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Thread: Active Interplanetary Missions

  1. #31
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    NASA lost contact with STEREO-B on October 1st following a system reset as a test for the planned SEL3 pass in which it would not have been able to contact Earth.

    B (Behind) is the STEREO orbiter trailing behind Earth, currently located at about -162 degrees halfway between the Sun-Earth-Lagrange Point SEL5 at -120 degrees and SEL3 at -180 degrees, opposite from the Earth on the other side of the Sun. STEREO-B was planned to enter a "side-lobe operations stage" on Dec 1st, during which it would only remain in extremely limited contact with Earth for one year while the Sun would pass between Earth and the orbiter. STEREO-A already entered this stage.

    The last image automatically publicized from STEREO-B was taken on September 27th:

    Attachment 38171
    (ultraviolet image of the sun at the 195 Angstrom bandpass)

  2. #32
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    This needs to be here:

    Attachment 38411

  3. #33
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    According to a member of the Venus Express science team, the orbiter is still well and alive.

    They're on the last fuel reserves though, which means the fuel will run out during any of the next regular orbit raising campaigns; these campaigns each include about 10 orbit correction maneuvers, and are scheduled for end of november, mid-february and early june - about one every 3.5 months. If they survive one, they'll continue to the next, then the next and so on.

    Current scientific mission during the remainder of Venus Express' lifetime is examining volcanism on Venus, both with infrared pictures of suspected volcanoes on the surface and by measuring the SO2 levels in the atmosphere (which are suspected to be sustained by volcanism). Whether there are active volcanoes on Venus has been debated since the 60s, with the alternative theory being that the SO2 level in the upper atmosphere rises and falls with highly dynamic weather pattern.

    Akatsuki, if JAXA manages the orbital insertion in 2015 or 2016, has a similar mission outline, along with studying patterns of heating in the atmosphere.

  4. #34
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    JUICE mission red book, version 1.0:

    ESA Science & Technology: JUICE Definition Study Report (Red Book)
    (7.5 MB PDF, around 130 pages)

    Juice has been fixed down into one of the biggest things we've ever sent out there, a whopping 4.7 ton wet mass spacecraft / 1.8 tons dry; the only bigger spacecraft making it to another planet was Cassini at 5.2 tons wet / 2.5 tons dry incl. entry probe. Juice will be the biggest spacecraft beyond earth's gravity well powered by solar panels, with the second-largest being NASA's Juno at 3.6 tons wet / 1.6 tons dry, currently enroute to Jupiter. NASA's larger Mars probes - such as Curiosity - have weighed in similar to Juno. The solar panels of Juice would be (at around 100mē) around 50% larger than those of both Juno (60mē) and Rosetta (64mē).

    The mission for Juice will be:
    - launch in 2020, 2022 or 2023 (below dates for 2022)
    - gravity assist flybys of: Luna (possibly), Venus, Earth, Mars
    - insert into orbit around Jupiter in 2030
    - transfer to high-latitude orbit (11 months)
    - Europa/Callisto flyby phase (1+9 months)
    - transfer to co-orbital movement with Ganymede (11 months)
    - inject itself into orbit around Ganymede in 2032
    - elliptic/high-altitude and circular/low-altitude orbits around Ganymede (5+4 months)
    - crash into Ganymede in 2033

    Ganymede will be studied for:
    • the extent and structure of its ice shell including its surface topography and processes
    • global mapping and high-resolution pictures of selected targets
    • its surface composition
    • possible biosignatures
    • its subsurface ocean
    • its magnetic field
    • origin and evolution of its volatiles, i.e. its atmosphere
    • ducts where water may be exchanged between the subsurface ocean and the surface

    Ganymede will be studied from a number of flybys (10+ in the coorbiting phase), high-altitude elliptic orbits (needed e.g. for magnetospheric study) and low-altitude orbits of around 500 km.

    Callisto will be studied for:
    • characterisation of its icy shell
    • detection and characterisation of a possible subsurface ocean
    • its surface composition, especially of non-ice components
    • its unique erosion processes
    • verification whether the moon is in hydrostatic equilibrium, and its differentiation

    Callisto will be studied in twelve flybys at 200-400 km distance.

    Europa will be studied for:
    • its surface composition
    • its subsurface ocean
    • possible biosignatures
    • possible liquid water pockets in shallow depths below the surface
    • ducts where water may be exchanged between the subsurface ocean and the surface

    Europa will be studied in two flybys, both at 400 km.

