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Sail Deployment: Reflections on LightSail 2

One thing that James E. Webb insisted on during his tenure as NASA administrator was that the space program was larger than an attempt to get humans to the Moon. The man who did so much to ensure that Apollo would succeed, and who will be rightfully honored in the form of the James Webb Space Telescope, was a proponent of exploration throughout the Solar System through robotic craft, and weather and communications satellites that would become part of a permanent reliance on a growing space infrastructure. Marc Millis noted some of the results in his recent essay.

For while the frustration of abandoning the Moon in the 1970s lingers, we do have over 4600 spacecraft in Earth orbit, many of them doing the kind of work Webb envisioned. We’ve completed the initial reconnaissance of the Solar System and made our first tentative ventures into the Kuiper Belt and out past the heliopause. We’re charting exoplanets and looking to explore Saturn’s largest moon. So these are things to keep in mind when frustration begins to build.

The anniversary of Apollo’s first landing was a time for looking back, but The Planetary Society has just reminded us that we have to keep looking ahead as well. With the successful deployment of the solar sail aboard LightSail 2, we are seeing the kind of change Millis talked about in action. Much of the space business has turned commercial, while we continue to sort out how to handle the change (SLS or Falcon Heavy?), and in the midst of this, private organizations using off-the-shelf hardware can produce crowd-funded missions of real value.

We’re in that confusing time — one that future historians will be able to sort out more readily than we can define it today — when the pace of technological change drives new models for the accomplishment of grand goals. How we interrelate big government projects with corporate space activities and private contributions will define an era that will one day have its own name, just as the 1960s could be partially defined by the term ‘Space Race.’ And it’s understandable that Planetary Society CEO Bill Nye should be proud of what his organization has accomplished: “We are advancing space science and exploration,” says Nye. “We are democratizing space. We are innovating.”

Apollo 8 gave us gorgeous photographs of our planet seen entire, a blue and brown crystal filling the frame. Now we have LightSail 2’s view of Earth, showing vast portions of the Pacific Ocean and part of the North American landmass. CubeSats in their various configurations make it possible for organizations like The Planetary Society as well as universities and other private groups to contemplate missions that move the ball forward. In the case of LightSail 2, we will have learned more about sail deployment, and orbit raising by the pressure of sunlight alone.

Image: This image of Earth, which shows the Pacific Ocean with Baja California and Mexico on the right, was captured by LightSail 2 on 18 July 2019 at 21:45 UTC while the spacecraft was in range of its ground station at Cal Poly San Luis Obispo in California. Though LightSail 2’s altitude is only 720 kilometers, its 185-degree, wide-angle camera lenses allow it to capture horizon-to-horizon Earth imagery. Credit: The Planetary Society.

The deployment command to LightSail 2 went out at about 1445 EDT (1845 UTC) on the 23rd, with the momentum wheel, responsible for orienting the sail in relation to the Sun, spinning up successfully. Now we wait for images of the deployed sail, which should be downloaded today.

Here’s a photo of the LightSail 2 team set up for sail deployment. It’s impossible to ignore the contrast between the Mission Control operations we see at NASA (think of the operation Chris Kraft ran!) and the ad hoc effort at Cal Poly. What makes this possible is vision, public financial support and technology trends working in favor of small, light spacecraft, not to mention gritty persistence. I’ll feel better when I’ve seen actual sail images, but for right now, things look good, and the entire Planetary Society team deserves our congratulations.

Image: This image shows The Planetary Society’s LightSail 2 team on console prior to sail deployment on 23 July 2019 at the Cal Poly CubeSat lab in San Luis Obispo, California. From left: Barbara Plante, Founder and President, Boreal Space; Alex Diaz, Avionics Engineer, Ecliptic Enterprises Corporation; John Bellardo, Associate Professor, Cal Poly San Luis Obispo; Dave Spencer, LightSail Project Manager, Associate Professor at Purdue University; Bruce Betts, LightSail Program Manager, Planetary Society Chief Scientist. Credit: The Planetary Society.

