Space Technology – #36

Space requires new technologies. Much like the space race of the 1950s, engineers are feverishly working to gain a competitive advantage. Mark Lombardi sits down to explore rad hardening, thermal vacuum chambers, space mining, CubeSats, and battery technology.

Hosted by Daniel Bogdanoff and Mike Hoffman, EEs Talk Tech is a twice-monthly engineering podcast discussing tech trends and industry news from an electrical engineer’s perspective.

Space requires new technologies. Much like the space race of the 1950s, engineers are feverishly working to gain a competitive advantage. Mark Lombardi sits down to explore rad hardening, thermal vacuum chambers, space mining, CubeSats, and battery technology.

 

Mark Lombardi – 25 years at HP/Agilent/Keysight. He worked for RT logic for a few years, where he got into space.

2:00 – Your odds of survival getting to space are better than getting to the top of Everest.

2:30 – Space mining from the Asteroid belt has the potential to create the worlds first trillionaire.

3:20 – We need to establish manufacturing in space. For example, what if you manufactured satellites on the moon instead of on earth?

4:00 – The main driver is price-per-pound

6:10 – The Space Force – it sounds a little silly at first but is very reasonable when you take a closer look.

7:45 – How do you test objects bound for space?

8:30 – Space is transitioning from government-only to commercial. Businesses are starting to explore how to add value to society and make a profit from space.

9:15 – Phased arrays, reusable rockets, LEO satellites are all changing space technology.

10:00 – Low earth orbit satellites have much lower delay. Geosynchronous satellites have a 250 ms propagation delay.

This has interesting implications for 5G – that 250 ms latency is too long for 5G requirements. So, LEO satellites are what will be used.

12:00 – Using LEO satellites will be deployed in force instead of as singles, as mentioned in the Weather Cubesat podcast.

13:45 – Ghana launched their own satellite, which is a huge step. They eventually won’t be dependent on others for their space access. And, they can do specialized things for reasonable prices.

15:00 – Announcements – we haven’t podcasted in a long time, sorry! We are switching to 1x per month

16:45 – Radiation hardening for electronics, sometimes called electronics hardening. Historically, you had to plan for a long life in a satellite. Now, you don’t have to.

17:30 – It’s also hard to get a rad hardened cutting-edge technology.

18:00 – LEO satellites get less radiation, so it’s less of a problem. And, since they are cheaper, you can build in an expected mortality rate.

19:00 – You can also rev hardware faster, allowing you to use newer technology. Think about imagers, the technology has moved a long way in seven years.

19:55 – Space is cold. Space is a vacuum. So, to test our gear you have to reproduce that on earth. To do that, we use special chambers.

20:50 – Thermal vacuum chambers (T vac) are used to test space objects. Automotive parts are actually very resilient to temperature changes and can be leveraged into space designs.

21:30 – What happens to electronics in space? The vacuum is a bigger challenge than the temperature changes.

23:30 – To get more bandwidth, we have to increase frequency. This leads to attenuation in the air and in cables. Some designers are switching to waveguides.

25:00 – With modular test equipment, you could potentially have test gear that can survive in space.

27:00 – What is the current and projected size of the space industry?

28:10 – What batteries are used in space? What factors into battery decisions? – Lithium ion batteries work well in space, and are used when we can charge them with solar energy.

28:40 – Deep space exploration uses all sorts of obscure battery technology.

29:10 – Electronic propulsion

30:05 – Over 150V, things get interesting. The breakdown voltage is different in space than it is on earth. So, designers have to be very careful.

Weather CubeSats – #30

We have surprisingly little knowledge of weather. When specifically does a cloud rain? How do these clouds form? We don’t have good answers to these questions. Getting those answers is an electrical engineering problem – one that a handful of professors and NASA are solving with CubeSats.

