Juno Mission - 2nd new frontier

gunsandrockets · Mar 11, 2007

Solar panels! On a Jupiter orbiter mission?? Alrighty then...

gunsandrockets · Mar 11, 2007

"Well this one is certainly a bold idea! They chuck an impactor at the surface, which skims up some ice grains that they then hope to collect as the spacecraft whizzes by at 10km/s (this of course does negate the need for a huge rocket because the whole mission is a flyby). I hardly think though that this is going to "provide evidence of life deep below." It is certainly not a "core sample". I still think such a mission is at least 10 years away technologically. Interesting nonetheless." Dagnabit! Why not use the same impactor/flyby architechture for a Phobos or Deimos sample return mission? Planning for a manned mission to Mars requires knowing if there is recoverable subsurface ice present at the Martian moons.

mithridates · Mar 11, 2007

Isn't it because they expect Russia to take care of that in two years? http://en.wikipedia.org/wiki/Phobos-Grunt <div class="Discussion_UserSignature"> ----- http://mithridates.blogspot.com </div>

gunsandrockets · Mar 11, 2007

"Isn't it because they expect Russia to take care of that in two years?" Ah, if only that were so! First off it is still questionable that the Russians will come up with the money to fly the mission. Secondly the possible ice on Phobos is probably 10m under the surface, and even that shallow probably only at a Polar location. The Russian probe is only going to scratch the surface compared to what is needed to find the ice.

3488 · Mar 12, 2007

Hi there. Solar Power will be possible, but the solar panels will have to be quite large & VERY efficient. Sunlight at Jupiter orbit averages about 4% or about one twentyfifth as strong on Earth or about 52.8 watts per square metre (as against 1,320 watts per square metre at Earth orbit)!! Andrew Brown. <div class="Discussion_UserSignature"> "I suddenly noticed an anomaly to the left of Io, just off the rim of that world. It was extremely large with respect to the overall size of Io and crescent shaped. It seemed unbelievable that something that big had not been visible before". Linda Morabito on discovering that the Jupiter moon Io was volcanically active. Friday 9th March 1979.http://www.launchphotography.com/ http://anthmartian.googlepages.com/thisislandearthhttp://web.me.com/meridianijournal </div>

JonClarke · Mar 13, 2007

Thanks Andrew. Given modest power requirements and current technology solar panels are quite feasible at Jupiter's distance. If Juno uses 200 watts like NH, if the irradiance is 50 w/m2, and the solar cells have the 25% efficiency of those on MRO, we would need 16 m2. If Juno needs 500 w like Galileo it would require 40 m2 of panels. Neither area is unreasonable, but the 16 m2 looks about right for the drawing given, assuming that the Juno bus is a similar size to NH. <div class="Discussion_UserSignature"> Whether we become a multi-planet species with unlimited horizons, or are forever confined to Earth will be decided in the twenty-first century amid the vast plains, rugged canyons and lofty mountains of Mars Arthur Clarke </div>

3488 · Mar 13, 2007

Hi Jon. You are very welcome. JUNO is a fantastic mission, a real chance to probe the inner nature of the beast. JUNO does use similar technology overall to New Horizons, hence its low energy efficiency power requirements. The JUNO Cam is a colour version of the LORRI camera on board New Horizons. kane007's illustration is accurate, so the solar panels shown as will be on the real craft. The diameter of JUNO will be 20 metres across. It goes to show how electronics have come along, solar power would not have been possible with the Pioneers' Voyagers or with Galileo (not as though they were energy hungry, far from it, given their performance). I for one will follow the developments very closely with this mission. A return to Jupiter. GREAT!!!!!!! Hopefully, before JUNO reaches final Jovicentric orbit, hopefully volcanic Io will be seen up close with the JUNO Cam!!!! Also I hope that Red Spot Junior lasts long enough for JUNO's arrival!!!!! The fact that JUNO will attempt at finding at how deep the atmospheric features go, such as the Great Red Spot, Red Spot Junior (if it still exists then) & the other anti cyclonic (high pressure) white ovals go into Jupiter's atmosphere, as compared to the cyclonic (low pressure) storms will be exciting. This will show how deep Jupiter's Troposphere go, & how the internal heat exchanges between Jupiter's interior & atmosphere. I wonder if precipitation rates can be measured. From the Galileo mission using infrared, it was thought that some of Jupiter's giant thunderstorms to the north west of the Great Red Spot, could be producing hailstones the size of footballs & rainfall that could be measured in metres per month!!! Andrew Brown. <div class="Discussion_UserSignature"> "I suddenly noticed an anomaly to the left of Io, just off the rim of that world. It was extremely large with respect to the overall size of Io and crescent shaped. It seemed unbelievable that something that big had not been visible before". Linda Morabito on discovering that the Jupiter moon Io was volcanically active. Friday 9th March 1979.http://www.launchphotography.com/ http://anthmartian.googlepages.com/thisislandearthhttp://web.me.com/meridianijournal </div>

