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Breakthrough Starshot: Early Testing of ‘Wafer-craft’ Design

Recent tests of a ‘wafer-craft’, an early prototype for what may one day be the ‘starchip’ envisioned by scientists involved with the Breakthrough Starshot project, have been successful. The work grows out of a NASA-funded effort led by Philip Lubin (UC Santa Barbara), whose investigations into large scale directed energy systems began in 2009. Lubin went on to perform multiple studies for NASA’s Innovative Advanced Concepts program developing the idea that would become known as DEEP-IN (Directed Energy Propulsion for Interstellar Exploration). His NIAC Phase 1 report studied as one option beamed propulsion driving a wafer-scale spacecraft.

Renamed Starlight, the proposal went on to Phase II funding as well as support from the private sector. A subsequent review by Breakthrough Initiatives led to endorsement of the concept within its Breakthrough Starshot effort. Breakthrough is devoting $100 million to studying the viability of sending a ‘starchip’ to a nearby star such as Proxima Centauri, a mission that, moving at 20 percent of lightspeed through laser-beamed propulsion, would arrive at its target within 20 years as opposed to the tens of thousands of years required for chemical propulsion.

But back to that prototype wafer-scale spacecraft, whose launch was conducted in collaboration with the United States Naval Academy. The craft rose into the stratosphere above Pennsylvania via balloon on April 12, 2019 — the 50th anniversary of the Gagarin flight — reaching an altitude of 32 kilometers. The test is part of what Lubin calls “a long-term program to develop miniature spacecraft for interplanetary and eventually for interstellar flight.”

Nic Rupert, a development engineer at UC Santa Barbara, describes the wafer-craft in its current incarnation:

“It was designed to have many of the functions of much larger spacecraft, such as imaging, data transmission, including laser communications, attitude determination and magnetic field sensing. Due to the rapid advancements in microelectronics we can shrink a spacecraft into a much smaller format than has been done before for specialized applications such as ours.”

Image: An artist’s concept of the wafer-craft. Credit: UC Santa Barbara.

The good news is that the chip performed exceptionally well, returning over 4,000 images of Earth by way of testing what may eventually emerge as a space technology that could turn interstellar. The process is iterative, working with off-the-shelf components that can be pushed to increasingly difficult conditions that will test the wafer-craft’s viability under extreme conditions of temperature and radiation, as well as its potential to survive impact with dust particles.

In other words, to get to ‘starchips,’ we must first get to ‘spacechips,’ and that begins with balloon flights well within the atmosphere to shake out early data on performance. The goal: A one-gram chip that contains within itself a functional spacecraft. At UC-Santa Barbara, an undergraduate group drawing on students from physics, engineering, chemistry and biology is conducting the balloon flights that may result in future, mass-produced interstellar probes.

This news release from UC-Santa Barbara notes that the ramping up of testing points to a suborbital flight next year. Early applications of the technology should involve missions closer to home; indeed, a laser beaming infrastructure would have applications for fast interplanetary travel as well as planetary defense against asteroids and other space debris. Thus testing funded by NASA and private foundations examines the viability of miniaturized spacecraft that, given the beaming resources, could one day give us a close-up look at Proxima Centauri b.

For more on the Starlight effort, visit its website.

Tomorrow I’ll keep the focus on fast interstellar missions in the form of some interesting ideas from a paper by Bing Zhang, an astrophysicist from the University of Nevada, on what he is calling ‘relativistic astronomy’ and its possibilities on the way to distant destinations.


Comments on this entry are closed.

  • Michael C. Fidler May 14, 2019, 9:17

    1/4-Scale 19 Element Phased Array with Hexapod from PI.

    I’m a little confused, they are showing a model laser array at 1/4 scale with camera lenses? Has there been some major breakthrough that we can now make desktop laser arrays for a .25 relativistic speed laser cannon???

  • Alex T. May 14, 2019, 12:32

    Funny to see on the “hexapod” video how “super powerful” laser array pointed directly to video camera :-) Poor operator most probably he/she was immediately vaporized :-)
    Really Pop-science as it is…

  • Alex Tolley May 14, 2019, 15:35

    I am not seeing any information about the “wafercraft” itself. How heavy is it compared to the 1 gm goal. What are its current specifications for imaging and communications? What are the difficulties anticipated to reach that 1 gm goal?

    As far as the sail itself, do we have progress on design and stability, especially with the high light intensity and acceleration required?

