The dive into Saturn's atmosphere is intended to ensure that some of Saturn's moons and especially Enceladus, which is estimated to have a subsurface ocean that shows signs of hydrothermal activities, will not be contaminated by terrestrial bacteria that may have survived inside the spacecraft and will remain pure for future research.
Watch the moment of the announcement of the loss of contact with the spacecraft and the end of the mission:
NASA's Cassini spacecraft ended its life by crashing into the planet Saturn today, September 15 at 14:55 p.m. Israel time, one minute after entering the atmosphere at an altitude of about 1,900 kilometers above the cloud layer of the giant planet. At this height, the air pressure is about 1 bar, equal to the air pressure at sea level on Earth. During the dive, its speed will reach 110 thousand km/h. The final touch will take place in the center of the day side of Saturn, at a latitude of 10 degrees north, so that the old spacecraft can be used until the last moment for photographs.
Cassini completes 13 years in the Saturn system and its moons. The dive into Saturn's atmosphere is intended to ensure that some of Saturn's moons and especially Enceladus, which is estimated to have a subsurface ocean that shows signs of hydrothermal activities, will not be contaminated by terrestrial bacteria that may have survived inside the spacecraft and will remain pure for future research. The spacecraft's fateful dive is the last act in the grand finale that included 22 weekly dives, which began at the end of April, through the gap between Saturn and its rings. No spacecraft had ever ventured this close to the rings.
Pictures until the last minute
When Cassini encountered Saturn's atmosphere, mission controllers would activate its flight control system in short bursts to counteract the thin gases that would surround it and keep Cassini's antenna dish pointed at Earth to transmit the mission's final and precious data. As the atmosphere thickens, the operators will be required to increase the activity of the engines, until it is no longer possible to maintain Cassini's stability and the spacecraft will begin to fall.
When the antenna turns only fractions of a degree from the direction of the Earth, the communication will be cut off permanently. As mentioned, the loss of the signal is expected to occur less than two thousand kilometers above the cloud tops. From this point Cassini will begin to burn up like a meteor. Within about 30 seconds after losing the signal, the spacecraft will begin to disintegrate; Within a few minutes, all the remains of the spacecraft are expected to be completely consumed in Saturn's atmosphere.
A video describing the most important event that occurred shortly after Cassini's arrival in the vicinity of Saturn in 2005: the landing of the European Huygens spacecraft on Titan, thanks to which we know today about many similarities between it and Earth.
An hour and a half of reverberations
The distance between the Earth and Saturn changes depending on the rotation of the Earth and Saturn around the Sun. At the time of the crash it would take the radio signals 83 minutes to reach Earth, which means that in practice the spacecraft will begin its fall at 13:31 but we only knew about it 83 minutes later.
"The spacecraft's final signal echoed through the solar system for nearly an hour and a half after Cassini itself disappeared," said Earl Mays, Cassini project manager at NASA's Jet Propulsion Laboratory (JPL) in Pasadena, California. "Even though we'll know for sure that Cassini has met its fate, its mission hasn't really ended as long as we receive its signals. Cassini's last transmissions were received by antennas at NASA's Deep Space Network complex in Canberra, Australia.
Cassini made up-to-the-minute observations using eight of the 12 scientific instruments on board to study the magnetosphere and plasma. The infrared and ultraviolet spectroscopes will collect data until the very last moment. NASA promised to publish the latest images as quickly as possible.
For information on the NASA website
More on the subject on the science website
- The farewell mission of Cassini - NASA's most beloved spacecraft
- Cassini will approach the rings on the last mission before crashing into Saturn
- Cassini successfully completed its first dive between Saturn and its rings
- Cassini discovered that the space between Saturn and its rings is almost completely free of dust particles
18 תגובות
rival
Are you sick of conspiracies too? Shame on you.
I read the comments and enjoy them... especially Haim Mazar's...
You just need to inform NASA managers that there are talented people here who know exactly what needs to be done ("immediately prepare two new Cassini spacecraft") and how the new spacecraft should be built ("reduce the weight of the power supply") and where and exactly when to send them ("one will be launched to Neptune and the other to Uranus").
A pleasure to read you, dear friends. Keep taking yourself seriously. Maybe one day it will work.
See you at NASA...
An issue that will have to be considered is the crew that will operate the spaceship. I think it's 200 or more employees. Mission accomplished, what next. These people feel a sense of emptiness, they will have to find a solution to this quickly. Placement in new positions or combining them in new tasks.
It turns out that it is not easy to pull out a bunch of programs from the warehouse and produce a new series of an old product. NASA is not pulling out the plans for the F1 engine and Saturn 5 rockets and instead is developing the SLS. Lockheed Martin is not starting to re-manufacture the F22, although the US Air Force is now regretting the termination of the project, given the performance and delays of the F35. Boeing does not start reproducing 757s whose production was stopped in 2004 even though it is now clear to them that this is exactly the intermediate size that the market wants today in terms of range and the number of passengers and is starting to design the 797 which will have similar features, etc.
What's more, maybe it's time to produce exploration spacecraft with a common base, as they did with Mariner, Voyager and the two rovers on Mars. After all, there may be a small difference in the mission definition of space vehicles that will explore Oron and Rehav. Obviously, the follow-up missions to Jupiter and Saturn will be somewhat different, because they will want to concentrate on collecting different types of information (for example, landing on Europa or Enceladus - even then efforts can be combined).
