing.

Reconditioning of the spacecraft's cryogenic helium dewar back to a temperature of 1.65 Kelvin has been completed and the dewar was sealed. This was essentially a topping-off process that also cooled the helium in the tank to a superfluid state near absolute zero. The topping continued until 95 percent of the helium in the dewar was in a superfluid condition. Since the dewar has now been closed out, the launch nominally would need to occur within about 90 days. A final top-off is set to occur at the launch pad to assure the helium will last the planned 16-month duration of the mission.

Operations to reinstall the solar arrays will begin on March 8. The spacecraft is currently scheduled to be transported to Space Launch Complex 2 on April 1 and mated to the Delta II rocket.

Meanwhile, the Boeing Delta II rocket is at Space Launch Complex 2, enclosed within the gantry-like mobile service tower. It has successfully completed its testing to date and will remain there until the GP-B spacecraft arrives. The solid rocket booster inspections performed as a precaution after the recent earthquake in central California have been completed with no anomalies observed. There are no Delta II launch vehicle issues or concerns at this time.

Government oversight of launch preparations and the countdown management on launch day is the responsibility of NASA's John F. Kennedy Space Center. The launch service is provided to NASA by Boeing Launch Services. (March 3, 2004 status report)

The Gravity Probe B spacecraft is in NASA's Payload Processing Facility 1610 on North Vandenberg Air Force Base in California. Preparations are on schedule for the launch, which is scheduled to occur on Saturday, April 17.

Powered-on testing of the spacecraft with the reworked ECU installed continues without problems.

Reconditioning of the spacecraft's cryogenic helium dewar back to a temperature of 1.65 Kelvin has been under way. This is essentially a topping off process that also cools the helium in the tank to a superfluid state near absolute zero. The topping continued until 95% of the helium in the dewar was in a superfluid condition. The dewar has now been closed out, so the launch nominally needs to occur within about 90 days. A final top-off is planned to occur at the launch pad to assure the helium will last the planned 16-month duration of the mission.

In other planned spacecraft processing, the Gas Management Assembly (GMA) is undergoing "rate of rise" testing that checks for leakage rates. The GMA provides the helium gas required to spin up the gyroscopes. It also performs magnetic flux reduction, or "flux flushing," to minimize noise or reduce the trapped magnetic field within each gyro's housing.

Operations to reinstall the solar arrays will begin on March 8. The spacecraft is currently scheduled to be transported to Space Launch Complex 2 on April 1 and mated to the Delta II rocket.

The Gravity Probe B spacecraft is in NASA’s Payload Processing Facility 1610 on North Vandenberg Air Force Base in California. Preparations are on schedule for the launch which is targeted to occur on Saturday, April 17.

The Experiment Control Unit (ECU) arrived at Vandenberg Feb. 4 from Lockheed Martin in Sunnyvale and was reinstalled into Gravity Probe B. Powered-on testing of the spacecraft with the ECU installed is under way. Indications are that Gravity Probe B and the ECU are performing as desired.

In other planned spacecraft processing, servicing of the Gas Management Assembly (GMA) is also under way. The GMA provides the helium gas required to spin up the gyroscopes. It also performs magnetic flux reduction, or “flux flushing,” to minimize noise or reduce the trapped magnetic field within each gyro’s housing.

The dewar with cryogenic liquid helium is connected to the ground support equipment, in preparation for servicing that will return the helium to a superfluid state. The filling of the spacecraft with helium begins today.

Operations to reinstall the solar arrays will begin in mid-March. The spacecraft is currently scheduled to be transported to Space Launch Complex 2 on April 1 and mated to the Delta II rocket.

Meanwhile, the Boeing Delta II rocket is at Space Launch Complex 2, enclosed within the gantry-like mobile service tower. It has successfully completed all testing to date and will remain there until the GP-B spacecraft arrives. There are no Delta II launch vehicle issues or concerns at this time.

The Gravity Probe B spacecraft is in NASA’s Payload Processing Facility 1610 on North Vandenberg Air Force Base in California. After final thermal vacuum chamber testing at Lockheed Martin in Sunnyvale, Calif., the Experiment Control Unit (ECU) was shipped to Vandenberg and arrived there Feb. 4. The ECU was reinstalled into the Gravity Probe B spacecraft over the weekend. Testing of the spacecraft with the ECU installed is now underway.

In other planned spacecraft processing, servicing of the Gas Management Assembly (GMA) is underway today. The GMA provides the helium gas required to spin up the gyroscopes. It also performs magnetic flux reduction, or “flux flushing,” to minimize noise or reduce the trapped magnetic field within each gyro’s housing.

Filling the dewar with liquid helium in preparation for cryogenic servicing of the spacecraft is planned for Feb. 13. The actual servicing of the spacecraft is scheduled to begin Feb. 16. Operations to reinstall the solar arrays are planned to begin in mid-March. The spacecraft is currently scheduled to be transported to Space Launch Complex 2 on Apr. 1 and mated to the Delta II rocket.

The Gravity Probe B spacecraft is in NASA’s Payload Processing Facility 1610 on North Vandenberg Air Force Base in California. It is awaiting the return of the reworked Experiment Control Unit (ECU).

The ECU is currently in Lockheed Martin spacecraft facilities at Sunnyvale, Calif. The reworking of the circuit board, installation into the ECU, functional testing and thermal vacuum chamber testing are all complete. The work has gone better than expected and the ECU will be returned to Vandenberg Air Force Base tomorrow Thursday, Feb. 5. Meanwhile this week, GP-B spacecraft test team members have been returning to Vandenberg in preparation for the arrival of the ECU.

In other planned spacecraft processing, battery reconditioning is scheduled for Feb. 6-8. The ECU will be reinstalled Feb. 9. Cryogenic servicing of liquid helium is scheduled for Feb. 16. Operations to reinstall the solar arrays are planned for Mar. 7–19. The spacecraft is currently scheduled to be transported to Space Launch Complex 2 on Apr. 1 and mated to the Delta II rocket.

