NASA is deferring until mid-March a decision that will delay either a Hubble Space Telescope servicing mission or the first test flight in the Ares 1 rocket development program.
Here's the situation:
The Ares 1X rocket is scheduled to blast off July 11 from launch pad 39B at Kennedy Space Center. But NASA has been keeping that complex "shuttle-ready" so a rescue mission could be launched from it if shuttle Atlantis sustains critical damage during a fifth and final Hubble Space Telescope servicing mission.
In order to make the July 11 launch date for the Ares 1X test flight, NASA would have to turn over pad 39B for modifications at least three months in advance. Atlantis and seven astronauts now are scheduled to blast off May 12 on the Hubble servicing flight.
NASA consequently is examining the possibility of using a single pad -- 39A -- to launch both the Hubble servicing mission and, if required, a rescue flight. Doing so would free up pad 39B for the Ares 1X test flight in July, but it would have a significant ripple effect.
Launch of Atlantis and the Hubble servicing crew would slip to May 26 so the rescue shuttle -- Endeavour -- could be hauled out to launch pad 39A to fuel its Orbital Manuevering System and Reaction Control System as well as the Hydraulic Power Units on its two solid rocket boosters.
Then Endeavour would be rolled back to the Vehicle Assembly Building, where it would remaining ready to roll out for a rescue flight. The early hypergolic servicing would enable NASA to roll Endeavour out to pad 39A and then launch on the rescue mission after an abbreviated countdown.
The ability to launch within about a week of the Hubble launch is critical because the Atlantis crew would not be able to seek safe haven on the International Space Station. The Hubble observatory is in an entirely different orbit and Atlantis would not have the propulsive power to fly to the outpost in an emergency.
A decision to proceed with single-pad operations for the Hubble mission and a potential rescue flight also would trigger a one-month slip in each of seven remaining International Space Station assembly and outfitting flights.
The last of those now is scheduled to fly in late May 2010. NASA is operating under a presidential directive to finish station assembly and retire the shuttle fleet by Sept. 30, 2010. The money spent on the shuttle program then would be funneled into the development of the Ares 1 and Ares 5 rockets as well as the Orion spacecraft and Altair Lunar Surface Access Module.
Senior NASA officials gathered late Thursday for a status briefing on preparations for the STS-125 Hubble servicing mission as well as the Ares 1X test flight. Preparations for a July 11 launch for the $360 million test flight are running about a month behind schedule while NASA remains on track for the May 12 Hubble launch.
NASA officials will meet in mid-March to reassess the situation and determine a course of action.
Meanwhile, preparations for the planned Feb. 12 launch of Discovery on a mission to deliver the final central truss segment to the station are proceeding without major problems, and an executive-level flight readiness review will be held Feb. 3 to firm up that date.
ABOUT THE IMAGE: Click to enlarge the NASA image of shuttle Discovery on launch pad 39A prior to the launch last February of the STS-122 mission to deliver the European Columbus science laboratory to the International Space Station.