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djellison
Posted on: Dec 8 2010, 09:48 PM


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Umm - no. Even if the KH11's still existed ( which they don't - I think they've all reentered ) - they have nothing for which a very significant propulsive upper stage (>10tons to Mars...that's one hell of an ask for any existing booster) could dock on to, they're not designed for the thermal environment for a cruise to Mars, they don't have solar arrays qualified for operation at Mars, and they're not equipped with communications equipment to talk to Earth from Mars either.

  Forum: Exploration Strategy · Post Preview: #167710 · Replies: 145 · Views: 312255

djellison
Posted on: Dec 8 2010, 09:44 PM


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Dead Parrot and/or Spam smile.gif
  Forum: Private Missions · Post Preview: #167708 · Replies: 240 · Views: 2300169

djellison
Posted on: Dec 8 2010, 08:17 PM


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QUOTE (ZLD @ Dec 8 2010, 11:34 AM) *
I'm a little puzzled by that with as much research as has gone into the four Mars rovers but I'm sure there is a more detailed reason.


Think about the surface conditions on Mars. Chilly, dry, but with electrical heaters 'normal' terrestrial electronics and electro-mechanics work ok

That simply isn't true on Venus. I doubt anything of the mobility system of MER would work on Venus. It's just too different.

QUOTE
A mission I'm quite interested in is a flying drone observer sent to Mars. I can't find the name of the proposal but I was puzzled at the time that they claimed it would be powered by batteries and only last a couple of hours.


Batteries for the electronics, a small rocket engine for the

QUOTE
Meanwhile the Solar Impulse team were releasing news about their first trip around the globe with a successful trip through a full night.


Aeronautics on Mars and Earth are very different. Solar Impulse used solar power ( lots of power at Earth ) and a very very efficient airframe

On Mars - the solar power is about half that on Earth ( so already, you're fighting a losing battle ). PLUS - you need an airframe as light and efficient as Solar Impulse just to get off the ground at all, because the air density is so very thin on Mars you have to have an astonishingly efficient airframe travelling at high speed just to generate enough lift to get off the ground.

Solar powered airplanes on Mars are an engineering challenge far far over and above Solar Impuls, and might not even be possible with anything on the engineers shopping list of today.

QUOTE
What better way to take a lot of data quickly over a vast area than from an aerial vehicle. Among other things, it would allow study of Olympus Mons and Valles Marineris, two very interesting geologic locations that are unlikely to be explored by rovers.


How about orbiters? You can take a lot of data, quickly, again and again, mapping those sites That's what killed Ares really, CRISM on MRO producing 6m/pixel hyperspectril Vis-IR mapping spectrometer data, HiRISE producing 25cm/pixel imagery etc etc.

  Forum: Exploration Strategy · Post Preview: #167697 · Replies: 145 · Views: 312255

djellison
Posted on: Dec 8 2010, 03:56 PM


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Nor is anyone here going to have an idea what it could be - and speculation of that nature is a best guessing and at worst, just down right unhelpful.

I would encourage all to carefully read http://www.unmannedspaceflight.com/index.p...st&p=167629 - Nick got it just right.
  Forum: Venus · Post Preview: #167669 · Replies: 736 · Views: 1262518

djellison
Posted on: Dec 8 2010, 07:43 AM


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These are proposals, ideas, a wish list.

There are no Venus rovers currently planned or funded.

A Venus 'in situ' explorer is proposed as one of three finalists for the New Frontiers program - but it is not a rover.
  Forum: Exploration Strategy · Post Preview: #167627 · Replies: 145 · Views: 312255

djellison
Posted on: Dec 8 2010, 12:53 AM


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I'm afraid your Venus rover in a decade and titan rover in 20 years are both far too optimistic. For either of those to be true - we would be seeing them in this decedal survey manifest of proposals - and we don't. moreover, the technical readiness for either simply isn't there. I'm afraid you're probably going to have to double those figures.
  Forum: Exploration Strategy · Post Preview: #167601 · Replies: 145 · Views: 312255

djellison
Posted on: Dec 7 2010, 08:54 PM


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That paper is 10 years old, and many other studies since have suggested alternative mechanisms for those landslides - including dry dust avalanches, CO2 sublimation etc. The wet theory behind them is less popular than a decade ago.
  Forum: Mars · Post Preview: #167580 · Replies: 30 · Views: 37446

djellison
Posted on: Dec 7 2010, 07:26 PM


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Den and ZLD - you're both forgetting one vital part of this puzzle. Air Pressure.

Surface conditions on Mars - at the very warmest - are playing around at the triple point of water. There would only be a tiny temperature window between ice melting, and evaporating away.

http://www.cims.nyu.edu/~gladish/teaching/...ase-diagram.jpg

There are times and places where liquid water could exist on the surface of Mars. Those times are uncommon, and brief.
  Forum: Mars · Post Preview: #167570 · Replies: 30 · Views: 37446

djellison
Posted on: Dec 7 2010, 07:19 PM


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If they're only getting 40s per 10 mins - that would explain the difficulty in getting the tracking data required to figure out the orbit. It takes a while to lock up on a signal and figure out the doppler etc
  Forum: Venus · Post Preview: #167569 · Replies: 736 · Views: 1262518

djellison
Posted on: Dec 7 2010, 07:12 PM


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IN one of his lectures, I'm sure Steve used the phrase 'Petrified Dinosaur Brain' to, in jest, describe Wopmay.