    Of more immediate interest is how much does the current waferchip cost if put into mass production? What needs to be done in development to make this a possible useful vehicle for rapid deployment. I am particularly thinking about targets like ‘Oumuamua which could be reached rapidly and imaged at low cost, rather than the rather expensive and sometimes fanciful plans put forward for a more conventional mission. Pushing a tiny craft to even 1000 km/s would get it to Jupiter orbit in just 10 days, allowing a quick imaging of some transient phenomenon as it flies by. Sending a number of them serially would provide imaging for as long as the craft stream was operating. The possibilities for mass manufacture and rapid deployment seem attractive, especially for a smaller laser array with gentler acceleration and less aggressive terminal velocities.

    • Michael Fidler May 15, 2019, 22:12

      What would promote a lot of support early on with less powerful optical or microwave beaming equipment??? Cheap mission to many of the solar system planets, moons, asteroids and comets and maybe something rare and exotic that comes passing thru. This would be a great way to promote it and would let an evolutionary approach to the wafer-crafts design, plus the beaming system.

  • Geoffrey Hillend May 14, 2019, 16:39

    It looks like they might have to put some kind of balloon or bubble around it as an outer shell or shield to protect it from the collisions of relativistic interstellar dust and debris.

  • Gary Wilson May 14, 2019, 19:58

    Is the photo a realistic depiction of the actual wafer? In that case how does it achieve attitude control as they suggest it can? It can fit in the palm of a hand but what is its mass? It took 4000 pictures successfully apparently. Can we see some of them?

  • Bill May 15, 2019, 10:01

    I’ve been able to find a bit of information. The photos it took are stored in an onboard flash drive and hopefully a sample will be made available. As for the specs, if you follow the link and scroll down to the pictures of the wafer craft models you can scroll right or left to see the specifications. The model flown is the Model A.


    • Alex Tolley May 15, 2019, 14:09

      Thank you. That answers some questions, e.g. it is 30x target mass, albeit without a sail. Current sail areal density is > 100 g/m^2, but NASA has proposals to reach 1.4 g/m^2. So assuming current technology and a 1 m^2 sail, the total mass is going to be 2 orders of magnitude larger than the Breakthrough Starshot target. For solar system use, perhaps we can consider a mesh microwave sail as a ground-based microwave emitter might work better than a laser beaming through the atmosphere. It has a 155 Mbs laser communication system. How far can it transmit which ground-based receivers we have? The cost for the wafer is <$150. Even if 10x the cost with a sail, this is a remarkably low cost and suitable for mass manufacture and deployment. The camera is 2 Mp, rather like earylish digital cameras and well below that of current smart phones. Nevertheless, this provides images better than 1k x 1k pixels, so the imaging should be quite good. This does look very promising indeed. I hope that some tests can be done soon on beaming sails. I would love to see some results of flying this wafer to the Moon.

  • Gary Wilson May 15, 2019, 13:14

    Terrific Bill. Thank you.

  • Gary Wilson May 15, 2019, 14:54

    One thing I’ve been wondering about (among many) is what is the cost per target for Breakthrough Starshot? After Proxima Centauri how much would it cost to go for the other known nearby star systems? Especially if we find more planets in their habitable zones. The laser setup would seem the most expensive part of the system. Will governments contribute? It’s too good an opportunity to waste.

    • ljk May 16, 2019, 11:27

      I just asked similar questions and more in the High Velocity Astronomy post above. Yes, the method of propulsion is the key sticking issue that has major questions which are not being properly addressed.

      If Breakthrough Starshot becomes the white paper that the BIS Daedalus fusion star probe became (and always was), then anything else being done about this project is just a paper tiger.

  • Curious May 15, 2019, 21:08

    Why does the simulation start with both craft and laser in LEO ? Wouldnt an elliptical orbit in the direction of eventual departure be more effective?

    • Eric Dahlstrom May 19, 2019, 4:47

      The plan is to accelerate the ‘starchip’ *very* rapidly (~minutes) to 0.2 c using powerful ground based lasers. Slight differences in initial velocity would not make much difference. Even adding 10 km/s would only contribute 0.00003 c to the starting velocity. Very accurate targeting would be extremely important – maybe a choice of a particular starting orbit would help with that.

  • Kevin Philip hambsch August 2, 2019, 13:54

    The round style disk wafer craft is approx. 10 cm diameter. I believe Philip is contemplating a three level (being developed) wafer style. Indeed a single 10 cm diameter disk has a surface area of approx. 78.54 cm squared of area (a far cry from 1 cm2), but it is the mass that is at issue: = or < 1 gram. Irrespective what scheme is employed for component layout, the mass must remain no greater than 1 gram.