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abalone
Posted on: Aug 20 2023, 09:40 AM


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Russian spacecraft has crashed into the Moon after it spun into an uncontrolled orbit, Russia's national space agency Roskosmos says.
https://www.abc.net.au/news/2023-08-20/russ...-moon/102753294
  Forum: Lunar Exploration · Post Preview: #261395 · Replies: 38 · Views: 17926

abalone
Posted on: Aug 19 2022, 03:52 AM


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Grains of dust from asteroid Ryugu older than our solar system
by Bob Yirka , Phys.org
https://phys.org/news/2022-08-grains-astero...lder-solar.html

...some of which have been dated to 7 billion years ago. The researchers found that the dust sample held grains identical to all of the others that have been seen in meteorites, showing that it too predates the solar system.
  Forum: Hayabusa2 · Post Preview: #258118 · Replies: 981 · Views: 852547

abalone
Posted on: Feb 7 2022, 03:09 AM


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Just out of interest what kind of power production could be expected if instead of horizontal panels it had them facing east west at say a 70deg tilt to the horizontal. That is almost vertical. I assume that dust accumulation would then not be an issue.
  Forum: InSight · Post Preview: #256176 · Replies: 1270 · Views: 856046

abalone
Posted on: Dec 28 2021, 11:50 PM


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Forward and aft sun-shield pallets successfully deployed.
https://blogs.nasa.gov/webb/2021/12/28/forw...eld-deployment/
  Forum: Telescopic Observations · Post Preview: #255661 · Replies: 297 · Views: 327105

abalone
Posted on: Apr 18 2021, 09:37 AM


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I'm curious to know if the balance weight impacts were detected. I had read the past posts and can't find any info. Have I missed it or don't we have any answers?
  Forum: InSight · Post Preview: #251673 · Replies: 1270 · Views: 856046

abalone
Posted on: Apr 15 2021, 01:58 PM


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The sharp edges are probably an artefact as a result of wind erosion rather than fracturing. The clue is that they all have a similar orientation
  Forum: Perseverance- Mars 2020 Rover · Post Preview: #251629 · Replies: 309 · Views: 127200

abalone
Posted on: Oct 27 2020, 05:21 AM


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QUOTE (marsbug @ Oct 27 2020, 03:23 AM) *
The SOFIA related paper from the announcement:

100-400g per ton of regolith, possibly only 1L for every 10T, not a lot. The news media is overblowning the significance. Unlikely to be able to collect enough economically to produce rocket fuel.
  Forum: Telescopic Observations · Post Preview: #248411 · Replies: 8 · Views: 42300

abalone
Posted on: Oct 22 2020, 04:34 AM


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Good spray of material with the nitrogen blast. This is what they were looking for to indicate a good potential for a sample

https://youtu.be/LJBv4reH9IU
  Forum: OSIRIS-REx · Post Preview: #248336 · Replies: 213 · Views: 179019

abalone
Posted on: Jul 19 2020, 04:53 AM


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The Hayabusa 2 spacecraft will release a sample return canister as it approaches Earth, then divert itself away from the planet and continue into space.
https://spaceflightnow.com/2020/07/16/aster...th-in-december/
  Forum: Hayabusa2 · Post Preview: #247656 · Replies: 981 · Views: 852547

abalone
Posted on: Sep 22 2019, 01:38 PM


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QUOTE (HSchirmer @ Sep 22 2019, 08:24 AM) *
One idea - most landers have some sort of ballast, make that ballast out of tungsten flechettes.
Release the flechettes into the landing ellipse, then let the rover check the newly drilled holes for readings.


I think that the ballast weights land a long way for the craft landing zone, that is probably why they haven't done that yet
  Forum: InSight · Post Preview: #245728 · Replies: 1270 · Views: 856046

abalone
Posted on: Mar 7 2019, 12:27 PM


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QUOTE (Paolo @ Mar 7 2019, 06:55 PM) *
one question comes to my mind after seeing the video, that I have not seen addressed: are all of the flying debris still gravitationally bound to Ryugu? will they fall back on it? will they end up in orbit? are we witnessing the birth of a mini-moon? or, finally, will they end in separate solar orbit?

Almost all of the fragments will either have escape velocity and disappear or not quite enough and settle back on the surface. A single kick from the surface can put an object into orbit but this orbit will have a perigee that is the same as the point it was kick off the surface. To go into a stable orbit it needs a second kick at some altitude above the surface to raise it perigee off the asteroids surface. The escape velocity is about 0.38m/s or about 1.35 km/h. This is one of the reasons why a cannon shell can not be fired into a stable orbit.

QUOTE (pandaneko @ Mar 7 2019, 11:20 PM) *
Why is it that the same fragments look shiny and then dark as they fly up rotating?

P

Id say some are sun illuminated and some in shadow
  Forum: Hayabusa2 · Post Preview: #244183 · Replies: 981 · Views: 852547

abalone
Posted on: Jan 24 2019, 11:04 PM


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I get the impression that its possibly evidence of been put together like a hailstone accretion and the lines and lumpy appearance might be an artifact of that. https://upload.wikimedia.org/wikipedia/comm.../94/Granizo.jpg Could also be the reason for the 'hamburger' shape if the individual lobe were slowly rotating during the accretion process before coming together.
  Forum: New Horizons · Post Preview: #243552 · Replies: 152 · Views: 226067

abalone
Posted on: Dec 13 2018, 01:10 AM


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QUOTE (nprev @ Dec 13 2018, 10:56 AM) *
Thanks, Propguy. smile.gif

Quick question re the WTS: How much is it expected to reduce the amount of temperature variation?

