[meteorite-list] All These Worlds Are Yours, Except Europa. Attempt No Landing There.

From: Gerald Flaherty <grf2_at_meteoritecentral.com>
Date: Mon Mar 21 13:24:56 2005
Message-ID: <014d01c528e3$6a147520$6401a8c0_at_Dell>

Extrodinary Guy!!
----- Original Message -----
From: "Sterling K. Webb" <kelly_at_bhil.com>
To: <meteorite-list_at_meteoritecentral.com>
Sent: Monday, March 14, 2005 3:03 PM
Subject: Re: [meteorite-list] All These Worlds Are Yours,Except Europa.
Attempt No Landing There.


> HI!
>
> I, for one, occasionally feel like we could do with a dose of monolith
> maker hijinks! Or any
> evidence of others -- beyond a Martian bacterium.
> To quote another novel of wonder*, "The Universe is a pretty big place.
> So, if it's just us, it
> seems like a terrible waste of space."
>
> Sterling Webb
>
> *Carl Sagan, CONTACT
> -----------------------------------------------------
>
> Darren Garrison wrote:
>
>> The monolith makers aren't going to be happy with this:
>>
>> http://news.bbc.co.uk/2/low/science/nature/4347571.stm
>>
>> Monday, 14 March, 2005, 13:16 GMT
>> Europe tells US: 'Come to Europa'
>> By Jonathan Amos
>> BBC News science reporter
>>
>> The next big cooperative European-US space mission will be to Europa, the
>> ice-crusted moon of
>> Jupiter.
>>
>> A joint working team is being set up to consider what sort of spacecraft
>> would be needed and what
>> each side could do.
>>
>> Officials in Washington and Paris are keen to follow up the spectacular
>> success of Cassini-Huygens
>> at Saturn.
>>
>> "It was a beautiful marriage and we really are looking to do a repeat,"
>> said Professor David
>> Southwood, from the European Space Agency (Esa).
>>
>> Southwood told the BBC News website that "Europe could do Europa on its
>> own", but that a cooperative
>> venture was extremely attractive.
>>
>> "It's a natural for the next big international collaboration in space"
>> Prof Fred Taylor, Oxford University
>>
>> Many scientists agree that Europa is now a high priority target for a
>> major mission.
>>
>> The moon, discovered by Galileo, is slightly smaller than the Earth's
>> Moon. Its covering of white
>> and brownish-tinted ice is riven with cracks that are probably the result
>> of stressing caused by the
>> contorting tidal effects of Jupiter's strong gravity.
>>
>> Researchers speculate that tidal heating may even have produced vast
>> oceans of water under the ice
>> sheet and that this environment could harbour micro-organisms.
>>
>> Convenient time
>>
>> The Esa director of science held discussions about Europa with
>> counterparts at the US space agency
>> (Nasa) at the end of last week. "I've definitely piqued their interest,"
>> he said.
>>
>> The discussions are at a very early stage - and a mission that would
>> launch no earlier than 2016 is
>> some way off becoming a reality.
>>
>> Nevertheless, Professor Southwood said it was a good time to consider how
>> the two agencies could
>> build on their Saturn experience, which has produced stunning images of
>> the ringed planet and put a
>> lander on the surface of Titan.
>>
>> EUROPA - MOON OF JUPITER
>>
>> Orbit: 670,900km from Jupiter
>> Diameter: 3,138km
>> Discovered by Galileo and Marius in 1610
>> Ice crust may be many tens of km deep
>>
>> The Americans had planned to go to Europa independently with their
>> Jupiter Icy Moons Orbiter (Jimo).
>> But the ambitious project, which would have used a nuclear propulsion
>> system, has been shelved as
>> Nasa re-focuses its budget on a White House initiative that could take
>> humans back to the Moon.
>> As a consequence, the European suggestion of a joint mission to Europa
>> has been favourably
>> entertained.
>>
>> As with Cassini-Huygens, Southwood envisages the new mission
>> incorporating a double-spacecraft
>> architecture.
>>
>> Surface imperative
>>
>> "You've got to have a relay satellite," he explained. "You go together;
>> you fly out there in tandem.
>>
>> "They separate after Jupiter orbit insertion and then you leave the relay
>> satellite in orbit around
>> Jupiter, preferably in a resonance with Europa.
>>
>> "Then there's a debate about what you do at Europa. Personally, I would
>> like deep-penetrating radar
>> [on an orbiter]. But that's because I'm a remote-sensing man.
>>
>> "I believe you get more by getting the global picture than you do by
>> scratching and sniffing the
>> surface."
>>
>> But the pressure to go down to Europa's cracked and blotchy surface would
>> be immense, said Professor
>> John Zarnecki, the principal investigator on the surface science
>> instruments loaded on to Huygens
>> for its Titan descent.
>>
>> "If it is technically feasible to go to the surface, you would want to do
>> that. Huygens' surface
>> image on Titan says everything," the Open University researcher enthused.
>>
>> "But, it may be that what you want to do - to look below Europa's ice -
>> you can do that better from
>> orbit.
>>
>> "The Esa-Nasa group that's going to be set up will look at just these
>> sorts of technical issues,"
>> added Professor Zarnecki, who has been party to the initial
>> trans-Atlantic discussions.
>>
>> Power needs
>>
>> Researchers at the German Aerospace Centre are already developing a
>> prototype technology that could
>> be used to melt through Europa's ice sheet. Any water might be a
>> considerable (and possibly
>> unreachable) way down - 20-30km down.
>>
>> Once under the sheet, the probe would take samples and drop mass to begin
>> a slow climb back up the
>> ice column. On the surface, it could then send data to an orbiter or
>> relay satellite for onward
>> transmission to Earth.
>>
>> DEVELOPING SPACE TECHNOLOGY
>>
>> Melting through Europa's ice
>>
>> Europe already has a major mission en route to Jupiter's orbit - the
>> Rosetta mission, which will
>> chase down a comet and put a lander on its surface. This has given Esa
>> the confidence to go it alone
>> to Europa if the Americans decide eventually not to participate in a
>> joint mission.
>>
>> But a key factor is likely to be power systems. Although solar panels
>> will work on spacecraft at
>> that distance, the desire for sufficient energy to drive many instruments
>> means any mission would
>> really need to go with radioisotope thermal generators (RTGs) - solid
>> state electrical generators
>> powered by the heat of radioactive decay.
>>
>> Europe has no expertise with RTGs - the Americans have, and Cassini
>> carries three to provide 700
>> watts to its systems.
>>
>> "I'd much rather do this with RTGs," said Professor Southwood. "And that
>> makes it almost certainly a
>> joint venture with the Americans and why should we do it separately?
>>
>> "This was waiting to happen. Someone just had to say it."
>>
>> Professor Fred Taylor, of Oxford University, UK, said the case for going
>> to Europa was compelling.
>>
>> "The attraction of Europa is that it is a water world - the surface is
>> frozen, of course, because of
>> its exposure to cold space, but not far underneath the ice is an ocean of
>> warm water.
>>
>> "We have never explored such a place beyond our own Earth, and the
>> technology required is not too
>> different from the successful US-European Cassini-Huygens mission, so
>> it's a natural for the next
>> big international collaboration in space," commented the scientist, who
>> worked on the 1990s Galileo
>> mission to Jupiter.
>>
>> "It will be much cheaper than Jimo, which is more of a long-term project
>> (and which has not been
>> abandoned completely)."
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Received on Mon 14 Mar 2005 05:16:04 PM PST