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LightSail Wakes Up After Silent Spell and Tries To Spread Solar Sails

Posted by samzenpus on from the tacking-around-the-moon dept.

An anonymous reader writes: After a second outage LightSail's controllers have re-established contact with the experimental spacecraft, and plan to begin the process for unfurling its photo voltaic sails. LightSail is a solar sail propelled test spacecraft that was launched on May 20. Two days later, it went offline because of a software glitch. "It's exciting," said William Sanford Nye, the [Planetary] society's chief executive, who is better known as Bill Nye the Science Guy. "It's anxious. It's anxiety producing."

72 comments

  1. speaking as a backer... by Anonymous Coward · · Score: 5, Insightful

    It's easy to criticize a low budget spacecraft. "They shouldn't have had a log file overflow". "They should have tested panel deployment under realistic conditions". That covered 99% of the comments in the previous slashdot thread about this thing.

    And some of those criticisms are valid, make no mistake... but I'm inclined to cut them a little slack. This is a citizen-funded spacecraft developed on a shoe-string budget with a tiny team, caught up in schedules not of their own making. The first attempt is for them to learn from, and learning they are. Not everything has gone perfectly! But they have several of these planned, and the lessons they learn from the first will be applied to the following ones.

    I think it is mildly incredible that within the next year or two, we might see a fucking Kickstarted spacecraft leave low earth orbit using a solar sail.

    1. Re:speaking as a backer... by FatdogHaiku · · Score: 4, Funny

      Shoestrings! Bah, they WISH they had shoestrings...
      all they got was some elastic from Bill Nye's loafers!

      --
      You have the right to remain sentient. If you give up the right to remain sentient, you will be elected to public office
    2. Re:speaking as a backer... by NostalgiaForInfinity · · Score: 1

      I think it is mildly incredible that within the next year or two, we might see a fucking Kickstarted spacecraft leave low earth orbit using a solar sail.

      Yes, particularly incredible given that the people who run the Planetary Society constaly speak out against the possibility of privately funded space exploration and are strongly lobbying for more government funding for NASA.

      But, then, the CubeSat launches appear to be subsidized by government, making the whole thing rather circular: NASA subsidizes CubeSat, which subsidizes the Planetary Society, which then advocates increased funding for NASA.

    3. Re:speaking as a backer... by Anonymous Coward · · Score: 0

      Why the hell was the parent post modded to -1?

    4. Re:speaking as a backer... by SgtAaron · · Score: 1

      It's easy to criticize a low budget spacecraft. "They shouldn't have had a log file overflow". "They should have tested panel deployment under realistic conditions". That covered 99% of the comments in the previous slashdot thread about this thing..

      You've done well.

    5. Re:speaking as a backer... by Rei · · Score: 1

      On the subject of solar sails, does anyone know whether it'd be possible to hybridize the solar sail and mini-magnetospheric propulsion concepts? I was thinking about the concept of deploying a fine, highly reflective superconducting dust from the spacecraft and letting it expand up to the point where it begins to lose opacity, then developing the magnetic field - the concept being that superconductors get naturally pinned to magnetic field lines, so they won't just drift off, and if they have a high enough reflectivity then they'll be cold and thus hit their critical temperature needed to be in a superconducting state.

      The idea is to completely lose the need for hundreds of square kilometers of structural reinforcements for the sail and to allow the sail to need no more thickness than that required to be mostly opaque rather than the thickness needed to not tear to shreds in assembly, on deployment, or due to spacecraft movements / oscillations / etc.

      --
      "99 dead duelists of Dios on the wall. 99 dead duelists of Dios! Take one's ring, pass it around..."
    6. Re:speaking as a backer... by Rei · · Score: 1

      What are you talking about? The Planetary Society has been opposing cuts to the Commercial Crew, which is the program that helped get the Ares 1 cancelled. "Commercial Crew" can be seen as the "NASA, Get The Heck Out Of The Launch Business" program. By contrast, in all of their posts about the new budget the Planetary Society has not once said anything positive about the increase in the budget for the SLS.

