NASA’s Space Communications and Navigation head points way to the future
CAPE CANAVERAL, Fla — During the hours prior to the launch of NASA’s Tracking and Data Relay Satellite “L” (TDRS-L, now known as TDRS-12) SpaceFlight Insider sat down with Badri Younes, NASA’s deputy associate administrator for its Space Communications and Navigation (SCaN) program office. He had a lot to say. Not just about the importance of that evening’s launch – but of the technology systems that the space agency is currently working on which will revolutionize the manner in which the space agency relays data from distant points in the solar system.
Younes is a large man with a ready smile. He is not afraid to speak his mind, to correct a misperception and to expound on an idea. Given the event which would light the skies in the coming hours, what Younes had to say was most timely. He detailed the short-term communications initiatives that NASA was working on – as well as long-term ones which have only now begun to take shape, those which could see us move away from using radio frequencies or “RF” altogether.
SpaceFlight Insider: First Mr. Younes, thank you for taking the time to sit down with us and chat.
Younes: “It’s my pleasure.”
SpaceFlight Insider: TDRS is all about space communications, can you provide us with a little background data regarding that?
Younes: “Definitely, we presently have a space network that relies on a set of data-relay satellites to provide near real-time support to users anywhere they are flying below the geostationary orbit. The technology evolved in the mid 70s and it has demonstrated its viability and robustness by supporting most, if not all of the missions that are flying around Earth.”
“The TDRS spacecraft is what is known as a bent-pipe spacecraft. Bent pipe means that it does not act on the data – it receives the data from the mission and relays it back to the ground where the processing of that data takes place. This has given us a lot of opportunities to innovate and introduce new capabilities on the ground… So the data rate has grown over the past so many years to get to a level that now everyone is comfortable with.”
“But still, on the spectrum domain you see the congestion and the demand for the lower frequency bands. When you add the growing demands within our community, it used to be they wanted a few kilobits, now they want megabits and soon they will be wanting gigabits. Anything that contains either audio or video requires a hi-fidelity connection
SpaceFlight Insider: What is one of the largest challenges that NASA is facing in terms of space communications presently?
Younes: “The missions that are requiring the most bandwidth are those that do sensing. Those missions which use things like synthetic aperture radar, they want the instrument so sensitive and the resolution so high they are going to wider and wider bandwidths.”
SpaceFlight Insider: When the public log onto their computers, they want to be able to watch streaming video and to do things in real-time. Are you using similar commercial efforts in what TDRS has been tasked to accomplish?
Younes: “In terms of capability, TDRS is unique. We have yet to find a matching capability in the commercial sector. That does not mean we didn’t rely on commercial products to produce TDRS. In terms of the architecture of TDRS and the capabilities that are on board – we cannot find them anywhere – even if we were to combine a number of commercial systems, the cost is going to be outrageously higher.”
“In terms of meeting the requirements of global coverage is almost non-existent. Most commercial satellites are focused on their market area on the ground. Not too many entities deal with space, so the capabilities of the commercial satellites are targeting a particular populated area – while for NASA all of space is our domain. That is why the capabilities of TDRS are focused on this aspect of NASA’s requirements.”
SpaceFlight Insider: We know that TDRS worked for shuttle and it currently supports both the International Space Station as well as the Hubble Space Telescope. What other missions utilize TDRS?
Younes: “Most Earth-observation satellites use TDRS for emergency support. They have a kind of open channel through our multiple-axis system that’s available to them 24-7 without any prior scheduling to communicate and provide telemetry to their mission operations centers to take place in the event of an emergency. These are polar-orbiting satellites which study the Earth. They don’t need real-time support they can afford some flexibility. They have maximum visibility and availability to dump data when they are over the polar area – that includes both the North and South poles where we do have facilities.”
“NASA has three networks and they have evolved independently, some are older than the others and we are now in the process of integrating all of them into a single, unified, cohesive network – catering to not only to the robotics and to the science missions but also to our human space flight efforts also. In the future we won’t have to have separate communications systems, we won’t have things scheduled three times, they will have a one-point entry to SCaN. We will have a network of networks.”
“You spoke earlier of our older systems. When we started to investigate the integrated network we noted that much of our network was kind of aging, some of the components were non-existent you had to go on eBay to buy them to keep the system going. If it wasn’t for the dedication and talent that we have in our operators and technicians we would have failed to provide the service we are providing today at a proficiency higher than 99.99 percent – better than AT&T!” (Laughs)
SpaceFlight Insider: Better be careful that’s going in the article!
Younes: “Well, no kidding!” (Laughs)
Pete Vrotsos: “You asked earlier about how many missions TDRS supports – it’s sixteen missions total and that varies from day-to-day. Certain missions use TDRS everyday whereas others only need it once or twice a week.” (Vrotsos, SCaN’s director of Network services also attended the interview and chimed in with this information).
Younes: “We also support all of the launch vehicles by-the-way, so when TDRS-L launches today it will be getting support from one of its brothers.”
SpaceFlight Insider: Would it be TDRS-K or one of the older models?
