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Inside the Mission To Europa (arstechnica.com)
An anonymous reader writes: Ars Technica details the political and engineering battles being waged to make it possible for NASA to land a probe on Jupiter's moon Europa. They have new information about mission plans; it sounds ambitious, to say the least. "First, the bad news. Adding a lander to the Clipper will require additional technical work and necessitate a launch delay until late 2023. At that time, the massive Space Launch System rocket NASA is developing could deliver it to Jupiter in 4.6 years. Once there, the lander would separate from the Clipper, parking in a low-radiation orbit.
The Clipper would then proceed to reconnoiter Europa, diving into the harsh radiation environment to observe the moon and then zipping back out into cleaner space to relay its data back to Earth. Over a three-year period, the Clipper would image 95 percent of the world at about 50 meters per pixel and three percent at a very high resolution of 0.5 meters per pixel. With this data, scientists could find a suitable landing site. ...The JPL engineers have concluded the best way to deliver the lander to Europa's jagged surface is by way of a sky crane mechanism, like the one successfully used in the last stage of Curiosity's descent to the surface of Mars. With four steerable engines and an autonomous system to avoid hazards, the lander would be lowered to the moon's surface by an umbilical cord."
The Clipper would then proceed to reconnoiter Europa, diving into the harsh radiation environment to observe the moon and then zipping back out into cleaner space to relay its data back to Earth. Over a three-year period, the Clipper would image 95 percent of the world at about 50 meters per pixel and three percent at a very high resolution of 0.5 meters per pixel. With this data, scientists could find a suitable landing site. ...The JPL engineers have concluded the best way to deliver the lander to Europa's jagged surface is by way of a sky crane mechanism, like the one successfully used in the last stage of Curiosity's descent to the surface of Mars. With four steerable engines and an autonomous system to avoid hazards, the lander would be lowered to the moon's surface by an umbilical cord."
"all these worlds
are yours except
europa
attempt no
landing there
use them together
use them in peace"
to land a sample extractor and launch it back to Earth?
Constellation killed itself, massive cost overruns were pushing it into the $150 - 230 Billion dollar range. SLS is bad, but nowhere near that bad coming in at the $40 - $80 Billion price range.
SpaceX's Dragon has already launched to orbit 8 times, including 6 full resupply missions to ISS, autonomously. It rides the Falcon-9, which has successfully reached orbit 18 times.
The manned Dragon capsule configuration (aka Dragon 2) is expected to do a demo flight in about a year. It was delayed by the accident investigation due to one faulty support spar (of which thousands had already flown) in May of this year. Falcon 9 is scheduled to return to flight in about a month, but it has a backlog of missions/payload before it can fly the Dragon 2 Demo flight, currently expected in the second half of 2016.
Yeah, we temporarily stumbled on manned space flight -- but we've done so before (e.g. after the two Shuttle disasters). It's not permanent.
If you can go to bed, knowing you did a valuable thing today, you're very lucky. If you can't... it's not bedtime
It's not Slashdot if someone reads TFA.
systemd is Roko's Basilisk.
If we all die in 2030 it will sure be a relief we don't have to worry about the year 2038 bug!
"There is more worth loving than we have strength to love." - Brian Jay Stanley
Actually, it was HAL. He was relaying a message, but he did radio that.
Obama resigned the US to defeat when he cancelled Project Constellation without extending the Space Shuttle program..
That's pretty clueless. Here's why. The Space Shuttle went nowhere after it demonstrated the conditional viability of reusable launch vehicles in the 80s. There's nothing that flew on the Shuttle that couldn't have been more cheaply flown on some other launch system. Further, the money spent on the Shuttle prevented the US from doing a lot of manned and unmanned work.
Constellation was no better for the same reasons. It's also worth noting that Constellation would not have survived competiton with the ULA launch vehicles (Atlas V and Delta IV), if the same cost and safety criteria had been applied to them as were applied to the ULA vehicles. However, the report that supposedly decided things in favor of the Constellation configurations (Shuttle-like stack), did so by deliberately understating risk of solid rocket motors, ignoring thrust oscillation of Ares I, and a few other deep problems of the configuration they chose. Then they came up with a completely bogus risk analysis to justify the choice they made.
We also ignore here that Bush did all the heavy lifting. By the time Obama came in, Shuttle and Constellation were both already walking dead.
SLS is a pale congressional substitute that is still being actively impeded and slow-walked by is cronies at NASA.
Crying shame really since we really need another dead end program to consume all that funding we could have used on real space projects. And it doesn't help that SLS is also underfunded by Congress, the only ones who claim to want it.
You do realize that you're talking about decelerating from a *minimum* of 1432 m/s (3426 mph) on impact. That's *if* you've already slowed down into the lowest possible orbit skimming right over the surface. Hitting straight from a Europa-intercept trajectory from Earth would be vastly faster.
"Padding" is not going to cut it. These sorts of impacts convert their impactors to plasma.
