Jump to content
Join the Unexplained Mysteries community today! It's free and setting up an account only takes a moment.
- Sign In or Create Account -

Farewell, silent Philae


Waspie_Dwarf

Recommended Posts

Farewell, silent Philae

Quote

Tomorrow, 27 July 2016 at 09:00 UTC / 11:00 CEST, the Electrical Support System Processor Unit (ESS) on Rosetta will be switched off. The ESS is the interface used for communications between Rosetta and the lander, Philae, which has remained silent since 9 July 2015.

Switching off the ESS is part of the preparations for Rosetta's end of mission. By the end of July 2016, the spacecraft will be some 520 million km from the Sun, and will start facing a significant loss of power – about 4W per day. In order to continue scientific operations over the next two months and to maximise their return, it became necessary to start reducing the power consumed by the non-essential payload components on board.

arrow3.gif  Read more: ESA

 

  • Like 3
Link to comment
Share on other sites

 

Philae didn't do everything they had hoped but she accomplished much of her mission and provided incredible data for future research.  So very  well done on this impossibly complex mission, congrats ESA and Rosetta still has a few tricks left but time is running out. 

  • Like 1
Link to comment
Share on other sites

I guess there is something to be said for nuclear power of space crafts. I believe that is what powers Cassini, the probe sent to Saturn. It would seem logical to me that an object like a comet that has a huge parabolic orbit and moves far away from the sun would be a prime candidate for such a propulsion system. Perhaps there are reasons for solar vs. nuclear, but solar seems a poor choice here.

Link to comment
Share on other sites

10 minutes ago, Sundew said:

would be a prime candidate for such a propulsion system.

It is NOT a propulsion system. The nuclear system on Cassini provides electrical power not propulsion.

 

11 minutes ago, Sundew said:

Perhaps there are reasons for solar vs. nuclear, but solar seems a poor choice here.

Do you really believe that ESA don't know what they are doing?

Nuclear systems present all sorts of problems, not least the danger of contamination in the event of a launch vehicle failure.

The Rosetta mission was designed specifically to examine the evolution of a comet during it's active period as it neared the Sun. It was never intended to continue it's mission once the comet became dormant again. As such solar power was the logical choice.

Modern radioisotope thermal generators (RTGs), such as those used by Cassini, generally use Plutonium 238. This is difficult and expensive to manufacture. There are only two countries in the world that do manufacture it , Russia and the USA (and the USA only recently restarted manufacture after a 25 year gap). That means it is simply not a viable option for ESA. (Only one European space probe, Ulysses, has used an RTG, and as a cooperative mission that was provided by NASA. Since the restart of 238Pu in the USA was at least partly brought about by the fact that NASA was running short of the stuff they were in no position to provide an RTG for Rosetta).

Solar power is efficient, safe and reliable, Where it was once not a viable option for missions beyond Mars progress means that it is now a reasonable choice for missions into the deeper solar system (this is the reason NASA chose solar over nuclear for the Juno mission to Jupiter even though it does nave access to 238Pu).

Far from being a poor choice solar power for Rosetta was the ONLY choice.

  • Like 1
Link to comment
Share on other sites

1 hour ago, Sundew said:

I guess there is something to be said for nuclear power of space crafts. I believe that is what powers Cassini, the probe sent to Saturn. It would seem logical to me that an object like a comet that has a huge parabolic orbit and moves far away from the sun would be a prime candidate for such a propulsion system. Perhaps there are reasons for solar vs. nuclear, but solar seems a poor choice here.

Rosetta spent years in space but was designed to study the transition of a comet going from dormant to full coma and back which means it would have plenty of sunlight to do its mission.  Also, there was a real shortage of Plutonium 238 when Rosetta launched so, as Waspie said, and RTG made little sense. 

Juno was in the same predicament which is one of the reasons she has one of the largest and most efficient solar panel arrays ever used on a space craft and she just recently broke the record for the most distant space mission to use a solar array. http://www.jpl.nasa.gov/news/news.php?feature=4818

Edited by Merc14
  • Like 2
Link to comment
Share on other sites

At least it succeeded in its mission - quite the accomplishment.

  • Like 1
Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
  • Recently Browsing   0 members

    • No registered users viewing this page.