Aboard the Atlas V: GOES-R's ride to space
Posted November 15, 2016
GOES-R, the most technologically advanced in NOAA’s fleet of weather satellites, is set to launch Saturday, Nov. 19, at 5:42 p.m. EST.
Anticipation for the launch is like nothing I’ve seen before. The words I hear meteorologists use to describe the capabilities of GOES-R are “game changer.”
I recently spoke at the National Weather Association’s annual meeting. After sharing ideas and resources for describing the kind of astronomy events you read about here in the WRAL Weather Blog with broadcast meteorologists from across the country, the very fist question from the audience wasn’t about meteor showers or eclipses. It was about GOES-R’s ride to space.
“GOES-R won't be launched on one of those rockets will it?” a concerned meteorologist asked, referring to recent SpaceX and Orbital ATK anomalies which resulted in vehicle and payload loss.
I assured her it would be atop the current reliability champion, the United Launch Alliance (ULA) Atlas V.
The Atlas family of rockets has a swords into plowshares story, originating in its development as an intercontinental ballistic missile for the Air Force in the late 1950s.
John Glen rode an Atlas D to become the first American astronaut to orbit Earth in 1962. The Atlas-Agena was used by the National Reconnaissance Office (NRO) to launch signals intelligence gathering satellites and then by NASA to launch robotic missions to the Moon in the 1960s. Variants of the Atlas have delivered satellites to orbit and exploration over the next nearly 50 years.
In 2002, the Atlas V made its maiden launch. This vehicle continues to be popular with NASA, the Air Force, and the NRO because of its flexibility and reliability.
Built around a common core booster, Atlas V customers can configure the rocket to meet their needs. The booster is powered by a single RD-180 engine capable of providing more than 860,000 pounds of thrust at liftoff. That main engine is capable of thrust vectoring gimbaling, enabling steering the rocket as it ascends. This enables longer launch windows, increasing the chance of overcoming technical or weather delays on launch day, saving money lost on fuel and personnel in a launch scrub.
Up to five solid rocket motors, each seven stories tall, can be strapped to the Atlas V to provide the extra power needed to overcome Earth’s gravity and lift payloads exceeding 16,500 pounds.
The Centaur upper stage is capable of restarting in space providing for a variety of orbits from Low Earth Orbit to geo-synchronous or Earth and Solar escape trajectories. A third stage was added for the launch of New Horizons, enabling the Pluto-bound spacecraft to further increase velocity and overcome the Sun’s gravity.
Payloads of varying shapes and sizes can be supported by six different payload fairings, the enclosure at the top of the rocket which protects the payload during ascent. These range from the nearly four-story tall Large Payload Fairing to the 5.5-story tall Extra Extended Payload Fairing.
Reliability comes from over 1,300 launches across the Atlas Family.
ULA proudly proclaims a perfect record for Atlas V over 66 launches, including the most recent of an Earth-observing satellite for DigitalGlobe. The claim is reasonable because the only two anomalous launches had no impact on the usefulness of the orbit provided.
In 2007, a pair of NRO satellites were placed into a lower than planned orbit due to a fuel leak in the rocket’s Centaur upper stage. The customer declared the mission a success and was able to use the satellite.
In March 2016, the first stage shut down five-second early while lifting the most massive payload to date, a Cygnus spacecraft to the International Space Station. The Centaur upper stage compensated and delivered the payload, helping Orbital ATK meet their Commercial Resupply contract with NASA while the company investigated the loss of their Antares rocket in November 2014.
On Saturday, GOES-R will be delivered to its new home 35,786 kilometers above Earth's equator by an Atlas V in the 541 configuration.
This indicates a five-meter wide faring, four strap-on solid rocket motors, and a single engine in the Centaur upper stage. This is identical to the rocket which helped deliver the Mars Science Laboratory and the Curiosity rover as well as two additional launches of NRO satellites.
Tony Rice is a volunteer in the NASA/JPL Solar System Ambassador program and software engineer at Cisco Systems. You can follow him on twitter @rtphokie.