Kryten

Ceres is still a differentiated body, and cryovolcanism requires a lot less decay heat then conventional volcanism, so that seems a plausible mechanism to me. Not possible; at this point in time, any uranium deposits have too much U-238 relative to -235 to sustain fission with light water. The natural reactors we've found were active over a billion years ago, when the proportion of -235 would've been much higher.

It could be ice if the protuberance is a cryovolcano, refreshing the surface every so often. If it is, we should catch signs of activity pretty soon.

Orbiting at Europa is very complex due to the radiation levels-it's tough to get the actual instruments hard enough, and you can't meaningfully shield them while still allowing them to function.

That's Dnepr, formerly the R-36M ICBM. The engines are also actually placed at the front of the stage (when used as an LV), meaning payloads need special covers to protect them from the plume.

They've been fine doing it with every single previous US spy satellite, and had no real issues with it. A payload small enough to fit in the X-37 cargo bay is not going to be one that's not worth going through all this bother with.

It should probably be noted that there's no Europa lander anywhere in the decadal survey. The planetary science community isn't asking for it.

That's what happens anyway. Would you rather it be a fire, or coffin flies?

Multi-flyby mission is superior to orbiter in terms of data return due to radiation and bandwidth issues-an orbiter would be fried pretty quickly by the radiation belt around europa, while a multi-flyby mission can dip into it and then transmit the data from a safe position. As for a lander-bear in mind we currently have little idea of real surface conditions. Designing for that is hard.

The options were a multi-flyby mission with a heavy EELV (Atlas V 551 or Delta IVH) or direct transfer with SLS. The multi-flyby trajectory would require the spacecraft to operate within Venus orbit and last about twice as long in transit in general, neither of which would be cheap. EDIT: Also that's for the base mission without a lander; building spacecraft and instruments that can survive these conditions is not cheap. Estimates for a lander from JPL itself are $700 million-$1 billion extra, and you can probably double that for real costs. If Shelby gets his wish and a lander does get funded, this will have no real prospect of actually flying.

Go for launch. Less than four minutes now.

That's a recap, they did that yesterday.

An Atlas V 501 carrying an X-37 uncrewed spaceplane and a number of secondary payloads is set to launch about 45 minutes from the time of this post. Coverage by ULA is here, and coverage by the planetary society (who operate one of the secondary payloads) is here. - - - Updated - - - ULA's webcast has started.

Does anyone have anything substantive on the next-generation launcher from Progress, possibly called Fenix? It could prove a useful backup in what looks to be a near-monopoly for Krunichev otherwise.

With Proton, there's also the issue that Krunichev are switching focus to Angara, and Angara is produced at the former Polyot plant in Omsk rather than the Proton facilities near Moscow. This could help with Krunichev's own skilled labour problems in the long term, but for now it means Proton is assembled by people with uncertain future prospects at facilities that will receive no upgrades and the bare minimum of maintenance.

The labour shortage is a lot older than the payment issues; there simply aren't enough in the region. I don't think they've ever broken having half the requested workforce at the site.

ESA were looking into potential co-operation the Chinese station program, but AFAIK that only extended to ESA astronauts on Shenzhou and perhaps supply flights.

More like 8%, at least for any significant length of time. Respiratory acidosis is not pleasant.

As people have already pointed out, the relative velocity of the Sun and Sirius is far higher than what the escape velocity of this proposed binary system would be, given observed masses and distances. Your proposal requires there to be huge discrepancies between the real and observed relative velocities, masses, or distances between Sirius and the Sun; provide some evidence or at least a possible mechanism for this, or stop wasting our time.

It not noticeably moving relative to us is a predictable relationship with the sun.

Commercial satellite operators typically purchase from a separate insurance company, while government launches are usually self-insured. Some launch companies have options to include a reflight clause in the contract; i.e. 'if the launch fails we'll build another one and put it up'; with a few exceptions, this is mostly restricted to the Chinese commercial launch group, China Great Wall.

I pulled it from Wikipedia's '20XX in spaceflight' series of articles, and collated it myself (possibly with a few errors). These particular pages are curated by a few people from the NSF forum, and tend to be trustworthy. I also switched the Soyuz-2.1a launch last week to a failure, as it's now looking clear that the booster was to blame.

I went through and totted up the statistics for all launches since 2009, with resultant % chances for the major players; Total for 2009-2015 Success/partial failure/failure Europe (Ariane+Vega) 40/0/0 India 16/0/2 Japan 19/0/0 Iran 4/0/2 PRC 88/1/2 Israel 2/0/0 SK 1/0/2 NK 1/0/2 Russia/CIS (inc. Soyuz from Kourou+Zenit) 195/4/12 US 118/2/3 US success rate=118/123=96% p. failure=1% failure=2% Rus. success rate=92% p. failure=2% failure=6% Europe success rate=100% Japan success rate=100% PRC success rate=97% p. failure=1% failure=2% % may not add to 100% due to rounding

Well, it's not as if it's all the same people. Soyuz production at Progress is completely unconnected to production of Proton and Rokot and Krunichev, which is not connected to Zenit and Dnepr at Yuzhmash or Strela at NPO Mash. Of all of these, Krunichev has the worst recent record by a good margin.

The same clause in the lease agreement that nixes Proton in Baikonur in the 2020s applies to all other hypergolic rockets. Together with the impending Zenit retirement, that leaves only Soyuz. I doubt Baikonur could, when in competition with Vostochny and Kourou, attract enough Soyuz launches to stay viable.

Angara is still Krunichev-any structural issues with the QC system will remain.