honeste_vivere
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2 answers
6 votes
107 views
Why put SunRISE in the graveyard? Why will it "fly slightly above geosynchronous orbit"?
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4 votes

Why will the SunRISE mission "fly slightly above geosynchronous orbit"? There are few advantages and practical reasons for doing so. The first advantage is trying to minimize Earth-based ...

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2 answers
6 votes
211 views
Are there more operating interplanetary missions today than in the past?
5 votes

Ultimately, I'm trying to figure out if NASA's decrease in funds is responsible for fewer missions... The decrease in launches and/or planned missions is due to budget cuts. ...what the funding ...

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1 answers
5 votes
306 views
How do solar flares and coronal mass ejections create proton storms?
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5 votes

How do solar flares and coronal mass ejections create proton storms? The proper answer to this questions fills multiple books and they all still end with lots of questions, but I will try to give a ...

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3 answers
6 votes
415 views
How can a solar storm be predicted?
2 votes

Satellites like DSCOVR are used to predict solar storms. No they are not. Spacecraft cannot predict solar storms. They can inform a user that something is coming toward Earth, but they cannot ...

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3 answers
6 votes
148 views
Can "space weather" refer to deep space environments or only to Earth's (or another planet's) upper atmosphere?
2 votes

Can the term "space weather" refer to the environment in deep space, or is it only in reference to Earth's (or another planet's) upper atmosphere? Just a quick addition to the already ...

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2 answers
2 votes
167 views
Can VLF be used to create a Mars barrier?
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2 votes

Can VLF be used to create a Mars barrier? The short answer is no because Mars does not have an intrinsic magnetic field, thus no uniform dipole magnetic field to generate a magnetosphere. I wrote an ...

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1 answers
5 votes
101 views
Which objects in our solar system are naturally protected from solar flares?
2 votes

There are two primary things that protect something from ionizing radiation with a source external to a planetary body: a magnetosphere for charged particles and an atmosphere for both charged ...

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1 answers
6 votes
219 views
What would happen to an astronaut on the surface of Mars if a Carrington-event-like superflare hit the red planet?
3 votes

There is a detailed review of space weather effects on humans in space by Townsend [2021]. They highlight several solar energetic particle (SEP) events that would have exceeded 30 day short-term ...

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2 answers
2 votes
133 views
Why hasn't DSCOVR's trajectory determination been updated in JPL's Horizons after 2015-Aug-4?
1 votes

While the DSCOVR attitude may not be in JPL's Horizons database, you can find attitude/orbit information from the Space Physics Data Facility (SPDF) at: https://spdf.gsfc.nasa.gov/data_orbits.html

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1 answers
3 votes
87 views
Did specific changes to DSCOVR's mission or design produce the change from "may not represent the best expenditure " to "strong and vital"?
4 votes

Were there any specific changes to the spacecraft's mission or design that led to the change from "...may not represent the best expenditure of NASA's limited science funding" to "...

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3 answers
16 votes
2k views
Why would a mission to Sun-Earth L1 have an instantaneous launch window?
2 votes

The issue with launch window wasn't whether the launch vehicle could get the object into space or even to L1, it's whether the last stage can still insert the object into a semi-stable orbit about L1. ...

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1 answers
5 votes
82 views
How was DSCOVR "fixed" so that sufficiently dynamic attitude determination is gotten from star cameras?
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1 votes

How was DSCOVR fixed? What software changes were implemented to allow sufficiently dynamic attitude determination from star cameras? What kinds of algorithms were added to make this possible? The ...

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1 answers
5 votes
125 views
What is the probability that a deep space crew is hit by a Solar proton storm?
1 votes

What is the probability that a deep space mission gets hit by such a Solar proton storm? There's a paper by Riley et al. [2018] (https://doi.org/10.1007/s11214-017-0456-3) that estimates the ...

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1 answers
3 votes
279 views
What is the story behind NICER's mission patch?
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1 votes

There is a mission patch on the side. I had always thought mission patches were for missions identified with a particular launch, but the NICER-SEXTANT mission is really a research program if I ...

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1 answers
6 votes
286 views
Decision making for NASA missions
2 votes

Generally NASA responds to the decadal surveys put together by the National Academies of Science for each major science branch (i.e., Earth, Planetary, Astrophysics, and Heliophysics). The decadal ...

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1 answers
5 votes
303 views
If Juno will experience lower levels of radiation than Galileo did why it will fail so much faster?
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3 votes

It looks like Juno has a much lower apoapsis (e.g., http://spaceflight101.com/juno/juno-mission-trajectory-design/) than did Galileo (e.g., http://solarsystem.nasa.gov/galileo/mission/journey-orbital....

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1 answers
1 votes
123 views
Where to read about early work in the detection of dust impacts on solar observing spacecraft?
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4 votes

in Wikipedia I see eighteen discoveries by WIND but not that particular one... Yes, I have not had a chance to update the list of Wind discoveries for quite a while but plan to do so soon. ......

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2 answers
8 votes
2k views
How does the Parker Solar Probe's heat shield protect it from dust near the sun?
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3 votes

@uhoh - Mistake, no. Poor phrasing, perhaps yes. It looks like the APL fact sheet is implying that the Solar Probe Plus heat shield must survive extreme temperatures, radiation, and dust impacts ...

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1 answers
9 votes
285 views
Did the Surveyor missions measure secondary radiation?
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4 votes

Have there been any measurements on neutron radiation performed by the Surveyor (or later) missions? The Lunar Reconnaissance Orbiter (LRO) has several instruments designed to determine the radiation ...

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1 answers
12 votes
577 views
What's the furthest a probe has travelled from Earth before returning?
7 votes

The best I could find was the Stardust mission, which went a little over ~2.5-3.0 AU away from Earth before returning (it landed so dust from comet Wild 2 could be analyzed). There are more examples ...

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1 answers
7 votes
2k views
How can solar wind be supersonic?
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5 votes

The speed of sound in space has multiple meanings because space is not a vacuum (though the number density of Earth's magnetosphere can be ~6-12 orders of magnitude more tenuous than the best vacuums ...

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3 answers
6 votes
424 views
Does NASA plan to land on Europa?
3 votes

Land, no... Study, yes! There is a new mission called JUICE lead by ESA and in partnership with NASA to study the Galilean moons of Jupiter. The entire purpose of the JUICE mission is to: to ...

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2 answers
13 votes
1k views
If something "falls off" the L2 or L1 point, where will it go?
3 votes

...when a spacecraft stationed there diverges toward either side of the saddle, and station-keeping is no longer maintained, where will it go? The Earth-Sun $L_{1}$ point is unstable, just like the ...

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1 answers
1 votes
122 views
from L1 to L2 (earth-sun system) using gravity assistance with the moon
1 votes

The Wind spacecraft did just this back in 2002-2004 over a series of several orbits. It used the moon to change its angular momentum, but it also used its thrusters during the maneuver. So ...

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