Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

New Horizons: Nasa spacecraft speeds past Pluto

bbc.co.uk

Post reply on HN
Print view View original

161–170 of 309 posts

Re: New Horizons: Nasa spacecraft speeds past Pluto

#161

Post by bdamm »

thwest wrote: post #155
tlb wrote: post #152

Earlier quoted context omitted.

Since you can see stars near the moon, you should be able to see stars near Pluto, which is less bright. More likely, there are no stars in the (very narrow) angle of the camera.

Perhaps no significantly bright stars. I find it unlikely that there are zero stars in that field of view, especially since the probe and planet are most likely roughly in the plane of the galaxy.

This is basically heresy, but what I've been told is that imaging stars from space is actually more difficult, because there is no diffusion of the local atmosphere to help increase the perceived size of the point light source.

Re: New Horizons: Nasa spacecraft speeds past Pluto

#162

Post by antjanus »

Sven7 wrote: post #154
kartikkumar wrote: post #147

Earlier quoted context omitted.

I realise that I made an unexplained logical leap to get to the last comment. Basically, based on my professional experience as a planetary scientist, it's my belief that the reason we don't have more satellites cruising through the Solar System is that we (and I mean scientists, engineers, administrators etc.) continue to fail in communicating their true value to the average person on the street. I think that media…

All you have to do is convince Kim Kardashian its important...

just send her a tweet with this then.

Re: New Horizons: Nasa spacecraft speeds past Pluto

#163

Post by ringshall »

kohanz wrote: post #111
ringshall wrote: post #101

Interesting note, as of today, the US is the first country to have successful spacecraft missions visit all of the classical planets. There is one big exception, of course: the Soviet Union was the first to have a spacecraft visit Earth, with Spunink. This category is completely arbitrary, especially given that Pluto is now considered a minor planet. Still, it's an achievement of note. Mercury - 1974, Mariner 10 Venu…

Not to shoot the messenger, but it annoys me when these things are viewed through the lens of artificial divisions such as nations. I understand that space exploration has been used as a tool to further many political machines, but it seems silly to me, especially when staring at a picture as beautiful as this from a distance that makes Earth seem so small, to think about the people living on this planet as anything…

I agree with you in the sense that space exploration is at its core a human, not national, achievement. National divisions are silly when seen in the context of the vastness of space. In a similar vein, I think Gene Roddenberry was right in thinking that true elimination of national boundaries will come after we meet sentient aliens for the first time - with an alien to compare ourselves against, we all see our common humanity much more clearly.

We're partway there. As you say, there is cooperation on the Space Station. Cooperation between the various space agencies on missions from telescopes to probes is commonplace. Look at Cassini: a NASA probe with a ESA lander. The Curiosity rover has a Russian instrument on it.

But we haven't reached the point yet where nationalism is no longer a part of the drive behind space exploration or other 'big-science' projects. I see competition for scientific glory as a healthy and productive form of competition, so I don't think we should completely shy away from it. It's akin to rival schools competing for academic glory - a kind of tribalism that results in achievements which benefit all.

Re: New Horizons: Nasa spacecraft speeds past Pluto

#164

Post by trothamel »

chasing wrote: post #160
kartikkumar wrote: post #89

Quote from a friend of mine on the team: "After 9.5 years and 6 billion km, we made it to Pluto 72 seconds ahead of schedule." Amazing! The views of Pluto and Charon already reveal how incredibly fascinating this system is. The dichotomy of their surface colours will most definitely lead to further insight into formation processes in the Kuiper Belt. Just such a shame that we can't land this time around. With the vol…

Any actual engineer will probably find this comment painfully naive, but here we go: If it's infeasible to slow down to get into orbit or land on Pluto, what about the feasibility of designing a probe to impact Pluto at XX km/sec and survive well enough to send back data. Like, fire a (metaphorical) bullet full of scientific instruments directly into the surface of the planet. Is it simply that we have no way to buil…

It's probably the former. It's been tried before, with Deep Space Two at mars - but didn't work.

There's also a sense that if you're going to spend tons of money to send a once-in-a-generation probe to an outer planet, it has to work.

Re: New Horizons: Nasa spacecraft speeds past Pluto

#165

Post by scrumper »

smackfu wrote: post #134
rootbear wrote: post #116

Earlier quoted context omitted.

In the press conference, the PI was asked about a future mission. He said that he has thought about orbiters and landers and considers the Pluto system to be a valuable science target. But he said that we need to study the New Horizons data for some years, to better design the next mission. At this time, they wouldn't know what the best instruments to send would be. Also, it is far from clear how to send a mission to…

> At this time, they wouldn't know what the best instruments to send would be. There's an interesting BBC documentary series on the planets, called The Planets, that has an episode covering the Voyager probes. They had to do some quick redesigns on them after Pioneer 10 and 11 visited the outer planets and found fun stuff like radiation and unexpected rings. They said that if they hadn't had the earlier probes, Voyag…

I second that recommendation, and it's currently on Netflix. It's a good documentary series. A little long in the tooth now, but only for the entirely positive reason that we've done a fair bit more planetary science since it was made.