Meanwhile, the Delta II rocket is at Space Launch Complex 2 enclosed within the gantry-like mobile service tower. It has successfully completed all testing to date and will remain there until the GP-B spacecraft arrives.

Gravity Probe B consists of four sophisticated gyroscopes that will provide an almost perfect space-time reference system. The mission will look in a precision manner for tiny changes in the direction of spin. Gravity Probe B will be launched into a 400-nautical-mile-high polar orbit for a 16-month mission.

The Gravity Probe B spacecraft is in NASA's Payload Processing Facility 1610 on North Vandenberg Air Force Base in California. It is awaiting the return of the reworked Experiment Control Unit (ECU).

The ECU is currently in Lockheed Martin spacecraft facilities at Palo Alto, Calif. The reworking of the circuit board, installation into the ECU and functional testing is complete. Final thermal vacuum chamber testing is under way. The ECU containing the associated circuit board will be returned for installation into the GP-B spacecraft by Feb. 10.

The battery charge continues to be monitored and there has been no significant change in the level of charge. The temperature of the dewar's main tank remains at 1.8765 K. The temperature is targeted to be no warmer than 1.880 K at launch. There is planned to be another cryogenic serving of cryogenic liquid helium in mid-February before the solar arrays are re-installed on the spacecraft.

Meanwhile, the Delta II rocket is at Space Launch Complex 2, enclosed within the gantry-like mobile service tower. It has successfully completed all testing to date and will remain there until the GP-B spacecraft arrives. As a result of the earthquake in central California earlier this month, inspections of the pad and the Delta rocket have been under way. No after-effects have been observed to the launch pad or the gantry. Precautionary testing of the solid rocket motors has been re-scheduled for Feb. 9.

The state of battery charge is monitored on a continuous basis and there has been no significant change in the level of charge. The temperature of the dewar’s main tank is 1.8765 K and has warmed from 1.648 K since the solar arrays were installed over the cryogenic access ports, after the last helium servicing. The temperature is targeted to be no warmer than 1.880 K at launch. However, since the solar arrays have been removed because of the stand-down, there is planned to be another cryogenic serving of liquid helium in mid-February.

The ECU was returned to Palo Alto, Calif., in December and is in Lockheed Martin Facilities there. The reworking of the circuit board was completed last week. The functional testing and thermal vacuum testing of the ECU were completed earlier this week as planned. Vibration testing is now underway. The circuit board will be returned for installation into the GP-B spacecraft by Feb. 10.

Meanwhile, the Delta II rocket is at Space Launch Complex 2, enclosed within the gantry-like mobile service tower. It has successfully completed all testing to date and will remain there until the GP-B spacecraft arrives. As a result of the earthquake in central California, near San Simeon, earlier this month inspections of the pad and the Delta rocket have been underway. Precautionary testing of the solid rocket motors is scheduled for next week. So far, nothing has been found that would be an issue for launch.

The Gravity Probe B mission is a relativity experiment developed by NASA’s Marshall Space Flight Center, Stanford University and Lockheed Martin. The spacecraft will test two extraordinary predictions of Albert Einstein’s general theory of relativity that he advanced in 1916: the geodetic effect (how space and time are warped by the presence of the Earth) and frame dragging (how Earth’s rotation drags space and time around with it). Gravity Probe B consists of four sophisticated gyroscopes that will provide an almost perfect space-time reference system. The mission will look in a precision manner for tiny changes in the direction of spin. Gravity Probe B will be launched into a 400-nautical-mile-high polar orbit for a 16-month mission.

The Gravity Probe B spacecraft is in NASA spacecraft processing facility 1610 on North Vandenberg Air Force Base in California. It is awaiting the return of the reworked Experiment Control Unit (ECU). The state of battery charge is monitored on a constant basis. The temperature of the dewar’s main tank is 1.864 K and has warmed from 1.648 K since the solar arrays were installed over the cryogenic access ports, after the last helium servicing. The temperature is targeted to be no warmer than 1.880 K at launch. However, since the solar arrays have been removed because of the stand-down, there is planned to be another cryogenic serving of liquid helium in mid-February.

The ECU was returned to Palo Alto, Calif. in December and is in Lockheed Martin Facilities there. The reworking of the circuit board is complete and it is currently undergoing thermal vacuum testing. This is scheduled to be finished late next week. The circuit board will be returned for installation into the GP-B spacecraft the week of February 10.

The Gravity Probe B mission is a relativity experiment developed by NASA’s Marshall Space Flight Center, Stanford University and Lockheed Martin. The spacecraft will test two extraordinary predictions of Albert Einstein’s general theory of relativity that he advanced in 1916: the geodetic effect (how space and time are warped by the presence of the Earth) and frame dragging (how Earth’s rotation drags space and time around with it). Gravity Probe B consists of four sophisticated gyroscopes that will provide an almost perfect space-time reference system. The mission will look in a precision manner for tiny changes in the direction of spin. Gravity Probe B will be launched into a 400-nautical-mile-high polar orbit for a 16-month mission.

Gravity Probe B is in NASA spacecraft processing facility 1610 on North Vandenberg Air Force Base in California. In work this week, the Experiment Control Unit (ECU) was removed yesterday, Tuesday, Dec. 9, and will be returned to Stanford University in Palo Alto, Calif., tomorrow, Thursday, Dec. 11.

The first of the four solar arrays was removed on Nov. 24, the second and third arrays were removed Nov. 25, and the last array was removed on Dec. 1.

The Delta II rocket is at Space Launch Complex 2 enclosed within the gantry-like mobile service tower and will remain there until the GP-B spacecraft arrives. The cryogenic helium remains aboard the spacecraft and will be topped off prior to going to the launch pad.

While no new launch date has been established, a Flight Planning Board meeting is planned for next week and the outcome could determine a possible target date or at least a new launch time frame.

