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Gravity Probe B

Testing Einstein's Universe

WEEKLY HIGHLIGHTS FOR WEEK ENDING 13 FEBRUARY 2004:

GRAVITY PROBE B LAUNCH DATE

Currently, the target date for the Gravity Probe B space vehicle to launch from Vandenberg Air Force Base in Southern California is Saturday, April 17, 2004. We are exploring the feasibility of pushing the launch date up to Thursday, April 15th, which is the earliest possible launch date. The exact time of launch depends on the date. On April 17th, the launch would be around 10:09 AM Pacific Daylight Time, and about 4 minutes later for each day prior, or 4 minutes earlier for each day thereafter.

We update these highlights every Friday, and we will post any new information about the launch on this Web site and on the new GPB Update email list as soon as it becomes available.

VANDENBERG AIR FORCE BASE OPERATIONS THIS WEEK

The following activities are currently underway at VAFB:
  • The GP-B pre-launch team returned to full force at Vandenberg last weekend. They removed the battery palette and installed the reworked Experiment Control Unit (ECU) and its various cables, including UV cables and brackets. The battery palette and cables were then re-installed, and the battery was charged.
  • The spacecraft and ECU were successfully powered on, and functional testing of the ECU on board the spacecraft has begun. All initial indications thus far show that the ECU is performing nominally onboard the spacecraft.
  • The Gas Management Assembly (GMA) is in the process of being serviced.
  • As of Thursday, the temperature of the dewar's main tank was 1.9132K. The Guard Tank level is 58.5 %, and the rate of rise is 23.10 mW. The dewar has been connected to Ground Service Equipment (GSE), in preparation for cryogenic filling—the iterative process of evacuations and fills that will return the helium in the dewar to a superflluid state, at a pre-launch temperature of 1.65 K. Dewar conditioning is scheduled to begin early next week.
  • The launch vehicle is surrounded by the Mobile Service Tower (MST) on the launch pad, and Boeing technicians are beginning preparations for installing the GP-B spacecraft inside the faring at the top of the launch vehicle.

GRAVITY PROBE B MISSION OPOERATIONS PROFICIENCY EXERCISE AT STANFORD

  • The first of two Gravity Probe B mission operations proficiency exercises was successfully carried out at Stanford this week.
  • The purpose of these exercises is to keep our mission operations team practiced and ready for launch and the GP-B mission.
  • This week's exercise went well, and it provided the team an opportunity to work through several important aspects of the Initial Orbit Checkout (IOC) phase of the mission timeline.

Photo: GP-B pre-launch team technicians are replacing the battery palette after installing the re-worked ECU. Click on the thumbnails to view enlargements of the photo.

GRAVITY PROBE B IN THE NEWS

Gravity Probe B was the lead story last Saturday, January 24, 2004, in two Internet publications: TechNewsWorld and E-Commerce Times. It was also featured in the Tech Wednesday section of Space.com on New Year's eve.

On Sunday evening, December 28, 2003, the Cover story on the CBS Evening News was on the subject of time—examined from both human and cosmic perspectives. The story featured interviews with a manager from Torneau Time Machines (the largest watch store in New York City), physicist Brian Greene (a proponent of String Theory), and our own Gravity Probe B Principal Investigator, Francis Everitt. Typical of television news, the entire story lasted a little over three minutes, but it was heart warming to see Francis and our spacecraft on the national news. Perhaps the best sound byte from Francis was a quote from St. Augustine that CBS chose not to use: "What was God doing before he made heaven and earth? ... He was preparing hell for those that would pry into such profound mysteries."

Click here to view a video clip of the CBS News story about time.

RECEIVE GRAVITY PROBE B WEEKLY HIGHLIGHTS BY EMAIL

If you are interested in automatically receiving these weekly highlights and other important GP-B mission information by email, you can subscribe to our Gravity Probe B Update email list by sending an email message to "majordomo@lists.Stanford.edu" with the command "subscribe gpb-update" in the body of the message (not in the Subject line). You can unsubscribe from this mailing list at any time by sending an email message to the same address with the command, "unsubscribe gpb-update" in the body of the message.

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