      The Planetary Society just wants to see space exploration and the advances in technology that make it possible. They really don't give a rat's arse who does it, although they're enough realists to recognize that NASA does, and will for the forseeable future, do the lion's share of it. And they want to see as large of a share of NASA's budget as possible go toward actual science. They're in love with missions like Galileo, Cassini, the MERs, MSL, Messenger, New Horizons, Rosetta, and on and on. Giant super-expensive rockets to launch craft to carry people around to make a big show for the cameras? Not so much.

      --
      "99 dead duelists of Dios on the wall. 99 dead duelists of Dios! Take one's ring, pass it around..."
    7. Re:speaking as a backer... by NostalgiaForInfinity · · Score: 1

      What are you talking about?

      http://bigthink.com/videos/nei...

      http://articles.latimes.com/20...

      The Planetary Society just wants to see space exploration and the advances in technology that make it possible.

      Almost everybody wants that. The question is how to go about it. Nye wants to redirect funding within NASA from programs like the ISS to interplanetary probes and pure science, which is certainly an improvement. Tyson, on the other hand, talks a lot about the supposed impossibility of financing private space exploration, which is a bad thing.

      In the end, I think both of these guys simple have stepped into shoes that are too big for them to fill and have no credible agenda for advancing the cause of space exploration. By needlessly speaking out against private space exploration, Tyson actually causes harm; he could easily take a more conciliatory tone even if he thinks public funding is important.

      I used to support the Planetary Society, but I don't think it's worthwhile anymore.

    8. Re:speaking as a backer... by Rei · · Score: 1

      I can't watch a Tyson video from here. But your Nye link says:

      What NASA should be: "The report, to me, is getting to an old problem of what we want to do. I believe, as a country, we want to move NASA from [being] an engineering organization to a science organization, and this is going to take years, decades. Now, through investment, we have companies emerging that are exploring space on their own and will ultimately lower the cost of access to low-Earth orbit, which will free up NASA to go to these new and exciting places.”

      That's not just "certainly an improvement", that's the very thing that I think almost all of us here want to see. And this is the chief executive officer of the Planetary Society speaking. So...? Whatever Tyson said (Tyson just being a board member), you're letting that ruin your view of the Planetary Society as a whole? We can see clearly what the Planetary Society is advocating for. It's in line with what Nye calls for. So what's the problem?

      I've never seen "speaking out against private space exploration" on their site. Quite to the contrary seen complaints about cuts to Commercial Crew, and a lot of excitement about what SpaceX is doing (Planetary Society blogger Jason Davis in particular has been covering it well).

      It sounds like you have a gripe with Tyson, not the Planetary Society.

      --
      "99 dead duelists of Dios on the wall. 99 dead duelists of Dios! Take one's ring, pass it around..."
    9. Re:speaking as a backer... by NostalgiaForInfinity · · Score: 1

      That's not just "certainly an improvement", that's the very thing that I think almost all of us here want to see. And this is the chief executive officer of the Planetary Society speaking. So...?

      The "investment" he is talking about is public funding for private launch capabilities, not private space exploration. In the end, their policy ideas seem to be largely "give NASA more funding, just change a little what they do":

      http://www.planetary.org/press...

      http://www.planetary.org/press...

      Whatever Tyson said (Tyson just being a board member),

      Nonprofits select board members that reflect their ideals. And the Planetary Society behaves consistent with what Tyson is saying.

      Commercial Crew

      Take it from NASA:

      NASA's Commercial Crew Program is a partnership between the agency and aerospace industry to develop and fly human space transportation systems.

      That is just NASA giving money and resources to aerospace companies so that those companies can then develop overpriced launch capabilities and enrich themselves at taxpayer expense. That has nothing to do with "private space exploration" and everything with crony capitalism. It's just more business as usual, and it's what got NASA into trouble in the first place.

      you're letting that ruin your view of the Planetary Society as a whole?

      No, what "ruined" my view of the planetary society is what they are doing and what they are advocating.

    10. Re:speaking as a backer... by Adriax · · Score: 2

      Correction, they had the elastic from Bill Nye's loafers.
      It's what gave them the knowledge to get his far. But then the Warehouse agents got a ping about an engineer being haunted by a disembodied voice saying his name with every step he took. Now the elastic sits on a shelf between Don Herbert's chemistry set and Jamie Hyneman's beret.

