CAPE CANAVERAL — The Atlas rocket to launch four formation-flying spacecraft for NASA in March began to take shape Wednesday at the assembly building adjacent to the Complex 41 pad.
The United Launch Alliance-made rocket will haul the Magnetospheric Multiscale mission, or MMS, satellites into orbit to study magnetic field explosions.
Liftoff is targeted for March 12 during a 30-minute launch window opening at 10:44 p.m. EST (0344 GMT) from Cape Canaveral.
Putting the two-stage rocket together got underway Wednesday morning as ULA workers brought the bronze-colored first stage to the Vertical Integration Facility for stacking operations.
By late morning, the booster was secured aboard its mobile launcher, anchored on small supports that protrude from the platform. At liftoff, explosive bolts free the rocket and those supports will retract into the platform walls as the vehicle powers its way off the pad.
Known as the Common Core Booster, the stage was pulled by a semi-truck up the road from the Atlas Spaceflight Operations Center high bay to the 30-story VIF building where workers attached lifting cranes. The 106.6-foot-long stage was rotated vertical, then maneuvered into the building and stood upright on the mobile platform.
The stage is equipped with a dual-nozzle RD-180 main engine that will burn kerosene fuel and supercold liquid oxygen during the initial minutes of flight.
On Friday and continuing early next week, a pair of solid rocket boosters will be mounted on the north- and south-sides of the first stage.
Giving the rocket an added kick off the launch pad are solid-propellant boosters made by Aerojet Rocketdyne. Considered the world’s longest monolithic — or single-segment — solid boosters, the motors provide the extra thrust needed to increase the Atlas 5’s payload-carrying capacity.
Each booster stands 67 feet tall, has a diameter of just over five feet and weighs 102,000 pounds at launch. The slender white rockets have a lightweight graphite epoxy casing with an erosion-resistant insulation. The solid fuel is high-performance class 1.3 HTPB propellant.
Also upcoming will be installation of the interstage adapter that tappers the 12.5-foot diameter first stage to the 10-foot-wide Centaur upper stage.
The cryogenic upper stage will be hoisted atop the interstage on Feb. 11 to complete the basic buildup of the Atlas 5.
Centaur’s single RL10 engine, fueled by liquid hydrogen and liquid oxygen, will perform the necessary burns to achieve orbital velocity and then shape the orbit for deployment of MMS.
The stage is 41.5 feet in length and also houses the navigation unit that serves as the rocket’s guidance brain.
The rocket is known as the 421 configuration of the multi-variant Atlas 5 family, which is tailored with strap-on solid boosters and different sized nose cones to match the cargo’s mass and size.
The four MMS spacecraft arrived from the Goddard Space Flight Center on Oct. 29 and Nov. 12 and have since undergone preflight testing at the Astrotech processing facility in Titusville.
The satellite will be encapsulated in the rocket’s nose cone at the end of this month in preparation for delivery to the VIF and mounting atop the Centaur in early March to finish assembly of the 195-foot-tall launcher.
“Processing remains on pace for a targeted March 12 launch,” a NASA spokesman says.
Rollout to the launch complex occurs the day before liftoff as the 1.4-million pound platform rides the rail tracks 1,800 feet from the VIF to the pad.
It will be the 53rd Atlas 5 launch and the second this year.