The Gravity Probe B mission is a relativity experiment developed by NASA's Marshall Space Flight Center, Stanford University and Lockheed Martin. The spacecraft will test two extraordinary predictions of Albert Einstein's general theory of relativity that he advanced in 1916: the geodetic effect (how space and time are warped by the presence of the Earth) and frame dragging (how Earth's rotation drags space and time around with it). Gravity Probe B consists of four sophisticated gyroscopes that will provide an almost perfect space-time reference system. The mission will look in a precision manner for tiny changes in the direction of spin. Gravity Probe B will be launched into a 400-nautical-mile-high polar orbit for a 16-month mission.

Gravity Probe B is in NASA spacecraft processing facility 1610 on North Vandenberg Air Force Base in California. In preparation for the repair necessary to the spacecraft, the payload attach fitting was removed on Nov. 20. The first of the four solar arrays was removed on Nov. 24, the second and third arrays were removed Nov. 25, and the last array was removed this week on Monday, Dec. 1.

A decision has been made that the cryogenic helium will not need to be offloaded from the spacecraft to remove the Experiment Control Unit (ECU) which is expected to occur late next week. The return to the factory of the ECU is expected on or about Dec. 15. Meanwhile, at Space Launch Complex 2, the Boeing Delta II rocket remains at the pad, enclosed within the gantry-like mobile service tower until the GP-B spacecraft arrives.

While no new launch date has been established, a Flight Planning Board meeting is planned for mid-December, and the outcome could determine a possible target date or at least a new launch time frame.

The Gravity Probe B mission is a relativity experiment developed by NASA’s Marshall Space Flight Center, Stanford University and Lockheed Martin. The spacecraft will test two extraordinary predictions of Albert Einstein’s general theory of relativity that he advanced in 1916: the geodetic effect (how space and time are warped by the presence of the Earth) and frame dragging (how Earth’s rotation drags space and time around with it). Gravity Probe B consists of four sophisticated gyroscopes that will provide an almost perfect space-time reference system. The mission will look in a precision manner for tiny changes in the direction of spin. Gravity Probe B will be launched into a 400-nautical-mile-high polar orbit for a 16-month mission.

Gravity Probe B is in NASA spacecraft processing facility 1610 on North Vandenberg Air Force Base in California. Last week, in preparation for the repair necessary to the spacecraft, the payload attach fitting was removed which is used in mating it to the Delta II.

The solar arrays are beginning to be removed from around the spacecraft for access to the experiment control unit (ECU). Yesterday, one of the four solar arrays was taken off, and a second array is being removed today. A third array will be removed today if time permits; otherwise, the third and fourth arrays will be removed next Monday and Tuesday after the spacecraft team returns from the Thanksgiving holidays.

A decision has been made that the cryogenic helium will not need to be offloaded from the spacecraft to remove the ECU for rework. Because decisions remain to be made on what will be necessary to restore Gravity Probe B to flight readiness, it is not possible at this time to determine a new launch date.

At Space Launch Complex 2, the Boeing Delta II rocket remains at the pad, enclosed within the gantry-like mobile service tower until the GP-B spacecraft arrives.

The Gravity Probe B mission is a relativity experiment developed by NASA’s Marshall Space Flight Center, Stanford University and Lockheed Martin. The spacecraft will test two extraordinary predictions of Albert Einstein’s general theory of relativity that he advanced in 1916: the geodetic effect (how space and time are warped by the presence of the Earth) and frame dragging (how Earth’s rotation drags space and time around with it). Gravity Probe B consists of four sophisticated gyroscopes that will provide an almost perfect space-time reference system. The mission will look in a precision manner for tiny changes in the direction of spin. Gravity Probe B will be launched into a 400-nautical-mile-high polar orbit for a 16-month mission.

Gravity Probe B is in NASA spacecraft processing facility 1610 on North Vandenberg Air Force Base in California. After a final review of test data before going to the launch pad, spacecraft management made a decision to reschedule the launch of Gravity Probe B. They want to address an issue of electronic noise on one of the two output channels of the No. 1 experiment gyro. This problem was found during testing and could compromise the quality of the data from the gyro. While a work around of the problem was considered, engineers decided that fixing the problem will provide the greatest chance of success over the planned 16-month life of the mission. This repair will restore full redundancy to the output of the experiment gyro.

Meetings are set to begin at Vandenberg Air Force Base on Friday. These will determine the approach to be taken for repair and thus how long the launch postponement will be; however, launch cannot occur during December. The difficulty has been found to be within the spacecraft’s experiment control unit (ECU).

Meanwhile, in preparation for the repair, the payload attach fitting used in mating to the Delta II is being removed today from the base of the spacecraft.

At Space Launch Complex 2, the rocket has successfully completed the scheduled prelaunch preparations up to this time, and there are no issues or concerns with the Delta II. The current plans are for it to remain at the pad, enclosed within the gantry-like mobile service tower until the spacecraft arrives.

The Gravity Probe B mission is a relativity experiment developed by NASA’s Marshall Space Flight Center, Stanford University and Lockheed Martin. The spacecraft will test two extraordinary predictions of Albert Einstein’s general theory of relativity that he advanced in 1916: the geodetic effect (how space and time are warped by the presence of the Earth) and frame dragging (how Earth’s rotation drags space and time around with it). Gravity Probe B consists of four sophisticated gyroscopes that will provide an almost perfect space-time reference system. The mission will look in a precision manner for tiny changes in the direction of spin.

Gravity Probe B will be launched into a 400-nautical-mile-high polar orbit for a 16-month mission.

Gravity Probe B is in NASA spacecraft processing facility 1610 on North Vandenberg Air Force Base. The installation of the four solar arrays, deployment testing and lighting tests have been successfully completed. The Delta II payload adapter was mated to the GP-B spacecraft on Thursday, Nov. 13.

The spacecraft’s cryogenic dewar was sealed prior to beginning solar array installation at a temperature of 1.648 K. The temperature is rising very slowly, but is expected to remain less that 1.88 K by the time launch occurs. The current temperature is 1.7175 K, which is well within the expected rate of rise. The dewar will be topped off at the pad prior to launch.

