Flying into orbit in small package
January 26, 2011
- SMDC-ONE is the first Army satellite launched in more than 50 years.
- "The Army is the largest user of data from space than any of the other services."
- "This opens up a new opportunity for the Army to do communications (via satellite) that are more efficient and cost effective."
- "The satellite's performance, the ground station's performance and the team here exceeded our expectations significantly."
REDSTONE ARSENAL, Ala. -- For 35 days, the comings and goings of employees in the Von Braun Complex parking lot here were the focus of a group of young engineers involved in an experiment with the first Army-built satellite launched in more than 50 years.
Those engineers weren't spying on employees. Nor were they looking for fodder for gossip or to start rumors. They were simply using the physical movements through the parking lot to test the capabilities of a 10-inch long, 10-pound satellite in orbit 200 miles above ground.
The Space and Missile Defense Command-Operational Nanosatellite Effect, known as SMDC-ONE, was launched Dec. 8, as a secondary payload on a Falcon 9 two-stage booster flown commercially by Space Exploration Technologies.
The nanosatellite remained in orbit 35 days, providing data on its operations, and proving its ability to receive text and images from a ground sensor and then to relay that data to a ground station. The Space and Missile Defense Command/Army Forces Strategic Command is the Army lead for the SMDC-ONE nanosatellite program.
"The Army is the largest user of data from space than any of the other services," said John London, nanosatellite technology program manager for SMDC/ARSTRAT's Technology Center at Redstone Arsenal. "The Army has been dependent mainly on the Air Force and the Navy for satellites they can use. There are some specific things that the Army needs from a satellite that are not being addressed today in terms of capability for Soldiers on the ground."
"This opens up a new opportunity for the Army to do communications (via satellite) that are more efficient and cost effective, and that can make it safer for Soldiers on the ground in very remote locations. Satellites could give them a communications lifeline," London explained.
The nanosatellite, similar in size to a bread box, launched from Cape Canaveral as one of several satellites that "hitchhiked" or "piggybacked" with the Falcon 9's primary payload, which was going to the same orbit as the International Space Station. Because of that, SMDC-ONE flew in an orbit lower than the 300-mile orbit it is designed for.
"The satellite's performance, the ground station's performance and the team here exceeded our expectations significantly," London said. "Our goal was to develop a satellite this size that could provide relevant capabilities to the war fighter."
In its low circular orbit, the satellite passed over Redstone Arsenal four to five times in every eight-hour period, each time giving engineers about five minutes to download image and text data. Those engineers, many recent college graduates and some still attending college, worked in teams of two to ensure they took advantage of the satellite passes.
The teams worked in a ground station, a simulated Forward Operating Base, at SMDC/ARSTRAT headquarters, using computers to monitor the satellite and to download information. "We wanted to make sure with this mission to demonstrate the direct readiness to the war fighter," London said.
Toward that end, three passive infrared and seismic motion sensors were placed in the shrubbery around the Von Braun Complex, where SMDC/ARSTRAT is located.
"We needed to simulate unattended ground sensor data," Dave Weeks, SMDC/ARSTRAT chief engineer, said. "We simulated monitoring trail activities with a seismic sensor that measured (the movement of) trucks and footsteps. The unattended ground sensors, known as UGS by Soldiers, were triggered just as they are while deployed in theater now."
In a real war environment, infrared and seismic sensors are placed by Soldiers along the parameters of Forward Operating Bases and in remote locations to provide data on enemy movements. UGS can transmit information to the headquarters of a forward operating base, but in remote locations Soldiers often have to get within close proximity to the sensors to retrieve data due to terrain and the area's horizon.
"They have to give up the covert aspect of taking data out of the sensors. If satellites are passing overhead they can't be seen by the enemy," London said. "You can take information out without the enemy knowing it and you don't have to expose troops to getting information in a hostile environment."
The nanosatellite covers a 1,200-mile radius, roughly the distance between the ground station at SMDC/ARSTRAT headquarters and a second ground station at the SMDC/ARSTRAT battle lab in Colorado Springs. The nanonsatellite requested data from the sensors, accepted data from the ground stations and provided data to the ground stations.
The two ground stations communicated with each other via the nanosatellite, a situation that became a point of interest to SMDC/ARSTRAT commander Lt. Gen. Richard Formica.
Antennas on the nanosatellite allowed engineers to track its progress as it orbited the earth, and to determine the times of day when the nanosatellite would pass over the Pacific Ocean, Colorado Springs and Redstone Arsenal. Because of that, engineers scheduled a demonstration time during which Formica would be able to communicate with the ground station in Colorado Springs via the nanosatellite.
