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Gravity Probe B

Testing Einstein's Universe

WEEKLY HIGHLIGHTS FOR WEEK ENDING 30 JANUARY 2004:


RECEIVE GRAVITY PROBE B WEEKLY HIGHLIGHTS BY EMAIL

Starting this week, we have set up a Gravity Probe B email list on the Stanford University list server. Anyone interested in automatically receiving these weekly highlights and other important GP-B mission information by email can subscribe 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.

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

Following is the current status of the GP-B spacecraft and launch vehicle at VAFB:
  • The Gravity Probe B spacecraft is being maintained in a stand-down state, awaiting the return of the reworked Experiment Control Unit (ECU). The reworked ECU is currently scheduled to be returned to VAFB on or before February 10, 2004, and full ground operations will then resume at Vandenberg.
  • Preparations for servicing the Gas Management Assembly (GMA) when the ECU returns have been completed. The flight covers on the GMA have been removed, and the GMA has been connected to the Ground Servicing Equipment (GSE) in preparation for functional testing with the reworked ECU. We are ready to refill the GMA with verified (99.9999% pure) Helium gas.
  • On Tuesday, January 27th, the temperature of the dewar's main tank was 1.8882 K, and the guard tank level was 46.2%. The guard tank is refilled weekly. The heat rate is 23.13 mW.
  • The battery charge is being monitored continuously during the stand-down period.
  • The Delta II launch vehicle, with the solid motors attached, remains on the launch pad, surrounded by the mobile service tower (MST).
  • TheGP-B prelaunch team will be returning to full strength at Vandenberg one day prior to arrival of the reworked ECU.

LOCKHEED MARTIN, PALO ALTO OPERATIONS THIS WEEK

  • Thermal vacuum testing of the reassembled ECU is nearing completion. Thus far, the ECU has performed nominally throughout the testing, and all indications are that the testing will be concluded successfully next week.
  • Overall, the ECU rework is proceeding slightly ahead of schedule for shipment back to Vandenberg AFB on or before February 10, 2004.

GRAVITY PROBE B MONTHLY REVIEW MEETING AT STANFORD

  • An all-day Gravity Probe B review meeting was held at Stanford on Wednesday, January 28, 2004. Presentations covering all facets of the program were made by Stanford and Lockheed Martin personnel.
  • GP-B managers from NASA Headquarters and Marshall Space Flight Center attended the meeting, along with a number of independent reviewers. The meeting went well, and GP-B is on track for a mid-April launch.

Photos: In the upper photo, Lockheed Martin photographer Russ Underwood captured the Gravity Probe B spacecraft on November 10, 2003 (Press Day) from a high perch in the vehicle processing room. Assuming that the reworking and testing of the ECU continues on schedule, the spacecraft will be returned to this launch-ready state by March, 2004. The lower photo shows the ECU (black box), which was removed from the spacecraft, on a test bench at Lockheed Martin in Palo Alto, CA. Click on the thumbnails to view enlargements of the photos.

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.

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