posted 01-21-2014 06:34 PM               

ESA's Rosetta to Comet 67P: questions, comments

This thread is intended for comments and questions regarding the updates under: ESA's Rosetta probe and lander to Comet 67P.

Rosetta is the first mission designed to orbit and land on a comet. It consists of an orbiter, carrying 11 science experiments, and a lander — called 'Philae' — carrying ten additional instruments, for the most detailed study of a comet ever attempted.

posted 01-21-2014 06:38 PM               

• After yesterday's (Jan. 20) spectacular receipt of first signal at 19:18 CET, ending 31 months of hibernation, the team have re-established full control over Rosetta.

• All basic parameters have been checked out, and it looks like Rosetta came through hibernation fine.

• For example, the propellant tank temperatures are running now at 7-9 deg C, slightly colder than the 10-15 deg C expected but well within predictions

• Power levels (i.e. electricity available from the huge solar panels) are fine and substantially similar to the levels prior to hibernation.

• The solar arrays appear not to have suffered very much degradation if any during 31 months.

• Team working today to start configuring the solid-state mass memory for use.

• Next big step will be warming up the reaction wheels and then spinning them up for verification; this will take several days.

• Acquisition of signal (AOS) yesterday came 18 minutes later than hoped for, but also well within expectations.

• The slight AOS delay was due to the on-board computer automatically rebooting itself at the beginning of the hibernation exit sequence; the team are looking into this (but Andrea stresses this is not problematic).

• The team has switched the spacecraft's transmitter to X-band; this means we can now get a decent download rate of about 9 kbps.

• Tracking has been provided via NASA's Canberra and ESA's New Norcia stations; NASA Goldstone was on call for backup; from now DSN stations will swap roles (Canberra will be on call for back-up).

posted 07-31-2014 05:18 PM            

The nucleus of Rosetta's target comet seen from a distance of 1,212 miles (1,950 km) on July 29, 2014.

posted 08-06-2014 05:33 AM               

After a decade-long journey chasing its target, ESA's Rosetta has today become the first spacecraft to rendezvous with a comet, opening a new chapter in Solar System exploration.

A question though: is Rosetta really the first probe to rendezvous with a comet?

posted 08-06-2014 12:57 PM            

quote:

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Originally posted by cspg:
The new released images are quite stunning.

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posted 08-06-2014 01:55 PM               

quote:

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Originally posted by Robert Pearlman:
A tattoo ten years in the making...

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posted 11-07-2014 06:13 AM               

Demonstrating Rosetta's Philae lander on the Space Station

ESA astronaut Alexander Gerst performs a demonstration of how ESA’s Rosetta mission will attempt to put a lander, called ‘Philae’ on the surface of comet 67P/Churyumov–Gerasimenko.

Alexander narrates the story of the Rosetta mission and performs a demonstration that visualises the difficulties of landing on an object that has little gravitational pull. Using the weightless environment of the Space Station, Alexander attempts to land ‘Philae’ (an ear plug) onto the surface of the ‘comet’ (an inactive SPHERES robot) with increasing levels of difficulty: a rotating comet that is not moving to one that is both rotating and moving.

This video is one of the six experiments and demonstrations in the Flying Classroom, Alexander will use small items to demonstrate several principles of physics in microgravity to students aged 10–17 years.

The Rosetta mission’s lander, Philae, will be deployed on 12 November at 08:35 GMT/09:35 CET from a distance of 22.5 km from the centre of the comet. It will land about seven hours later, with confirmation expected to arrive at Earth at around 16:00 GMT/17:00 CET.

posted 11-11-2014 02:25 PM               

Schedule of some key milestones on Nov. 12:

• 12:35 a.m. CST (0635 GMT): Earliest Go/No Go - final decision for landing
  
• 01:35 a.m. CST (0735 GMT): Latest Go/No Go - final decision for landing
  
• 04:03 a.m. CST (0903 GMT): Philae separation (Forecast; 94-sec window)
  
• 11:02 a.m. CST (1702 GMT): Expected landing and receipt of signal (Forecast; 40 minute variability)

posted 11-12-2014 10:50 AM               

The mission's controllers are weighing whether to try firing the harpoons again.

posted 11-13-2014 06:38 AM               

Yesterday was exhausting! I actually performed three landings,15:33, 17:26 and 17:33 UTC.

posted 11-13-2014 11:15 AM               

quote:

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Originally posted by gliderpilotuk:
Elsewhere the focus seems to be on the "failure" of the probe to attach itself securely rather than the amazing feat of traveling millions of miles for a spot landing on a fast-moving comet.

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posted 11-14-2014 02:14 PM               

"Comet 67P is NOT a comet," the letter continues. "Some 20 years ago NASA began detecting radio bursts from an unknown origin out in space. It would later be known that these had likely come from the direction of the now named comet 67P. It does show signs on its outside of machine like parts and unnatural terrain."

Ending on an ominous note, it adds: "Whatever this object is, it did not ask to be found or scrutinised."

posted 11-14-2014 02:52 PM               

Of course if you prefer the alien artifact story ... be my guest.

posted 11-14-2014 07:20 PM               

Our lander's asleep

With its batteries depleted and not enough sunlight available to recharge, Philae has fallen into 'idle mode' -- a possibly long silence. In this mode, all instruments and most systems on board are shut down.

"Prior to falling silent, the lander was able to transmit all science data gathered during the First Science Sequence," says DLR's Stephan Ulamec, Lander manager, who was in the main control room at ESOC tonight.

"This machine performed magnificently under tough conditions, and we can be fully proud of the incredible scientific success Philae has delivered."

Contact was lost at 00:36 UTC [6:36 p.m. CST], not long before the scheduled communication loss that would have happened anyway as Rosetta orbited below the horizon.

From now on, no contact would be possible unless sufficient sunlight falls on the solar panels to generate enough power to wake it up. The possibility that this may happen was boosted this evening when mission controllers sent commands to rotate the lander's main body, to which the solar panels are fixed. This may have exposed more panel area to sunlight.

The next possible communication slot begins on Nov. 15 at about 10:00 UTC [4:00 a.m. CST]. The orbiter will listen for a signal, and will continue doing so when its orbit enables communication visibility.

The hugely successful Rosetta mission will continue, as the spacecraft tracks comet 67P/C-G on its journey to the Sun. Rosetta is the first spacecraft to rendezvous with and orbit a comet and has already returned incredible scientific data.

posted 11-15-2014 10:54 AM            

Prior to falling silent, the lander was able to transmit all science data gathered during the First Science Sequence," says DLR's Stephan Ulamec, Lander manager, who was in the main control room at ESOC tonight

posted 11-15-2014 11:38 AM               

The paper model can be found on the ESA Rosetta outreach website