      --
      I don't suffer from insanity, I enjoy every minute of it!
    11. Re:speaking as a backer... by khallow · · Score: 1

      Eh, the Planetary Society does have some screwed up priorities. But they made it happen.

    12. Re:speaking as a backer... by FatdogHaiku · · Score: 1

      Like they could keep Hyneman's beret! It was already spotted crawling across the desert, inching it's way back to San Francisco... At last report it was trying to use coyote bones as a frame to convert itself into a kite of some kind.

      --
      You have the right to remain sentient. If you give up the right to remain sentient, you will be elected to public office
    13. Re:speaking as a backer... by Rei · · Score: 1

      The "investment" he is talking about is public funding for private launch capabilities, not private space exploration. In the end, their policy ideas seem to be largely "give NASA more funding, just change a little what they do":

      NASA getting out of the launch business and dedicating its budget purely to science is the ideal way to maximize science. If you're dreaming of the day where Joe Blow from Statesville Tech launches his own Cassini, you're going to be dreaming for a very, very long time. In the foreseeable future, apart from perhaps extremely limited cubesats and the like, basic interplanetary research is only going to come from entities like NASA.

      That is just NASA giving money and resources to aerospace companies so that those companies can then develop overpriced launch capabilities

      Overpriced? Commercial Crew has led to - after decades of stagnation - a sudden and massive drop in launch prices. How is it not something to be heralded?

      --
      "99 dead duelists of Dios on the wall. 99 dead duelists of Dios! Take one's ring, pass it around..."
    14. Re:speaking as a backer... by NostalgiaForInfinity · · Score: 1

      NASA getting out of the launch business and dedicating its budget purely to science is the ideal way to maximize science.

      Really? Where does the money NASA "invests in multiple American companies" to develop crew launch capabilities come from?

      To accelerate the program’s efforts and reduce the gap in American human spaceflight capabilities, NASA awarded more than $8.2 billion in Space Act Agreements (SAAs)

      If you're dreaming of the day where Joe Blow from Statesville Tech launches his own Cassini, you're going to be dreaming for a very, very long time.

      So the dichotomy you pose is "Joe Blew from Statesville Tech" vs massive NASA crony capitalist spending; are you just being a dishonest debater or is that really the only two alternatives you understand?

      All NASA needs for its scientific missions are launch capabilities for probes, and there is plenty of commercial incentive for providing those even without NASA spending or funding. Furthermore, if NASA thinks that its spending is needed to create those launch capabilities, it should do so without playing favorites with particular companies; that is, it should say "we will order 50 launches at a maximum price of $X per launch".

      Overpriced? Commercial Crew has led to - after decades of stagnation - a sudden and massive drop in launch prices. How is it not something to be heralded?

      How does "basic interplanetary research" require handing vast amounts of money to US aerospace companies for launching people into space?

      Claiming that NASA is only focusing on science is a lie, and calling its crony capitalist spending "private space flight" is also a lie. NASA is the same old inefficient boondoggle it has always been, and instead of helping us get into space faster, it is impeding space exploration and space flight. We'd be better off without NASA; we'd be sacrificing some nice science in the short term but it would be worth it.

  2. they're not "photovoltaic sails" by sribe · · Score: 5, Informative

    Sheesh. Nothing PV about them. (There are separate PV panels which provide power, but they are completely unrelated to the sail.)

    1. Re:they're not "photovoltaic sails" by Irate+Engineer · · Score: 5, Funny

      Welcome to Slashdot, where even the submitters don't bother to RTFA!

      --

      Left MS Windows for Linux Mint and never looked back!

      Vote for Bernie in 2016!

    2. Re:they're not "photovoltaic sails" by MillionthMonkey · · Score: 1

      Although you do still get 50% of the force from sunlight hitting a dark PV cell as opposed to being reflected. Probably not a big factor here, though.

  3. This should be a major embarrassment by mykepredko · · Score: 0

    Bill Nye is great at making science understandable to kids but clearly he doesn't know what it takes to put together a team that knows how to design a satellite.