The recently appointed commander visited a conference room where the nanosatellite's progress in orbit and the information it was relaying to the ground station could be monitored. The engineers set up an exchange where Colorado Springs sent a welcome message to Formica via the satellite. The Arsenal ground station was able to retrieve and display the message on the conference room monitor.
"We had a tentative schedule and it was nerve-wracking to make sure everything worked like it was planned," said engineer Josh Martin, a recent Auburn University electrical engineering graduate.
The nanosatellite first passed over Colorado Springs before passing over the Arsenal.
"Their pass came five minutes before ours," Martin said. "We set up a text file. When it flew over here we could communicate with the satellite and pull down and display on a laptop a welcome message that Lt. Gen. Formica could see on the screen" in a conference room.
Martin was among a team of young engineers, and University of Alabama-Huntsville math and engineering students who were eager to be in on the "ground floor" of a nanosatellite program.
They are described by SMDC/ARSTRAT officials as "the new core of engineers coming in" to SMDC.
Besides Martin, those engineers included Jacqueline Nelson, a graduate of the University of Central Florida; and Ryan Wolff, a graduate of the University of Louisville; and Kenya McLin, a graduate of Tuskegee University. UAH students included Iris Lin, a sophomore mechanical engineering student; Stephanie Cleveland, a senior electrical engineering student; Amanda Mahan, a sophomore computer science student; and Jenny Horton, a master's student studying math.
"This really is a great opportunity for us," Martin said.
As opportunities go, data gathering from ground stations and sensors was also a major feat for the nanosatellite. The nanosatellite program's initial goal was only to demonstrate its ability to communicate, not to gather data.
"Involving sensors with the satellite was not even on the drawing board for the first mission," Weeks said. "But we decided at the last minute to have it folded in in real time. We had some outside hopes it would be successful. We said 'Let's go for it and see if it works.'"
By so doing, the nanosatellite demonstrated its "relevance to actual fielded hardware," London said.
When it did pass over Redstone, engineers collected temperature and sensor data as well as data on the nanosatellite's position, power generation, battery voltage and signal strength. They would also gather information from the satellite regarding images and sensor data, said Mark Ray, an engineering lead for the nanosatellite program.
Eventually, the nanosatellite lost all its battery voltage. On Jan. 10 and 11, its signal strength was very weak. On Jan. 12, it burned up as it fell out of orbit over southeast Indonesia.
"It died on Wednesday morning," Ray said. "We had met all our objectives before its last two days."
While the one nanosatellite covers 1,200 miles, to get the type of continual coverage of a traditional satellite, the Army would need a constellation of 30 to 40 nanosatellites. But, at a cost of $300,000 to $400,000 each, the nanosatellite is much more affordable than one traditional military or communication satellite that costs in excess of a billion dollars, London said.
The number of satellites needed to fully cover an area varies depending on where that area is in relation to the equator. The closer to the equator, the fewer satellites are needed to provide coverage.
"A traditional military satellite may be more capable than a nanosatellite. But for niche capabilities, for text messages and for reaching remote troops, these nanosatellites could be a lifesaving resource for the Army," London said. "The technology world has allowed us to put a lot more capabilities in a small package."
In addition, the size of traditional military satellites make them an easy target for an enemy while nanosatellites are more covert, he said. Nanosatellites can also be built much faster.
"When a nanosatellite is in orbit, they are hard to detect, hard to track by the enemy," he said.
Currently, there are plans to fly three satellites in the 2012 time frame. The goal is to have regular launches of the inexpensive satellites as secondary payloads aboard other rockets, or put them in orbit by a smaller booster rocket known as the Multipurpose NanoMissile System.
"The next step in testing is to use fielded Army radios to communicate text and image data to and from the satellites," London said.
Engineers would like to test the nanosatellites in an orbit 300 miles above the earth, rather than the 200-mile orbit they were required to use for the first test.
"At 300 miles, the satellite can stay up longer. There is less atmospheric drag and the orbiting circle is bigger," London said. The full operational life of the nanosatellite is more than 12 months when launched in the 300-mile orbit.
While this nanosatellite is a communications satellite charged with retrieving and relaying information from ground sensors, plans call for also developing imaging nanosatellites that can actually take pictures of the ground.
Developing, testing and demonstrating the abilities of the nanosatellite is easy compared to funding issues facing the program, said Steve Casson, deputy director for SMDC/ARSTRAT's Space and Cyberspace Directorate.
"These engineers have done a lot with a little. But there is still a lot of work to be done. In the culture of the Army, we're challenged to get the amount of funding we need to accomplish what we want to do," he said.
"This is low cost and low infrastructure. Its millions of dollars versus billions of dollars for traditional satellites. The challenge is not the technology. We've got the capability and the talent to do the job. The challenges have to do more with internal, with how the Army will adapt to this technology."