Atlas V With OSIRIS-REx Moves To The Launch Pad

Image Credit: Colorado Space News

Image Credit: Colorado Space News

September 7, 2016 – The United Launch Alliance Atlas V rocket made the trek from the Vertical Integration Facility to Space Launch Complex 41 at Florida’s Cape Canaveral Air Force Station on Wednesday. NASA’s OSIRIS-REx spacecraft is encapsulated in the protective payload fairing on top of the rocket.

OSIRIS-REx stands for Origins, Spectral Interpretation, Resource Identification, Security-Regolith Explorer. The OSIRIS-REx spacecraft was built by Lockheed Martin Space Systems in Littleton, Colorado, and will be NASA’s first mission to sample an asteroid. The return of pristine samples with known geologic context will enable precise analyses that can’t be duplicated by spacecraft-based instruments. Pristine carbonaceous materials have never before been analyzed in laboratories on Earth and could hold clues to the origin of the solar system and likely organic molecules that may have seeded life on Earth.

OSIRIS-REx encapsulated in the rocket's large payload fairing. Image Credit: Colorado Space News

OSIRIS-REx encapsulated in the rocket’s large payload fairing. Image Credit: Colorado Space News

The rocket’s large payload fairing (LPF) is 14 ft in diameter. The LPF is a bisector (two-piece shell) fairing consisting of aluminum skin/ stringer construction with vertical split-line longerons. The vehicle’s height with the PLF is approximately 189 ft.

Atlas rockets have evolved over four decades to become a highly reliable launch vehicle. The Atlas V booster family provides a variety of vehicles that are capable of launching a wide range of spacecraft and satellites. The Atlas V 411 rocket that will be used for this mission is a unique configuration that includes only one solid rocket booster.

The Atlas V booster is 12.5 ft in diameter and 106.5 ft in length. The booster’s tanks are structurally rigid and constructed of isogrid aluminum barrels, spun-formed aluminum domes, and intertank skirts. Atlas booster propulsion is provided by the RD-180 engine system (a single engine with two thrust chambers). The RD-180 burns RP-1 (Rocket Propellant-1 or highly purified kerosene) and liquid oxygen, and delivers 860,200 lb of thrust at sea level. The Atlas V booster is controlled by the Centaur avionics system, which provides guidance, flight control, and vehicle sequencing functions during the booster and Centaur phases of flight. One solid rocket booster (SRB) provides an additional 348,500 lb of thrust at liftoff.

The Centaur upper stage is 10 ft in diameter and 41.5 ft in length. Its propellant tanks are constructed of pressure-stabilized, corrosion resistant stainless steel. Centaur is a liquid hydro- gen/liquid oxygen- (cryogenic-) fueled vehicle. It uses a single RL10-A-4-2 engine producing 22,330 lbf of thrust. The cryogenic tanks are insulated with a combination of helium-purged insulation blankets, radiation shields, and spray-on foam insulation (SOFI). The Centaur forward adapter (CFA) provides the structural mountings for the fault-tolerant avionics system and the structural and electrical interfaces with the spacecraft.

Centaur engines can start and re-start multiple times in space, enabling insertion of a spacecraft into a low Earth parking orbit, followed by a coast period and finally, insertion into geosynchronous transfer orbit. They’re also capable of direct insertion into an inter-planetary trajectory.

Image Credit: United Launch Alliance

Image Credit: United Launch Alliance

Liftoff is scheduled for Thursday, September 8 at 5:05 p.m. MDT. Click here to view some countdown milestones and key events that take place after the countdown begins.

United Launch Alliance has its headquarters in Centennial, Colorado.