You can track LightSail 2’s condition on its own Mission Control page, which offers data on temperature, degree of rotation, control mode and location over the Earth. 40,000 private donations (totalling in the region of $7 million) went into LightSail 2 over 10 years. The results of the effort will also feed a NASA project called Near Earth Asteroid Scout, which will likewise employ CubeSat technology to visit an asteroid early in the 2020s. Launched by a Falcon Heavy, LightSail 2 emphasizes today’s mix of commercial, corporate and private effort.

I fall back on what Marc Millis said in these pages on Monday:

It is my hope that progress will continue along all these fronts and improve the human condition. The next steps toward the Moon, Mars and recreational spaceflight will usher in a new era, a suitable name for which will probably be conceived years later. It’s certainly no longer a “space race” with only one finish line. It is the beginning of a new stage of humanity.

{ 19 comments… add one }
  • Mike Serfas July 24, 2019, 10:19

    What a beautifully disturbing globe! By imaging a wider angle than the eye, Lightsail 2 stunningly reminds us that despite the appearances, we never really view half of a planet or moon from a single point.

  • Alex Tolley July 24, 2019, 12:53

    The scene of the engineers at their laptops is a great counterpoint to the Apollo Mission Control, although not that much different from that of other satellite and robotic rover control centers. However, what is evident is how far behind space communication systems are from terrestrial ones. If Lightsail 2 had been operating close to teh ground, using WiFi or cellular communication, tracking and control could have been managed by connecting to the crafts web server. But in orbit, tracking requires a lot more expensive hardware such as radio telescope tracking and receiving of the signals.

    To truly “democratize space” we really need a space-based internet and communication infrastructure. This will allow control of spacecraft from computers anywhere on the planet, at a vanishingly low cost. Think of this as the much-vaunted “internet of things (IoT)” extended into space.

    These are early days for such space experiments. May LightSail 2 prove a great success, and perhaps more importantly, inspire many others to think about attempting something new in space.

    • Paul Gilster July 24, 2019, 13:34

      Vint Cerf, who as you know invented TCP/IP and so much of what became the Internet, has been active at JPL and elsewhere on the matter of networking in the Solar System. It becomes essential given how overloaded the current Deep Space Network is, and the need to point a big dish at a tiny target each time you need to acquire a signal. New variants of TCP/IP come into play here, with built in allowance for the delays prompted by distance. We need to be in a place where all the spacecraft operating at a given target are networking their data for transmission back to Earth through a single craft. Early days indeed, but such networking is coming.

    • Alex Tru July 26, 2019, 3:34

      IoT – is very popular abbreviation present days, but there is absolutely nothing new, no absolutely any know-how is hidden behind this term…
      The Same “old” TCP/IP protocol…
      I do not think it is good approach to make connection between IoT and supposed future solar system wide communication network…
      May it will be better to invent the new definition, some extension of World Wide Web to Space Wide Web :-) or similar.

  • Neil Stahl July 24, 2019, 13:34

    The potential future of humanity in space, alone, makes it worthwhile to tackle and manage global warming so that potential can be realized.

    • Antonio July 24, 2019, 14:14

      Huh? What does global warming have to do with humanity in space?

      And what does this missin have to do with humanity in space? Certainly humans will not use lightsails to travel the Solar System. Also, the PS is pretty against the manned space program (for example, for Mars exploration), preferring robots.

      • Neil Stahl July 24, 2019, 18:57

        Global warming can, depending on how far we let it advance, at best damage our economy and at worst end human life. It has a great deal to do with humanity’s future, in space or not.

        • Antonio July 25, 2019, 2:46

          XDD No.

          • Gary Wilson July 25, 2019, 12:29

            You’re absolutely correct Neil. Global warming is an existential threat. If we want to continue to have a habitable planet from which to explore space along with many other things we must stop emitting billions of tons of greenhouse gases each year. This isn’t fantasy or a joke, it’s reality. Pretending otherwise or being in denial won’t help future generations. The scientific evidence is overwhelming and has been for several decades Antonio. Best wishes to you in educating yourself about this crisis.

            • Michael July 25, 2019, 14:17

              We are all allowed our own opinion on the global warming subject, but if it did occur the atmosphere inflates causing satellites to orbitally decay earlier.