Younes: “One of the older models, TDRS-K is now sitting in a location as a spare. We always tend to exhaust the existing generation and then move on to the newer generation.”
“Getting back to our earlier discussion, we decided that we needed additional data relay satellites and we needed to have them take care of our load through 2025. This brought us into the third-generation of these satellites and into the multiple axis processing to the ground. That’s what is different about the third generation it takes the multi axis, it enhances it, it puts it back on the spacecraft rather than on the ground.”
“At the same time that this was going on, we decided, ‘hey, we made progress with optical communications, especially when it applies to free space laser communication, where you don’t have the fiberglass as a medium and we have evolved the technology through level 6 of readiness and we recently demonstrated this capability from the Moon.”
SpaceFlight Insider: “For the novice, what is level 6 readiness?
Younes: “That’s when the technology has been moved from the bench to be tested for its readiness to go into operation. Above that you have levels seven-through-nine. Once you reach nine? You’re ready to go operational. At level six, it means that the technology has matured. It does not mean that you cannot change it, it means that it is ready to be used for the application intended for it.”
SpaceFlight Insider: Which brings us to the laser communications system that was tested on LADEE (NASA’s Lunar Atmosphere and Dust Environment Explorer – currently in orbit around the Moon).
Younes: “We were worried about the acquisition of the signal during that test because you are talking about two narrow beams intersecting and aligning at such a far distance. That was why we decided to take this optical payload and put it on a data relay satellite and have it demonstrate its capabilities. We called it Laser Communications Relay Demonstration or ‘LCRD.'”
SpaceFlight Insider: So essentially you opted to send the demo model on LADEE to test out how it would work in real-world conditions?
Younes: “Definitely, while it was a demo model, it was a production-type demo. We showed that we could achieve the data rate with a ten centimeter aperture. To achieve this with RF? You would need a huge antenna.”
SpaceFlight Insider: Like the antennas on LADEE?
Vrotsos: “You would need something even larger to relay 620 Megahertz.”
Younes: “It depends on the frequency band that you are using. As you go up in frequency, the wavelengths get shorter, so the antenna and hardware shrink.”
“So now we are in the next phase, we have this LCRD effort going on and we are already doing the study to conceptualize the next-generation relay satellite that’s going to benefit from the introduction of these technologies. These include reconfigurable radios and not only are they reconfigurable but they are also smart radios, radios that can adapt. Reconfigurable radios are different than the old way which we built our radios.”
SpaceFlight Insider: So, when you say ‘smart radios’ can you give us a little more information regarding that?
Younes: “Essentially, these are radios that can learn by themselves and then adapt to their environment, based on cognitive science. Because you can study, you can learn and then adapt. You take a child, initially they don’t know certain things and over time they take in information and overtime, especially when you repeat the same information – learning takes place. The same is true for radios and any other type of machine that can be trained.”
SpaceFlight Insider: Is this like artificial intelligence?
Younes: “It’s a step further than the AI, which is kind of linear and rule-based. What we’re doing with the smart radios is not rule-based, there is a kind of non-linear mathematics that enters into the making of the engine that allows it to learn the same way a child may learn. It’s not bound by the knowledge that it was introduced to when it was designed and this allows it to keep on evolving.”
SpaceFlight Insider: Getting back to LCRD on LADEE, can you tell us a bit about future applications?
Younes: “The bandwidth on this system is unlimited, so at a time when we were hurting for spectrum, it provided us with a solution and it also in terms of power, weight, volume that an optical payload can occupy – it is extremely small compared to the RF. So we saw the benefit in this system compared to the old, big communications payloads, that they could replace them with smaller, laser payloads and make room on the spacecraft for additional scientific instruments.”
“They also can benefit from the increased data rate, you know. Before, much of the science was bounded because people were limited by the amount of bandwidth. Let me provide you with an example. From Mars, we have Curiosity when it landed everyone was enjoying seeing the pictures and we were transmitting at a data rate lower than 6 megabits per second – because that’s the capability that we have now for Mars. Now, imagine if we went to 600 megabits per second – you’re talking streaming video.”
SpaceFlight Insider: Could we see a similar system on NASA’s Mars 2020 rover?
Younes: “Actually, we’re doing a study right now to see of the rover is appropriate for such an application and NASA can get a good return on its investment. So we have been looking for a ride to Mars to evolve a slightly bigger aperture laser payload. So we’re trying to determine if the Mars 2o2o rover is the right place for it or if we should wait for 2022 when we will be talking about an orbiter. The decision will be made based off the performance that we will be getting. If we put it on the orbiter, we’d be able to support all users at a high data rate. If we were to put it on the rover – you can’t benefit from it except for that one particular vehicle. So we are going to wait and see what the study says. If we have a mission in 2022? That’s one that I’m going to fight for to put optical or laser communications on board for a data rate of around or a slightly higher than 100 megabits per second – initially.”
SpaceFlight Insider: What is the applications in terms of NASA’s Orion Multi-Purpose Crew Vehicle or the various commercial efforts the agency is conducting for those missions such as New Horizons which are out beyond the gas giants in the Kuiper Belt?
