Catch up on stories from the past week (and beyond) at the Slashdot story archive


Forgot your password?
For the out-of-band Slashdot experience (mostly headlines), follow us on Twitter, or Facebook. ×

Comment: Re:So is this a Soyuz thing? (Score 5, Informative) 58 58

The launch window is small because ISS has to be essentially lined up in orbit in a tight tolerance (called the phase angle) to rendezvous this quickly. Usually the Soyuz plays "catch up" over 2 days by flying lower (and faster) than ISS. You can control the closing rate between the vehicles by altering the altitude difference between them, which allows you to make up differences in the orbits between the vehicles. Those differences are usually just fallouts of other things, like having uncertainty in launch dates, getting the altitude just right for other vehicles (there is about a rendezvous a month at ISS), etc. It's not because Soyuz is slow, it's because spreading the rendezvous over 2 days gives you some targeting flexibility.

You have less margin to work with when you are trying to get there in 4 orbits instead of 34 orbits. Hitting that target with both ISS and Soyuz is hard but it's more about ground targeting than performance of the launch vehicle. The launch vehicle didn't give any extra oomph to get there faster, the ground essentially had the vehicle phasing in a tight tolerance at launch. They also sped up some of the tracking that was being done and turning that around into updated burns for the next orbit instead of coasting to a set of burns the next day, which was a bunch of work for the ground in a short period of time.

The Russians that devised this actually published it - it's an interesting read if you have access to the journal or want to spend $32:

Comment: Re:Just out of curiosity... (Score 1) 275 275

About 10 years ago I was at the VAB when all 4 orbiters were at KSC. There are only 3 bays in the Orbiter Processing Facility, and at the time the fourth shuttle was usually in Palmdale on a maintenance rotation. On the rare occasion where all four were at KSC, one had to be left in a corner somewhere waiting for it's turn in an OPF bay.

So, as I walked into the VAB (which is essentially a 50 story open bay, with a lot of open space) off on the left is Discovery, engines out, parked in the corner with a huge tarp suspended over it to protect it from stuff falling from above. It looked a little forlorn over there - literally "parked with a sheet over it". It was sort of surreal, because it was like seeing someones old project car in the corner of their garage, except it was an orbiter.

Anyways, even in this sort of storage you wouldn't be able to fly it again. The engineering and manufacturing infrastructure which supports the shuttle has been dissolved or is in the process of being dissolved. The physical orbiter was only a small piece of that infrastructure, which ran the gamut of things from trajectory analysts, simulators, manufacturing facilities for tanks, a control center staffed by trained personnel, etc. etc. It's not like pulling an aircraft out of storage, restoring it, and flying it. The space industry and space systems are still very specialized and rely on significant amounts of engineering, specialized equipment, and specialized knowledge on the part of the engineers and technicians supporting a particular system. Hopefully that will change soon.

Comment: Re:White Room (Score 1) 275 275

I'd take it more as the white room crew making a patriotic statement than a religious reference. In many of the employees, there is a pretty significant sense of national service, both on the part of the government and contractor employees. I would say the majority of employees (at least the ones I worked with, who were mainly engineers) were primarily motivated by things other than a paycheck, which in most cases was smaller than a similar private sector position.

One interesting thing about the "God" reference - I'm not particularly religious, but to some it was not all about the science and engineering when there are people onboard. I've worked manned and unmanned launches. When there are people you actually know and work with daily onboard, it's got a whole different sense about it - and it would cause religious feelings to well up in some people who ordinarily were fairly agnostic.


The White House Listed On Real Estate Website 123 Screenshot-sm 123

Forget visiting the White House, if you have $10 million you can own it. At least that is the price for the president's home on the real estate website Redfin. From the article: "Obviously this is an error. It looks like Redfin software pulled an example listing from the website by mistake. That example listing was the White House. We have e-mailed Redfin for comment." I know it's historic but it still looks a bit on the high side according to the comparables in the area.

Comment: Re:speaking of NASA (Score 5, Informative) 134 134

So what DO you do when the battery charger bursts into flames on orbit?

I'll reinforce your point here. Knowing something about the fire response strategy on ISS you do the following:

1) If you actually are lucky enough to witness the charger burst into flames, remove the power from it, hit the fire alarm, put on a mask, and expend a CO2 based fire extinguisher on it. The mask keeps you from asphyxiating yourself with the extinguisher.

2) If you don't physically see what happens (which is most likely, ISS is big and some modules may go unattended for hours) - the combustion products will trip off a cabin smoke detector in the module. That will stop ventilation inside the module and ring the alarm. In most cases, this will put out a fire in zero g - fires tend to smother themselves without gravity to force convection currents.

Meanwhile, not having any knowledge other than a smoke alarm from a module, the crew will converge in a safe haven in the vehicle away from the fire. Two (of the 6) may go forward to investigate with masks, fire extinguishers, and a hand held device to detect combustion products (mainly so they know if they are entering a lethal pocket of CO or other gases). Hopefully the module isn't a total fog of combustion products - if it is, the crew is likely to isolate it and leave it. If you don't know what the fire source is (because you can't see it), it may well end up that the entire module ends up getting powered down to ensure an electrical fire isn't being fed. This of course has some pretty serious ramifications as well - shutting down power to a module is not a simple event to reverse (since all the computers, cooling, lights, etc. go down with it). It's likely that collateral damage to a module's systems would happen if that were done.

Even if you do understand what happened and know it's out, the harmful gases from burning plastic aren't going to just go away on their own, they have to be scrubbed out with deployed fans and special canisters. It would take weeks to clean up.