Historically, we’ve used large satellites and ground-based systems to track weather patterns, but CubeSat arrays are becoming a viable option. In this episode, Daniel Bogdanoff sits down with the leading researchers in this area to hear about the challenges and advancements being made in this area.

We have surprisingly little knowledge of weather. When specifically does a cloud rain? How do these clouds form? We don’t have good answers to these questions. Getting those answers is an electrical engineering problem – one that a handful of professors and NASA are solving with CubeSats.

Historically, we’ve used large satellites and ground-based systems to track weather patterns, but CubeSat arrays are becoming a viable option. In this episode, Daniel Bogdanoff sits down with the leading researchers in this area to hear about the challenges and advancements being made in this area.

Interviewees:

Charles Norton – JPL Engineering and Science Directorate POC
Joel T Johnson – ECE Department Chair and Professor at The Ohio State University
Christopher Ball – Research Scientist at The Ohio State University
Dr. V. Chandrasekar (Chandra) – ECE Professor at Colorado State University
Eva Peral – Radar Digital Systems Group Supervisor at JPL

Agenda

Intro

Space is changing. Big, expensive satellites used to be our only option. But, as you’ve probably heard on this podcast, when it comes to technology the world is always shrinking – and satellites are no exception. And that’s what we’re exploring today, specifically, the way cubesats (miniature satellites) are revolutionizing the way we look at earth’s weather.

Hi, my name is Daniel Bogdanoff, and welcome to EEs Talk Tech. In our last episode, I brought you all along with me to Wallops flight facility in Virginia for a rocket launch. It was an eye-opening experience for me, and I wanted to cover more than was reasonable for a single episode. So today, we’re blending the style of last episode and our standard interview-style podcast. I sat down with some EE professors from Ohio State University and Colorado State University to talk about their cube sat projects – all of which monitor weather using radiometers or radar and are pretty high tech.

I also apologize in advance for the background noise during the interviews, I’ve done the best I can to minimize the noise and voiceover parts I feel are hard to hear. I’ve also used clips from their NASA TV presentations wherever possible.

Let’s get started, and hear a little bit about the advantages of CubeSats from Charles Norton.

Advantages of CubeSats [1:05]

Cubesats are nice not just because they’re cheaper and smaller. Thanks to the miniaturization of new technologies in both their physical size and their power consumption, we can deploy more systems, more rapidly, and at a lower cost. They also require smaller teams to develop and operate, and can even have higher measurement accuracy than existing assets.

CubeRRT [3:51]

At its core, CubeRRT is all about making radiometry measurements better by processing out man made emissions – leaving only the earth’s natural emissions.

From NASA: “Microwave radiometers provide important data for Earth science investigations, such as soil moisture, atmospheric water vapor, sea surface temperature and sea surface winds. Man-made radiofrequency interference (RFI) reduces the accuracy of microwave radiometer data, thus the CubeSat Radiometer Radio Frequency Interference Technology Validation (CubeRRT) mission demonstrates technologies to detect and remove these unwanted RFI signals. Successful completion of the CubeRRT mission demonstrates that RFI processing is feasible in space, high volumes of data may be processed aboard a satellite, and that future satellite-based radiometers may utilize RFI mitigation.”

TEMPEST-D [8:00]

Instead of having a big satellite sitting in geosynchronous orbit, an array of CubeSats can be put in orbit such that they each pass over the same spot at set intervals. With some careful calibration, differences in the measurement equipment gets normalized out and they get good weather data.

From JPL: “TEMPEST-D is a technology demonstration mission to enable millimeter wave radiometer technologies on a low-cost, short development schedule. The mission … reduces the risk, cost, and development duration for a future TEMPEST mission, which would provide the first ever temporal observations of cloud and precipitation processes on a global scale.  For TEMPEST-D, JPL developed a mm-wave radiometer payload that operates at five channels from 89 to 182 GHz and fits in a 4U volume within the 6U CubeSat.”

