Mars Global Surveyor and TES go to Florida

by Greg Mehall, TES Systems Engineer, Arizona State University

TES in Florida

Right now we are "Go!" for launch on November 6, 1996. Mars Global Surveyor (MGS) arrived at Cape Canaveral, Florida, on August 14th. Preparations are underway to load MGS into a Delta II rocket so it will be ready for launch!

MGS will reach Mars next September, 1997. Onboard is the Thermal Emission Spectrometer (TES), one of five instruments that will examine the Red Planet. TES is controlled at Arizona State University (ASU) and will map the minerals on the martian surface.

Final preparations for shipment of the MGS spacecraft to Cape Canaveral were completed over the last couple of months. In my last TES News update, we were in the middle of MGS systems-level testing at Lockheed Martin, in Denver, Colorado. The final preparations for the spacecraft thermal/vacuum testing were completed during the first three weeks of June. This included covering the spacecraft with thermal blankets, placing temperature sensors on the spacecraft and throughout the vacuum chamber, and mounting the spacecraft inside the enormous chamber.

Into a "Space" Simulation Chamber

The chamber door was finally closed and "pump down" started on June 22. The air in the chamber was pumped out, in order to simulate the vacuum of space. The entire spacecraft was tested over various temperatures and configurations, just as we did with the TES in May. The thermal/vacuum testing was performed around the clock through July 6. The instruments were turned on during the first half of the test when the spacecraft was in the mapping simulation mode. During this mode, the instruments viewed a target on one wall of the chamber that simulated the planet Mars. On the top of the chamber, an intense light was projected onto a mirror that simulated the Sun. All other regions of the chamber were cooled to -180 C (-292 F) to simulate the cold temperature of deep space. This vacuum chamber configuration allowed us to accurately model the environment that the spacecraft will encounter during its mapping mission. This test was the best opportunity, prior to launch, to verify the performance of the spacecraft and instruments with all elements of the spacecraft operating. The good news is that the spacecraft and the science instruments all performed well throughout this test. This test was crucial in proving that the spacecraft and science instruments were capable of operating satisfactorily during the various phases of the 3-and-1/2 year mission.

The Mars Global Surveyor Thermal Emission Spectrometer (TES) instrument. Hughes, Santa Barbara Remote Sensing, Goleta, California, Photo 96-6-35(8).

Aligning the Instruments, TESting the TES

After spacecraft thermal/vacuum testing was completed, the spacecraft was removed from the chamber and the final alignments of the instruments were performed. This was done so that all of the instruments will view the same spot on the martian surface.

After alignments were completed during the second week of July, the post-environmental testing began. These were the final tests performed before being shipped to the Cape. The purpose of these tests was to verify that all of the subsystems of the spacecraft and instruments were still functioning correctly after they had been subjected to all of the environmental tests that were performed over the previous months. In addition, it gave us a benchmark of how well the spacecraft and payloads were performing prior to shipment to the Cape.

One of these tests actually simulated the entire MGS project ground computer and communications system. During this test we controlled the TES instrument from Arizona State University. We sent commands to the TES instrument in Denver and received TES data at our computers at ASU! This allowed us to test the actual system we will use during the mission.

NASA Checks it Out

On July 31 and August 1, the MGS project held the "Spacecraft Pre-Ship Review" in Denver. The purpose of this review was to convince a panel of "experts" from NASA and the science community that the MGS spacecraft and science payload was ready to be shipped to the Cape. The Lockheed Martin personnel responsible for each of the spacecraft subsystems and each of the science instrument's Principal Investigators had to present the status of their spacecraft subsystem or science instrument. The review went very well with very few concerns. Everyone agreed that we have an excellent spacecraft and science payload! This review was the final step prior to shipment of the spacecraft to Florida.

We Got Ourselves a Convoy

On August 12th, the MGS spacecraft was loaded into a large shipping container. This container is important because it is needed to physically protect the spacecraft during its move, as well as maintain a clean, dry climate while in transit. The container was loaded onto a truck's flatbed trailer and held in a building at Lockheed Martin for the night. Later that afternoon, the Air Force's C-17 cargo plane arrived at Buckley Air National Guard Base, outside Denver. This is a rather new type of cargo plane that is used primarily for military cargos like tanks and trucks. This was an unusual opportunity for NASA to deliver one of its spacecraft on this type of airplane. The MGS ground support equipment was loaded onto the plane that evening so that the spacecraft could be loaded quickly the following afternoon.

Mars Global Surveyor Time Line

Launch into Space-- November 1996
Arrive in orbit about Mars-- September 1997
Primary Mission-- January 1998 to January 2000
Extended Mission-- January 2000 to ???

I was lucky! I got to be part of the team that would actually fly on the plane with the spacecraft! There were 21 members of the MGS project and 10 aircraft crew personnel that would be on board. On the next afternoon, the convoy to Buckley Air National Guard Base began to form. It included the truck carrying the MGS, a lead and trail van, 2 Sheriff escorts (police cars!), and the vans carrying the 21 passengers. Many of the Lockheed Martin employees that spent the last two years working on the spacecraft came to watch and cheer as the convoy drove away. The convoy took about one half hour to reach Buckley. After we reached the base, the truck carrying the MGS was parked in one of the base hangers until the C-17 crew arrived.

The airplane crew arrived at about 7:00 p.m., and the shipping container was gently lifted off the flatbed and slowly hoisted into the cargo bay of the aircraft. It was a slow, tedious process that took a little over an hour. The container fit in the airplane with only a few feet of clearance to spare.

Overnight Express Delivery

At 9:00 p.m., we all boarded the plane in preparation for takeoff. The seating in the C-17 consisted of fold-down seats along both sides of the cabin.

Most of the center of the cabin was occupied by the shipping container and support equipment. Despite the cold, cramped and noisy quarters, we were all pretty excited. We took off from Buckley at 10:15 p.m. The flight to Florida took about 3 and 1/2 hours. Some passengers tried to sleep but I think we were all too excited!

On August 14, at 4:00 a.m., the Mars Global Surveyor spacecraft and its crew arrived at the "Skid Strip" at Cape Canaveral Air Force Base, Florida. We were greeted by many of the other MGS personnel, the press, and humidity! The spacecraft and support equipment were unloaded from the C-17 in about 1 hour. The shipping container and other equipment were loaded onto flatbed trailers and transported across the causeway to the PHSF (Payload Hazardous Servicing Facility) at Kennedy Space Center. This is where all of the testing will be done before MGS is taken to the Delta II launch pad in early October.

Inside view of the Delta II Rocket that will be used to launch Mars Global Surveyor in November 1996.

Getting Ready for the Rocket

The MGS spacecraft was unloaded from its shipping container and placed in the PHSF cleanroom later that day. All of the support equipment and computers have been set up in the adjoining building for tests that will occur during last two weeks of August and into September. When the final testing is completed, the MGS spacecraft will be placed on top the Delta II launch vehicle. We are very excited about the coming launch! The first launch opportunities will be on November 6 at 12:11 p.m. and 1:15 p.m. (Eastern Standard Time), as long we don't encounter any serious problems. I will update you on the final stages of the spacecraft integration and testing as well as the launch preparations as they are completed over the next 2 and 1/2 months in the next edition of the TES News. Until then ... To Mars!!

Back to Contents of TES News September 1996

TES Engineer Steve Silverman (left) with the Mars Global Surveyor spacecraft at Lockheed Martin in Denver, Colorado. The TES instrument is indicated with an arrow. Photo by Philip Christensen, July 1996.