  Forum: Opportunity · Post Preview: #167567 · Replies: 548 · Views: 280127

djellison
Posted on: Dec 2 2010, 06:48 PM


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I read it as Astro-Zero for years smile.gif
  Forum: Opportunity · Post Preview: #167329 · Replies: 548 · Views: 280127

djellison
Posted on: Dec 2 2010, 01:31 AM


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Could be that it's a very 'dark' filter (i.e. it's bandpass is either narrow, or well outside the best efficiency of the ccd, or both) and thus requires long exposure times and thus the raw unprocessed imagery is prone to noise.
  Forum: Cassini's ongoing mission and raw images · Post Preview: #167290 · Replies: 52 · Views: 45782

djellison
Posted on: Dec 2 2010, 01:18 AM


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QUOTE (EDG @ Dec 1 2010, 05:07 PM) *
Also, were the Hyperion images the result of a targeted flyby of that moon


http://www.planetary.org/explore/topics/ca.../tour.html#2010

Sun, Nov 28, 2010
2010-332T03:29Nontargeted flyby of Hyperion (141H)
Inbound 71756.3 km flyby, speed = 4.9 km/s, phase = 73°


Thanks Emily smile.gif

  Forum: Cassini's ongoing mission and raw images · Post Preview: #167287 · Replies: 52 · Views: 45782

djellison
Posted on: Nov 30 2010, 10:18 PM


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Awesome - can't wait to add these as normal maps to Eyes on the Solar System smile.gif
  Forum: Cassini general discussion and science results · Post Preview: #167241 · Replies: 10 · Views: 14075

djellison
Posted on: Nov 30 2010, 12:27 AM


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Thinking out-loud - http://www.unmannedspaceflight.com/index.p...0&start=100 - Any chance of a SMART 1 tweak to the reason I still love looking at a dos box smile.gif
  Forum: Image Processing Techniques · Post Preview: #167207 · Replies: 133 · Views: 1805616

djellison
Posted on: Nov 28 2010, 06:01 PM


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Bingo. The problem wasn't that the antenna moved, the problem was that it GOT moved.
  Forum: Jupiter · Post Preview: #167163 · Replies: 269 · Views: 1144848

djellison
Posted on: Nov 28 2010, 09:35 AM


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Careful on the broad assumptions there EDG, that antenna had very high heritage from the TDRSS antenna design. It was a low risk, good flight heritage component. There are moving components in spacecraft. reaction wheels, antenna gimbals, solar array gimbals.... heck, it's thought the most recent Delta IV heavy launch contained a NRO spacecraft with an antenna of many TENS of metres as an in space deployable.

NASA far from learnt to never build a probe with an unfolding umbrella antenna again - they are on the TDRSS sats launch SINCE galileo - infact two on each spacecraft
http://en.wikipedia.org/wiki/Tracking_and_...Relay_Satellite

Six TDRS launches have taken place since Galileo - for a total of 12 very very similar antennae, all of which deployed without incident.

  Forum: Jupiter · Post Preview: #167148 · Replies: 269 · Views: 1144848

djellison
Posted on: Nov 24 2010, 05:54 PM


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I don't think MI's been through an entry - it has no symptoms of being meteoritic (fusion crust etc ) and indeed its angular edges would almost preclude such an adventure would they not?
  Forum: Opportunity · Post Preview: #167024 · Replies: 548 · Views: 280127

djellison
Posted on: Nov 24 2010, 04:38 PM


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QUOTE (eoincampbell @ Nov 24 2010, 08:08 AM) *
I don't remember seeing inclined, "mesh" type dunes (esp. inside craters) on our travels...



Unless I'm missing something - these dunes are not significantly different to those in Endurance and Victoria.
  Forum: Opportunity · Post Preview: #167016 · Replies: 548 · Views: 280127

djellison
Posted on: Nov 24 2010, 04:03 PM


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Oh - I don't for one second think we're going to 'see' them in those visualizations of the radar return for the Nucleus. If there's anything present, it'll be in the signal in some other way.
  Forum: Cometary and Asteroid Missions · Post Preview: #167012 · Replies: 378 · Views: 339596

djellison
Posted on: Nov 24 2010, 06:57 AM


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They did use Arecibo with Hartley 2. It'll be interesting to see, if with the benefit of hindsight, they can say 'Yup - we saw the golf balls'
  Forum: Cometary and Asteroid Missions · Post Preview: #167000 · Replies: 378 · Views: 339596

djellison
Posted on: Nov 23 2010, 11:22 PM


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It certainly looks comparable in size to something like Wopmay back up at Endurance.
  Forum: Opportunity · Post Preview: #166984 · Replies: 548 · Views: 280127

djellison
Posted on: Nov 23 2010, 08:48 PM


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Ahh - so were you speaking to the camera via USB from the board running the RTOS, or was it just guesstimated times before launch in a script? By custom firmware, I'm assuming CHDK.
  Forum: Private Missions · Post Preview: #166973 · Replies: 4 · Views: 11858

djellison
Posted on: Nov 23 2010, 07:45 PM


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You appear to have been attacked by a giant edge of space squid. ARHGHGHGH runaway smile.gif

Extra special kudos for this : http://www.francescobonomi.it/minihab/stra...eplanet_big.jpg - very VERY good indeed!!

What camera did you fly, what orientation did you have it in and how did you trigger it?
  Forum: Private Missions · Post Preview: #166968 · Replies: 4 · Views: 11858

djellison
Posted on: Nov 21 2010, 02:07 AM


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For those wondering about Rosetta... remember, Deep Imapct flew past Hartley 2 at 12km/sec.

Rosetta will be rendezvousing with C-G, i.e. close to ZERO km/sec - it's just the speed imparted by the out gassing process that will be troublesome
  Forum: Cometary and Asteroid Missions · Post Preview: #166877 · Replies: 378 · Views: 339596

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