Starship Asterisk*

BMAONE23 wrote:Orin,
Did you mean Hours instead of Minutes?
It takes light 4 hours to reach Neptune from the Sun

orin stepanek wrote:
And today there is only 7 AU left to reach New Horizons' initial destination!

orin stepanek wrote:
And today there is only 7 AU left to reach New Horizons' initial destination!

neufer wrote:

orin stepanek wrote:
And today there is only 7 AU left to reach New Horizons' initial destination!

http://www.planetary.org/blogs/emily-la ... ubble.html

orin stepanek wrote:

http://www.jhu.edu/jhumag/1105web/pluto.html wrote:
Two hundred days from Pluto, nine years after launch, the real work of New Horizons will begin
as LORRI starts making images...

Ralph, using less power than a nightlight, will record close-up color images.

Alice will probe Pluto's atmosphere with its ultraviolet imaging spectrometer.

• Bob & Carol & Ted & Alice

neufer wrote:

• Bob & Carol & Ted & Alice

neufer wrote:

orin stepanek wrote:

http://www.jhu.edu/jhumag/1105web/pluto.html wrote:
Two hundred days from Pluto, nine years after launch, the real work of New Horizons will begin
as LORRI starts making images...

Ralph, using less power than a nightlight, will record close-up color images.

Alice will probe Pluto's atmosphere with its ultraviolet imaging spectrometer.

• Bob & Carol & Ted & Alice

John Hopkins Magazine, as in Orin's post
...close-encounter imager named Ralph would create visible light and infrared images, as well as thermal maps of the planet, plus use a spectrometer to study Pluto's surface composition. An ultraviolet imaging spectrometer called Alice — Stern named them after Ralph and Alice Kramden, characters from the 1950s television comedy series The Honeymooners — would analyze the composition of Pluto's skimpy atmosphere.

MargaritaMc wrote:
I just HAD to find out who or what Ralph and Alice are - especially as the operations manager of NewHorizons is Alice Bowman!

Did she go along for the ride

John Hopkins Magazine, as in Orin's post

...close-encounter imager named Ralph would create visible light and infrared images, as well as thermal maps of the planet, plus use a spectrometer to study Pluto's surface composition. An ultraviolet imaging spectrometer called Alice — Stern named them after Ralph and Alice Kramden, characters from the 1950s television comedy series The Honeymooners — would analyze the composition of Pluto's skimpy atmosphere.

orin stepanek wrote:
New Horizon now less that 800 days from rendezvous with the Pluto system! A new speculation suggests that Pluto could have as many as 10 moons and a ring system! http://news.discovery.com/space/astrono ... pgn=fbsci1

neufer wrote:

orin stepanek wrote:
New Horizon now less that 800 days from rendezvous with the Pluto system! A new speculation suggests that Pluto could have as many as 10 moons and a ring system! http://news.discovery.com/space/astrono ... pgn=fbsci1

Shouldn't this thread read: Where New Horizons are?

orin stepanek wrote:
You're just joshing; right?

neufer wrote:What, me josh?

orin stepanek wrote:New Horizon now less that 800 days

orin stepanek wrote:

orin stepanek wrote:
New Horizon now less that 800 days

OK! I can see clearly now; I mispelled New Horizons!

http://www.planetary.org/blogs/guest-blogs/2013/20130520-new-horizons-encounter-planning-accelerates.html wrote:
New Horizons: Encounter Planning Accelerates
Posted By Alan Stern, 2013/05/17 10:18 CDT

<<Back in 2005 and 2006, when Pluto’s second and third moons (Nix and Hydra) were discovered, searches by astronomers for still more moons didn’t reveal any. So the accidental discovery of Pluto’s fourth moon by the Hubble Space Telescope in mid-2011 (during a search for Plutonian rings) raised the possibility that the hazards in the Pluto system might be greater than previously anticipated. Those concerns were amplified when Hubble discovered a fifth moon in 2012. As a result of those discoveries, the New Horizons science and operations teams began to more carefully scrutinize the true level of hazards to our spacecraft at closest approach and devise mitigation strategies to make sure the encounter with Pluto would be successful.

We’ve now largely completed that work and presented the results to both an independent, NASA-appointed technical review team, led by the Jet Propulsion Laboratory’s Keyur Patel, and then to senior executives at NASA Headquarters. Both groups have concurred with our findings, which I can summarize as follows:

• 1) The Pluto system appears to be far safer than early fears and initial calculations indicated when the new moons began popping up. In fact, the best current models predict a 0.3% (1-in-300) chance of a mission-ending impact near closest approach on the nominal trajectory. Much of the reason for this lowered risk assessment is that more sophisticated dust-impact models revealed a decrease (by about a factor of 100) in lethal impact probability for trajectories that fly into the region where New Horizons is aimed now – a region where the gravitational effects of Pluto’s largest moon Charon clear debris. Another important factor is that when we tested spacecraft components against high-velocity impacts using gun ranges in New Mexico and Ohio, we found the spacecraft shielding is considerably “harder”– that is, more resistant to impacts – than preflight estimates indicated.
  