A Simulated Flight test, a “plus count” that tests the launch vehicle systems as if the vehicle were in powered flight, was successfully completed on Nov. 6. The exercise that involves loading of liquid oxygen aboard the first stage and a limited “minus count” was successfully conducted on Nov. 4.

Marshall Space Flight Center’s equivalent of a Mission Readiness Review was held on Wednesday, Nov. 12. This review, chaired my MSFC, is intended to certify readiness of Gravity Probe B for flight, the readiness of the spacecraft operations team and readiness of mission personnel and ground stations to achieve the science objectives.

The GP-B test results during the period that the spacecraft has been undergoing activities in processing facility 1610 are now having a final assessment prior to an engineering review to be held on Monday, Nov. 17. This review will determine the readiness of GP-B to go to the pad. It will also cover the readiness of the Delta II launch vehicle for spacecraft erection and for proceeding with final prelaunch activities. Gravity Probe B will be placed into a transportation canister on Tuesday, Nov. 18 and transported to Space Launch Complex 2 the following day on Nov. 19.

The final major test before launch, the Flight Program Verification, will be conducted on Nov. 21. This is an integrated test conducted after the Gravity Probe B spacecraft is mated atop the second stage of the launch vehicle. The Delta II fairing will be installed around the spacecraft on Nov. 25 as part of final preparations for launch.

The Gravity Probe B mission is a relativity experiment developed by NASA’s Marshall Space Flight Center, Stanford University and Lockheed Martin. The spacecraft will test two extraordinary predictions of Albert Einstein’s general theory of relativity that he advanced in 1916: the geodetic effect (how space and time are warped by the presence of the Earth) and frame dragging (how Earth’s rotation drags space and time around with it). Gravity Probe B consists of four sophisticated gyroscopes that will provide an almost perfect space-time reference system. The mission will look in a precision manner for tiny changes in the direction of spin.

Gravity Probe B will be launched into a 400 nautical-mile-high polar orbit for an 18-month mission.

Gravity Probe B is in NASA spacecraft processing facility 1610 on North Vandenberg Air Force Base. Solar array installation began on Tuesday. There are four arrays to be installed and tested. Two of the four arrays are now installed, and installation of the third solar array is in progress. Installing each array is a 3-day process and includes a functional deployment test. Solar array installation activities are targeted for completion by Friday, Nov. 7. The Delta II payload adapter will be delivered to the spacecraft processing facility on Nov. 10.

The spacecraft’s cryogenic dewar was sealed prior to beginning solar array installation at a temperature of 1.648 K. The temperature is rising very slowly, but is expected to remain less that 1.88 K by the time launch occurs. The current temperature is 1.695 K, which is well within the expected rate of rise. The dewar will be topped off at the pad prior to launch.

At the launch pad, integrated testing of the vehicle continues on schedule. Qualification testing has been completed on the Redundant Inertial Flight Control Assembly (RIFCA). This is the navigation and guidance control unit for the Delta II. The tests simulated launch conditions in the unique helium environment that will be created within the payload fairing by the Gravity Probe B spacecraft. Routine integrated guidance and control system checkout of the vehicle was successfully completed as scheduled last week.

An exercise that involves loading of liquid oxygen aboard the first stage and a limited “minus count” was successfully conducted yesterday, Nov. 4. A Simulated Flight test, a “plus count” that tests the launch vehicle systems as if the vehicle were in powered flight, is being performed today.

Marshall Space Flight Center’s equivalent of a Mission Readiness Review is scheduled to be held in Huntsville on Nov. 12.

In final launch preparation activities, Gravity Probe B will be transported from the spacecraft processing facility to Space Launch Complex 2 on Nov. 19 and hoisted atop the second stage. Then the final major test before launch, the Flight Program Verification, will be conducted on Nov. 20. This is an integrated test conducted after the Gravity Probe B spacecraft is mated atop the second stage of the launch vehicle. The Delta II fairing will be installed around the spacecraft on Nov. 25 as part of final preparations for launch.

The Gravity Probe B mission is a relativity experiment developed by NASA’s Marshall Space Flight Center, Stanford University and Lockheed Martin. The spacecraft will test two extraordinary predictions of Albert Einstein’s general theory of relativity that he advanced in 1916: the geodetic effect (how space and time are warped by the presence of the Earth) and frame dragging (how Earth’s rotation drags space and time around with it). Gravity Probe B consists of four sophisticated gyroscopes that will provide an almost perfect space-time reference system. The mission will look in a precision manner for tiny changes in the direction of spin.

Gravity Probe B will be launched into a 400 nautical-mile-high polar orbit for an 18-month mission.

Gravity Probe B is in NASA spacecraft processing facility 1610 on North Vandenberg Air Force Base. Solar array installation began on Tuesday. There are four arrays to be installed and tested. The first array is now installed and testing of it is under way today. Solar array installation activities are targeted for completion on Nov. 7. The Delta II launch vehicle/payload adapter will be delivered to the spacecraft processing facility on Nov. 10.

The spacecraft’s cryogenic dewar is currently 96 percent full of cryogenic superfluid liquid helium and maintaining the desired temperature of 1.66 Kelvin. The dewar will be topped off at the pad prior to launch.

An exercise that involves loading of liquid oxygen aboard the first stage and a limited “minus count” will be conducted on Nov. 4. A Simulated Flight test, a “plus count” that tests the launch vehicle systems as if the vehicle were in powered flight, will be performed on the following day, Nov. 5.

Marshall Space Flight Center’s equivalent of a Mission Readiness Review is scheduled to be held in Huntsville on Nov. 12.

