Open source probe development

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gunsandrockets

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Every space probe in recent years seems to be a one-off custom job. The exceptions, such as Venus Express and Mars Express, proving the rule. The customized nature of robotic space probes seems to me a major cause of the high cost of unmanned space exploration. The probes themselves costing way more than the cost of the launch vehicles which transport them to their destinations.<br /><br />I had an opportunity last summer to put some of these questions to a few people involved with NASA missions; why does every probe need to reinvent the wheel? Why can't some form of uniformity or standardization be utilized to bring mission costs down?<br /><br />The basic answer is because scientists rather than engineers are the primary drivers of mission design. And the most important thing to the scientists is including the most up-to-date type of measuring instruments into the spacecraft. So no attempt is made to even use a standardized spacecraft bus! Every mission is unique. Every mission is a customized job. And therefore every mission is costly.
 
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mithridates

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You and I seem to agree on quite a bit. I've often thought the exact same thing - why not have a standard probe design that can be modified and added on to when necessary in order to save costs? Something similar to computers where they are designed more or less the same but each with their own strong points - cost, feature a, feature b, etc.<br /><br />Something else I've also wondered about is why not have smaller countries make probes with older technology? There's nothing wrong with making a really cheap probe to go somewhere like a near-Earth asteroid if we've never been there before; certainly preferable to not sending a probe there at all as it closes in on and passes by the Earth. I wrote an editorial on that in a newspaper here in Korea in 2004 (in Korean) but it was two pages from the back of the 5th biggest newspaper in the country - meaning that almost nobody read it.<br /><br />BTW, how did you get the chance to pose those questions to NASA? <div class="Discussion_UserSignature"> <p>----- </p><p>http://mithridates.blogspot.com</p> </div>
 
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gunsandrockets

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"BTW, how did you get the chance to pose those questions to NASA?"<br /><br />You meet all kinds of interesting people at a worldcon...<br /><br />http://www.worldcon.org/<br /><br />...worldcon 2006 was in Los Angeles.<br /><br />
 
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pathfinder_01

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<br />I think most if not all of the cost comes from the testing of the probes. It does no good to send a probe somewhere and have it fail. From what I can tell they try to use as many previously used sub systems as possible, but each mission is unique. And that uniqueness limits things. <br /><br />In addition Scientist want more capability. Which is different than just the latest instruments and that drives up cost. Finally a space probe is very different from a lab. Mass for instruments is limited. Space for instrument is limited. Power is limited. The Operating environment is much harsher than an air condition lab. These all will drive up the cost. <br /><br /><br /><br />An example of increasing capability is seen with the exploration of Jupiter. For instance Pioneer 10 and 11 flew by Jupiter, but lacked computers and a tape drive and could not send data about the planet when out of radio contact or be preprogrammed to perform complex maneuvers. They didn’t have true camera but used their spectrographs to capture pictures. The pictures sent back were little better than what you could see from a telescope at the time and the pictures lacked the color green since the spectrograph was not a true camera. The Pioneers flew by Io but missed the volcanic activity (either because the radiation at Jupiter was worse than expected or their “Cameras” were so bad). The Pioneers did sense that there was something odd about Io with their magnetometer, but no pictures. <br /><br /><br /><br /> The Voyagers had much better cameras, and could do complex maneuvers and could save data to a tape for latter replay. With those abilities they discovered Io’s volcanism. <br /><br /><br /> Galilio went into orbit around Jupiter with even better instruments the ability to perform complex maneuver and save data. But it also dropped a probe into Jupiter(adding complexity) and going into orbit and using gravitational assists by Jupiter’s moons likewise added complexity. <br /><br />An example of the ne
 
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gunsandrockets

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"I think most if not all of the cost comes from the testing of the probes. It does no good to send a probe somewhere and have it fail..."<br /><br />"...In addition the purpose of these missions is to collect science data so scientists should have a heavy say in the mission. If the engineers ran it, they would be much more conservative about the missions..."<br /><br />My opinion is that the involvement of the scientists in the design of the spacecraft (as opposed to say, mission objectives) drastically escalates the price of robotic probes, because each probe becomes a unique custom crafted vehicle. New spacecraft are designed to fit around the desired instruments instead of fitting instruments into a preexisting spacecraft. Every mission becomes a first test flight.<br /><br />If engineers had more control over the spacecraft design, standardized design would drive costs down, cheaper individual missions would mean MORE missions could be flown, and total science return would increase even though any individual mission would not have cutting edge technology. With cheaper more numerous space probes, an individual mission could afford to take higher risks because your 'exploration basket' has more 'eggs'. Loss of any one mission would mean less of a loss than how we do things now when every probe is too precious to afford risking to misfortune.
 