I imagine that the soil covered by the WTS will provide some extra heat capacity that will stabilize the temp variation somewhat more than the air temperature
  Forum: InSight · Post Preview: #242550 · Replies: 1270 · Views: 856046

abalone
Posted on: Oct 11 2018, 08:48 PM


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Japan delays touchdown of Hayabusa2 probe on asteroid: official
http://www.spacedaily.com/m/reports/Japan_...ficial_999.html

JAXA project manager Yuichi Tsuda said they needed more time to prepare the landing as the latest data showed the asteroid surface was more rugged than expected.
  Forum: Hayabusa2 · Post Preview: #241429 · Replies: 981 · Views: 852547

abalone
Posted on: Sep 22 2018, 02:08 PM


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http://www.hayabusa2.jaxa.jp/topics/20180922/
Surface images
https://pbs.twimg.com/card_img/104347041706...mp;name=600x314
  Forum: Hayabusa2 · Post Preview: #241081 · Replies: 75 · Views: 96702

abalone
Posted on: Jul 20 2017, 12:34 PM


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QUOTE (nprev @ Jul 20 2017, 03:07 AM) *
Amazing! The animated gif in the article clearly shows a gradual dimming and brightening...surely a demonstration of how small (and how slowly orbiting) MU69 really is given that it took observable time to occult an exceedingly small stellar disc.

Remarkable achievement, Alan, as per you & your team's usual. smile.gif

Great news, 5 occultations, so the obvious questions are why didn't any of the scopes detect it on 3rd June and what are the Sofia results?
  Forum: New Horizons · Post Preview: #236636 · Replies: 573 · Views: 684780

abalone
Posted on: Oct 20 2016, 09:44 AM


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"Schiaparelli Mars probe's parachute 'jettisoned too early'"
QUOTE
Europe's Schiaparelli lander did not behave as expected as it headed down to the surface of Mars on Wednesday.

QUOTE
But it is at the end of this parachute phase that the data indicates unusual behaviour. Not only is the chute jettisoned earlier than called for in the predicted timeline, but the retrorockets that were due to switch on immediately afterwards, fire for just three or four seconds. They were expected to fire for a good 30 seconds.

In the downlinked telemetry, Schiaparelli is seen to continue transmitting a radio signal for 19 seconds after the apparent thruster shutoff.



http://www.bbc.com/news/science-environment-37715202
  Forum: ExoMars Program · Post Preview: #233046 · Replies: 177 · Views: 191236

abalone
Posted on: Feb 12 2016, 11:09 AM


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Time-lapse: The Assembly of the James Webb Space Telescope Primary Mirror
https://www.youtube.com/watch?v=1d1sHLkmNQI
  Forum: Telescopic Observations · Post Preview: #229512 · Replies: 297 · Views: 327105

abalone
Posted on: Oct 24 2015, 12:08 PM


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NASA's New Horizons spacecraft has carried out the first in a series of four initial targeting maneuvers designed to send it toward 2014 MU69 - a small Kuiper Belt object about a billion miles beyond Pluto, which the spacecraft historically explored in July.

The maneuver, which started at approximately 1:50 p.m. EDT on Oct. 22, used two of the spacecraft's small hydrazine-fueled thrusters, lasted approximately 16 minutes and changed the spacecraft's trajectory by about 10 meters per second.
The remaining three KBO targeting maneuvers are scheduled for Oct. 25, Oct. 28 and Nov. 4.
http://www.spacedaily.com/reports/Maneuver...Target_999.html
  Forum: New Horizons · Post Preview: #227577 · Replies: 573 · Views: 684780

abalone
Posted on: Oct 15 2015, 12:20 PM


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Any news yet on when the first burn is due?
  Forum: New Horizons · Post Preview: #227294 · Replies: 573 · Views: 684780

abalone
Posted on: Jul 16 2015, 12:46 PM


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QUOTE (climber @ Jul 16 2015, 04:50 AM) *
Another answer, 100m delta V:

That's a bit confusing 100m/s, what does that include?
  Forum: New Horizons · Post Preview: #223750 · Replies: 573 · Views: 684780

abalone
Posted on: Jul 15 2015, 12:59 PM


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QUOTE (Paolo @ Jul 15 2015, 11:41 PM) *
this paper should answer most of your questions:
http://www.hou.usra.edu/meetings/lpsc2015/pdf/1301.pdf

Thanx
  Forum: New Horizons · Post Preview: #223492 · Replies: 573 · Views: 684780

abalone
Posted on: Jul 15 2015, 11:32 AM


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Just out of interest, what delta V do each of the candidates need compared to the delta V still in the tank? or What is NH's the cone of reachability and how close is each to the edge?

Have any followup observations been done or are planed by Hubble to identify any further targets now that the search area is smaller?
  Forum: New Horizons · Post Preview: #223488 · Replies: 573 · Views: 684780

abalone
Posted on: Jul 14 2015, 03:40 AM


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Looks like some of the dark areas are elevated terrain
Release Date: July 13, 2015
http://pluto.jhuapl.edu/Multimedia/Science...JHUAPL-SWRI.png
  Forum: New Horizons · Post Preview: #223180 · Replies: 1286 · Views: 6852602

abalone
Posted on: Jul 13 2015, 01:53 AM


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New Horizons’ newest images reveal Pluto’s largest moon Charon to be a world of chasms and craters.
http://www.nasa.gov/feature/charon-s-chasms-and-craters
  Forum: New Horizons · Post Preview: #222977 · Replies: 729 · Views: 526445

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