The Gravity Probe B mission is a relativity experiment developed by NASA’s Marshall Space Flight Center, Stanford University and Lockheed Martin. The spacecraft will test two extraordinary predictions of Albert Einstein’s general theory of relativity that he advanced in 1916: the geodetic effect (how space and time are warped by the presence of the Earth) and frame dragging (how Earth’s rotation drags space and time around with it). Gravity Probe B consists of four sophisticated gyroscopes that will provide an almost perfect space-time reference system. The mission will look in a precision manner for tiny changes in the direction of spin.

Gravity Probe B will be launched into a 400 nautical-mile-high polar orbit for an 18-month mission.

Gravity Probe B is in NASA spacecraft processing facility 1610 on North Vandenberg Air Force Base. Further testing of the Super Quantum Interference Device (SQUID) readouts are under way and will be complete this week. The SQUID are ultrasensitive magnetometers that can detect a change in the tilt of a spinning gyroscope to an angle of 0.1 milliarc-seconds, equivalent to viewing the width of a human hair at a distance of 100 miles. Ordnance installation and testing began on Tuesday and is scheduled for completion on Saturday. Solar array installation will start on Monday, Oct. 27, as scheduled.

With the Delta II first and second stages erected on the launch pad, integrated testing of the vehicle has been under way over the past week. Yesterday, qualification testing began on the Redundant Inertial Flight Control Assembly (RIFCA). The RIFCA is the navigation and guidance control unit for the Delta II. The tests this week simulate launch conditions in the unique helium environment that will be created within the payload fairing by the Gravity Probe B spacecraft. This will be followed on Oct. 29 by routine integrated guidance and control system checkout of the vehicle.

The Gravity Probe B mission is a relativity experiment developed by NASA’s Marshall Space Flight Center, Stanford University and Lockheed Martin. The spacecraft will test two extraordinary predictions of Albert Einstein’s general theory of relativity that he advanced in 1916: the geodetic effect (how space and time are warped by the presence of the Earth) and frame dragging (how Earth’s rotation drags space and time around with it). Gravity Probe B consists of four sophisticated gyroscopes that will provide an almost perfect space-time reference system. The mission will look in a precision manner for tiny changes in the direction of spin.

Gravity Probe B will be launched into a 400 nautical-mile-high polar orbit for an 18-month mission.

Gravity Probe B is in NASA spacecraft processing facility 1610 on North Vandenberg Air Force Base. Testing of the Super Quantum Interference Device (SQUID) readouts are under way this week. The SQUID are ultra-sensitive magnetometers that can detect a change in the tilt of a spinning gyroscope to an angle of 0.1 milliarc-seconds, equivalent to viewing the width of a human hair at 100 miles. A test to verify the reliability of the SQUID is scheduled for Friday, Oct. 17. The electrical system testing that was under way last week has been completed successfully. Ordnance installation is scheduled for Oct. 20-24, and solar array installation is scheduled to begin Oct. 27.

With the Delta II fully erected on the launch pad, integrated testing of the vehicle began earlier this week on Tuesday, Oct. 14. A qualification test in a helium environment is scheduled on Oct. 22 for the Redundant Inertial Flight Control Assembly (RIFCA). This is the navigation and guidance control unit for the launch vehicle. Since the Gravity Probe B spacecraft will be venting helium inside the fairing during the countdown and in flight, engineers want to know what effect, if any, this environment could have on the RIFCA.

This will be followed on Oct. 29 by routine integrated guidance and control system checkout of the vehicle. An exercise that involves loading of liquid oxygen aboard the first stage and a limited “minus count” will be conducted on Nov. 4. A Simulated Flight test, a “plus count” that tests the launch vehicle systems as if the vehicle were in powered flight, will be performed on the following day, Nov. 5.

The Gravity Probe B mission is a relativity experiment developed by NASA’s Marshall Space Flight Center, Stanford University and Lockheed Martin. The spacecraft will test two extraordinary predictions of Albert Einstein’s general theory of relativity that he advanced in 1916: the geodetic effect (how space and time are warped by the presence of the Earth) and frame dragging (how Earth’s rotation drags space and time around with it). Gravity Probe B consists of four sophisticated gyroscopes that will provide an almost perfect space-time reference system. The mission will look in a precision manner for tiny changes in the direction of spin.

Gravity Probe B will be launched into a 400-mile-high polar orbit for an 18-month mission.

Gravity Probe B is in NASA spacecraft processing facility 1610 on North Vandenberg Air Force Base. The processing activities continue to go well and are on schedule. Electrical system testing began yesterday, Oct. 8. Ordnance installation is scheduled for Oct. 20-24, and solar array installation is scheduled to begin Oct. 27.

Conditioning of the dewar to a superfluid state has been completed. Conditioning is the process of taking liquid helium at a temperature of about 4 Kelvin (-452 degrees F) to a colder state, known as superfluid, which will allow the helium to last throughout the duration of the mission. Filling the dewar with superfluid helium is a slow and repetitive process. The dewar is now 95% full of superfluid helium at a temperature of 1.65 Kelvin (-456 degrees F), and it will be maintained in this state from now until launch.

The attachment of the nine strap-on solid rocket boosters in sets of three each day began on Monday, Oct. 6. The second set was erected on Oct. 7, and the final set was mated yesterday, Oct. 8. Integrated testing of the vehicle will begin next week on Oct. 14. This will be followed on Oct. 29 by guidance and control system checks. An exercise that involves loading of liquid oxygen aboard the first stage and a limited “minus count” will be conducted on Nov. 4. A Simulated Flight test, a “plus count” that tests the launch vehicle systems as if the vehicle were in powered flight, will be performed on the following day, Nov. 5.

The first stage of the Boeing Delta II was erected on Space Launch Complex 2 on Monday, Sept. 15, as scheduled. Mating of the second stage atop the first stage also occurred as planned on Sept. 18.

In final launch preparation activities, Gravity Probe B will be transported from the spacecraft processing facility to Space Launch Complex 2 on Nov. 18 and hoisted atop the second stage. Then the final major test before launch, the Flight Program Verification, will be conducted on Nov. 20. This is an integrated test conducted after the Gravity Probe B spacecraft is mated atop the second stage of the launch vehicle. The Delta II fairing will be installed around the spacecraft on Nov. 25 as part of final preparations for launch.