RainCube [11:47] & the Origami Antenna

From JPL: “RainCube (Radar in a CubeSat) is a technology demonstration mission to enable Ka-band precipitation radar technologies on a low-cost, quick-turnaround platform. RainCube developed a 35.75 GHz radar payload to operate within the 6U CubeSat form factor. This mission will validate a new architecture for Ka-band radars and an ultra-compact lightweight deployable Ka-band antenna in a space environment to raise the technology readiness level (TRL) of the radar and antenna from 4 to 7 within the three year life of the program. RainCube will also demonstrate the feasibility of a radar payload on a CubeSat platform.”

Foldable Antenna [12:20]

1.5U volume, Ka-band 35.75 GHz RADAR antenna.

Why Measure Weather from Space? [15:00]

These are just a few of the cubesat projects that went up on the OA9 rocket launch. To hear more about that, check out EEs Talk Tech electrical engineering podcast episode #29 – The Long Road to Space.

 

Radar and Electronic Warfare

Learn about radar basics and get a peek into the world of aerospace electronic warfare. Hosted by Daniel Bogdanoff and Mike Hoffman, EEs Talk Tech is a twice-monthly engineering podcast discussing tech trends and industry news from an electrical engineer’s perspective.

Phil Gresock, Keysight’s Radar Lead, sits down with us to discuss the basics of radar and give us a peek into the world of aerospace electronic warfare.

Agenda:

00:20 Adaptive cruise control for cars works really well.

1:00 the history of radar – the original radar display was an oscilloscope in WWII. (radar test equipment)

http://www.pearl-harbor.com/georgeelliott/scope.html

1:45 Early warning radar

2:00 The rumor that carrots are good for your eyesight was a British misinformation campaign.

2:58 The British had the “chain home radar system” all along the coast that pointed to their western front. They wanted early warning radar because they had limited defensive forces. By knowing what was coming, they could allocate defenses appropriately.

3:45 Radar originally was a defensive mechanism.

3:50 How does radar work? You send out a pulse that is modulated on a carrier frequency. If that pulse gets reflected back, we can do some math and work out how far away something is.

4:30 Typically, there’s a specific frequency used. For long range radar, like search and early warning radar, a lower frequency is used.

5:15 What does a modern radar system look like?

It depends on the application. Early warning systems are often anchored on old oil rigs. The rigs have a radome installed on them.

6:25 How does radar detect something so small and so far away? A lot of it depends on the frequencies and processing techniques you use.

6:40 There are some radar techniques you can use, for example bouncing off of the sea, the earth, the troposphere.

7:15 Radar also has some navigational benefits. For example, wind shear flying into Breckenridge airport. A change in medium is measurable.

8:10 Radars also get installed on missiles to do some last-minute corrections.

8:35 Ultimately, the goal of radar is to detect something. You’re trying to figure out range, elevation (azimuth), velocity, etc.

Different target sizes and ranges require different pulse widths, different frequencies, etc.

Azimuth is easy to determine because you know what direction your radar is pointing.

To detect velocity with radar you can use doppler shift.

10:30 Radar cross section analysis gives even more information.

11:00 There are spheres in space for radar calibration. You can send pulses to the sphere and measure what you get back.

Radar calibration sphere in low earth orbit:
http://www.dtic.mil/docs/citations/ADA532032 (for full paper, click the “full text” link)

11:40 There are also reflectors on the moon so you can use laser telescopes to measure the reflection.

Mirrors on the moon:
https://en.wikipedia.org/wiki/Lunar_Laser_Ranging_experiment

12:30 NASA put reflectors in space.

12:58 So, you send a pulse out and get a return signal, but there was a scattering effect. There are libraries for what a return pulse for different objects looks like so you can identify what you are looking at.

14:00 Radar counter intelligence techniques.

First, you have to know you are being painted by radar. Military jets have a number of antennas all around it. And, you generally know what radars are being used in a theater of operation. So, there will be a warning that will let you know you are being painted by a certain type of radar.

