We recently lost:
Opportunity
Hubble
Kepler

Now we’ve also lost Dawn.

Looks like it ran out of fuel a little earlier than expected. It will remain in orbit around Ceres.

Https://dawn.jpl.nasa.gov/news/news-detail.html?id=7275

Some of the latest images from Dawn are on https://dawn.jpl.nasa.gov/multimedia/images/ceres.html#gallery-1

Well done Dawn.

Will this be a permanent orbit or will it eventually crash into Ceres?

Bubblecar said:

Well done Dawn.

Will this be a permanent orbit or will it eventually crash into Ceres?

I’m pretty sure it will crash into Ceres. There’s a note in one of the articles that it has a 99% chance of being still in orbit after 50 years. To me that means that it could crash any time after that.

This close-up image of the Vinalia Faculae in Occator Crater was obtained by NASA’s Dawn spacecraft in its second extended mission, from an altitude as low as 34 kilometers. This image is superposed to a similar scene acquired from an altitude of about 385 km.

This image reveals the intricate pattern between bright and dark material across this flow feature, which scientists will use to infer the history of this area, in particular the role of the fractures in the exposure of bright salts onto the surface.

Fracture Network on the Floor of Occator Crater. This image was obtained by NASA’s Dawn spacecraft on July 26, 2018 from an altitude of about 152 kilometers.

This mosaic of Cerealia Facula combines images obtained from altitudes as low as 35 km above Ceres’ surface. The mosaic is overlain on a topography model based on images obtained at 385 km altitude. No vertical exaggeration was applied.

Using information about Ceres’ gravity and topography, scientists found that Ceres is “differentiated,” which means that it has compositionally distinct layers at different depths. The most internal layer, the “mantle” is dominated by hydrated rocks, like clays. The external layer, the 40-kilometer thick crust, is a mixture of ice, salts, and hydrated minerals. Between the two is a layer that may contain a little bit of liquid rich in brine, it extends down at least 100 kilometers. The Dawn observations cannot see below 100 kilometers in depth. Hence, it is not possible to tell if Ceres’ deep interior contains more liquid or a core of dense material rich in metal.

I’m surprised that it doesn’t have an iron-nickel core. I bet it does.

(PS. Why does Chrome in Windows work so much better than Chrome in Android. Both are by Google. I couldn’t either copy image addresses, save images or see the text descriptions on Android).

On one hand, there is no atmospheric drag.

On the other hand, there’s a bit of irregularity in mass distribution in Ceres and Dawn is close enough that these will tend to tug the orbit. There’s also drag from solar wind.

It’s a safe bet that it will eventually crash on Ceres but it could take thousands of years.

dv said:

On one hand, there is no atmospheric drag.

On the other hand, there’s a bit of irregularity in mass distribution in Ceres and Dawn is close enough that these will tend to tug the orbit. There’s also drag from solar wind.

It’s a safe bet that it will eventually crash on Ceres but it could take thousands of years.

Oh, and, nice job, Dawn. Very nice concept for a mission. Achieved a lot of firsts but most importantly it’s the first mission to go into orbit about a body (other than Earth, duh) and then go back into interplanetary transfer and go into orbit about another body. This could not have been done affordably with conventional rocketry so it was a also a very nice proof of concept for ion rocketry.

Latest news on Hubble

https://www.sciencenews.org/article/hubble-telescope-has-been-busy-coming-back-online

Tau.Neutrino said:

Latest news on Hubble

https://www.sciencenews.org/article/hubble-telescope-has-been-busy-coming-back-online

Maybe they should rename it ‘Lazarus’.

captain_spalding said:

Tau.Neutrino said:

Latest news on Hubble

https://www.sciencenews.org/article/hubble-telescope-has-been-busy-coming-back-online

Maybe they should rename it ‘Lazarus’.

> Hubble worried astronomers when it ran into unexpected trouble recently, forcing mission scientists to put it into safe mode while they sorted the problem out. But the space telescope has more than made up for its time off since returning to work on October 26. Hubble is back to observing galaxies and stars, implementing programs that scientists around the world have proposed months ago.

Oh wonderful! I missed that news.

The blog of the Parker Solar Probe has been very busy lately – the first of 24 encounters with the Sun is in progress now. That makes it the closest ever spacecraft to the Sun and the fastest spacecraft ever. We eagerly await contact after the end of the period of closest approach. Perihelion is Nov 5.

https://blogs.nasa.gov/parkersolarprobe/2018/10/31/parker-solar-probe-starts-first-solar-encounter/

The good news about Hubble first appeared here.

https://www.nasa.gov/feature/goddard/2018/update-on-the-hubble-space-telescope-safe-mode

NASA’s Hubble Space Telescope returned to normal operations late Friday, Oct. 26, and completed its first science observations on Saturday, Oct. 27 at 2:10 AM EDT. The observations were of the distant, star-forming galaxy DSF2237B-1-IR and were taken in infrared wavelengths with the Wide Field Camera 3 instrument. The return to conducting science comes after successfully recovering a backup gyroscope, or gyro, that had replaced a failed gyro three weeks earlier.

A gyro is a device that measures the speed at which the spacecraft is turning, which is necessary to help Hubble turn and lock on to new targets. One of Hubble’s gyros failed on Oct. 5, and the spacecraft’s operations team activated a backup gyro the next day. However, the backup incorrectly returned rotation rates that were far in excess of the actual rates.

Last week the operations team commanded Hubble to perform numerous maneuvers, or turns, and switched the gyro between different operational modes, which successfully cleared what was believed to be blockage between components inside the gyro that produced the excessively high rate values. Next, the team monitored and tested the gyro with additional maneuvers to make sure that the gyro was stable. The team then installed additional safeguards on the spacecraft in case the excessive rate values return, although this is not anticipated.

On Thursday, the operations team conducted further maneuvers to collect gyro calibration data. On Friday, Hubble performed activities similar to science observations, including rotating to point at different sky locations, and locking on to test targets. The team completed all of these activities without issue.

Late Friday, the team began the process to restore the scientific instruments to standard operating status. Hubble successfully completed maneuvers to get on target for the first science observations, and the telescope collected its first science data since Oct. 5.

In other spacecraft news, China and France have just launched a joint satellite to view Earth’s wind and waves simultaneously using a pair of radars, one built by China for the waves and one by France for the wind. It will be multi-wavelength.

According to tonight’s TV news from China.