    The issues (by my count):
    1. The .csv file error where no limit checking was put in place.
    2. Relying on a cosmic ray/energetic particle to reset the system.
    3. Not designing a power supply to keep the batteries charged from the solar cells.
    4. Not placing the satellite high enough where they can measure an unbalanced force on the sails from the sun. It sounds like as soon as the sails unfurl, the satellite will re-enter Earth's atmosphere because of high altitude drag.

    It seems like there was a lot of hubris that went into this project and not a lot of good old fashioned engineering that relied upon working with and listening to people who have successfully orbited satellites in the past.

    I can't imagine that there weren't more than a few experts that would have been happy to critique the designs for free - simply because they believed in the project and wanted to see it succeed (how many engineers out there haven't read Clarke's "The Wind from the Sun" and been inspired by it?).

    --
    Mimetics Inc. Twitter
    1. Re:This should be a major embarrassment by Anonymous Coward · · Score: 5, Informative

      It sounds like as soon as the sails unfurl, the satellite will re-enter Earth's atmosphere because of high altitude drag.

      You realize that is intentional, yes? They are limited by being a small secondary payload on a launch funded and primarily meant for another purpose. They are launching a subsequent sail next year that is designed to leave LEO rather than re-enter, as this one was planned to do all along.

      Yes, they should not have had the log file problem, but this is their first ever spacecraft, designed on fuck-all budget as far as such things go. Please point us all to the web page(s) for YOUR operational spacecraft, so that we can see how the really good people do it. I'm sure we could all learn from your perfection.

    2. Re:This should be a major embarrassment by Dereck1701 · · Score: 4, Informative

      "4. Not placing the satellite high enough"

      While I agree with your other points this one is likely out of their control. Cubesats due to their lack of backups, limited quality control and no attitude/orbit control systems are almost always put into low orbits that will degrade on their own within a year or so. And given this satellites obvious faults its probably not such a bad policy. There is enough junk in orbit as is without us throwing droves of dead cubesats into the mix.

    3. Re:This should be a major embarrassment by sjames · · Score: 5, Informative

      And yet, they have a workaround for the csv problem, the reset did happen (and they were fairly sure it would), the batteries are now charged and the sail is deploying, and they expected it to re-enter fairly soon after deployment.

      This is the test mission and it's quite successful in spite of problems. All with limited experience and a shoestring budget. They have learned a lot in the process, all of which will contribute to the success of the real thing which will fly soon.

    4. Re:This should be a major embarrassment by Anonymous Coward · · Score: 5, Insightful

      Wait, lemmegetthisstraight - it's somehow a "major embarrassment" to have put a spacecraft in orbit, which is sending back photos, was funded by space enthusiasts out of their own pockets, and has now achieved the nearly all of its intended objectives?

      Because they have now had a successful sail deployment, which was what this thing was supposed to do. The only remaining thing is to send back a picture of the deployed sail. Despite the glitches, it has done everything they wanted from it, including acting as a test to shake out problems for the next one.

      If only anything I've ever done in MY life could be such as "major embarrassment"...

    5. Re:This should be a major embarrassment by Irate+Engineer · · Score: 5, Informative

      This was a test flight on a shoestring budget. This thing was never going to sail anywhere. The whole idea was to see if the power management and sail deployment could be accomplished in a CubeSat footprint. Re-entry was planned to occur soon after sail deployment and it's not a surprise or a disappointment. Not bad for a Kickstarter.

      --

      Left MS Windows for Linux Mint and never looked back!

      Vote for Bernie in 2016!

    6. Re:This should be a major embarrassment by thegarbz · · Score: 2

      but clearly he doesn't know what it takes to put together a team that knows how to design a satellite.

      The problem was if he put together a team that did know how to design a satellite he never would have managed to do it within the required budget. Let's not forget how much they were trying to accomplish, with how little, and despite all their problems lets also not forget how far they've managed to come.

    7. Re: This should be a major embarrassment by Anonymous Coward · · Score: 1

      Well, I'm not a space guy, just worked with avionics, but I would have started with a RTOS instead of Linux. Hint hint.

    8. Re:This should be a major embarrassment by umghhh · · Score: 2

      It is/was like a normal corporate or any other project then? Low on budget and with other project parameters (skill of a crew, time etc) also constrained. I'd say with all that they went ok. It was after all only a test flight. The main mission being scheduled for 2016.

