A new photo of Mars from the Hubble Telescope | Hacker News Reader

A new photo of Mars from the Hubble Telescope

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79 pointsTomte21 comments

At a cost of $10 billion I still think the Hubble is one of the best investments that high science has offered us. The images it produces have to be the most fascinating and valuable pieces of data humanity has ever produced.

Hubble's successor, the James Webb, is scheduled to launch in a couple of years. It will orbit the Sun rather than the Earth (at the L2 Earth-Sun Lagrange point) with a mirror more than twice the diameter of Hubble's. The images that it will produce are expected to be even more stunning than Hubble's. These are truly great times we're living in.

I knew little about Larange points[0] or the James Webb[1] before reading your comment and spending 10 minutes on Wikipedia. The L2 is a stable orbit with the Earth between the L2 point and the sun; the Webb is a telescope that seems twice as large as the Hubble scheduled for launch in 2018. Fascinating stuff!

As noted in the Webb article:

>The JWST will operate near the Earth-Sun L2 (Lagrange) point, approximately 1,500,000 km (930,000 mi) beyond the Earth. Objects near this point can orbit the Sun in synchrony with the Earth, allowing the telescope to remain at a roughly constant distance and use a single sunshield to block heat and light from the Sun and Earth. This will keep the temperature of the spacecraft below 50 K (−220 °C; −370 °F), necessary for infrared observations.

There's a great picture[2] on Wikipedia comparing sizes of major telescopes.

[0]https://en.wikipedia.org/wiki/Lagrangian_point

[1]https://en.wikipedia.org/wiki/James_Webb_Space_Telescope

[2]https://en.wikipedia.org/wiki/File:Comparison_optical_telesc...

The L2 orbit is not a stable one, it is an unstable equilibrium point in the gravitation field of Earth and the Sun, so objects at this point or in orbit around it will slowly drift away and will need small active trajectory corrections to stay around.

Idle speculation, but I wonder if the distance will impair service, repair and upgrades, all of which I believe Hubble has benefited from

Yes.

No human has ever been out that far into space. Though I suspect by the time it launches it is conceivable SpaceX and NASA could actually put a mission together to do that since at SpaceX prices repairs might be cost effective.

On that note, is it possible for the mission operators to put the telescope in earth orbit first, make sure everything is working, then repair if needed before sending it out to L2?

No. It would be too warm to take good observations. And the mirror unfolds in sections, and isn't AFAIK equipped to fold back down again for the journey to L2. And repairing in LEO would still be tremendously expensive in any case.

Yup, it's a one shot deal, mostly.

That said, as the parent post mentioned, the cost of all those servicing missions was very high. It actually would have been cheaper, overall, to just launch a new one, or several. However, because of the weirdness of the Shuttle program, most of the actual cost of the Shuttle missions to service the Hubble weren't charged against Hubble's budget (substantially because the Shuttle program was looking for reasons it was useful). At nearly the full cost of building the Hubble itself per servicing mission (about $1.2 billion plus extras per flight) it really didn't make any financial sense.

And now that the Shuttle program is over, it wouldn't be a factor anyway. Putting the JWST in low Earth orbit wouldn't make it any easier to be serviced, since there are no vehicles capable of servicing. But it would make it impossible for it to do it's primary mission.

Moreover, we've gotten a lot better at building spacecraft and space telescopes since Hubble was constructed, most likely JWST will do just fine.

Unmanned satellites aren't generally serviced, even ones in low Earth orbit. The Hubble is an extremely rare exception.

It makes servicing impossible. The telescope will eventually run out of fuel and stop working.

Still, the quality of the images it expected to be so much better than Hubble that the limited lifespan will be a worthwhile trade-off.

There was a lot of "great times" if we are talking about tech development. It was also a great time to board a locomotive at the beginning of the XIX century. Then, I think a great time not too abstract would be to actually go to Mars more than looking at pictures.

For now I think of manned space exploration as a vanity. It's so ludicrously expensive compared to robotic exploration that, in my mind, it's impossible to justify. It's just "cool."

Eventually we'll need manned spaceflight to escape this rock, but we have more pressing concerns at the moment.

Some more images from ISRO MOM.

http://www.isro.gov.in/pslv-c25-mars-orbiter-mission/picture...

Thanks for the link. This image out of all posted there compares directly to the one taken by Hubble : http://www.isro.gov.in/sites/default/files/galleries/Picture...

The article from NASA themselves is a lot better, with a lot more information: http://www.nasa.gov/feature/goddard/2016/new-hubble-portrait...

Also, the headline is less click-baity.

And the site doesn't auto play audio at high volume and wake your girlfriend when she's asleep but you can't!

Just shows a black page on mobile Firefox, but works in mobile Chrome.

NASA's Instagram post has a surprising amount of detail in the photo description that helped orient me to the features in the photo: https://www.instagram.com/p/BFmwqJNIaLU/

Could someone provide a link to the high res photo?

I always thought Mars was red and dusty. That image looks more like Earth than not!

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