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Future Venus Missions
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post Jan 12 2015, 11:45 PM
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QUOTE (katodomo @ Jan 12 2015, 03:03 PM) *
Preferably with a limited-time frame of operations, nothing multi-year...


Given the slow rotation of Venus, that is asking to give up a lot. Creating views from different angles to give you 3D topography are automatically going to be more than one year of mission time if you want to cover a substantial part of the planet. Using MESSENGER as a reference, I don't expect anyone to vote against a Venus proposal for which a four or five year lifetime could be expected. At least not on that basis alone (i.e. they prefer some other mission entirely). Expecially given how fast it would get there.
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vjkane
post Jan 13 2015, 05:05 AM
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QUOTE (katodomo @ Jan 12 2015, 01:03 PM) *
Realistically, going by the recommendations from the committee for the ESA L2/L3 selection, the thing that has a chance of getting through (and then a good chance for selection) is a moderately cheap high-resolution radar mission, something that builds on, renews and improves the Magellan data. Preferably with a limited-time frame of operations, nothing multi-year, and preferably with a proven, technologically mature bus.

Since Magellan, synthetic aperture radar (SAR) has advanced a great deal, and a number of Earth observing satellites now use it. This gives a solid technology base for a Venus radar mission that significantly improves on Magellan's resolution. The general wisdom is that such a mission could be done within the price cap of either a NASA Discovery or an ESA M-class mission. The various proposals vary in how much of the planet would be re-imaged and the focus of the scientific questions (which relates to what gets re-imaged). Most of the proposals also include a thermal emission spectrometer for low resolution (~50 km) composition studies and radio tracking for improved gravity studies. Some proposals also have some other instruments. (Discovery proposals seem to have fewer instruments, probably because the proposers have to pay for the instruments; M-class missions seem to have more, probably because instruments are paid for outside of ESA's budget.)


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Phil Stooke
post Jan 13 2015, 02:16 PM
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Better topography is high on many lists for desired Venus data sets. Magellan altimetry is extremely poor relative to MOLA and LOLA data - a result of having to use radar instead of lasers. There is stereo SAR for parts of Venus, but as yet no integrated global topo dataset. Radar interferometry is touted as a way to get high resolution topography and it would be highly desirable. That plus targeted partial SAR coverage at very high resolution would make a fantastic difference to our understanding of Venus.

But so would almost everything else that is being proposed! Personally, I would like to see surface imaging with MER Pancam-type coverage and resolution instead of the partial strip coverage from Venera cameras, for a few different terrain types.

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stevesliva
post Jul 9 2015, 09:59 PM
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Saw this today in AWST:
Semibouyant Aircraft Could Explore Venus’s Upper Atmosphere

It is a pie-in-the-sky from Northrup Grumman... a big inflatable lifting-body pie.

Seems there is an older writeup of it with some nice images here:
The Inflatable Plane That Would Float Like a Leaf Through Venus’s Atmosphere

It's called VAMP, and the latter link points to a Jan 2013 presentation:
http://www.lpi.usra.edu/vexag/meetings/STI...%20Approved.pdf
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JRehling
post Oct 2 2015, 04:07 PM
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The next slate of Discovery mission candidates has 2 Venus missions in the 5 finalists (the other 3 are all aimed at asteroids). NASA has, remarkably, only sent two missions to Venus since 1967, and none since 1989. The drought may be over.

VERITAS would be an orbiter that would use radar and radio science to study the surface of Venus, returning an excellent map of the entire surface.

DAVINCI would be an entry probe that would give us precise measurements of atmospheric composition and descent imaging.

I'd love it if either of these made the selection, and if both of them could fly eventually. (The asteroid missions aren't bad, either.) All of our Venus knowledge comes from instruments that are now 25-30 years out of date, and this leads to significant deficits in our knowledge of how Venus and therefore, terrestrial planets in general evolved. As we start to get curious about Earth-sized planets orbiting Sun-like stars elsewhere, it's a little crazy that we have one that can be reached with just a 3-month cruise and we've decided to ignore it.
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ZLD
post Oct 2 2015, 05:43 PM
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Won't probably happen due to the constraints of the program but there would be some cost savings in sending both together. That would be my preference.


