|
|
Thread Tools | Display Modes |
#1
|
|||
|
|||
Problems with Cassini?
Anyone hear that the mission is not going well and Cassini is way off
course? |
#2
|
|||
|
|||
Problems with Cassini?
Um... No.
Last update from the Cassini team reported everything is going well. And, by the way, there isn't much of a way for Cassini to be 'way off course.' It isn't a ship, or a car, or a truck. It's a spacecraft, in the vacuum of space. There isn't any wind, or water or currents to act on Cassini's motion, just the constants of the gravitational fields of Saturn (and its moons to a much smaller extent) and the distance of Cassini to those bodies. (yes, yes, the Sun is also a factor, as well as the other planets, but the amount of gravitational attraction is miniscule) Cassini fired it's rocket to slow itself just enough that it would not escape Saturn's gravity back on July 1st (or June 31st depending on your timezone). Thanks to a little thing called the Doppler shift (1) Cassini started and ended the 'burn' with almost exactly the expected velocity and direction. Cassini won't be using that rocket for a long while now. The only other propulsion on Cassini are the cold gas jets used to turn the spacecraft to point where it needs to point. What did you hear? Jeffrey Cornish (1) radiation emitted by objects (like radio waves from Cassini's radio transmitter) have their frequency stretched when moving away from an observer and compressed when approaching. You've heard this when an emergency vehicle has passed you with it's sirens on. It's also known as redshift/blueshift for electromagnetic radiation. "Marshall Karp" wrote in message ... Anyone hear that the mission is not going well and Cassini is way off course? |
#3
|
|||
|
|||
Problems with Cassini?
"Jeffrey Cornish" wrote in message ... Thanks to a little thing called the Doppler shift (1) Cassini started and ended the 'burn' with almost exactly the expected velocity and direction. Okay, correction he Thanks to a little thing called the Doppler shift (1) _The Cassini team were able to confirm that_ Cassini started and ended the 'burn' with almost exactly the expected velocity and direction. |
#4
|
|||
|
|||
Problems with Cassini?
"Marshall Karp" wrote in news:mPOdnd3oi_cEF2PdRVn-
: Anyone hear that the mission is not going well and Cassini is way off course? No, exactly the opposite. What's your source of misinformation? --Damon |
#5
|
|||
|
|||
Problems with Cassini?
"Damon Hill" wrote in message 34... "Marshall Karp" wrote in news:mPOdnd3oi_cEF2PdRVn- : Anyone hear that the mission is not going well and Cassini is way off course? No, exactly the opposite. What's your source of misinformation? There was an article on space.com for the Palm by Leonard David about earth weather systems causing some communications problems. I can't find the article on space.com, but maybe the OP misunderstood this article? BV. |
#6
|
|||
|
|||
Problems with Cassini?
"Benign Vanilla" wrote in
: "Damon Hill" wrote in message 34... "Marshall Karp" wrote in news:mPOdnd3oi_cEF2PdRVn- : Anyone hear that the mission is not going well and Cassini is way off course? No, exactly the opposite. What's your source of misinformation? There was an article on space.com for the Palm by Leonard David about earth weather systems causing some communications problems. I can't find the article on space.com, but maybe the OP misunderstood this article? Ah, probably confused by the solar occultation; for a few days communications was minimal because Saturn was so close to the Sun from Earth's perspective. --Damon |
#7
|
|||
|
|||
Problems with Cassini?
Damon Hill wrote:
There was an article on space.com for the Palm by Leonard David about earth weather systems causing some communications problems. I can't find the article on space.com, but maybe the OP misunderstood this article? Ah, probably confused by the solar occultation; for a few days communications was minimal because Saturn was so close to the Sun from Earth's perspective. --Damon There was some concern on orbit insertion day that weather conditions at one of NASA's Deep Space Tracking dishes in Australia (Canberra I believe) might be too windy to allow them to deploy the antenna. However the weather improved enough to allow them to use it. As the previous poster also mentioned Saturn with Cassini, as seen from Earth passed behind the Sun making data transmission quite difficult. From the weekly sastus reports: "Solar Conjunction occurs when the Sun is between the spacecraft and Earth. This year it will last from July 5 through July 11, and is a time of reduced commanding and downlink capability. During this period the project will uplink a command file consisting of 10 no-op commands sent every 5 minutes, 10 to 20 times daily. The purpose of the test is to accumulate statistics for uplink reliability at decreased separation angles." |
#8
|
|||
|
|||
Problems with Cassini?
In message , Damon Hill
writes "Marshall Karp" wrote in news:mPOdnd3oi_cEF2PdRVn- : Anyone hear that the mission is not going well and Cassini is way off course? No, exactly the opposite. What's your source of misinformation? --Damon Http://www.coasttocoastam.com, according to his other post with the same subject line. Richard Hoagland quoting an un-named source. This might be connected to a new page on the enlightened one's own site at http://www.enterprisemission.com/, titled "Is NASA Sending the Cassini Mission to its Doom ?!" but it's so badly laid out I can't be bothered to look at it. |
#9
|
|||
|
|||
Problems with Cassini?
JRS: In article , dated Wed, 21
Jul 2004 09:13:40, seen in news:sci.space.shuttle, Jeffrey Cornish posted : Cassini fired it's rocket to slow itself just enough that it would not escape Saturn's gravity back on July 1st (or June 31st depending on your timezone). Which time zones have 31 days in June? -- © John Stockton, Surrey, UK. Turnpike v4.00 MIME. © Web URL:http://www.merlyn.demon.co.uk/ - w. FAQish topics, links, acronyms PAS EXE etc : URL:http://www.merlyn.demon.co.uk/programs/ - see 00index.htm Dates - miscdate.htm moredate.htm js-dates.htm pas-time.htm critdate.htm etc. |
#10
|
|||
|
|||
Problems with Cassini?
In message , Dr John Stockton
writes JRS: In article , dated Wed, 21 Jul 2004 09:13:40, seen in news:sci.space.shuttle, Jeffrey Cornish posted : Cassini fired it's rocket to slow itself just enough that it would not escape Saturn's gravity back on July 1st (or June 31st depending on your timezone). Which time zones have 31 days in June? Double Summer Time in Len Deighton's "Bomber"? |
Thread Tools | |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
Cassini TV Coverage Schedule | Brian Webb | Space Shuttle | 1 | June 27th 04 07:56 PM |
Current Space Station Problems | ElleninLosAngeles | Space Shuttle | 0 | October 24th 03 05:21 AM |
TMI Report:People problems vs. Equipment | Jim M Bowden | Space Shuttle | 0 | October 22nd 03 08:08 AM |
Newsgroup posting problems? | Jon Berndt | Space Shuttle | 5 | September 30th 03 01:57 PM |
criticality 1 or knownn problems | Lynndel Humphreys | Space Shuttle | 2 | July 27th 03 04:38 PM |