The spacecraft arrived at Vandenberg Air Force Base on July 11 from the Lockheed Martin plant in Sunnyvale, Calif.

The Gravity Probe B mission is a relativity experiment developed by NASA’s Marshall Space Flight Center, Stanford University and Lockheed Martin. The spacecraft will test two extraordinary predictions of Albert Einstein’s general theory of relativity that he advanced in 1916: the geodetic effect (how space and time are warped by the presence of the Earth) and frame dragging (how Earth’s rotation drags space and time around with it). Gravity Probe B consists of four sophisticated gyroscopes that will provide an almost perfect space-time reference system. The mission will look in a precision manner for tiny changes in the direction of spin.

Gravity Probe B will be launched into a 400-mile-high polar orbit for an 18-month mission.

Gravity Probe B is in NASA spacecraft processing hangar 1610 on North Vandenberg Air Force Base. The spacecraft and mission team have successfully completed a four-day mission simulation.

Conditioning of the dewar to a superfluid state has been completed. Conditioning is the process of taking liquid helium at a temperature of about 4 Kelvin (-452 degrees F) to a colder state, known as superfluid, which will allow the helium to last throughout the duration of the mission. Filling the dewar with superfluid helium is a slow and repetitive process. The dewar is now 95% full of superfluid helium at a temperature of 1.65 Kelvin (-456 degrees F), and it will be maintained in this state from now until launch.

In upcoming spacecraft activities, electrical testing is scheduled for Oct. 8, ordnance installation is scheduled for Oct. 20-24, and solar array installation is scheduled to begin Oct. 27.

The first stage of the Boeing Delta II was erected on Space Launch Complex 2 on Monday, Sept. 15, as scheduled. Mating of the second stage atop the first stage also occurred as planned on Sept. 18.

The attachment of the nine strap-on solid rocket boosters in sets of three is scheduled for Oct. 6-8. Integrated testing of the vehicle will begin on Oct. 14. This will be followed on Oct. 29 by guidance and control system checks. An exercise that involves loading of liquid oxygen aboard the first stage and a limited “minus count” will be conducted on Nov. 4. A Simulated Flight test, a “plus count” that tests the launch vehicle systems as if it were in powered flight, will be performed on the following day, Nov. 5.

Gravity Probe B will be transported from the spacecraft hangar to Space Launch Complex 2 on Nov. 18 and hoisted atop the second stage. Then the final major test before launch, the Flight Program Verification, will be conducted on Nov. 20. This is an integrated test conducted after the Gravity Probe B spacecraft is mated atop the second stage of the launch vehicle. The Delta II fairing will be installed around the spacecraft on Nov. 25 as part of final preparations for launch.

The spacecraft arrived at Vandenberg Air Force Base on July 11 from the Lockheed Martin plant in Sunnyvale, Calif.

The Gravity Probe B mission is a relativity experiment developed by NASA’s Marshall Space Flight Center, Stanford University and Lockheed Martin. The spacecraft will test two extraordinary predictions of Albert Einstein’s general theory of relativity that he advanced in 1916: the geodetic effect (how space and time are warped by the presence of the Earth) and frame dragging (how Earth’s rotation drags space-time around with it). Gravity Probe B consists of four sophisticated gyroscopes that will provide an almost perfect space-time reference system. The mission will look in a precision manner for tiny changes in the direction of spin.

Gravity Probe B will be launched into a 400-mile-high polar orbit for an 18-month mission.

Gravity Probe B is at NASA spacecraft processing hangar 1610 on North Vandenberg Air Force Base. Conditioning of the dewar to a superfluid state has been completed. Conditioning is the process of taking liquid helium at a temperature of about 4 Kelvin (-452 degrees F) to a colder state, known as superfluid, which will allow the helium to last throughout the duration of the mission. Filling the dewar with superfluid helium is a slow and repetitive process. The dewar is now 95% full of superfluid helium at a temperature of 1.65 Kelvin (-456 degrees F) and it will be maintained in this state from now until launch.

In upcoming spacecraft activities, electrical testing is scheduled for Oct. 8, ordnance installation is scheduled for Oct. 20-24, and solar array installation is scheduled to begin Oct. 27.

The first stage of the Boeing Delta II was erected on Space Launch Complex 2 on Monday, Sept. 15, as scheduled. Mating of the second stage atop the first stage also occurred as planned on Sept. 18.

Upcoming is the attachment of the nine strap-on solid rocket boosters in sets of three scheduled for Oct. 6-8. Integrated testing of the vehicle will begin on Oct. 14. This will be followed on Oct. 29 by guidance and control system checks. An exercise that involves loading of liquid oxygen aboard the first stage and a limited “minus count” will be conducted on Nov. 4. A Simulated Flight test, a “plus count” that tests the launch vehicle systems as if it were in powered flight, will be performed on the following day, Nov. 5.

Gravity Probe B arrived at Vandenberg Air Force Base on July 11 from the Lockheed Martin plant in Sunnyvale, Calif. The mission is a relativity experiment developed by NASA’s Marshall Space Flight Center, Stanford University and Lockheed Martin. The spacecraft will test two extraordinary predictions of Albert Einstein’s general theory of relativity that he advanced in 1916. Gravity Probe B consists of four sophisticated gyroscopes to be launched into a 400-mile-high orbit for a mission lasting 18 months.

Gravity Probe B is at NASA spacecraft processing hangar 1610 on North Vandenberg Air Force Base. The pumping down of the dewar which is filled with cryogenic liquid helium continues. This brings the environment within the dewar to a near vacuum. It will then be refilled to the level necessary to achieve and maintain superfluid conditions.

The first stage of the Boeing Delta II was erected on Space Launch Complex 2 on Monday, Sept. 15, as scheduled. Mating of the second stage atop the first stage is planned for tomorrow, Sept. 18. Attachment of the nine strap-on solid rocket boosters in sets of three is scheduled for Oct. 6-8.

