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Boeing teams gearing up for reshuffled launch schedule BY JUSTIN RAY SPACEFLIGHT NOW Posted: August 21, 2005 While one Delta 4 rocket remains bolted to its Florida launch pad awaiting better orbital conditions to deploy a U.S. weather observatory in a couple of months, Boeing crews are preparing to conduct a critical dress rehearsal for the first West Coast liftoff of the next-generation booster.
A pair of batteries on the rocket reached their expiration date and with replacements several weeks from being ready, coupled with lighting requirements for the satellite, the launch has been postponed until around October 6. The batteries power the rocket's flight termination system - the safety self-destruct package that would destroy the vehicle if it veered off course during ascent. A fresh batch of batteries won't be ready for a few weeks. "It is the availability that we're tracking. Our next crop of batteries is in testing and they will be available by mid-September. In fact, by mid-September there will be batteries available to support the entire Delta fleet," Rick Navarro, Boeing's director of Delta launch operations, explained during an interview. Further complicating matters in rescheduling the launch is the GOES-N spacecraft's orbital lighting constraints. The seasonal period of extended eclipse between Earth and the sun began last week, reducing the energy levels available to the solar-powered satellite during the early phases of orbit raising, deployments of appendages and initial checkouts. Not wanting to risk the spacecraft by launching during this time, officials have opted to keep GOES-N grounded until early October when the lighting conditions will improve. Engineers are analyzing how soon the next launch attempt will be possible. "It continues to be looked at by the spacecraft community to see if it can be refined. Our planning date continues to be October 6," Navarro said. "What we're doing between now and then is going into a stable vehicle configuration," Navarro said. Safing of the onboard systems, disconnecting ordnance and depressurizing tanks will put the rocket in a stable "caretaker configuration" for a few weeks until the launch campaign is restarted. The actual chore to replace the two expired batteries from the Delta 4 rocket's second stage equipment shelf isn't a difficult job, Navarro said. A few miles down the road from the Delta 4 pad is Complex 17 where a Delta 2 rocket has been assembled to launch the next Global Positioning System military navigation satellite for the U.S. Air Force. That rocket is waiting to receive its two safety system batteries for launch in the second half of September. Pre-launch preparations for that rocket have progressed to a "very stable stopping point right at the end of stand-alone vehicle processing." "The next step is literally to bring the spacecraft to the pad and do integrated testing," Navarro said. Meanwhile, the inaugural launch of Boeing's Delta 4 rocket from the overhauled Space Launch Complex-6 (SLC-6) pad at Vandenberg Air Force Base in California is nearing. That booster, flying in the same configuration as the GOES-N rocket with two cryogenic stages, a four-meter payload fairing and two strap-on solid rocket motors, could launch by the end of September. A Wet Dress Rehearsal, or WDR, is scheduled for this Friday to run through a complete launch day simulation. "This is our final rehearsal before entering countdown and it will be a full fidelity exercise like what we've done with all of the Delta 4 vehicles. We'll load hydrogen and oxygen in the (first stage) and second stage," Navarro said. "We'll run through the entire countdown sequence. Really it won't look any different than it will on launch day in terms of all of the countdown activities. In fact, we'll going into T-minus 5 minutes and counting and proceed all of the way to what would be engine start. We'll stop short of engine start and then recycle. Everything will be exercised." Navarro said the West Coast countdown should look virtually identical to the ones performed at Cape Canaveral. "That's part of our goal is to be able to process these vehicles similarly, and that obviously includes the countdown actions. So other than some minor facility differences, which are almost transparent, the countdown process, the countdown manual and the way we go about it is the same. So you'd recognize every element of the count on the same timeline as we just did for GOES." The Boeing-made booster will be the largest rocket ever flown from SLC-6, which has a history dating to the Air Force's Manned Orbiting Laboratory project of the 1960s. It's also the former California launch pad for the space shuttle, but the site was mothballed in the late 1980s before any shuttles flew from the complex. The site was used briefly in the 1990s for Lockheed Martin's small Athena rocket. The Delta 4 currently stands on the pad without its payload -- a classified spy spacecraft cargo for the U.S. National Reconnaissance Office. The payload will be transported to SLC-6 and bolted atop the rocket once a successful WDR is completed. "Assuming everything goes well (with the WDR), then we will get with the customer, the NRO, and make that assessment of when is the right time to bring the payload to the pad. We'll do a data review in conjunction with them, make sure we didn't have any surprises. At this point, we believe we've taken all of the surprises out of it because it's a Medium+4,2 (configuration rocket), which we know how to do well, and we've done two cryogenic tanking tests here at SLC-6. "So this (WDR) should wrap it all up. We'll get with the customer, look at the data and decide on a spacecraft (transport) date." Although a precise date for the launch has not been established either, officials are targeting a liftoff in the late-September time frame. "It's in flux. We're just looking forward to WDR and then we'll firm that up." Boeing also has a Delta 2 launch from Vandenberg on September 29 carrying a pair of Earth research satellites for NASA, giving the company four launches from four pads in a short stretch. "It's an exciting time for Delta," Navarro said. |
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