LightSail Wakes Up After Silent Spell and Tries To Spread Solar Sails 72
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."
speaking as a backer... (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.
Re:speaking as a backer... (Score:5, Funny)
all they got was some elastic from Bill Nye's loafers!
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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.
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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
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What are you talking about? The Planetary Society has been opposing cuts [planetary.org] 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 p
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http://bigthink.com/videos/nei... [bigthink.com]
http://articles.latimes.com/20... [latimes.com]
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 spa
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I can't watch a Tyson video from here. But your Nye link says:
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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... [planetary.org]
http://www.planetary.org/press... [planetary.org]
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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 fores
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Really? Where does the money NASA "invests in multiple American companies" to develop crew launch capabilities come from?
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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.
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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
they're not "photovoltaic sails" (Score:5, Informative)
Sheesh. Nothing PV about them. (There are separate PV panels which provide power, but they are completely unrelated to the sail.)
Re:they're not "photovoltaic sails" (Score:5, Funny)
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Re:This should be a major embarrassment (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.
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Sometimes one needs Real Engineering(tm). This is an engineering test. To get to the point where Real Science(c) can get done.
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Re:This should be a major embarrassment (Score:5, 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.
Re:This should be a major embarrassment (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.
Re: This should be a major embarrassment (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.
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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?
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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.
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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.
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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.
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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.
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"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
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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.
Re:This should be a major embarrassment (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"...
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Yes it has: http://www.planetary.org/blogs... [planetary.org]
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All His emails are on Hillary's server.
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So Christ exchanged emails with the Anti-Christ?
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Latest data says the sail is deployed:
http://spaceflightnow.com/2015... [spaceflightnow.com]
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I am a happy backer. I have no regrets and will continue to fund them to some extent.
Re:This should be a major embarrassment (Score:5, Informative)
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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.
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"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.
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It is/was like a normal corporate or any other project then?
No. It wasn't.
Re:This should be a major embarrassment (Score:5, 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."
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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 a
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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 cont
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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.
Dual outages (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.
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crowdfunding and publicity campaign (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 [kickstarter.com]
Jason Davis' blog has mission updates:
http://www.planetary.org/blogs/jason-davis/ [planetary.org]
This is a test mission. Still a historic achievement for solar sailing, though. The real LightSail mission will launch in 2016.
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While it is not technically "tacking," gravity provides the counter force that allows a spacecraft to steer with a lightsail.
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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.