Space & Science

[Fate]

the latest science experiments on the iss

http://news.bbc.co.uk/1/hi/sci/tech/8053363.stm

[MinaHarker]

I note the Hubble maintenance mission is going well. I hope the Science Museum have updated their spacey bit - Jason and I went a while back and their displays were all pre-Hubble! It's an amazing instrument, and has lasted 19 years already!

[Fate]

heres a query - how come the voyagers have been working for over 40 years far away from the nearest service centre. but hubble needs a service every few years??????

[Jason Thompson]

Differences in design and function. Voyager was always intended to be a one-way flight, so they knew it had to work for at least 12 years without failing, or at least without failing totally. It also didn't have to be quite so good at station-keeping. Hubble has to aim at the same spot for up to days at a time gathering light. That's not an easy thing to manage. Additionally, with the knowledge that Hubble could be serviced if necessary the engineering didn't have to be quite so robust. The Voyagers are not functioning in tip-top condition any more, and would qualify for servicing if they could be reached.

It's also worth pointing out that Hubble servicing missions often also upgrade instruments for new ones, and are not just repairs.

[Fate]

thanks som e interesting point there. the best pics of hubble on bbc

http://news.bbc.co.uk/1/hi/in_pictures/8041583.stm

[Jason Thompson]

Some excellent pictures there. I must say I rather like this one, though...

God's message to his creation?

[MinaHarker]

The current mission is only the 5th servicing mission, and it should allow Hubble to continue operating until 2014. That's 24 years of continuous use, in the harsh environment of space - only 5 servicings. I think that's pretty good.

[Andrew Curnow]

Certainly better than my car.

[Fate]

Certainly better than my car.

it has speed of orbit of 7500mpersec or about 4.5 miles a second

http://en.wikipedia.org/wiki/Hubble_Space_Telescope

so thats a service every 125 million miles. way better than a car

[Andrew Curnow]

Yeah, I'm not getting anything like that sort of mileage, not even in fifth gear.

[Philipnet]

Some excellent pictures there. I must say I rather like this one, though...

God's message to his creation?

That's an "Up Yours" from God.

Gee, thanks God, up yours to!

[Fate]

Some excellent pictures there. I must say I rather like this one, though...

God's message to his creation?

how wuud!!!

i bet thats a picture theyll omit from the school textbooks it almost looks like a tornado in space if not for the "finger". how big is the thing? is it one of those dust clouds which is light years accross? what makes such irregular shapes, i would hav ethought that such things shoould be more spherical really

[Jason Thompson]

what makes such irregular shapes, i would hav ethought that such things shoould be more spherical really

Space isn't empty. There are stellar winds, supernova shockwaves, and all sort of other currents, as well as gravitational variations depending on the mass distribution. Clouds in space are as likely to be twisted into irregular shapes as clouds on Earth, really. Just as well, since those irregularities can eventually lead to gravitational collapse and stellar birth.

[MinaHarker]

I hope no-one here has fallen for the "Mars being the size of the Moon" rubbish that is being emailed around. It turns up every year about this time.

[WhiteCrowNZ]

Having just finished work on an aircraft avionics software project for Harrier - another piece of equipment which is kind of aged now, it's interesting to read the discussions on the Space Shuttle computer. Avionics equipment has to be so rigorously tested, and just can't keep pace with commercial developments. The equipment I've used always feels about 5 years behind on a good day.

I guess I have mixed emotions about the Space Shuttle - I remember as a kid it feeling like the pinnacle of technology. I bought into everything about it being about as safe as you could imagine, and it would open up the universe for us. I remember being really upset after the Challenger incident.

Anyway this is lengthy, but an interesting criticism on the space shuttle,

http://en.wikipedia.org/wiki/Critici...huttle_program

The Orion which will replace it feels almost a step backwards, Apollo revisited, but then again it seems a vehicle which will be much safer.

http://en.wikipedia.org/wiki/Crew_exploration_vehicle

[Jason Thompson]

The Orion which will replace it feels almost a step backwards, Apollo revisited,

Why not revisit Apollo? After all, it worked. In any case, any vehicle design that sits the bit that has to come back intact at the top of the launch stack rather than bolted to the side has an automatic safety advantage over the shuttle design.

