'Slick Six' launch pad hosts its first Delta 4 rocket

Posted: May 26, 2003

The Boeing Delta 4 rocket and its rebuilt West Coast launch pad came together for their first meeting this month, giving technicians the opportunity to test how everything fits.

The Delta 4 rocket stage is lifted upright at Vandenberg's SLC-6 launch pad. Photo: Lloyd Nagle/Boeing
Space Launch Complex 6 at Vandenberg Air Force Base in California has been overhauled to serve as the starting point for polar-orbit launches of next-generation Delta 4 rockets carrying secret reconnaissance satellites and military weather observatories.

The SLC 6 facility -- called "Slick Six" -- was first built in the 1960s for the Air Force's Manned Orbiting Laboratory and then redone in the 1980s for space shuttle missions. But both projects were cancelled before any launches occurred.

Construction for the Delta 4 program has been ongoing for a couple of years, installing new equipment and modifying the existing shuttle-era structures to handle the Boeing rocket.

The first Delta 4 arrived at Vandenberg in January. It has been housed in the Horizontal Integration Facility -- a new hangar at the complex where the rockets are tested and their stages connected. The vehicles are transported horizontally to the launch pad and lifted upright using the pad's hydraulic erector platform.

With the construction phase now completed at Slick Six, the Common Booster Core first stage and interstage section of the inaugural West Coast Delta 4 rocket took its place atop the pad for the first time May 14, kicking off two weeks of tests.

"We are doing what we call a mechanical fit check. We are not hooking the vehicle up to any systems, other than we are providing air conditioning to the vehicle in the areas that need to be environmentally protected," Ken Liptak, Boeing's site manager at SLC 6, explained in an interview.

"While it is on the pad we are...putting down platforms, the levels of the (mobile service tower) where workers would access the rocket, verifying we have the adequate space and don't have any interference with the rocket," Liptak said.

"We do have some discrepancies -- a quarter of an inch here, an eighth of inch there. Once the rocket comes down, we will have crews going in and making some minor modifications to the platforms so when we do put it up for flight, we know everything is going to work as expected."

The other key objective during the launch pad tests was practicing the attachment of strap-on solid rocket boosters to the Delta 4's first stage. Workers used an inert motor to rehearse mounting the booster to each of the four attach points on the Delta 4.

"That all went well. We did a soft mate in each of the three positions and then in the fourth position a hard mate, took it up to flight tension, and verified all the interfaces were as expected. We had no anomalies. Then we took it down and sent it back to the solid rocket motor processing facility," said Liptak.

The first Delta 4 mission from Vandenberg will use two solid motors.

Liptak says the "pathfinder" activities have progressed well, although more time has been needed for some procedures than spelled out in the schedule.

"That is to be expected. We are going to go very slow and be very careful and we are going to observe things. What we are trying to do is identify potential conflicts that need to be worked on. As we identify something, we are going to stop and make sure we document it well before we proceed.

"We have really had no significant issue other than the timelines have run a little bit long."

This file photo shows the Mobile Assembly Shelter on the left (structure with the large American flag) and the Mobile Service Tower on the right. The rocket will stand next to the Fixed Umbilical Tower in the center of the pad complex. Photo: Justin Ray/Spaceflight Now
Plans call for the Delta 4 to be returned to its hangar later this week. The upper stage will be added to the rocket before it is rolled back to the pad in early-to-mid October for another round of pathfinder testing.

That next visit to the pad will feature the attachment of a simulated payload atop the rocket, a critical test for Boeing and its customer on the first Vandenberg Delta 4 launch -- the National Reconnaissance Office.

"We are doing something a little unique on the mission. Our customer wants to do this pathfinder early so if there is an issue relative to how we interface with the payload and bringing it to the pad, if there is anything we need to change in our processes, they want to have adequate time to get those factored either into the payload's processes, launch vehicle processes or the integration processes," said Liptak.

"We will go through all of the connections of all of the systems to the vehicle, verify all of the systems communicating with the rocket and that we can communicate from the simulated payload, out through the umbilicals, down through the interface racks and out to a facility where the payload (ground support equipment) is going to be, and verify all those systems work well."

A series of countdown dress rehearsals and fueling tests will follow in preparation for launch in early 2004.

Officials had been targeting liftoff this December. However, the mission was pushed back a few months at the NRO's request. A new launch date has not been formally announced.

"My focus, right now, is I want to get through (pad) activation and I want to get my pathfinders out of the way," Liptak says.

"I am really pleased with where we are. We are right on track."

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