    9. Re:This should be a major embarrassment by Anonymous Coward · · Score: 0

      According to the FA, the sails have not been deployed yet.

    10. Re:This should be a major embarrassment by Whiteox · · Score: 2

      Yes it has: http://www.planetary.org/blogs...

      --
      Don't be apathetic. Procrastinate!
    11. Re:This should be a major embarrassment by sysrammer · · Score: 1

      Sometimes one needs Real Engineering(tm). This is an engineering test. To get to the point where Real Science(c) can get done.

      --
      His ignorance covered the whole earth like a blanket, and there was hardly a hole in it anywhere. - Mark Twain
    12. Re:This should be a major embarrassment by sysrammer · · Score: 1

      It is/was like a normal corporate or any other project then?

      No. It wasn't.

      --
      His ignorance covered the whole earth like a blanket, and there was hardly a hole in it anywhere. - Mark Twain
    13. Re:This should be a major embarrassment by sysrammer · · Score: 4, Interesting

      Adding more people to a project does not necessarily increase the chances for success. And, since the Planetary Society has a lot of educational outreach, I'm guessing that they included a lot of relative novices that learned a *hell* of a lot from the successes, but even more from the failures.

      Anyways, I include this Planetary Society blurb because I believe this is one of the pathways to the solar system.

      "Through this proof-of-concept mission, we will use CubeSats to open new paths beyond Earth and, one day, potentially to other planets with an inexpensive, inexhaustible means of propulsion: photons, solar energy in its purest form."

      --
      His ignorance covered the whole earth like a blanket, and there was hardly a hole in it anywhere. - Mark Twain
    14. Re: This should be a major embarrassment by sysrammer · · Score: 1

      An RTOS is an obvious advantage. I wonder what the disadvantages of it were, as I assume they would have considered this. Expense? Resources? Experience? All of the above?

      --
      His ignorance covered the whole earth like a blanket, and there was hardly a hole in it anywhere. - Mark Twain
    15. Re: This should be a major embarrassment by sjames · · Score: 2

      None of the problems they have had would have been solved by an RTOS, but it would have added cost. Sometimes an RTOS is really necessary, sometimes usually getting things done on time is good enough. Since the LightSail doesn't even have engines which may need to be fired with precision, RTOS wasn't really called for.

    16. Re: This should be a major embarrassment by Anonymous Coward · · Score: 0

      Starting with "let's design this for space" mindset would have led them to having the right OS and the right design strategies. Something about writing for an RTOS makes you think about what you're doing every step of the way. It doesn't always work, and there are amateur hacks who don't know enough to react to it, but as an amateur hack, at least I got the big picture that we have to think about what will happen in every failure case.

    17. Re:This should be a major embarrassment by Anonymous Coward · · Score: 0

      According to the FA, the sails have not been deployed yet.

      I think that was true at the time of TFA, but now, they have received packets from the spacecraft indicating the sail has deployed. Yay Lightsail!!

    18. Re: This should be a major embarrassment by scubamage · · Score: 1

      FYI, there are RTOS variants of linux. They aren't mutually exclusive.

    19. Re:This should be a major embarrassment by MillionthMonkey · · Score: 1

      Bill! Bill Nye! Is this you? Big fan!

    20. Re: This should be a major embarrassment by sjames · · Score: 1

      They seem to have done reasonably well for such a low budget not to mention a launch schedule dictated from outside their project (when you're getting a free ride, you leave when the driver is ready). One hint is that the reset after a hardware upset actually restored the craft to functionality after crashing on a software error.

    21. Re:This should be a major embarrassment by Applehu+Akbar · · Score: 1

      Latest data says the sail is deployed:
      http://spaceflightnow.com/2015...

    22. Re:This should be a major embarrassment by Anonymous Coward · · Score: 0

      Yeah we don't have computers either because no where in the Bible did jesus use a laptop.