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ngunn
post Oct 2 2015, 06:25 PM
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I found a little more about DAVINCI on the AAAS website:

DAVINCI would drop a spherical metal ball through the Venusian atmosphere. Studded with sensors, the probe would relay its measurements to Earth via the carrier spacecraft. It would also make the first images of Venus’ surface since the Soviet Venera landers of the 1970s. Glaze says her team will aim DAVINCI at Venus’ “tesserae,” regions of crumpled terrain that are thought to be the remnants of continents. “They’re really mysterious -- we don’t know what they are,” she says. “We’ll be taking pictures of these for the first time.”
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elakdawalla
post Oct 2 2015, 08:18 PM
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I have the following tidbit of additional information from Lori Glaze:
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Mission: Venus atmosphere probe to collect targeted trace & noble gases & isotopes, plus temp, pressure, winds, and imaging. Launch Nov 2021; Touchdown Jun 2023
And this from David Grinspoon:
QUOTE
Descent imaging. Vis & near-IR. Mass spec. Tunable laser spectroscopy. Atmospheric structure instrument.


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scalbers
post Oct 2 2015, 09:41 PM
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As a comparison I wonder how VERITAS radar would compare with Magellan and related maps of the surface?

And would DAVINCI imagery be comparable to what Huygens saw on Titan?


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JRehling
post Oct 2 2015, 10:23 PM
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I think we can expect roughly a 4x improvement in radar resolution vs. that of Magellan, but I'm just estimating that from Cassini and other proposed Venus missions that sit hazily in my memory.

Huygens delivered about 3-4x the precision of Pioneer Venus and the Venera missions in determining atmospheric composition. This could be a radical improvement in scientific understanding, because determining the ratio of noble gas isotopes depends upon accuracy better than the abundance of the rarest isotope you care about. The best Venus measurements were made with tech that is already 30-40 years old!

I don't know how to estimate the quality and value of descent imaging. Venus has a heck of a lot more light reaching the surface than Titan does, but the devil's in the details as to what you see when you look down on Venus: It's never been done before. If the whole area has the same albedo, then it might look pretty bland from above. It's up to Venus to deliver something to look at.

I don't know if DAVINCI would make it to the surface and give us a (partial) panorama from there. Usually, things that have dropped into Venus' atmosphere have made it to the ground, but the cameras may not be side-looking (?).
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scalbers
post Oct 2 2015, 10:34 PM
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If this is a spherical probe we could hope for full 360 degree (spherical) imaging? This is becoming more popular in some terrestrial cameras on the market.


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machi
post Oct 3 2015, 10:58 AM
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QUOTE (scalbers @ Oct 2 2015, 11:41 PM) *
As a comparison I wonder how VERITAS radar would compare with Magellan and related maps of the surface?


Resolution in case of imaging at least 4 better (30m vs 120m globally) and topography at least 40 better horizontally (250m vs 10-30km) and 6 vertically (+/-5m vs +/-31.5m).
It means better topographic map of Venus than we have now for Mars!


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Paolo
post Oct 3 2015, 01:20 PM
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QUOTE (elakdawalla @ Oct 2 2015, 10:18 PM) *
Launch Nov 2021; Touchdown Jun 2023


why so long? it takes much less than 19 months to get to Venus using a conventional Hohmann orbit
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Explorer1
post Oct 3 2015, 03:31 PM
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Maybe it won't be a conventional transfer? Perhaps solar electric propulsion or an Earth gravity assist?
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vjkane
post Oct 3 2015, 04:04 PM
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QUOTE (Paolo @ Oct 3 2015, 05:20 AM) *
why so long? it takes much less than 19 months to get to Venus using a conventional Hohmann orbit

A goal of the mission is to descend over one of the tesserae. They may need a transfer orbit that provides a specific set of solar illumination and visibility from Earth tracking stations over the entry point.


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