    During the transfer phases between orbits and the approach phase, Juice will study:
    • Jupiter itself
      • magnetosphere
      • atmosphere
    • the larger moon Io
      • volcanic activity
      • composition and surface distribution at regional scale
    • the four smaller moons Thebe, Amalthea, Adrastea and Metis
      • physical shape
      • bulk composition
      • origin
      • interaction with ring system (for Thebe and Amalthea)
    • irregular satellites
      • if possible with close flyby during approach
    • Jupiter's ring system
      • physical and chemical composition
      • 3D imaging
    Last edited by kato; 20 Nov 14, at 21:21.

  5. #35
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    JUICE has been greenlighted for its implementation phase:

    ESA Science & Technology: JUICE mission gets green light for next stage of development

  6. #36
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    Quote Originally Posted by kato View Post
    They're on the last fuel reserves though, which means the fuel will run out during any of the next regular orbit raising campaigns
    Current periapsis raising campaign for Venus Express is ongoing, in 9 microburns - one every day from Nov 23rd till Dec 1st. Five out of nine burns successful so far.

  7. #37
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    Venus Express has now officially been declared dieing.

    Venus Express goes gently into the night / Venus Express / Space Science / Our Activities / ESA

    Fuel ran out during the last periapsis raising campaign (probably on the sixth burn), and VEX lost its attitude control. Telemetry contact could still be reestablished, though only to affirm that VEX will plunge into the atmosphere sometime around mid-January.

  8. #38
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    In the past five months, i.e. during its routine science phase so far, Gaia has observed 6.76 billion transits of stars, and has taken a total of 88.9 billion measurements. In the seven months before that, i.e. since its launch and during the commissioning phase, Gaia observed another 4.34 billion transits of stars, and took another 56.9 billion measurements. Both combined have so far yielded 9.2 Terabyte of scientific data.

    Gaia has during those five months in the routine phase scanned the entire sky at least once, and is mapping on average 40 million stars per day. Afaik, the expected number for the five-year mission should be about 40 billion transits and 630 billion measurements for 1 billion stars.

    Consumables aboard Gaia, i.e. cryogenics, look good so far, leading project scientists to hope for an extension past the planned five year mission currently. Due to Gaia's software becoming more sensitive to changes in the sky with every pass, a possible extension yields significantly higher results. One estimate for this is that if Gaia operated ten years instead of five, it is estimated to discover up to 3.3 times the planned number of about 21,000 Jupiter-sized exoplanets within 500 parsec.

    There's now an Android version of the Gaia App since last month btw: https://play.google.com/store/apps/d...id=edu.ub.gaia
    Last edited by kato; 25 Dec 14, at 20:39.

  9. #39
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    The service module of Chang'e-5T1 is currently located at Earth-Moon L2, and therefore being beyond lunar orbit falls within this thread's constraints

    The ca 3-ton DFH-3 bus spacecraft (same bus as Chang'e-1 and -2 and the TDRS-like GEO satellites Tian-Lian-1,-2,-3) was moved to EML2 after circling around the moon with its Earth reentry capsule payload and delivering it into Earth atmosphere. Chang'e-5T1-SM is not a scientific probe, but an engineering test spacecraft; it therefore doesn't carry any particular sensors either, outside a single main camera and sensors necessary for navigation.


    It will leave EML2 once again in January, moving into orbit around the moon to perform further testing for the Chang'e-5 sample return mission, providing ground personnel the opportunity to train and react while observing the planned docking maneuvers in lunar orbit (in February and March). In April the spacecraft will photograph prospective landing sites for Chang'e-5.

    Attachment 38861

  10. #40
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    Akatsuki successfully adapted her course towards Venus in a burn last month. She is currently slated to attempt orbital insertion in December and if successful, will then monitor Venus for another three years.

    Akatsuki's success is relevant insofar as she'll be the only active probe in orbit of a planet other than Earth or Mars after 2017, even if only for an extra year: Outside short 6-month "changeovers" twice we'll consistently have had active probes at other planets for 40 years, beginning only 3 years after the first orbiter was sent to any planet other than Mars. Come 2018, we'll be in for a six-year break until 2024 (BepiColombo), then another five-year break from 2026 to 2030 (JUICE and Europa Clipper).

    At least unless India's proposed mission to Venus gets under wraps. Tentatively aimed for a launch date between 2017 and 2020.
    Last edited by kato; 28 Sep 15, at 19:12.

  11. #41
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    ESA's ExoMars TGO and EDM are on their way to Mars btw.

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