    23. Re:This should be a major embarrassment by NostalgiaForInfinity · · Score: 1

      It seems like there was a lot of hubris that went into this project

      That would be the case if the primary purpose of this mission was scientific or engineering related. But it really seems mostly publicity-related. After all, the people running the Planetary Society do not believe in private space exploration; they are mainly just advocating more funding for NASA. A cynic might say that if they produce a mission that barely limps along, that's the best outcome for their goals: it gets people involved while at the same time "demonstrating" the need for large amounts of government funding.

      how many engineers out there haven't read Clarke's "The Wind from the Sun" and been inspired by it?

      I don't know what inspired you, but the idea of space travel by solar sails is much older than that. I used to enjoy Clarke, but as I have gotten older, have found him too much of a statist for my taste.

    24. Re: This should be a major embarrassment by Anonymous Coward · · Score: 0

      It's not an either/or proposition: there are RTOS variants of Linux.

      But they probably use Linux for the front end and control and have various small processors running RTOS elsewhere.

    25. Re:This should be a major embarrassment by ChrisMaple · · Score: 0

      Non sequitur. The Bible did not record every time Jesus took a leak; that doesn't mean he never did.
      All His emails are on Hillary's server.

      --
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    26. Re:This should be a major embarrassment by KGIII · · Score: 1

      I am a happy backer. I have no regrets and will continue to fund them to some extent.

      --
      "So long and thanks for all the fish."
    27. Re: This should be a major embarrassment by Anonymous Coward · · Score: 0

      Could be, but there are also real linux-rtos systems running the rtos on the main CPU. See Xenomai for a free and open source one.

      It's basically a rtos under which linux is ran as the idle task with lowest priority.

    28. Re:This should be a major embarrassment by Yoda222 · · Score: 2

      I agree with you for point 1 and 2.

      But for the point 3, it looks like they actually designed the power supply to keep the batteries charged. They just have reach a level where the safe power mode has been activated, disabling all non essential function from the spacecraft. (it's a design choice to consider TM/TC as critical or not, I would say that it should stay on, but it can be discussed) Note that reaching a charge level that low could be linked to the fact that they have lost for several days the contact due to 1 and 2, which has delayed the SA deployment. (I haven't look in detail the design of the satellite, but usually a satellite get less power when the solar array are not deployed)

      And for the point 4, it's a "design" choice. They have looked for a cheap launch to test a first version of their satellite, and found that one.

    29. Re:This should be a major embarrassment by Anonymous Coward · · Score: 0

      So you are saying that Jesus did have a laptop?

    30. Re:This should be a major embarrassment by sjames · · Score: 2

      You forget, they had an absolute drop dead date. They could either fly and fix any remaining problems during the mission, or they could scrub.

    31. Re:This should be a major embarrassment by silentcoder · · Score: 2, Informative

      You realize that Bill Nye was one of the Engineers who designed the Boeing 747 right ? His credentials as an engineer were pretty damn well established before he ever hosted a children's show.
      And clearly he has experience working in teams doing massive engineering projects on hugely complicated designs.

      What he may not have much experience with is those teams working on a budget slightly less than the one you get from the sperm bank.

      --
      Unicode killed the ASCII-art *
    32. Re: This should be a major embarrassment by ComputerGeek01 · · Score: 1

      Likely their teams experience with a real-time platform and I strongly suspect additional cost of compatible equipment. I would bet an arm that the dev community for drivers in Linux is exponentially larger then that of any RTOS on the market.

    33. Re: This should be a major embarrassment by Anonymous Coward · · Score: 0

      I've used half a dozen RTOSs, written a few, including one in space, and although I don't know the requirements or this satellite, I can't really imagine any advantage. There are a number of free RTOSs available but not with the breadth of utilities of Linux which is a major plus.

      An RTOS is important when scheduling deadlines must be met 100% or something bad happens with the hardware, eg missing a few frames of updating a thrust vector while a position state is being evaluated. Normally you are talking about milliseconds of criminality and this is where you need an RTOS

    34. Re:This should be a major embarrassment by LeadSongDog · · Score: 1

      Damn amateurs... Any decent coder would have made sure there's no buffer overflow that would jam system... I'm little surprised they dint catch CSV file overflow in testing phase in lab..

      Because no pro coder has ever overflowed a buffer. Hell, MS built a business model on shipping defective code.