              • Parker Shaw July 26, 2019, 14:06

                Michael, isn’t it a good thing to clear the space junk more quickly to ensure a safer human/robot space expansion era?

            • Antonio July 25, 2019, 16:29

              It’s you who needs education. Global warming exists, but thinking that it’s an existencial threat is a joke.

              • Gary Wilson July 26, 2019, 13:28

                Debate about science is a very important part process. I respect your right to an opinion about climate change Antonio. I do encourage people to read peer reviewed climate science literature to help them understand what is happening. Journals such as Science, PNAS and Nature give people access to the important work being done by climate scientists and review articles summarize the recent work of many of these scientists.

  • Robin Datta July 24, 2019, 22:08

    Human bodies did not evolve towards adaptation to survive over multigenerational time in space. “Borrowing” the furs of various animals has compensated for the absence of the needed adaptations to various regions on Earth. Sadly, however, there are no known beings in space that we may “borrow” from their armamentarium to enhance our survival there.

    As long as we identify “humanness” with Homo sapiens (brain) wetware based software intelligence, the human body will perforce be the sine qua non for the human “conquest” of space. If we can transcend that biological imperative by including artificial intelligence as the natural extension beyond human wetware and software, then the exploration of the universe will not be haltered by biology.

    Even habitable worlds can be sought and colonized by humans under the aegis of such artificial intelligence, acting both as master and servant.

  • Ljk July 24, 2019, 23:04

    At last some images of the unfurled sail from Earth orbit…


  • ljk August 2, 2019, 14:11

    Jason Davis

    July 31, 2019

    LightSail 2 Spacecraft Successfully Demonstrates Flight by Light

    Years of computer simulations. Countless ground tests. They’ve all led up to now. The Planetary Society’s crowdfunded LightSail 2 spacecraft is successfully raising its orbit solely on the power of sunlight.

    Since unfurling the spacecraft’s silver solar sail last week, mission managers have been optimizing the way the spacecraft orients itself during solar sailing. After a few tweaks, LightSail 2 began raising its orbit around the Earth. In the past 4 days, the spacecraft has raised its orbital high point, or apogee, by about 2 kilometers. The mission team has confirmed the apogee increase can only be attributed to solar sailing, meaning LightSail 2 has successfully completed its primary goal of demonstrating flight by light for CubeSats.

    “We’re thrilled to announce mission success for LightSail 2,” said LightSail program manager and Planetary Society chief scientist Bruce Betts. “Our criteria was to demonstrate controlled solar sailing in a CubeSat by changing the spacecraft’s orbit using only the light pressure of the Sun, something that’s never been done before. I’m enormously proud of this team. It’s been a long road and we did it.”


  • Mike Serfas August 4, 2019, 19:19

    According to the Planetary Society, “The orbit-raising phase of the mission will last about a month. LightSail 2 does not have the precision to maintain a circular orbit, so as its apogee rises, its perigee will decrease. Eventually, atmospheric drag will overcome the thrust from solar sailing, ending the primary mission.” I was curious… is the main limitation on circularizing the orbit that the sunlight comes from only one direction? If somebody could arrange periodically to shine a light a few times brighter than the sun on an area the size of a boxing ring passing overhead, could they save this ship?

  • ljk August 7, 2019, 9:37

    Jason Davis • August 6, 2019

    LightSail 2 Nears 2 Weeks of Solar Sailing

    The Planetary Society’s LightSail 2 spacecraft is continuing to sail on sunlight in Earth orbit. The high point, or apogee of the spacecraft’s orbit around the Earth was 729 kilometers on Monday, 5 August—an increase of 3.2 kilometers since sail deployment on 23 July.

    The spacecraft has also captured a few new images, which are available on our raw image downlink page.

    Full article here:


    Amazing image of LightSail 2 over Earth here:


  • ljk August 7, 2019, 9:44

    Solar sailing, at long last

    The Planetary Society announced last week that its LightSail 2 mission successfully changed its orbit using a solar sail. Jeff Foust reports on the accomplishment and the long path that led up to it.

    Monday, August 5, 2019


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