Hello from Sputnik 2. I am receiving you.
If only we had some sort of seasonally-appropriate story about middle-eastern people seeking refuge being turned away by the heartless.
Hello from Sputnik 2. I am receiving you.
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I'm not an AC and I'm standing by my opinion. Let's see if you're willing to do the same.
"So long and thanks for all the fish."
Indeed, there was actually a lot that flew on the Shuttle that couldn't have flown on any other launch vehicle - and we're not just talking people and a much more capable deployment system. Between 1988 and 2004 the Shuttle was the highest payload launch vehicle in the world. And the lower end of that range is questionable, as Energia never flew in its heavy lift configuration. In 2004 the Delta IV Heavy came online with slightly more payload capacity than the Shuttle, And really while it "came online" in 2004, its first successful launch wasn't until 2007. The Titan IVB came fairly close to the shuttle's nominal payload (which, BTW, could be increased in certain launch configurations) from 1997 to 2005, but wasn't as large. The same could be said about the Proton M from 1999 onwards and Ariane V from 2002. The Space Shuttle nonetheless had 15% more payload capacity and much more capable launch abilities than these systems (as well as being the only large payload return system in the world that ever operated for more than a few test flights). During the timeperiods these systems weren't available, the next closest systems to the Shuttle in terms of payload had only 3/4ths of its launch capacity.
Part of the reason they kept the Shuttle flying for so long (many had wanted to retire it much sooner) was that there were some ISS modules that could only be launched by the Shuttle.
There were a lot of things that nearly came to be that would have significantly boosted the Shuttle's payload even more, such as the ASRM. They had also started work on the five-segment booster, which would have vastly increased the Shuttle's payload (it's now part of SLS). If there had ever been demand, it had been determined that the payload bay could have been modified into a 30-74 seat passenger area, with a launch cost of 1,5 million USD per passenger (flights per passenger on Soyuz cost $20-40m)
Hello from Sputnik 2. I am receiving you.
It's unfortunate, it really is. I can still think of justification for a space-bus, regardless of costs.
But you can't disregard cost. Economics is key to understanding why we no longer launch the Space Shuttle or have a replacement reusable vehicle. In order for a reusable launch vehicle (RLV) to be competitive per launch with an expendable launch vehicle (ELV), the RLV needs to launch several dozen times a year.
With a small RLV, NASA probably could have afforded to maintain that high launch rate. But for the much larger Shuttle it just wasn't possible.
As to revisionist history, by 1990, it was clearly demonstrated that the Space Shuttle would not live up to its billing. It couldn't maintain the desired flight rate; it wasn't going to carry the desired payloads; and it didn't have the desired customers (the DOD stopped using the Shuttle shortly thereafter). Yet here we are 25 years later and NASA still doesn't have a replacement for the Shuttle.
With NASA's flat funding (for about four decades!), the money that would have gone into developing a Shuttle replacement and in running deep space manned missions instead went into Shuttle operations and the International Space Station (ISS) a remarkably expensive boondoggle.
NASA is again duplicating that failure mode with vast funding going to the Space Launch System even though there is no viable plan or funding for using the vehicle.
There were a bunch of spy satellites which had the same structure, same optics more or less, and same fairing size as the Hubble Space Telescope (HST) which were launched on a variety of vehicles (Shuttle, Titan IV, Delta IV Heavy).
Further, you mentioned mass. The HST weighed only 11 tonnes which is well in the range of more than half a dozen launch vehicles operating today as well as many more over the past thirty years. However, it's the physical dimensions which constrains the choice of launch vehicle. The Shuttle simply doesn't offer enough of an increase in fairing size to justify itself, especially given the launch vehicles that were eventually able to handle equivalent spy satellites.
Moving on, development of the Hubble was very expensive, estimated to be over $1.4 billion of $2.5 billion (with much of the development cost due to the launch delay from the Challenger accident). This is a one time cost. Thus, construction costs of the HST and of any additional telescopes would be on the order of $0.5-1 billion, depending on whether launch costs were included.
Since we have also five repair missions, which dependent on how you account for them, range from roughly $2.5 billion to $12.5 billion (reflecting the marginal cost of an additional mission $0.5 billion to marginal plus annual costs of $1.5 billion). Assuming that the Shuttle would have operated anyway, one gets $2.5 billion as roughly the launch costs of the additional missions. In addition, there are development costs with the original repair mission and additional equipment installed. So right here, we're looking at at least two telescopes. There are development (among other things to address optical and gyroscope issues found with the original HST) and launch costs which would still be several hundred million. So at least two telescopes in cost, possibly three once you including the higher development costs from the original launch delay due to dependence on the Shuttle.
If the HST actually had $0.5 in construction costs, then you might be look at 4 or 5 HST-equivalent telescopes which could be built and launched for the cost of the original HST's dependence on the Shuttle and subsequent repair missions.