Perseverance

[Rezillo]

Well, on entry to the Martian atmosphere, the whole craft is encased in a heatshield to cope with a temperature of 1300C as it heats up from atmospheric friction. No camera is going to like that very much! No atmosphere on the moon, so no heating.

The backshell to the heatshield is discarded only 60 seconds before touchdown so there is a short window for use but I doubt that the data transmission rate to Mars would cope with streaming video. Nasa has promised audio and HD video of the landing later to experience "what it's like to land on Mars"

Just checked and the data rate from rover to orbiter is up to 2mb/s but from orbiter to earth is 160/500 bits per second or faster to/from the Deep Space Network's 34-meter-diameter antennas or at 800/3000 bits per second or faster to/from the Deep Space Network's 70 meter-diameter antenna.

https://mars.nasa.gov/mars2020/spacecraft/rover/communications/

 

[Joey Shabadoo]

Well, on entry to the Martian atmosphere, the whole craft is encased in a heatshield to cope with a temperature of 1300C as it heats up from atmospheric friction. No camera is going to like that very much! No atmosphere on the moon, so no heating.

The heatshield is discarded only 60 seconds before touchdown so there is a short window for use but I doubt that the data transmission rate to Mars would cope with streaming video. Nasa has promised audio and HD video of the landing later to experience "what it's like to land on Mars"

Just checked and the data rate from rover to orbiter is up to 2mb/s but from orbiter to earth is 160/500 bits per second or faster to/from the Deep Space Network's 34-meter-diameter antennas or at 800/3000 bits per second or faster to/from the Deep Space Network's 70 meter-diameter antenna.

Incidentally, we lose contact with probes as they enter atmospheres at high speed as they become enveloped with plasma cause by the friction which blocks all radio signals in and out.

Which is why when the Chinese say they've got hypersonic ballistic anti-ship missiles that they can guide onto the target, they're talking bollocks.

 

[Joey Shabadoo]

 

[matticus]

We're starting to realise that the moon landings were a walk in the park.

 

[Oldhippy]

Allegedly. 🙄

 

[newfhouse]

By that logic nothing is live anywhere ever. It takes a non-zero amount of time for signals to travel any distance. And it sort of depends on your perception of how time works.

Spooky.

 

[midlife]

Spooky.

I see what you did there

 

[C R]

I see what you did there

Someone should mention EPR.

 

[lazybloke]

Well, on entry to the Martian atmosphere, the whole craft is encased in a heatshield to cope with a temperature of 1300C as it heats up from atmospheric friction. No camera is going to like that very much! No atmosphere on the moon, so no heating.

The backshell to the heatshield is discarded only 60 seconds before touchdown so there is a short window for use but I doubt that the data transmission rate to Mars would cope with streaming video. Nasa has promised audio and HD video of the landing later to experience "what it's like to land on Mars"

Just checked and the data rate from rover to orbiter is up to 2mb/s but from orbiter to earth is 160/500 bits per second or faster to/from the Deep Space Network's 34-meter-diameter antennas or at 800/3000 bits per second or faster to/from the Deep Space Network's 70 meter-diameter antenna.

https://mars.nasa.gov/mars2020/spacecraft/rover/communications/

500 bits per second is a bit of a logjam. Perhaps they could use PKZIP.EXE to make the most of it.

Fingers crossed there is an HD video of the final descent, that would be AWESOME to see.


There was a lot of fuss from Nasa about the "7 minutes of terror". I reckon the "Mars One" colony project has lost a few applicants after hearing that.

 

[Darius_Jedburgh]

Anyone remember The Roswell Incident?

 

[Oldhippy]

I have a lot of books on the subject and met a number of the serious academics looking for answers.

 

[Edwardoka]

Enceladus does look cool! But you can't have your cake and eat it:
sure, criticise the elaborate sky-crane - but then propose missions to SATURN?!?

My dear fellow, the difference between sending a craft to Mars and sending one to Saturn is simply one of calculation and time.
Carefully crafted gravitational slingshots do all the hard work, which is why missions to the outer solar system usually involve multiple flybys of Venus to pick up speed.

Enceladus' atmosphere is a lot more variable than that of Mars (on account of most of it spewing from the literal hellmouth on the south pole), so landing would present a bigger challenge, but apart from that

 

[Edwardoka]

View attachment 574624

 

[Drago]

Which is why when the Chinese say they've got hypersonic ballistic anti-ship missiles that they can guide onto the target, they're talking bollocks.

Don't be quite so sure on that. Hypersonic weapons still travel thousands of miles slower than a body on re-entry, which is typically 17,500 MPH, or nearly Mach 23. Interplanetary re-entry velocities are even higher. A Mach 6 or 8 hypersonic weapon is playing with a different with a different, much lesser level of physics altogether.

Then there are other factors, proximity, signal strength, even refquency (light isn't so afected, so lasers for transmitting data may be viable). And it has yet to be established if the Chinese have active guidance, or if the missile itself is reactive outside guidance, such as smart weapons steering themselves towards a laser painted target rather than responding to a directly received signal.

The Chinese claims are still dubious, but they're far from being in the realm of science fiction.

 

[Edwardoka]

I did not know this, but pretty cool. There's a drone helicopter on board the rover, running Linux, using open source software, and with a mobile phone processor.

It's just a proof-of-concept, but if it works and fulfils its mission, it could potentially pave the way for using off-the-shelf components in future missions.

https://spectrum.ieee.org/automaton...erance-helicopter-rover-fly-autonomously-mars