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Comet Probe Philae Unanchored But Stable — And Sending Back Images

Posted by timothy on from the overengineering-is-the-best-kind dept.

An anonymous reader writes with an update to the successful landing of the ESA's comet probe Philae, which (as mentioned yesterday) had problems attaching to the surface of the comet's Rosetta: "BBC now reports that Philae is stable on the surface. Although no source claims so, we can all imagine a faint humming of 'Still Alive' coming from the probe." Not just stable, but sending pictures while it can. From the article: The probe left Rosetta with 60-plus hours of battery life, and will need at some point to charge up with its solar panels. But early reports indicate that in its present position, the robot is receiving only one-and-a-half hours of sunlight during every 12-hour rotation of the comet. This will not be enough to sustain operations. As a consequence, controllers here are discussing using one of Philae's deployable instruments to try to launch the probe upwards and away to a better location. But this would be a last-resort option. New submitter Thanshin notes that the persistent Philae bounced a few times, and actually performed 3 landings, at 15:33, 17:26 & 17:33 UTC.Thanshin adds links to a handful of relevant Twitter feeds, if you want to follow in something close to real time: Philae2014; esa_rosetta; and Philae_MUPUS (MUlti PUrpose Sensor One).

3 of 132 comments (clear)

  1. Sideways by Thanshin · · Score: 4, Informative

    Now Philae seems to be sideways and under the shadow of a cliff that only let's it have sunlight 1,5h per 12h cycle.

    That amount of sunlight may not be sufficient to keep Philae operating beyond its 60h battery autonomy.

    Most info seems to appear first in BBC news

  2. Re:Couldn't they have used an RTG? by trout007 · · Score: 4, Informative

    They are still used but it's in short supply because you need to create it in special reactors. And funding is a problem.

    http://en.wikipedia.org/wiki/P...

    --
    I love Jesus, except for his foreign policy.
  3. paste from Reddit... by SternisheFan · · Score: 4, Informative
    Got fresh news from the team, they are broadcasting live right now on french TV ! Philae landed, and bounced slowly for 2 hours, and travelled 1km away the targeted site. Yes 1000m. It's now stopped slanted, some cams are shooting the sky, other the ground, and other nearby rocks, as seen on the first photo. It's inside some kind of hole, not much sun for the solar panels. EDIT1: It landed on the core of the comet, it sees the light from the sun for about 1 to 2 hours per day. In the next days/week the angle of the comet will change relative to the sun, and it very likely the solar panel will get more sunlight so more power for the probe. EDIT2 : Many labs are performing right now and performed the whole night. For now they put the drilling on hold since they don't know if it's tied to the ground or not. Drilling op is also power hungry so it's kinda a good thing it's on hold since there's not much sun available for the panels. Battery life been re-estimated to 50-55hours due to the lack of sunlight. This includes the 7 hours of descent.They are constantly adjusting missions goals, depending on conditions, power available, etc, EDIT3 : The probe has been working to gather scientifict data the whole time, including during the bounces. There's already a large amount of data available, whatever happens next.

    EDIT4 : It's resting on "hard" ground, with a layer of dust about 30cm, and that's good news because it allows measurements to proceed as planned. As in, it's not burried into soft soil.

    EDIT5 : Solar panels are deployed, radio link is up and running, but the fact the probe is slanted/in a hole/random ground limits the time it can communicate with the orbiter, altho that's not jeopardizing the mission. There's already a lot of things transmitted successfully to the orbiter. Contact between the orbiter and the probe can be done twice per day. EDIT6 : The first place it touched the comet was exaclty where it was planned, flat and cosy, too bad it didn't harpoon there. EDIT7 : Next contact will be near 19:30GMT, until 23:45GMT approx. This night they made contact with the probe (from the orbiter) at about 4:00GMT, and at 5:30GMT they had safely recovered all the data from the first batch of tests. From the ESA blog :

    The team are ensuring that Rosetta maintains an orbit that is optimised for lander communication support; they are planning a manoeuvre (thruster burn) today to be conducted on Friday that will help keep Rosetta where it should be. Rosetta already conducted a burn last night as part of this effort.

    Rosetta is presently sending signals to the ground stations at about 28 Kbps; Ignacio says that the spacecraft's own telemetry downlink uses about 1 or 2 Kbps of this, so the rest is being used to download science data from Rosetta and lander science and telemetry from the surface.

    Important press conference from ESA at 13:00GMT. Over now. http://rosetta.esa.int/ EDIT8 : So there was more photos, and details. Important bit, they're planning on righting the lander, studying the best way to do it. First rebound was about 1000m long, 0.38m/s up, lasted 2 hours. 2nd rebound was 0.03m/s, 7 minutes long. Then it stuck itself in the side of the crater at the 3rd impact.

    EDIT9 : Harpoons received the signal to fire, but didn't activate. There's no indication of damage on solar panels. The lander can hibernate and may likely still work several monthes from now, even if under limited power. They confirmed the orbiter will make adjustement tomorrow morning (friday) to optimize communication time with the lander. Operations are prioritized, from the less risky to the most.

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