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April Newsletter

Does Space Matter?

Two key technologies required to enable the exploration and exploitation of the solar system are space data communications systems and space vehicle propulsion. While the development of the core communication protocols (Delay & Disruption tolerant Networking (DTN)) is quite robust, deployment and planned adoption is essentially limited to space agency missions to earth orbit and the planned Lunar Gateway and LunaNet. NASA is committed to using DTN for manned missions to Mars, but other than some high-level architecture papers, there are no concrete plans for the development of the proposed Solar System Internet (SSI). That is somewhat understandable, given the natural conservatism of space agencies and the uncertainty of long-range planning when a changeable Congress holds the budget strings.

In fact, there are many reasons for optimism about the future of DTN:

  • The IETF DTN Working Group is slowly but surely cranking out DTN standards
  • CCSDS is concomitantly cranking out Blue Books (recommended standards for civilian space flight)
  • DTN is used for some comms on ISS
  • NASA is committed to DTN for Lunar Gateway and LunaNet (after some initial hesitancy—as recently as mid 2019 they were planning to use TCP/IP)
  • NASA/JPL continues to publish updates to ION (NASA’s implementation of the Bundle Protocols)
  • Commercialization of space is coming fast– YET… adoption is slow…
    • It’s mostly all about TCP/IP for now

Need for DTN as fx of distanceThe reason for this bullet can be explained by the graphic to the left: it’s all about where business investments are now and how those regions of space are affected by delay. The vast majority of even planned commercial use of space is concentrated within Low and Medium Earth Orbit (LEO & MEO) satellites—within the green circle. There is no significant delay here and current terrestrial communication protocols (like TCP/IP) work just fine. “If it ain’t broke, don’t fix it!”

The next major commercial thrust will be in cislunar space. That’s the region generally enclosed by the yellow ellipse in the graphic. Here, TCP/IP kinda sorta works, and given the NRCO orbit of the Lunar Gateway, which never loses LOS with Earth, NASA was originally tempted to use it. We wrote about this back in 2019, urging NASA to use DTN instead for a variety of reasons. Doubtless for reasons other than our blog posting, NASA decided to deploy DTN on Lunar Gateway and LunaNet. We assume that commercial entities involved in the initial business endeavors on the moon will therefore be using DTN.

The third region (depicted by the open-ended red ellipse in the graphic) is where the delay becomes so great that TCP definitely breaks. DTN will not be optional. But no one besides space agencies is doing anything out here. Yet.

The draw to exploit this region will be irresistible. “The first trillionaires will be those who mine in space”—Neal Degrasse Tyson. Forbes magazine, Bloomberg News and other pundits are predicting that commercialization of space—particularly Near Earth Asteroids (NEA’s) represents a huge business opportunity. Some go even further, saying that our ability to mine Technology-Critical Elements (TCE’s) from space is critical to the very survival of our increasingly technology-dependent civilization.

TCE’s are a group of about 35 elements (about 17 Rare Earth elements, 6 platinum group elements and another 12 “assorted” elements). They are critical to emerging technologies either because of their rarity (as in “Rare Earth Elements”) a striking increase in demand, or both. An example would be tantalum, which is required for the manufacture of capacitors and resistors contained in most electronic devices. A small number of asteroids are expected to be significant sources of these rare (on earth) elements particularly the platinum group elements. Their high value-to-mass ratio may make it worthwhile to transport them back to earth.

DTN is an established technology waiting for adoption by the emerging space industries (and buildout of required infrastructure). There is another arena where development is needed in order to support the opportunities for expanded exploration and exploitation of space: improved propulsion systems for space vehicles. There have been drastic improvements in the cost per pound of boosting satellites into orbit. That has been coupled with the miniaturization of satellites themselves to make Cube Sats available to small businesses and graduate students alike.