      --
      Oh, I'm sorry sir, I thought you were referring to me, Mr. Wensleydale.
    35. Re:This should be a major embarrassment by Coren22 · · Score: 1

      So Christ exchanged emails with the Anti-Christ?

      --
      APK likes to ask for responses to the same things over and over. Maybe he just likes the responses?
    36. Re: This should be a major embarrassment by stoatwblr · · Score: 2

      RTOS is not needed, nor is it practical.

      The only thing they really missed out on design-wise was having a hardware watchdog reboot it faster than it would have otherwise done.

      I've been building those into remotely deployed systems for 35+ years. The top of a mountain may not be LEO but not having to helicopter out to hit a reset button because you can't drive out through 15-foot deep snowdrifts saves a few thousand dollars the first time you get a lockup.

    37. Re:This should be a major embarrassment by stoatwblr · · Score: 1

      "They could either fly and fix any remaining problems during the mission, or they could scrub."

      This is the essence of flying any space probe where you're a hitchhiker. It's why Beagle didn't quite complete its mission and it's why what was left of the original Solar mission ended up being dug out out of a south american swamp by the french foreign legion (there's a piece of that sitting in a glass case not far from me).

      All in all they did well. They'll do better next time and that is the essence of cubesats (learning from your mistakes).

    38. Re:This should be a major embarrassment by stoatwblr · · Score: 1

      "The problem was if he put together a team that did know how to design a satellite he never would have managed to do it within the required budget"

      People who "know how to build satellites" would never fit what they know how to build into a cubesat even if they were free. Believe me, I've watched them trying.

    39. Re: This should be a major embarrassment by Anonymous Coward · · Score: 0

      RTOS would have been great. Hindsight is 20/20.

      Advantages: predictability, fail over (hence no bugs like what they encountered), performance.
      Disadvantages: cost, support, developer skill level needed, infrastructure & integration approach.

      Note the disadvantages listed are critical to a project like this. All you aerospace engineers have a huge luxury...

      Granted, using linux in RT, Xenomai or preempt kernel favors would be sufficient for what they are doing.

      I wouldn't be surprised that you couldn't do what they are doing with a high end Arduino, or SoC Arm running Linux-Preempt (if you need some hard RT). The only thing that would screw it all up is serial communication handling...

  4. Dual outages by Anonymous Coward · · Score: 2, Funny

    Rumor has it the LightSail team installed software they downloaded from SourceForge, the bundled adware blew the stack and caused outages. Next time they'll know not to download anything from SourceForge.

    1. Re:Dual outages by MillionthMonkey · · Score: 2

      I'm wondering if a solar sail could still work after having an Ask toolbar install itself across the top. Can the information coming back from the sail be used at all if it's being proxied through binkiland.com?

  5. crowdfunding and publicity campaign by BatesMethod · · Score: 5, Informative

    The LightSail kickstarter crowdfunding campaign is still active. Moneys donated at this point will help fund a publicity campaign.

    https://www.kickstarter.com/projects/theplanetarysociety/lightsail-a-revolutionary-solar-sailing-spacecraft

    Jason Davis' blog has mission updates:

    http://www.planetary.org/blogs/jason-davis/

    This is a test mission. Still a historic achievement for solar sailing, though. The real LightSail mission will launch in 2016.

  6. Tacking around the moon by Anonymous Coward · · Score: 0

    On an irrelevant note, I don't believe that "from the tacking-around-the-moon dept." is actually a thing. From what I understand of sailing, the resistance of the water is what enables a sailing ship to sail into the wind. With no water resistance, you can only put before the wind, you can't sail into it, so tacking (or wearing) would also not be a thing.

    1. Re:Tacking around the moon by pscottdv · · Score: 2

      While it is not technically "tacking," gravity provides the counter force that allows a spacecraft to steer with a lightsail.

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    2. Re:Tacking around the moon by BranMan · · Score: 1

      Actually, from what I understand it's the resistance of the keel that lets a sailing ship tack into the wind. The keel is long and thin seen from the front and wide and flat seen from the side - so in one sense it is water resistance, but its resistance of sideways motion vs. front to back motion. A flat bottomed rowboat can't tack even if you add sails - no keel. Learned that from Peabody and Sherman a few centuries ago.