Gravity Probe B will be transported from the spacecraft hangar to Space Launch Complex 2 on Nov. 18 and hoisted atop the second stage. The Delta II fairing will be installed around the spacecraft on Nov. 24 as part of final preparations for launch. Gravity Probe B arrived at Vandenberg Air Force Base on July 11 from the Lockheed Martin plant in Sunnyvale, Calif.

Gravity Probe B is a relativity experiment developed by NASA’s Marshall Space Flight Center, Stanford University and Lockheed Martin. The spacecraft will test two extraordinary predictions of Albert Einstein’s general theory of relativity that he advanced in 1916. Gravity Probe B consists of four sophisticated gyroscopes to be launched into a 400-mile-high orbit for a mission lasting 18 months. (September 17, 2003 status report)

Gravity Probe B is at NASA spacecraft processing hangar 1610 on North Vandenberg Air Force Base. The pumping down of the dewar which is filled with cryogenic helium is continuing this week. This brings the environment within the dewar to a near vacuum. It will then be refilled to the level necessary to achieve and maintain superfluid conditions.

Preparations are beginning for the planned erection next week of the Delta II launch vehicle at Space Launch Complex 2. Due to some observed delaminations within the layers of material that comprise the solid rocket booster nozzle exit-cone liners, some additional time is necessary to perform a precautionary change out of three of the nine boosters assigned for this mission. The additional time required means that the launch is being rescheduled for Saturday, Dec. 6.

The start of erection activities of the Boeing Delta II remains scheduled to begin on Sept. 15 with the erection of the first stage. The second stage is now planned for mating atop the first stage on Sept. 18. Attachment of the nine strap-on solid rocket boosters in sets of three is scheduled for Oct. 6-8.

Gravity Probe B will be transported from the spacecraft hangar to Space Launch Complex 2 on Nov. 18 and hoisted atop the second stage. The Delta II fairing will be installed around the spacecraft on Nov. 24 as part of final preparations for launch. Gravity Probe B arrived at Vandenberg Air Force Base on July 11 from the Lockheed Martin plant in Sunnyvale, Calif.

Gravity Probe B is a relativity experiment developed by NASA’s Marshall Space Flight Center, Stanford University and Lockheed Martin. The spacecraft will test two extraordinary predictions of Albert Einstein’s general theory of relativity that he advanced in 1916. Gravity Probe B consists of four sophisticated gyroscopes to be launched into a 400-mile-high orbit for a mission lasting 18 months.   (September 10, 2003 status report)

Gravity Probe B is at NASA spacecraft processing hangar 1610 on North Vandenberg Air Force Base. In processing activities this week, the initial filling of the dewar with cryogenic helium has been performed. This prepared the dewar for the upcoming series of about 6 -7 cycles of pumping down the tank to a near vacuum, then refilling as necessary, to achieve the superfluid conditions. The first pump-down began on Wednesday, Sept. 3.

The electromagnetic interference (EMI) test and the Gas Management Assembly (GMA) “rate of rise” test were successfully finished as scheduled.

The erection of the Boeing Delta II launch vehicle at Space Launch Complex 2 remains scheduled to begin on Sept. 15 with the erection of the first stage. Attachment of the nine strap-on solid rocket boosters in sets of three is scheduled for Sept. 17-19. The second stage is planned for mating atop the first stage on Sept. 22. Gravity Probe B will be transported from the spacecraft hangar to Space Launch Complex 2 on Oct. 29 and hoisted atop the second stage. The Delta II fairing will be installed around the spacecraft on Nov. 5 as part of final preparations for launch.

Gravity Probe B arrived at Vandenberg Air Force Base on July 11 from the Lockheed Martin plant in Sunnyvale, Calif.

Gravity Probe B is at NASA spacecraft processing hangar 1610 on North Vandenberg Air Force Base. In processing activities this week, the electromagnetic interference (EMI) test has been successfully completed. The Gas Management Assembly (GMA) "rate of rise" testing is under way and is successful to date with three days of the test remaining. Certification testing of the pump module in preparation for conditioning the dewar was successfully completed. The dewar conditioning, a process of pumping down the tank to near vacuum conditions, is currently under way. Initial servicing to load the dewar 95 percent full of cryogenic liquid helium is scheduled to begin next week. The spacecraft is currently on internal power and a trickle charge of the battery is occurring. Loading of an updated version of the mission software is pending.

Gravity Probe B arrived at Vandenberg Air Force Base on July 11 from the Lockheed Martin plant in Sunnyvale, Calif.

Gravity Probe B is a relativity experiment developed by NASA's Marshall Space Flight Center, Stanford University and Lockheed Martin. The spacecraft will test two extraordinary predictions of Albert Einstein's general theory of relativity that he advanced in 1916. Gravity Probe B consists of four sophisticated gyroscopes to be launched into a 400-mile-high orbit for a mission lasting 18 months. (August 27, 2003 status report)

In the Gravity Probe B hangar, verification of new flight and mission software on the spacecraft was downloaded and has been verified. This activity was completed on Aug. 2. The Compatibility Test Van (CTV), which contains equipment to simulate NASA’s ground network of tracking stations and the Tracking and Data Relay Satellite System completed testing with the spacecraft on Aug. 15. Testing of the spacecraft’s RF systems is under way this week.

Gravity Probe B arrived at Vandenberg Air Force Base on July 11 from the Lockheed Martin plant in Sunnyvale, Calif. It was taken to NASA spacecraft processing hanger 1610 located on North Vandenberg Air Force Base. The spacecraft was unloaded from its transporter, placed onto an assembly and test stand, and the soft shipping cover removed.