Sat V payload ratio

But conventional rockets are still really inefficient in terms of the amount of fuel required to put payload into orbit. This is typically expressed in terms of Payload Fraction (what percentage of the entire spacecraft launch weight does the payload represent?). While some newer platforms represent substantial improvements, most haven’t improved much since the days of the Apollo missions. Case in point: the Payload Fraction for the Space-X Starship (4.3%) is only slightly better than the Saturn V (5.3%) to boost payload into Earth orbit. However, the Payload Fraction for the Saturn V dropped to less than 1.5% when boosting to escape velocity. As the photo at left shows, even the most powerful rockets are metal tubes of mostly fuel…

There are a number of small companies involved in potentially game-changing development work on technologies like Nuclear Thermal Rockets, solar wind sails and others that can vastly improve Payload Fraction, reduce fuel costs as well as reduce travel times to Jupiter and beyond. There is an excellent webinar produced by Space Matters available on YouTube with representatives from a number of these companies discussing the technologies involved as well as the challenges to overcome. It is available for viewing at: They are a relatively new YouTube Channel, but seem to be producing several videos a month. They also have a profile of astronaut Story Musgrave and another webinar on space policy. Check them out!


PNT in Space

2021-04-27_6-52-22IPNSIG Board Member Dr. Alberto Montilla has recently written an article entitled “Positioning, Navigation and Timing (PNT) in space”. It’s available at:

Alberto explains the basics of PNT and explains how the GPS and other PNT systems provide this service to devices like your cell phone on the earth’s surface. On the moon, PNT becomes even more critical than on earth. The lack of recognizable landmarks can make even short distance navigation hazardous (ask the Apollo 14 astronauts who almost got lost during their EVA). So NASA intends to provide PNT services as part of its LunaNet deployment on the moon. In order to leverage existing infrastructure and overcome technical challenges in extending PNT services to the moon, NASA and other agencies have been working to extend this range by taking advantage of a radiation pattern effect: the side lobe coverage.

Beyond that, NASA has been working on ways to provide PNT services to spacecraft in deep space. This required the development of highly miniaturized atomic clocks which could be launched into space. For more details on this fascinating topic, read Alberto’s article.

Hubble Telescope Spacecraft Webinar

2021-04-10_21-19-37 Hubble WebinarThe Silicon Valley Technology History Committee and IEEE LMAG will be presenting a free webinar on the Hubble Telescope Spacecraft Tuesday, April 20, 2021, from 1:30 p.m. – 3:00 p.m. PDT. Attendance is free, but you must register to attend. You may register here.

More information about the event, including a detailed abstract and speaker bios, can be viewed here.


March Board Meeting Summary

The IPNSIG Board met last Thursday, 18-Mar-2021. We wanted to update our members about that meeting and the major items discussed and decisions reached.

1) The Board decided to apply for Chapter status within ISOC later this year. The decision was made to further expand and broaden the impact of IPNSIG activities as a standing ISOC chapter. Time frame for the application process to start is probably the beginning of the third quarter. No action will be required of current members. If our application is approved, current SIG members will become Chapter members.

2) The Board confirmed that we will complete filing with the State of California and the United States Internal Revenue Service to establish our 501(c)3 nonprofit corporation status. This will greatly facilitate fund raising and is a requirement for Chapter formation.
3) The Board confirmed earlier discussions that we will continue to coordinate and assist in organizing the annual STINT Workshops. If you recall, we helped STINT last year in securing speakers for its annual workshop and in marketing the event.

4) Kaneko updated the board regarding early planning for a Projects Working Group (PWG) Workshop to be conducted as a webinar, which is to be conducted jointly with the Strategy Working Group (SWG).  Stay tuned for more information

Thanks for your continued participation and support.


Artist_s_impression_of_OPS-SAT_articleOPS-SAT is a CubeSat (small form factor satellite based upon 10CM cube-shaped modules) launched by the European Space Agency (ESA) late in 2019. Its mission: demonstrate improvements in mission control capabilities based on a cheaper, more capable (in terms of computing power) satellite platform. Even though only a 3U CubeSat measuring (exclusive of solar panels) only 96 mm × 96 mm × 290 mm (3.8 in × 3.8 in × 11.4 in) and weighing in at only 7 kg (15.4 lbs.), OPS-SAT  delivers impressive capabilities: its experimental computer is 10X more powerful than any current ESA spacecraft.

Such computational power in such a tiny package enables a lot of innovation. Space agencies have traditionally been relatively conservative when it comes to the pace of innovation, This is understandable: space vehicles and missions are expensive to plan and deploy. During the Space Shuttle era, the average NASA mission cost was $450M. This has rapidly decreased over the last 13 years. Cost per pound to put something into orbit was $10K then. Today, SpaceX is advertising $2.5K per pound.