15:30 Get Daniel on a fighter jet

16:05 How do you stop your radar from being detected or interfered with? There are a few techniques.

Radar frequency hopping is changing the frequency used from pulse to pulse.

Radar frequency modulation changes the modulation pulse to pulse – phase shifts, amplitude changes, frequency chirps, etc.

This helps avoid detection, get better performance, or reduce susceptibility to jamming.

If you know how your radar responds to different signals, you have a lot of flexibility in what signal you use.

How do you spoof a radar? You have to know what is incident upon you and know how that will act over time. You can send out pulses advanced or lagging in time or with different Doppler shifts to give misinformation to the receiver.

You can also drown out the pulses so that your pulses get read instead of your reflections.

You have to have an intimate understanding of the radar you’re trying to defeat, a good system to handle that quickly, and good knowledge that something is actually happening.

We need radar profile flash cards.

Radar peak energies are anywhere from kilowatts to Megawatts.

21:10 A recent US Navy ship had a new hull design, and it has to turn on a beacon because it had so little reflections.

https://www.forbes.com/sites/niallmccarthy/2016/10/14/some-of-the-numbers-behind-the-u-s-navys-new-zumwalt-class-destroyer-infographic/#da435a170597

22:00 Phil thinks radars are pretty cool, and it shows up in a lot more places than you’d expect.

Radar stands for “radio detection and ranging.”

 

Intro to RF – EEs Talk Tech Electrical Engineering Podcast #21

Learn about RF designs, radio frequencies, RADAR, GPS, and RF terms you need to know in today’s electrical engineering podcast!

We sit down with Phil Gresock to talk about the basics of RF for “DC plebians.” Learn about RF designs, radio frequencies, RADAR, GPS, and RF terms you need to know in today’s electrical engineering podcast!

 

Agenda:

RF stands for radio frequency

00:40 Phil Gresock was an RF application engineer

1:15 Everything is time domain, but a lot of RF testing tools end up being frequency domain oriented

2:15 Think about radio, for example. A tall radio tower isn’t actually one big antenna!

3:50 Check out the FCC spectrum allocation chart

4:10 RF communication is useful when we want to communicate and it doesn’t make sense to run a cable to what we’re communicating to.

4:50 When you tune your radio to a frequency, you are tuning to a center frequency. The center frequency is then down converted into a range

6:30 Check out Mike’s blog on how signal modulation works:

7:00 Communication is just one use case. RADAR also is an RF application.

8:10 The principles between RF and DC or digital use models are very similar, but the words we use tend to be different.

Bandwidth for oscilloscopes means DC to a frequency, but for RF it means the analysis bandwidth around a center frequency

9:22 Cellular and FCC allocation chart will talk about different “channels.”

Channel in the RF world refers to frequency ranges, but in the DC domain it typically refers to a specific input.

10:25 Basic RF block diagram:

First, there’s an input from an FPGA or data creating device. Then, the signal gets mixed with a local oscillator (LO). That then connects to a transmission medium, like a fiber optic cable or through the air.

Cable TV is an RF signal that is cabled, not wireless.

Then, the transmitted signal connects to an RF downcoverter, which is basically another mixer, and that gets fed into a processing block.

13:50 Tesla created a remote control boat and pretended it was voice controlled.

15:30 Does the military arena influence consumer electronics, or does the consumer electronics industry influence military technology?

16:00 GPS is a great example of military tech moving to consumer electronics

17:00 IoT (internet of things) is also driving a lot of the technology

18:00 The ISM band is unregulated!

19:15 A router uses a regulated frequency and hops off the frequency when it’s being used for emergency communications

20:50 RADAR, how does it work?

22:22 To learn more about RF, check out App Note 150 here:

http://www.keysight.com/main/editorial.jspx?cc=US&lc=eng&ckey=459160&id=459160&cmpid=zzfindappnote150