GRAIL Lunar Twins Mated to Delta Rocket at Launch Pad


With blastoff just 2 ½ weeks away, NASA’s GRAIL lunar twins completed a major milestone towards launch today (Aug. 18) when they were mated to the top of the Delta II Heavy rocket that will boost them to the moon. Launch is slated for Sept. 8 at 8:37 a.m. EDT.

This morning the tightly wrapped $496 Million duo took their last trip on Earth before beginning their nearly four month journey to the Moon. GRAIL A & GRAIL B were carefully transported 15 miles (25 km) from the clean room processing facility at the Astrotech Space Operation’s payload processing facility in Titusville, Fla to Space Launch Complex 17B (SLC-17B) at Cape Canaveral Air Force Station in Florida.

“The GRAIL spacecraft transportation convoy to SLC-17B departed Astrotech at 11:55 p.m. EDT on Wednesday, Aug. 17, “ said Tim Dunn, NASA’s Delta II Launch Director in an interview with Universe Today. “The spacecraft, inside the handling can, arrived at the launch pad, SLC-17B, at 4:00 a.m. this morning.”

“The spacecraft was then hoisted by the Mobile Service Tower crane onto the Delta II launch vehicle and the spacecraft mate was complete at 9:30 a.m.”

Crane lifts GRAIL A & B to the top of the Mobile Service Tower on Aug. 18. The probes are wrapped in protective plastic sheeting inside the handling can. Credit: NASA/Kim Shiflett

Technicians joined the nearly identical and side by side mounted spacecraft onto the top of the guidance section adapter of the Delta’s second stage. The Delta II was built by United Launch Alliance (ULA).

“Tomorrow, the GRAIL spacecraft team will perform functional testing on both the GRAIL A and GRAIL B spacecraft,” Dunn told me.

“The next major milestone will be performance of the Integrated Systems Test (IST) on Monday, (8/22/11).

“Today’s spacecraft mate operation was flawlessly executed by the combined ULA and NASA Delta II Team,” said Dunn.

These tests will confirm that the spacecraft is healthy after the fueling and transport operations. After further reviews of the rocket and spacecraft systems the GRAIL team will install the payload fairing around the lunar probes.

NASA’s twin GRAIL Science Probes ready for Lunar Expedition
GRAIL B (left) and GRAIL A (right) spacecraft are mounted side by side on top of a payload adapter inside the clean room at Astrotech Space Operations facility. The spacecraft await lunar launch on Sept. 8, 2011. Credit: Ken Kremer

NASA’s dynamic duo will orbit the moon to determine the structure of the lunar interior from crust to core and to advance understanding of the thermal evolution of the moon.

“We are about to finish one chapter in the GRAIL story and open another,” said Maria Zuber, GRAIL’s principal investigator, based at the Massachusetts Institute of Technology in Cambridge in a statement. “Let me assure you this one is a real page-turner. GRAIL will rewrite the book on the formation of the moon and the beginning of us.”

The GRAIL launch will be the last for a Delta II in Florida.

GRAIL A & B lunar twins arrive at Pad 17B. Credit: NASA/Kim Shiflett

Technicians hoist GRAIL A & B lunar twins inside the handling can at Pad 17B. Credit: NASA/Kim Shiflett

Read my prior features about GRAIL
GRAIL Twins ready for NASA Science Expedition to the Moon: Photo Gallery