3488 · Mar 13, 2007

Hi gunsandrockets. You are right. I too doubt that the Russians will have the cash for such a mission. FobosGrunt will require ESA & or NASA participation, no matter what. ------------------------------------------------------------------------------------------------------------------------------- Phobos indeed does have a low density, only about 20% denser than ice (Deimos probably too). Both Phobos & Deimos are though to be captured type C, Carbonaceous asteroids, much like asteroid 253 Mathilde, encountered by the 433 Eros bound NEAR Shoemaker spacecraft. Tracking revealed 253 Mathilde to be less than 10% denser than ice. This leads to two possibilities. Either 253 Mathilde & / or Phobos & Deimos are rubble piles held together by gravity or they contain a lot of hidden ice, much like dwarf planet 1 Ceres??? If anyone is interested, the route to be taken by JUNO is below. Andrew Brown. <div class="Discussion_UserSignature"> "I suddenly noticed an anomaly to the left of Io, just off the rim of that world. It was extremely large with respect to the overall size of Io and crescent shaped. It seemed unbelievable that something that big had not been visible before". Linda Morabito on discovering that the Jupiter moon Io was volcanically active. Friday 9th March 1979.http://www.launchphotography.com/ http://anthmartian.googlepages.com/thisislandearthhttp://web.me.com/meridianijournal </div>

JonClarke · Mar 13, 2007

Phobos Grunt now has Chinese participation and the UK is also interested in Phobos sample return. This increases the lilikihood of the mission actually flying. Jon <div class="Discussion_UserSignature"> Whether we become a multi-planet species with unlimited horizons, or are forever confined to Earth will be decided in the twenty-first century amid the vast plains, rugged canyons and lofty mountains of Mars Arthur Clarke </div>

brellis · Sep 14, 2007

Juno Update <div class="Discussion_UserSignature"> I'm a recovering optimist - things could be better. </div>

3488 · Sep 14, 2007

Thanks brellis. I like the JUNO mission objectives very much. <img src="/images/icons/laugh.gif" /> . Andrew Brown. <div class="Discussion_UserSignature"> "I suddenly noticed an anomaly to the left of Io, just off the rim of that world. It was extremely large with respect to the overall size of Io and crescent shaped. It seemed unbelievable that something that big had not been visible before". Linda Morabito on discovering that the Jupiter moon Io was volcanically active. Friday 9th March 1979.http://www.launchphotography.com/ http://anthmartian.googlepages.com/thisislandearthhttp://web.me.com/meridianijournal </div>

MeteorWayne · Oct 5, 2007

10.03.07 John Yembrick Headquarters, Washington 202-358-0602 john.yembrick-1@nasa.gov George Diller Kennedy Space Center, Fla. 321-867-2468 george.h.diller@nasa.gov CONTRACT RELEASE: C07-051 NASA SELECTS LAUNCH SERVICES PROVIDER FOR JUNO JUPITER MISSION CAPE CANAVERAL, Fla. - NASA's Launch Services Program office at the Kennedy Space Center, Fla., has selected Lockheed Martin Commercial Launch Services of Littleton, Colo., for the Juno mission to Jupiter. The $190 million contract award is a competed firm-fixed-price task order. It includes the launch service for an Atlas V model 551 rocket, payload processing, launch vehicle integration, and the necessary tracking, data and telemetry support. The spacecraft is scheduled to lift off from Cape Canaveral Air Force Station, Fla., in August 2011 on an interplanetary trajectory to Jupiter. Juno will arrive at Jupiter in August 2016 to uncover the secrets hidden beneath the planet's thick, colorful clouds. Juno's remote sensing and gravity science measurements will characterize Jupiter's interior, atmosphere and polar magnetosphere with the primary science goal of understanding the planet's origin and evolution. A principal investigator from the Southwest Research Institute in San Antonio leads the Juno mission. For more information about the Juno mission, visit: http://juno.nasa.gov <div class="Discussion_UserSignature"> But the Krell forgot one thing John. Monsters. Monsters from the Id. I really, really, really, really miss the "first unread post" function </div>

h2ouniverse · Oct 6, 2007

in reply to : ------------------Solar panels! On a Jupiter orbiter mission?? -------------- Yes, RTG are too expensive. And technologies now exist to enhance yield and get reasonable array areas. They even evisage using that up to Saturn. ESA too has development going on (LILT: Low Illumination Low Temperature). Regards.