The erection of the Boeing Delta II launch vehicle at Space Launch Complex 2 is currently scheduled to begin on Sept. 15 with the erection of the first stage. Attachment of the nine strap-on solid rocket boosters in sets of three is scheduled for Sept. 17-19. The second stage is planned for mating atop the first stage on Sept. 22. Gravity Probe B will be transported from the spacecraft hangar to Space Launch Complex 2 on Oct. 29 and hoisted atop the second stage. The Delta II fairing will be installed around the spacecraft on Nov. 5 as part of final preparations for launch.

Download and verification of new flight/mission software was completed on Saturday, Aug. 2. The Compatibility Test Van (CTV), supplies equipment to simulate NASA’s ground network and space network, testing is scheduled to begin the week of Aug. 11.

Gravity Probe B arrived at Vandenberg Air Force Base on July 11 from the Lockheed Martin plant in Sunnyvale, Calif. It was transported to NASA spacecraft processing hanger 1610 located on North Vandenberg Air Force Base. The spacecraft was unloaded from its transporter, placed onto an assembly and test stand, and the soft shipping cover was removed.

The erection of the Boeing Delta II launch vehicle at Space Launch Complex 2 is currently scheduled to begin on Sept. 15 with the erection of the first stage. Attachment of the nine strap-on solid rocket boosters in sets of three is scheduled for Sept. 16-18. The second stage is planned for mating atop the first stage on Sept. 19. Gravity Probe B will be transported from the spacecraft hangar to Space Launch Complex 2 Oct. 29, and hoisted atop the second stage. The Delta II fairing will be installed around the spacecraft on Nov. 5 as part of final preparations for launch.

Gravity Probe B is a relativity experiment developed by NASA's Marshall Space Flight Center, Stanford University and Lockheed Martin. The spacecraft will test two extraordinary predictions of Albert Einstein's general theory of relativity that he advanced in 1916. Gravity Probe B consists of four sophisticated gyroscopes to be launched into a 400-mile-high orbit for a mission lasting 18 to 24 months. (August 6, 2003 status report)

Functional testing of Gravity Probe B and the initial liquid helium cryogenic servicing was performed last week in spacecraft processing hangar 1610. Also, the telescope stray-light test was performed last week.

Gravity Probe B arrived at Vandenberg Air Force Base on July 11 from the Lockheed Martin plant in Sunnyvale, Calif. It was transported to NASA spacecraft processing hanger 1610 located on North Vandenberg Air Force Base. The spacecraft was unloaded from its transporter, placed onto an assembly and test stand, and the soft shipping cover was removed.

The erection of the Boeing Delta II launch vehicle at Space Launch Complex 2 is currently scheduled to begin on Sept. 15 with the erection of the first stage. Attachment of the nine strap-on solid rocket boosters in sets of three is scheduled for Sept. 16-18. The second stage is planned for mating atop the first stage on Sept. 19. Gravity Probe B will be transported from the spacecraft hangar to Space Launch Complex 2 Oct. 29, and hoisted atop the second stage. The Delta II fairing will be installed around the spacecraft on Nov. 5 as part of final preparations for launch.

In spacecraft processing hangar 1610, functional testing of Gravity Probe B and the initial liquid helium cryogenic servicing are being performed this week. Also scheduled is a telescope stray-light test.

The erection of the Boeing Delta II launch vehicle at Space Launch Complex 2 is currently scheduled to begin on September 15 with the erection of the first stage. Attachment of the nine strap-on solid rocket boosters in sets of three is scheduled for Sept. 16-18. The second stage is planned for mating atop the first stage on Sept. 19. Gravity Probe B will be transported from the spacecraft hangar to Space Launch Complex 2 on Oct. 29 and hoisted atop the second stage. The Delta II fairing will be installed around the spacecraft on Nov. 5 as part of final preparations for launch.

Gravity Probe B arrived at Vandenberg Air Force Base on July 11 from the Lockheed Martin plant in Sunnyvale, California. It was taken to NASA spacecraft processing hanger 1610 located on North Vandenberg Air Force Base. The spacecraft was unloaded from its transporter, placed onto an assembly and test stand and the soft shipping cover removed. Mechanical and electrical ground support equipment is being set up and the necessary connections made with the spacecraft. Battery charge/discharge cycles are underway as part of the battery conditioning process.

The erection of the Boeing Delta II launch vehicle at Space Launch Complex 2 is currently scheduled to begin on September 15 with the erection of the first stage. Attachment of the nine strap-on solid rocket boosters in sets of three is scheduled for September 16 - 18. The second stage is planned for mating atop the first stage on September 19. Gravity Probe B will be transported from the spacecraft hangar to Space Launch Complex 2 on October 29 and hoisted atop the second stage. The Delta II fairing will be installed around the spacecraft on November 5 as part of final preparations for launch.

Gravity Probe B arrived at Vandenberg Air Force Base last night from the Lockheed Martin plant in Sunnyvale, California. Today it was taken to NASA spacecraft processing hanger 1610 located on North Vandenberg Air Force Base.

Upcoming operations entail unloading the spacecraft from its transporter and placing it onto an assembly and test stand. Mechanical and electrical ground support equipment will then be set up and necessary connections made with the spacecraft. Spacecraft battery conditioning will also begin.

The erection of the Boeing Delta II launch vehicle at Space Launch Complex 2 is currently scheduled to begin on September 15 with the erection of the first stage. Attachment of the nine strap-on solid rocket boosters in sets of three is scheduled for September 16 - 18. The second stage is planned for mating atop the first stage on September 19. Gravity Probe B will be transported from the spacecraft hangar to Space Launch Complex 2 on October 29 and hoisted atop the second stage. The Delta II fairing will be installed around the spacecraft on November 5 as part of final preparations for launch.

Gravity Probe B is a relativity experiment developed by NASA’s Marshall Space Flight Center, Stanford University and Lockheed Martin. The spacecraft will test two unverified predictions of Albert Einstein’s general theory of relativity that he advanced in 1916. Gravity Probe B consists of four sophisticated gyroscopes to be launched into a 400-mile-high orbit for a mission lasting 18 to 24 months. (July 11, 2003 status report)

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