Re: New Horizons: Nasa spacecraft speeds past Pluto

#166

Post by grinich »

chasing wrote: post #160
kartikkumar wrote: post #89

Quote from a friend of mine on the team: "After 9.5 years and 6 billion km, we made it to Pluto 72 seconds ahead of schedule." Amazing! The views of Pluto and Charon already reveal how incredibly fascinating this system is. The dichotomy of their surface colours will most definitely lead to further insight into formation processes in the Kuiper Belt. Just such a shame that we can't land this time around. With the vol…

Any actual engineer will probably find this comment painfully naive, but here we go: If it's infeasible to slow down to get into orbit or land on Pluto, what about the feasibility of designing a probe to impact Pluto at XX km/sec and survive well enough to send back data. Like, fire a (metaphorical) bullet full of scientific instruments directly into the surface of the planet. Is it simply that we have no way to buil…

A bullet travels about 1,700 MPH. New Horizons is going about 36,300 MPH.

The probe weighs 480 kilograms, so it's kinetic energy is approximately 63.2 Gigajoules. For reference, this is like 15 tonnes of TNT released on impact. Hard to make something that survives those kind of conditions.

Re: New Horizons: Nasa spacecraft speeds past Pluto

#167

Post by kartikkumar »

bdamm wrote: post #156
kartikkumar wrote: post #147

Earlier quoted context omitted.

I realise that I made an unexplained logical leap to get to the last comment. Basically, based on my professional experience as a planetary scientist, it's my belief that the reason we don't have more satellites cruising through the Solar System is that we (and I mean scientists, engineers, administrators etc.) continue to fail in communicating their true value to the average person on the street. I think that media…

What, Kepler is fighting to keep the lights on? The greatest mission that NASA has ever undertaken? I'm saddened to hear that.

Well Kepler did win that fight. NASA fortunately decided to breathe life into an extended mission called K2 [1]. This didn't happen without A LOT of back and forth between administrators and scientists though.

[1] http://kepler.nasa.gov/news/index.cfm?FuseAction=ShowNews&Ne...

Re: New Horizons: Nasa spacecraft speeds past Pluto

#168

Post by jccooper »

chasing wrote: post #160
kartikkumar wrote: post #89

Quote from a friend of mine on the team: "After 9.5 years and 6 billion km, we made it to Pluto 72 seconds ahead of schedule." Amazing! The views of Pluto and Charon already reveal how incredibly fascinating this system is. The dichotomy of their surface colours will most definitely lead to further insight into formation processes in the Kuiper Belt. Just such a shame that we can't land this time around. With the vol…

Any actual engineer will probably find this comment painfully naive, but here we go: If it's infeasible to slow down to get into orbit or land on Pluto, what about the feasibility of designing a probe to impact Pluto at XX km/sec and survive well enough to send back data. Like, fire a (metaphorical) bullet full of scientific instruments directly into the surface of the planet. Is it simply that we have no way to buil…

Bullet goes about 1.2 km/s at best. New Horizons is going ~14 km/s relative to Pluto. That's a heck of an impact to survive. You could do it on Earth by braking in the atmosphere, but there's not a lot of that on Pluto.

Re: New Horizons: Nasa spacecraft speeds past Pluto

#169

Post by Patrick_Devine »

bdamm wrote: post #156
kartikkumar wrote: post #147

Earlier quoted context omitted.

I realise that I made an unexplained logical leap to get to the last comment. Basically, based on my professional experience as a planetary scientist, it's my belief that the reason we don't have more satellites cruising through the Solar System is that we (and I mean scientists, engineers, administrators etc.) continue to fail in communicating their true value to the average person on the street. I think that media…

What, Kepler is fighting to keep the lights on? The greatest mission that NASA has ever undertaken? I'm saddened to hear that.

It's not helped by being hobbled with two of four broken reaction wheels. It's awesome that we've figured out a way to keep prolonging the mission.

You can't argue with the results though; Over a thousand planets discovered with another four thousand candidates. I'm not sure why we don't have multiple Kepler-like missions running simultaneously to map out our entire section of the Milky Way.

Re: New Horizons: Nasa spacecraft speeds past Pluto

#170

Post by thwest »

bdamm wrote: post #161
thwest wrote: post #155

Earlier quoted context omitted.

Perhaps no significantly bright stars. I find it unlikely that there are zero stars in that field of view, especially since the probe and planet are most likely roughly in the plane of the galaxy.

This is basically heresy, but what I've been told is that imaging stars from space is actually more difficult, because there is no diffusion of the local atmosphere to help increase the perceived size of the point light source.

Ah yes it is reasonable that several other characteristics make the sensor less likely to register photons from the field of view here. (The sensor/lens could also have some spatial frequency response characteristics that filter out non-diffused stars). I don't find it reasonable that there are no stars in that field of view though :)
Post reply on HN