3488 · Oct 11, 2007

Launch Vehicle Atlas 5 selected for launch of JUNO. Article here. Andrew Brown. <div class="Discussion_UserSignature"> "I suddenly noticed an anomaly to the left of Io, just off the rim of that world. It was extremely large with respect to the overall size of Io and crescent shaped. It seemed unbelievable that something that big had not been visible before". Linda Morabito on discovering that the Jupiter moon Io was volcanically active. Friday 9th March 1979.http://www.launchphotography.com/ http://anthmartian.googlepages.com/thisislandearthhttp://web.me.com/meridianijournal </div>

h2ouniverse · Oct 13, 2007

Great news, for that means they should have comfortable margins vs launch mass.

alokmohan · Oct 13, 2007

Purpose?

h2ouniverse · Oct 13, 2007

Being marginal in terms of launch mass in the course of a program generates constraints: * risk for instruments * more iterations on design * adverse pressure when investing some mass in redesigns, repairs, reworks = /> detrimental to safe technical solutions Plus: more fuel can be loaded, providing extra lifetime and/or more safety in case of unexpected overconsumption Best regards.

JonClarke · Oct 13, 2007

I suspect the later. Look how long Galileo took compared to Voyager or Pioneer. Jon <div class="Discussion_UserSignature"> Whether we become a multi-planet species with unlimited horizons, or are forever confined to Earth will be decided in the twenty-first century amid the vast plains, rugged canyons and lofty mountains of Mars Arthur Clarke </div>

jimfromnsf · Oct 13, 2007

New Horizons had a solid 3rd stage to provide the additional velocity. At New Horizon's velocity a spacecraft would need a larger amount of fuel to brake into orbit

comga · Oct 13, 2007

vishniac "..how come it took New Horizons 6 months to cross jupiter orbit but will take 5 years for Juno? " New Horizons is not stopping anywhere. It needs to move fast, to get to Pluto before we all die of old age (and Pluto's atmosphere freezes). Jupiter is a source of momentum, (and a target for practicing getting science) not its destination. (BTW, it took 13 months for NH to get to Jupiter.) Juno is to go into orbit around Jupiter. It cannot arrive with high relative velocity. The goal is to enter Jupiter's sphere of influence with as little speed as possible. That minimizes the amount of energy needed to brake into orbit.

alokmohan · Oct 14, 2007

JUNO to face giant,eh?Can you tell me if JUNO is name of greek or roman god?

alokmohan · Oct 14, 2007

Is nit mamed JUNO for that reason?

JonClarke · Oct 14, 2007

It would be a completely different mission. I find it hard to imagine any conceivable improvement in solar power that would have it feasible for Saturn, let alone further out. Aerocapture is a possibility. Galileo's descent probe survived much harsher forces during direct entry than would be experienced during aerocapture, so that should not be a problem. One problem might be that aerocapture means a you end up in a low circular low orbit, and to study the moons of any of the giant planets you want a higher ellipical orbit. Jon <div class="Discussion_UserSignature"> Whether we become a multi-planet species with unlimited horizons, or are forever confined to Earth will be decided in the twenty-first century amid the vast plains, rugged canyons and lofty mountains of Mars Arthur Clarke </div>

JonClarke · Oct 14, 2007

Juno was the name in Roman mythology to the sister and wife of Jupiter. The Greeks called her Hera, and she was a most formidable lady. <div class="Discussion_UserSignature"> Whether we become a multi-planet species with unlimited horizons, or are forever confined to Earth will be decided in the twenty-first century amid the vast plains, rugged canyons and lofty mountains of Mars Arthur Clarke </div>

alokmohan · Oct 14, 2007

Mission named after her?

Juno Mission - 2nd new frontier

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