  2) The baselined New Horizons closest-approach aim point is one of the safest possible aim points – if not the safest aim point – in the Pluto system. This is because we’re headed to a closest approach in the region that Pluto’s Texas-sized moon Charon efficiently clears of debris. In fact, Charon offers such a good hazard-removal service that even if a recent impact onto a small moon created debris near Charon’s orbit just months before encounter, Charon would clear almost all of it by the time the spacecraft arrives.

Thanks to these three findings, we’re much more confident that unless something new and unexpected comes up between now and encounter, our current plan, which has been optimized to maximize the encounter science return, is to the best level of current knowledge, safe.

But to be still more prudent, we’re also implementing plans during the final weeks of approach in summer 2015 for New Horizons itself to search for hazards that we can’t see from Hubble or Earth-based telescopes. And we’ve also added “fail safe” data downlinks just two days and one day before the encounter to send home the best images and spectra stored on the spacecraft’s recorders, just in case our current estimates are wrong and we do lose New Horizons at closest approach. It’s always better to plan this way, just as the Apollo astronauts collected contingency samples right after stepping onto the moon in case they had to make a hurried getaway before their moonwalks could be completed.

And – just as every space shuttle mission included (but never used) plans to land after just one orbit of Earth if the spacecraft wasn’t healthy enough to continue – we are also prudently planning two alternate encounter sequences that we can upload to New Horizons as late as 10 days before closest approach, in the unlikely event that our hazard observations on final approach raise new cautions.

[b][color=#0000FF]The New Horizons team studied numerous alternate flybys, called SHBOTs, before recommending to NASA a pair of backups to protect New Horizons from possible impact hazards in the Pluto system.[/color][/b]

---

These backup encounter sequence plans are called SHBOTs, an acronym for Safe Haven By Other Trajectory.

Our first SHBOT is called GIS, for Generic Inner SHBOT. It continues on the nominal trajectory and aim point, but for three hours near closest approach, we repoint the spacecraft so its dish antenna can shield it from impacts. This pointing attitude, called Antenna to Ram (or ATR), would cost us some science because we won’t be as free to point the science instruments toward Pluto system targets during those three hours. But tests and modeling show this provides a factor of three to four times increase in success probability, and reduces the estimated loss of mission probability to about 1 in 1,000.

Our second SHBOT is called DIS, for Deep Inner SHBOT. DIS also uses the ATR attitude. It also directs the spacecraft toward a much closer encounter with Pluto – just inside 3,000 kilometers from Pluto’s surface, compared to the nominal encounter close approach of about 12,500 kilometers from the surface. Why go closer, not farther, to avoid hazards? Because if we go close enough, we can benefit from the fortuitous “drag clearing” of debris particles from Pluto’s extended upper atmosphere! DIS has more severe science impacts than does GIS, but there is a strong consensus among the team that it’s both the best choice if late-breaking news tells us the nominal trajectory is unexpectedly riskier than we’re comfortable with, and losing some science to execute Deep Inner SHBOT is far better than losing the mission to a lethal impact.

Before I close this column out, I also want to update you on mission status and other project news.

Currently, New Horizons itself is about 2.6 billion miles from the Sun, and only about 600 million miles from Pluto. Arrival at Pluto is just under 700 days away – still a long time, but much less than the nearly 2,700 days we’ve been traveling since launch!

New Horizons is healthy and on course, with all systems and science sensors working. On May 21, we’ll wake the spacecraft from its most recent, 100-plus day hibernation to begin a busy annual checkout, which will include thorough checks of all backup systems, instrument payload calibrations, and an update of our fault protection software with the next-to-last planned set of enhancements before we start the Pluto encounter in January 2015 – just over 19 months from now.

This summer’s wakeup will also include our most comprehensive on-the-spacecraft close-encounter rehearsal. For nine days, beginning July 5, New Horizons will execute all the activities of its final week on approach to Pluto, closest approach day, and then some of the post-encounter timeline as well. This rehearsal follows up on our successful encounter-day practice from last summer.

After the nine-day rehearsal, we’ll downlink a large amount of data through NASA’s Deep Space Network to evaluate how the rehearsal went, collect more cruise science data, conduct more spacecraft navigation tracking, and then put New Horizons back into hibernation on August 21 for another 4½ months, while the team works on SHBOT encounter sequencing.

Also this summer, we’ll be close enough to resolve Pluto from its large moon Charon using our long-focal length telescopic imager called LORRI. The first week of July is also the 35th anniversary of Charon’s discovery and – entirely by coincidence – we’ll be taking our first images of Charon at the same time of year that the moon was discovered, back in 1978!>>

http://www.urbandictionary.com/define.php?term=shbot&defid=4768711 wrote:
SHBOT: a fantastic celebration of friendship between two people

Arrival at Pluto is just under 700 days away – still a long time, but much less than the nearly 2,700 days we’ve been traveling since launch!

orin stepanek wrote:

Arrival at Pluto is just under 700 days away – still a long time, but much less than the nearly 2,700 days we’ve been traveling since launch!

I think it should read just under 800 days!

http://www.nasa.gov/mission_pages/newho ... index.html

• Still a long time.

neufer wrote:

• Still a long time.