Fighting a fire in a closed environment is very different than something you would do in your home. In zero gravity, most of the control is by prevention - don't use flammable materials, stop ventilation on a detected fire so it doesn't spread, don't use things that generate poison air when they burn, etc. Even a minor fire that many of us have encountered at one time or another (smoked electronics, plastic bag on fire, etc.) would be an extremely serious event in space. That's why so much time is spent making sure equipment conforms with fire prevention standards.


+ - Space Station Astronauts Gain Internet Access

cyclone96 writes: Internet access on the International Space Station went live this morning. The crew now has full browsing capability via a special LAN and the Ku-band data link on the Tracking and Data Relay Satellite (TDRS) network, as described in this NASA press release. Flight Engineer T.J. Creamer used the access to post to twitter. Previous astronaut twitter postings had been performed through a third party on the ground via email.

Facebook Master Password Was "Chuck Norris" 319 Screenshot-sm 319

I Don't Believe in Imaginary Property writes "A Facebook employee has given a tell-all interview with some very interesting things about Facebook's internals. Especially interesting are all the things relating to Facebook privacy. Basically, you don't have any. Nearly everything you've ever done on the site is recorded into a database. While they fire employees for snooping, more than a few have done it. There's an internal system to let them log into anyone's profile, though they have to be able to defend their reason for doing so. And they used to have a master password that could log into any Facebook profile: 'Chuck Norris.' Bruce Schneier might be jealous of that one."

Comment: Re:ATV? Progress? (Score 5, Informative) 297 297

Disclaimer - I work for NASA.

I don't think the cost per kg of cargo is a driving factor on this decision. The US government has a vested interest in supporting both SpaceX and Orbital on the COTS contract. If successful the vehicle SpaceX is developing will provide a domestically produced launch vehicle that has shows some promise in having a lot of launch flexibility and much cheaper rides to orbit.

Additionally, if SpaceX is successful it will provide some negotiation power in getting upmass to ISS (the rides get more expensive when Progress is the only game in town) and will also provide some competition on government contracts to the United Launch Alliance consortium of Boeing and Lockheed Martin.


Nanocar Wins Top Science Award 175 175

Lucas123 writes "A researcher who built a car slightly larger than a strand of DNA won the Foresight Institute Feynman Prize for experimental nanotechnology. James Tour, a professor of chemistry at Rice Univ. built a car only 4 nanometers in width in order to demonstrate that nanovehicles could be controlled enough to deliver payloads to build larger objects, such as memory chips and, someday, even buildings, like a self-assembling machine. Tour and a team of postgraduate and postdoctoral researchers constructed a car with chassis, working suspension, wheels and a motor. 'You shine light on it and the motor spins in one direction and pushes the car like a paddle wheel on the surface,' Tour said. The team also built a truck that can carry a payload."

Comment: Re:Are there many high level PT jobs anywhere? (Score 4, Interesting) 396 396

We actually had an interesting situation where I work (spacecraft operations). We had a senior aerospace engineer depart after 15 years to become an airline pilot, of all things (decided to turn a hobby into a job).

About a year later, he came back part time because the routes he flew left him with large blocks of free time at irregular periods during the month, and he was getting bored (because before his "hobby" was flying....and he stopped doing that on his days off!).

It was a win-win situation. He'd give us 40-60 hours a month of hourly work when it was convenient for him. We kept his hopper full of things like documentation, training, and other stuff that most senior guys consider dreg work. Even though he now has enough seniority to avoid pilot furloughs, he'll volunteer to drop his flight hours if the airline needs him to. He just increases his hours with us (and he's so good, we'll take whatever he gives us up to full time).

Since he's not interested in advancing up the ladder, he really does a great job on this low-visibility stuff that really helps an organization run well if it's done right.

Comment: Re:Hopefully this is only the beginning. (Score 5, Informative) 83 83

I understand your point, however this particular software is basically a system for tracking vehicle "funnies" on the ground, it's not something that is in the loop of the vehicle flight software or something used to make critical decisions. The old system is pretty dated and unwieldy to use (I've used it, I work for NASA). We're obligated to try out cheaper alternatives to custom code to see if it works for us without compromising what we are trying to do.

Sometimes it does work for us - the Mission Control Center workstations and the onboard command and control laptops on the Space Station were all recently converted to Red Hat. It is in many ways better than the old proprietary unix solutions because with the source it's easy to do our own mods to the software. We still test the daylights out of it since that is critical software, but it's a lot easier to support since we have the source code and can do our own bug in-house bug investigations, patch it, or rip out things we don't want/need.

Comment: Re:Eh (Score 2, Interesting) 405 405

I guess I'll take exception to calling astronauts the "annointed elite". Read through the biographies of the current crop of astronauts, and you'll see a pretty broad demographic of military officers, researchers, doctors, and even a teacher. Almost all came from a middle class background and got where they are through hard work.

The astronaut selection process is completely merit based, albeit extremely selective (since there's way more applicants than openings).

I'd be interested in what your propose NASA do to put "normal citizens" into space. Right now NASA and a couple of other government agencies are SpaceX's main funding source, and SpaceX probably has the best chance of coming up with a private ride to orbit for normal (albeit rather rich) citizens to go to space based on this work.


(Useful) Stupid BlackBerry Tricks? 238 238

Wolfger writes "Continuing the recent (useful) stupid theme: I've recently become a BlackBerry user, and I'm in love with the obvious(?) tricks, such as installing MidpSSH to access my home box remotely. But I'd like to know what more experienced Crackberry addicts can share."

The computer is to the information industry roughly what the central power station is to the electrical industry. -- Peter Drucker