Gogblog vodcast #2: Watch an Atlas 5 launch of a military satellite from Goddard’s Flight Dynamics Facility
One recent Saturday in August, I woke at 4:30 a.m., rubbed my eyes in the early morning darkness, and headed for Goddard Space Flight Center to watch the launch of an Atlas 5. The rocket blasted off from Cape Canaveral in Florida, carrying a military communications satellite into high geosynchronous orbit.
My perch: the Flight Dynamics Facility, which I described in an earlier post about FDF’s support of Shuttle and Space Station missions.
The FDF operations area is a large room packed with computer workstations. The mission of the FDF is to provide precise pointing coordinates to enable ground stations and satellites to track launch vehicles like the Atlas V into space. FDF also pitches in to track the Shuttle orbiter and the Space Station in low-Earth orbit to maintain links to the ground.
This video, with voiceover by FDF junior systems engineer Jason Laing, explains some of the major events in the launch of the Atlas V:
Today the Atlas will carry the Advanced Extremely High Frequency (AEHF) satellite, the first of three. The system will provide secure global military communications between ground, sea, and air.
Start of show: I got in at around 6 a.m. and met the lead engineer for this launch, Syed Hasan. Bleary-eyed but alert, he got in at 12:30 a.m. to begin check-outs of the computer and communications systems. By Syed’s side for the launch: James Cappellari. A nearly 50-year veteran of NASA, Cappellari helped to develop and implement the Space Network. I deposited the obligatory bucket of donut-like objects in the FDF break room and got ready for “start of show.”
Start of show in the FDF is 10 minutes before launch, which today is slated for 7:07 a.m. At start of show, a TDRS satellite hovering above the U.S. East Coast will start tracking the Atlas right on the pad. Today it is TDRS 10, but TDRS 4 is also available for East Coast launches.
FDF’s partner in this and other launches is the White Sands Complex in New Mexico, which controls the satellites comprising NASA’s Space Network. Eight TDRS satellites currently provide global tracking, communications, and data links for manned and unmanned spacecraft. When rockets phone home, it is often via the TDRS network.
About the time I arrived at FDF, Syed sent something to White Sands called an autothroughput test vector. This tests the system that would allow FDF to send pointing data directly to the TDRS satellites during launch, bypassing White Sands.
But that would only happen if the satellites drifted off their targets and needed to be repointed. Throughout the launch the ELV (expendable launch vehicle) team at FDF watches to make sure the satellites are pointing at the rocket and able to track it accurately. FDF supports 10 to 15 ELV launches per year.
The rocket “talks” to the ground via data links, so accurate pointing is important. During Space Station missions, accurate pointing of TDRS’ high bandwidth antennas allows astronauts and cosmonauts to wave hello to us earthlings via video downlink. Scientific spacecraft also use TDRS to pipe data to the surface on a regular basis. Without accurate pointing of the TDRS satellites, NASA’s operations in low-earth orbit would be much more limited.
As lead engineer on the ELV team today, Syed runs some FDF software called acquisition data generator, which he would use to create and send a pointing correction vector during launch, if needed. Rows of numbers on his monitor allows Syed to keep an eye on the actual “beam angles” of the TDRS antennas indicating what direction they point.
But FDF now has another tool in their kit for making sure the Space Network is on target. It’s called the SN Beams Display, and it was developed by FDF engineers with a combination of commercial and in-house software code. Today, FDF’s John Bez is manning the SN Beams.
The SN Beams creates a live view of the spacecraft from pad to orbit as well as the TDRS “beams.” Each beam is a cone of space, rendered in green or white, that indicates the position and coverage of the antenna. When a launch vehicle or satellite leaves the beam, it is out of range to that particular satellite, and another in the network must pick up the tracking — sort of like relay racers passing the baton.
During launches, the SN Beams provides visual clues to the FDF about the difference between where each satellite is supposed to be pointing (green), based on pre-calculated pointing data, and where the satellites are actually pointing (white).
Two other members of the team, Eric Smith and Jason Laing, are on hand to check the position of the launch vehicle at several key stages of the launch based on actual telemetry data from the rocket. For this they use two terminals running the “LRP” software, for Launch Reentry Processor. If the craft is not where it’s supposed to be, it might be necessary to adjust the pointing data for the TDRS satellites.
Here is a video of the launch of the AEHF rocket! This is video from the launch contractor, ULA:
Atlas away! The magic moment finally comes at 7:07 a.m., when the Russian-made RD-180 main engine roars to life, supplemented by four solid rocket boosters strapped onto the first stage.
10…9…8…7… you know the rest. There is something about a countdown that is thrilling. It’s a high-stakes game when you launch a multi-billion dollar satellite. There is little room for error.
The early events happen quickly.
At 1:40 into the launch the SRBs cut out; 16 seconds later they jettison. The SN Beams shows this in detail, as three little cartoon SRBs pop off the Atlas V booster and fall into the video game Atlantic Ocean. The live feed from Florida just shows the brilliant plume of the rocket receding into the blue sky.
At 3:27 the faring on the front of the Atlas pops open like two clamshells, exposing the satellite mounted to the top of a Centaur second-stage booster. The main engine is still burning.
At 4:17 the main engine shuts down, an event FDF people call MECO (“mee-koe”), for main engine cut-off. After a short coast, the second stage “Centaur” fires up.
At 14:08, the Centaur shuts off and the vehicle coasts for almost 8 minutes. Then, at 22:17, it fires up again for about 5 minutes to accelerate the satellite into the higher geosynchronous orbit. The Centaur will cut out and finally release the AEHF satellite 51 minutes into the launch.
Two hours after launch, it’s “end of show” for the FDF. At this point, FDF no longer has responsibility for supplying pointing data to White Sands. However, they continue to monitor for some time, just in case their services are needed.
Big fat planet: I have to say, watching this all on the SN Beams was a real surprise to me, because it shows just how huge Earth is and how puny even the mighty Atlas V is in comparison. After the rocket had been blasting away furiously for almost five minutes, it was still barely over the Atlantic Ocean, heading east.
At 10 minutes, the launch vehicle was screaming through the atmosphere at more than 15,000 mph, the Centaur was still firing. After 20 minutes, the craft was barely over West Africa. At the moment the satellite was released, 51 minutes into the launch, it hadn’t completed a single orbit yet.
This tells you that Earth is BIG and massive. Escaping its gravity to a geosynchronous altitude of 22,500 miles requires a lot of fuel and a lot of time.
OH AND DID I MENTION? All opinions and opinionlike objects in this blog are mine alone and NOT those of NASA or Goddard Space Flight Center. And while we’re at it, links to websites posted on this blog do not imply endorsement of those websites by NASA.