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pathfinder_01

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Actually probes often do not have cutting edge technology. Between the time it takes to design, test and launch the thing it is already behind. Much less the time it takes to get there. The MER rovers have 8 bit computers, gasp! Now they do have very unique items. For instance the MER solar panels are not the ordinary sort of solar panel. They were chosen for improved power output.<br /><br />Now as for just plugging in instrument, well in the case of an space probe or frankly almost any machine made by ,man, it isn’t simple to just plug something in. You can affect power consumption, heatingcooling, center of mass ect. Plus again it does no good if the instrument can not work properly due to spacecraft design. <br /><br />As for everything being a test flight, well frankly any time you launch a probe it is a test flight. Even if they are identical. The Voyagers, Pioneers, and MER all have things that went wrong on one probe, but not the other. <br /><br />As for unqiness, well there are lots of similarities between probes. Pioneer, Voyager, Galileo are all derived from the Mariners. The MER are derived from Pathfinder. <br /><br />As for more missions, well the deep space network is pretty busy these days. There are lots of instances where data is left on the probe because the probe is awaiting a time that it can transmit without interfering with another. In order to have more missions you would have to beef up ground support or have much shorter missions.<br /><br />Finally the volume of data is not quite as important as the quality. And sometimes you don’t need an armada to do the job. For instance the Viking orbiters mapped almost the whole surface of mars in the 70ies. All of that work done from just two probes. <br /><br />Also I question the idea of more is better. The USSR launched more missions to mars than the USA, but the USSR never had a succesful mars mission. If they had spent more time testing their technology and planning perhaps they would have done bett
 
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gunsandrockets

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Hmmm...so current NASA practices are perfect?<br /><br />Let's see if I can pick apart your positions one by one!
 
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gunsandrockets

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"Also I question the idea of more is better. The USSR launched more missions to mars than the USA, but the USSR never had a succesful mars mission."<br /><br />There are several problems with your statement.<br /><br />1) By my count the number of Mars missions launched by the U.S. and Russia/USSR are equal, at 17 each.<br /><br />2) The Russians had a particular fascination with Mars, absorbing much of their deep space probe effort compared to the United States. So looking only at Mars missions is a misleading comparison when examining the numbers game.<br /><br />If you compare the total number of deep space unmanned missions mounted by the U.S. vs Russia, the U.S. has launched far more missions than Russia. By my count the U.S. has launched at least 62 deep space probes, 23 of which were launched at the moon alone during the 1960's!<br /><br />3) The failure rate of Russian Mars missions has nothing to do with the kind of spacecraft strategy I was advocating. <br /><br />Looking at the Russian Mars missions several things are apparent. First off seven out of the 17 failures were due to the launch vehicles, not the Mars probes. Secondly the Russian missions were large, sophisticated designs, 11 of which were launched by the big Proton rocket. About the only standardization employed was the Russian habit of launching duplicate pairs of spacecraft for mission redundancy (for all the good it did them).<br /><br />UPDATE<br /><br />Wow. I had to increase(!) the number of U.S. missions because I overlooked the 5 Lunar Orbiter missions in the 1960's.<br /><br />another update!<br /><br />Just added one more to the total for the Messenger mission to Mercury that I missed. <br />
 
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pathfinder_01

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“Looking at the Russian Mars missions several things are apparent. First off seven out of the 17 failures were due to the launch vehicles, not the Mars probes. Secondly the Russian missions were large, sophisticated designs, 11 of which were launched by the big Proton rocket. About the only standardization employed was the Russian habit of launching duplicate pairs of spacecraft for mission redundancy (for all the good it did them).”<br /><br />And what were the US designs during that time period? I wouldn’t call them simple. The Vikings were large and sophisticated and was launched by the Titan. The difference, they made it to mars and sent data. I am not saying NASA is perfect, but they seem to be able to do the job quite often. When it comes to mission that launch on million dollar rockets and can only be sent when there is a window testing is important. And I suspect that a huge amount of cost comes from testing. <br /><br /><br />As for standardization of probes, well Viking, Pathfinder and MER used the same shape of mars reentry capsule with similar materials. The shape by the way was based off the Apollo capsule. MER and pathfinder use the same suspension system <br /><br />Cassini, Galileo, Voyager, Viking are all evolutions of the Mariner Series. <br /><br /><br />The trouble is there are limits to standardization. A fly by does not need large rockets and huge amounts of fuel to get into orbit nor does it need to worry as much about approach speed. A probe that goes to the moon is probably best powered by solar panels. A probe for deep space is limited to RTG. If you use RTG then you need to locate instruments and electronics away from the radiation. If you use solar panels then you need batteries (which add mass and take up space) and those solar panels can shade instruments. All of these impact a mission hugely .<br /><br />All of these differences drive cost up. In addition scientist doesn’t want to send the same instruments to the planet on each mission. The
 
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gunsandrockets

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Not conceding an inch eh? That's okay.<br /><br />I took some time to carefully search for all the information neccessary to demolish your claims regarding Russian vs U.S. missions. I'll get to your other points too eventually, but be patient.
 
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