OPS-SATsizeAs can be seen from the image at the left, OPS-SAT is really small, making it feasible to share the cost of boosting a satellite into space with many other users, substantially reducing mission costs. More specifically, tiny satellites like OPS-SAT represent much less financial risk. Larger ESA satellites can cost up to €60M to put in orbit. OPS-SAT cost only €1.4M.

Beyond lower financial risk, OPS-SAT is so robust, it can literally be rebooted if necessary to recover from an error. It’s actually a satellite within a satellite. Control can be swapped between the two and they monitor each other. This degree of robustness allows real time experimentation on critical control functions during flight.

7 years in development, it’s the first nanosatellite to be directly owned by ESA and controlled by ESA/ESOC. Its high-powered 800 MHz processor allows “normal” software (Linux, JAVA, and Python) to control the satellite. Firmware can also be upgraded during flight.

OPS-SAT’s uplink is 4 xs higher than any other ESA spacecraft. Uplinks of up to 50 mb/sec are possible on RF links. It has a laser receiver, which should be capable of even higher uplink and downlink speeds.

It’s also designed to be open in order to encourage innovation. Experiment uploads were encouraged for corporations, academic institutions and even individuals. More information about registering to become a part of the OPS-SAT community and for instructions about how to submit software for approved registration is available at: Further information about testing, uploading and running software are also available there. Experimentation on OPS-SAT is available at no cost until November, 2021.

The OPS-SAT program is innovative in both its approach to satellite hardware AND it’s organization to encourage innovation by many stakeholders. As of mid-December, 2020, 153 experiments had been registered with the OPS-SAT community.

We will continue looking into the OPS-SAT program by looking at one of its first successful experiments involving DTN. We’ll follow that with a profile of the company behind that experiment: D3TN. More coming soon…

Some short, introductory YouTube videos:



IPNSIG Newsletter March, 2021

iPNSIG logo white backgroundAmong the key advantages that led to the emergence of the TCP/IP protocol suite as the foundation of the Internet architecture was publication of the TCP/IP specifications as fully open standards, which could be implemented by anybody.  Proprietary networking architectures such as IBM’s Systems Network Architecture (SNA), Digital Equipment’s DECnet, and the Xerox Network Systems (XNS) framework lent themselves less easily to widespread adoption.

In the Interplanetary Networking community we are trying hard to replicate that success by establishing universally available open Delay-Tolerant Networking standards.  We hope to encourage a wide range of interoperable protocol implementations that can address all the use cases that anyone can think of.

So far, progress is encouraging.  Among the implementations of Bundle Protocol that we know of are:

  • DTN2, the original reference implementation, developed largely by Mike Demmer at UC Berkeley.
  • DTN2’s lineal descendant DTNME, currently in use for International Space Station (ISS) operations and maintained by NASA’s Marshall Space Flight Center.
  • ION, likewise in use for ISS operations, developed and maintained mainly at NASA’s Jet Propulsion Laboratory.
  • cFS BPlib, soon to fly on the PACE mission, developed and maintained at NASA’s Goddard Space Flight Center.
  • An implementation developed by the European Space Agency (ESA).
  • IBR-DTN, developed at Technische Universität Braunschweig.
  • uPCN, developed by D3TN GmbH, Dresden.
  • HDTN, a high-speed implementation developed at NASA’s Glenn Research Center.
  • PyDTN, written in Python X-Works.
  • Experimental implementations written in Java, Go, and Rust.

More important than the number and variety of implementations, though, is the demonstrated interoperability of those implementations.  Interoperation venues have ranged from the informal, as in the uPCN/PyDTN interoperability testing performed at the IETF 101 Hackathon, to the operational, as in the ION/DTNME-based architecture supporting ISS and the ION/BPlib framework supporting PACE.

In January an international team executed an especially gratifying testbed demonstration, in preparation for a planned interoperation experiment that will include Lunar Ice Cube mission communications.  The testbed included:

  • One DTN node running cFS BPlib, emulating the Lunar Ice Cube spacecraft.
  • One DTN node running ION, emulating the Lunar Ice Cube mission operations center.
  • One DTN node running ESA’s implementation of BP, emulating an ESA ground station, which forwarded bundles between the other two nodes.