[WhiteCrowNZ]

Why not revisit Apollo? After all, it worked. In any case, any vehicle design that sits the bit that has to come back intact at the top of the launch stack rather than bolted to the side has an automatic safety advantage over the shuttle design.

I totally agree with you - after all the Russians have done wonders with their Soyuz capsule after some teething troubles.

The Orion capsule has potential for a robust and safe spacecraft.

But that said, you know the Shuttle being sold to us in the 70s as a kind of airplane into space (even though it isn't), has a kind of schoolboy appeal. Hey I thought HOTOL sounded a great idea.

Anyway with it's problematic history, I do agree with a lot of the critics links, there were a lot of compromises made in the shuttle design which have led to the two tragedies. Building a robust central capsule after sending a massive space vehicle up in the past does feel like a step backwards in a way. But it's a much more flexible unit in terms of potential future missions, and importantly safer.

[Jason Thompson]

the Russians have done wonders with their Soyuz capsule after some teething troubles.

That's something of an understatement. The basic Soyuz design is unchanged after over forty years, and the basic launcher is the same as it was over 50 years ago. A few upgrades here and there in the intervening years, but at a quick glance you wouldn't immediately be able to tell the early Soyuz launches from the more recent ones.

Additionally, variants of the Soyuz spacecraft have been used as unmanned vehicles, and Soyuz was the basis for the design of the Porgress cargo vehicle used to resupply the ISS and Mir.

The Orion capsule has potential for a robust and safe spacecraft.

It certainly does, and it is designed to be at least partially reusable.

there were a lot of compromises made in the shuttle design

A lot indeed. That's what happens when you have design by committee. It doesn't need those huge delta wings, for starters...

which have led to the two tragedies.

That's partly design but largely management and flawed reasoning. If you look at the three major disasters in NASA's history, you find that the same basic root cause persists: we've always done it that way and nothing has gone wrong, therefore it is safe.

Building a robust central capsule after sending a massive space vehicle up in the past does feel like a step backwards in a way.

It does, but only because NASA abandoned capsules in favour of the shuttle. Had there been a continuing expendable spacecraft program, as there has been in Russia, it wouldn't feel so strange to be talking about using one now. Thanks to business politics, NASA was effectively forced into putting all its eggs into one shuttle-shaped basket from 1975 onwards, and things like the Saturn V were specifically decommissioned and production terminated just to avoid competing with the shuttle for heavy lift requirements.

[WhiteCrowNZ]

Of course the irony is that going back to a point, the shuttle has quite low computing power on board.

And it was seen as a manned platform for launching satellites. But the advances in computers and automation have meant we're at the point where all this is obsolete, machines can take care of this themselves.

The point about management problems is a very good one. I was going to mention it myself last post, but it could so easily have got bogged down. The Challenger disaster program on Ch4 was a hot topic at work, as you can imagine in avionics there are similar safety concerns vs management desires to get things out. Thankfully the management at BAE were much better listeners than those at NASA.

[Jason Thompson]

The shuttle still has one unique function, which is that it allows for repair and retrieval of satellites. I'm not sure whether that's considered in the Orion design.

It is unfortunate that the shttle never lived up to its promise, but the slashes in budget, compromises in design and problems in operation have left it far less than it was supposed to be.

[WhiteCrowNZ]

Well I don't think it ever allowed for retrieval of a satellite. It has been considered too dangerous to bring a satellite back down to orbit. Yes it means we have a more disposable attitude to satellite, but maybe that's no bad thing.

There's no reasons really why an Orion can't be used as a hub for a repair job. Just send it up there with an EVA hub module to dock with, perform the mission and then dispose of before returning with. The Orion does seem like a basic item yes, but quite flexible if you send it up in combination with another module.

[Jason Thompson]

NASA's Lunar Reconnaisance Orbiter launched yesterday. Soon we shall have images of the lunar surface with sufficient resolution to make out the landers left there in the six Apollo landing missions. I reckon they'll have some pictures of the sites in time for the 40th anniversary of the first landing in July.

[Si Hunt]

Wasn't the Moon Landing faked? You can see the strings people!

Si.

[Jason Thompson]

Do you really want me to get into that?

[Zbigniev Hamson]

Seeing as it's a NASA probe they'll obviously be able to doctor the photos before release to include this "evidence" of the lunar landings anyway.