Say you are not ashamed to believe all this nonsense and these cheap NASA computer simulations the only space that exists is in the mind of those who believe this nonsense
Benjamin May
Not necessarily
Haim Mazar
You may be right. You just have to remember that the launches are very expensive and the spaceship has a very long journey planned.
To my ears (who are completely unprofessional in the field) your proposal sounds like a shortcut to procedures that could pour a lot of money down the drain.
Benjamin May
I didn't say it was easy. The information that came from Neptune is meagre. That was when Voyager 2 passed by. In 1989 it is in no way similar to a spacecraft entering orbit around it. Everything you mentioned does not stand in any contradiction with the construction method of Out of the shelf. Rather, thanks to the miniaturization you mention and rightly so, there is still room to attach one sub-spacecraft and maybe one more to the spacecraft. Moreover, thanks to the miniaturization that reduces the weight of the spacecraft, it will be possible to use a smaller launcher, What requires an examination of the relationship between the weight of the spacecraft and the weight of the spacecraft and the cost of the launch.. You definitely need to weigh all the factors and still with all the complexity it is possible to overcome this and not wait for the spacecraft to be launched in 10 or 15 years. It's basically a matter of decision.. All the complicated problems, with all their complexity, it's not in the sky.
Long live a stranger. It is not that simple.
It depends, for example, on the question of whether we would like to send a new spacecraft with a measuring tool of the type that was already there or
make different types of measurements.
There is also the matter of weight and volume. If we take new components "off the shelf" it is absolutely clear that they have undergone miniaturization since Cassini was launched. Does it make sense to you to send a truck (as Cassini was relative to what can be built today) when you can send a racing car? It should also be remembered that the energy consumption for the components
Similar in their performance, it has decreased prodigiously since Cassini was launched, would like to say that it is also possible to reduce the weight of the power supply.
When you understand the design cost compared to the other factors (the cost of the launcher for example which can be smaller or carry
a stronger acceleration rocket) it seems to me that it is better to plan everything again.
Miracles
What you say justifies my approach. Take the skeleton of the Xsini and put equipment on it using the Out of the shelf method. It might be more complex, but it's still better than waiting 20 years to see close-ups of Neptune's clouds. You have the head of an engineer. Think about it.
Life
I have nothing against outdated equipment. The problem is that many components probably do not exist today, and new components will be needed. Cassini's processors were old even before Cassini was built, because in the world of aviation and space it takes a long time to approve such a component. You don't want to know what processors are flying the 747 today….
Any engineering change is very expensive, and today there are newer spacecraft. What's more - there is a good chance that 30-40 years ago they made more reliable things.
Miracles
So what about the outdated equipment. He proved himself supremely and supremely. In the same way, it would be possible to say that when a new spacecraft is developed and when it reaches Neptune, for example, it would be possible to say that the equipment that will be developed for it is outdated compared to the equipment that will exist on the day of arrival to the planet, since the planning of a spacecraft and the duration of such a flight takes years. There is no end to it. The Xsini development plans were not thrown away. If necessary, it will be possible to place, for example, a new high gain antenna, or new cameras. I assume you know the Out of the shelf production method; Remind you that this is how the Pathfinder red SUV was built, it prevented the spacecraft from working and transmitting valuable information to Israel? . .
Haim Mazar
I don't think there is any ability to build a new Cassini today. One reason is that many Cassini components are obsolete, and replacing existing components will be complex and expensive. A second reason is that I believe there are many parts that are one-offs - the main antenna for example (my guess), the motors and so on. A third reason is lack of knowledge - unfortunately, not everything is written and there is a lot of opinion in such systems. This piece of information must have been lost by now.
And just to think that when they started building Cassini we were still with DOS3
And from now on every year there will be a class meeting of all those who participated in this unprecedented project..
In order not to lose Cassini's momentum, two new Cassini spacecraft must be prepared immediately, one for Neptune and the other for Uranus, the launch will be within a year from today at the latest. Each spacecraft will be attached to a sub-spacecraft, a satellite or a lander, one will be assigned to Triton, the moon of Neptune, and the other to Miranda, the moon of Uranus. For this purpose it will also be possible to use a copy of existing spacecraft such as the LRO that orbited the moon. The advantage of such a program is that they use a spacecraft that has already proven itself. It's cheaper than developing a new spaceship and saves the development time of a new spaceship which by nature takes years.
Haim Mazar
And from now on every year there will be a reunion of all those who took part in this unprecedented project.
In order not to lose the momentum of the Cassini, it is advisable to immediately prepare two new Cassini spacecraft. One will be launched to Neptune and the other to Uranus. Each of them will be attached to a sub-spacecraft or one lander will be assigned to Neptune's moon Triton and the other to Uranus' moon Miranda. The launch should be a year from now at the most. The advantage of such a plan is that you can use a spacecraft that has proven itself. There is no need to develop a new spacecraft that costs hundreds of millions of dollars.
A question that interested me - theoretically, could the spacecraft escape near the end of Saturn's orbit (they said it even had 2% fuel left on it) and instead of merging with it go out into the vast space and just cruise it even without scientific missions? (In my opinion, there is something magical and wonderful about a thing and an object that is made by the hands of humanity and continues some kind of never-ending journey, some kind of messenger of ours to the infinite spaces...)
An amazing project, which started from the madness of one person.
And think that when the construction of the spaceship started we were roughly with DOS 3.