The cFS BPlib code base does not include an implementation of Licklider Transmission Protocol, instead relying on Aggregate Custody Signaling (ACS) for reliability in bundle transmission.  However, the ESA BP implementation does not include an implementation of ACS; instead, the ION node closes the custody transfer loop with the emulated spacecraft, with the ESA node forwarding bundles from the ION node including the aggregate custody signals.

This may be the first demonstration of sustainable Solar System Internet architecture, relying on the interoperability of different BP implementations developed by different national space agencies.  We think it won’t be the last.

Executive summary of the IPNSIG Strategy Workshop


WS images


The IPNSIG Strategy Working Group (SWG) carried out a workshop on How can we build a sustainable IPN? on Feb. 22nd.

For the first time in history, high level strategic principles and the strategic approaches to guide the deployment of a Solar System Internet (SSI) driven by the Inter-Planetary Networking technology has been discussed with 85 participants from 10 nations across the globe.

Thanks to every IPNSIG community member who attended, and with your inputs, we are now halfway on our road to deliver a Strategy Report on how to deliver an SSI.

Link to recorded session:

Workshop slides can be viewed here.

At the workshop, the SWG presented their vision on how the SSI architecture or its operation model could change over time in the 30 to 100 years and shared their views on the key principles that would support the evolution of it.

The SWG introduced the key principles that include Collaboration, Global Standards, Stability, Democracy, Affordability, Expandability and Security.

As the construct of SSI is a human endeavor, the SWG presented their strategic approaches on the concept of vision sharing, co-creation, risk sharing and pooling & sharing to be put in place by the public and the private sectors.

Excellent views were shared by the participants:

  • Global standards are the enablers to cultivate business cases and eventually an ecosystem by the commercial sector.
  • Entities who provides funds to build SSI may have control over the Global standards.
  • Cultivating public interest is significant and will be a strong thrust to realize our endeavors in SSI.

IPNSIG will be planning for more workshops in the future.


STINT Workshop at IEEE SMC-IT – Call For Papers, Talks, and Topics

Dear IPNSIG community,
This is a kind invitation to the 8th International Workshop on Space-Terrestrial Internetworking (STINT Workshop 2021). (We apologize for possible double posting.)STINT is a perfect venue for publishing related studies and catching up with latest advances in general, theoretical problems as well as specific, practical aspects in the context of space-terrestrial networking.

This edition will be held at the IEEE SMC-IT 2021, occurring in full on-line mode on July 27-29, 2020, and will include three distinct sessions:
* Paper session: accepted full-papers will be published in IEEEXplore (deadline has been extended from Feb 28th to March 15th!!!).
* Invited talk session: experts in selected topics will share latest updates/demonstrations.
* Discussion session: live debate with audience participation on related hypotheses.

Important dates:
- Paper submission deadline: February 28 March 15, 2021
- Paper notification: April 3, 2021
- Invited talk proposal deadline: May 1, 2021
- Discussion topic proposal deadline: May 1, 2021
- Paper camera ready: May 7, 2021
- STINT Workshop: July 27-29, 2020

More details at the STINT website:

Best regards,

STINT Steering chairs
* Juan A. Fraire (CONICET, SaarUni)
* Marius Feldmann (TUD)
* Edward J. Birrane (APL)
* Scott C. Burleigh (JPL-NASA)

Technical Documentation Working Group Announcement

IPNSIG Logo starfield

We are pleased to announce the membership of our Technical Documentation Work Group:

Work Group Lead:  Scott Burleigh

Work Group Members:   Laura Chappell, Henry Danielson, Daniel Kalemi, Scott Landman, Ben Scott, Ginny Spicer

The Work Group has begun meeting and is making progress toward organizing IPN information resources into an easily accessible online library.  Watch for announcements as we begin compiling this highly heterogenous digital reference.


Last Minute Reminder: IPNSIG Workshop

Reminder: Workshop: How to build a sustainable IPN? Coming very soon! (read: next Monday 22-Feb-2021)

Follow the link below for early registration, as places are limited to 300 active participants.


For more information, read the full post:

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