First steps - back to the moon.

[rhinochopig]

Didn't see this so apologies if a repost.

The SLS gets its first wind-tunnel test.

http://phys.org/news/2012-11-sls-flies-langley-tun...

[Eric Mc]

Long way to go.

[rhinochopig]

Eric Mc said:

Long way to go.

It is, but someone once said they'd put the first man on the moon by the end of the decade, and they did

The SLS is one of the most critical components for exploring the Moon and beyond to Mars. It excites me anyway; especially as I was too young to see man land on the moon.

[Caruso]

They'll be visiting an asteroid before the moon hopefully, which will be more interesting IMO.

[Eric Mc]

rhinochopig said:

Eric Mc said:

Long way to go.

It is, but someone once said they'd put the first man on the moon by the end of the decade, and they did

The SLS is one of the most critical components for exploring the Moon and beyond to Mars. It excites me anyway; especially as I was too young to see man land on the moon.

No sense of national urgency this time so nothing will be happening within a decade. We already have had two "return to the moon" false starts previously - 1988 and 2004.

[Simpo Two]

Why are we redesigning the wheel? Why not build more Saturn Vs? They worked in the 1960s, they can work in the 2010s. Chemistry hasn't changed.

Eric Mc said:

No sense of national urgency this time so nothing will be happening within a decade. We already have had two "return to the moon" false starts previously - 1988 and 2004.

But the Mayan calendar predicts the end of the world on 21 December, so we only have 3 weeks to blast off and found a moon colony and save the human race!

[Eric Mc]

Simpo Two said:

Why are we redesigning the wheel? Why not build more Saturn Vs? They worked in the 1960s, they can work in the 2010s. Chemistry hasn't changed.

Eric Mc said:

No sense of national urgency this time so nothing will be happening within a decade. We already have had two "return to the moon" false starts previously - 1988 and 2004.

But the Mayan calendar predicts the end of the world on 21 December, so we only have 3 weeks to blast off and found a moon colony and save the human race!

Technology and materials have changed though.
The Saturn V is essentially 1950s technology. However, one of the SLS options is to use the Satrurn V F1 engines so it is on the cards that elenents of the first stage, at least, of the Saturn V will be used. The second and third stages of the Saturn V used liquid hydrogen/oxygen engines - similar in concept to those used in the Space Shuttle. Modified Shuttle engines are also part of the SLS concept.

So, there is going to be a fair amount of carry over of technology from both Apollo and the Space Shuttle in the SLS/Orion combination - married to new materials and structures. It isn't a question of reinventing the wheel, It's a case of readapting the wheels devised over 50 yerars of rocket development into a new vehicle which should be at least as capable as the Saturn V.
I am sure there will be a heap more reusability in the SLS/Orion than there was in the Saturn V too.

[jmorgan]

They did divert into a delivery truck for a while so they have to learn the skills again. The irony is the Russians are still plodding along nicely.

Reading that they recently discovered cracks in the capsule.

[Eric Mc]

Which is par for the course during the ground based tests, to be honest.

[jmorgan]

Just trying to find a suitable linky and came across a certain Rachel Kraft in the news release. Coincidence?


Anyway.

http://www.spaceflightnow.com/news/n1211/23eft1cra...

[Eric Mc]

His daughter is called Kristi-Anne, not Rachel.

It could be a grand-daughter though.

[jmorgan]

Just one of life's ironies then.

[MartG]

As Eric says, technology has moved on a lot since the Saturn family of launchers were designed, so it does actually make sense to design a new launcher using more up-to-date components.

Although the RS-25 SSME engine was originally designed back in the 70s it has been evolved during the lifetime of the Shuttle, with the RS-25D version being capable of a max. of 111% of the original version's thrust. Once the ex-Shuttle SSMEs have been used up, plans are underway for cheaper non-reuseable versions ( either RS-25E or RS-25F ) to be developed, so the basic engine is still evolving. Similarly the SLS core stage structure is based on the latest super-lightweight version of the Shuttle external tank, modified for the greater structural loads expected for the inline v. piggyback payload configuration. The tank structure is considerably lighter than that used by the Saturn V.

The only way it would have made sense to reuse Saturn Vs would have been if the Saturn had been kept in service, with its design being evolved over time to encompass the same technology updates embodied on the Shuttle systems. Having said that ( as Eric points out ) there are plans to use updated F-1 engine designs in the Block 2 SLS boosters, though this is just one of a number of options currently being investigated by NASA.

Thankfully, with Obama having been re-elected, there is no new administration wanting to cancel everything the previous administration did, so SLS stands a reasonable chance of getting at least the first couple of test flights launched.

[Simpo Two]

MartG said:

As Eric says, technology has moved on a lot since the Saturn family of launchers were designed, so it does actually make sense to design a new launcher using more up-to-date components.

My dustbin is plastic. It works. I don't need a carbon fibre one... Just because there is new tech doesn't mean you have to use it - there is a bizarre modern habit to keep piling in more and more 'tech', and the more you pile in, the more it costs and the more likely something is to go wrong. I think you have to put the objective first, and achieve it in the simplest way, not the most complex.

[Eric Mc]

Up to a point you are right - but the technicians who work on and design rockets today are trained and expert on these newer materials. If they were told "The new rocket must contain the same materials and structure as the 50 year old Saturn V design", you would be making life far more difficult for them than if they were using the technology they understand.

In fact, it would be far more costly to back engineer using half century old technologies and probably forgotten techniques.

[MartG]

Simpo Two said:

My dustbin is plastic. It works. I don't need a carbon fibre one... Just because there is new tech doesn't mean you have to use it

But if a carbonfibre component masses half that of a plstic component, it requires less fuel to launch into orbit.

[Simpo Two]

MartG said:

But if a carbonfibre component masses half that of a plstic component, it requires less fuel to launch into orbit.

You're right, but I have no plans to launch my dustbin into orbit



If the ability to re-make Saturn Vs is lost (like the leading spar of a Hawker Hurricane) then fair point, take another route.

[jmorgan]

I look at it this way, if they had not diverted to the shuttle then the Saturn would have evolved and would not be materially the equivalent to the 1960's version and might even be replaced with something else. It would have evolved.

[Eric Mc]

As has happened with the Russian R7/Soyuz rocket. It has evolved steadily over the decades.

Once the Saturn family came to an end and the personnel retired or died off, the chances of being able to resurrect the programme got less and less with each passing year.

[MartG]

jmorgan said:

I look at it this way, if they had not diverted to the shuttle then the Saturn would have evolved and would not be materially the equivalent to the 1960's version and might even be replaced with something else. It would have evolved.

If they hadn't developed the shuttle, and kept the Saturn, then it would have evolved like you say. At a wild guess I think new materials and a general tidy-up of over-engineered parts would have knocked at least 10% off the structural weight of it, while uprated engines such as the F-1A and the J-2S would also have increased performance. I would also have expected that some of the variants on the basic design such as the INT-20 ( 4 engined 1st stage, no S-II, S-IVB as the 2nd stage ) and the INT-21 ( almost identical to the Skylab launcher ) would have seen the light of day, and that additional Skylab flights would have been made.