Younes: “For Orion we still have the traditional capabilities and presently it is configured for that purpose, so when I talked about the testing on LADEE and the future testing on a data relay satellite. This is driven by the need to implement this and to introduce this technology for near-Earth applications. Deep space requirements are a little different than those from near-Earth.”
“I see a huge benefit to the near-Earth community as you are taking the optical, the fiber networks that are on the ground and put it into space. The same capabilities can provide an order of magnitude better performance and capabilities at much lower costs. All of these things entered into our consideration as we looked into how to evolve the capabilities. Now, when you look at the LADEE demonstration which relayed 622 megabits per second from the Moon, imagine a satellite that is in close proximity, then you’re talking orders of magnitude better, higher data rate. We’re talking about 60 to 100 gigabits per second…”
SpaceFlight Insider: How long were we in the period of communications technology prior to the LADEE demonstration?
Younes: “You have to allow for the technology to mature and we reached a point where we were able to deploy it on LADEE. Now, we need to evolve it more. But, you cannot just plug it into some of the systems we currently have, you have to ensure that other supporting systems are configured to use the new technology. Because you need to build the new optical payloads, you need to find the ride, the satellite that is going to carry it and you need to probably modify the technology to optimize it to the environment where it is going to work. While LADEE was good from the Moon to the Earth, you don’t have the problem of locating Earth, you can find it immediately. Now, imagine you are a data relay satellite trying to find a spacecraft that is traveling at 17,000 miles per hour.”
“So, its a different scenario, you benefit by taking what you’ve built and develop it further. In addition to developing the technology that you are developing to put on a data relay satellite. You then need to go to the low-Earth user, a mission in low-Earth-orbit. So we are potentially at looking at the International Space Station to be the host for this next step. If, after the ISS, we can sufficiently demonstrate the capabilities? we would go operational after that.”
SpaceFlight Insider: Okay this is something different than your efforts on Mars?
Younes: “Yes, I’m separating the data relay mission from one conducted in deep space. As I mentioned earlier, in terms of deep space we are still waiting for a ride to evolve the comm payload.”
“Separate from that, I have another effort to test involving the optical communication systems for use around Earth, the Moon, all the way out to two million kilometers away from Earth. The station would be a demo, it has been an excellent laboratory for a lot of different experiments, biological, medical, technology, material, whatever we’ve needed to test. We also use the station to develop communications capabilities. I presently have a test bed on board the space station that is testing all kinds of new protocols, all new wave forms, testing in the Ka-band and it has been returning a lot of good data. Actually we helped the U.S. Air Force fix something that was wrong with their GPS signal, especially the new frequency that they added for civil use. Given that the test bed is already there, the space station is all the more necessary as an environment to move forward. I’m extremely happy that we’ve extended the station’s operations through 2024. I personally see it may be extended further until we have another activity or structure in place to provide us with support.”
SpaceFlight Insider: If there was one thing that you are working on that you feel is the most important for the public to understand?
Younes: “We are really evolving technology to meet future needs and requirements. We are not talking five, ten, fifteen or even twenty years down the road, we are looking decades down the road because you cannot build these systems for the immediate future. These types of infrastructures are costly and we need to make sure that once we put them in place that they can serve us for as long as we need to lower the cost of operation to the agency. I want the public to know that everything we have evolved and everything that will be evolving is not be just for NASA use – everything we do is for the benefit of the taxpayers. When we produce an advanced technology, we transfer it to the commercial sector. In the very-near future the communications sector will be revolutionized by the concepts that I’ve talked about and the capabilities that we are building. And we are not alone at NASA, we work with other agencies – piggybacking on each other’s investment because recently the budget has been a little constrained, but we did not let this constrain our work, you know. We started to rely more and more on each other’s activities. You do block “A” and I will do block “B” and then, you know, this is how it’s going on. We are advancing and working for NASA is a rewarding career because it is the only place where you can build and realize your dreams. Not matter what your dreams are, within the agency there are all kinds of disciplines and specialties.”
SpaceFlight Insider: Indeed, Mr. Younes, we know you are a very busy man, so please accept our thanks for sitting down and chatting with us about NASA’s space communications efforts.
Younes: “You’re very welcome, enjoy the launch!”
Badri Younes is NASA’s Deputy Associate Administrator for Space Communications and Navigation (SCaN). He oversees the agency’s space communications and navigation program elements. The SCAN Program Office is located at NASA’s Headquarters in Washington D.C. All of the space agency’s communications, navigation efforts to include NASA’s Space Network (SN), Near-Earth Network (NEN), and Deep Space Network (DSN) fall under his purview. One of Younes primary focuses is the development of new communications technologies which are viewed as being vital to the agency’s space exploration efforts.
Jason Rhian spent several years honing his skills with internships at NASA, the National Space Society and other organizations. He has provided content for outlets such as: Aviation Week & Space Technology, Space.com, The Mars Society and Universe Today.