32 votes
Accepted

How to check, if there is currently an increased solar activity?

Looks pretty darned quiet to me right now: You can find that here, along with other measures of space weather. By the way, cosmic rays and solar activity are two entirely different things. Cosmic ...
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22 votes

Place a satellite at Sun-Mars L1 to shield Mars from Sun radiation

This answers the question on how to block ions coming directly from the Sun from hitting Mars by a satellite stationed at L1. It does not cover the fact whether such a shield is effective in reducing ...
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18 votes

How does Venus' thick atmosphere survive against the solar wind?

The mass of Mars is so small, and its magnetic field so weak that it cannot hold onto carbon for a long period of time, making almost all of it to escape. (Venus and Earth are close to identical in ...
17 votes
Accepted

Would a nuclear propelled spaceship still need a storm shelter?

The basic idea here is to turn to have the shield you have towards the Sun. That does actually work, because the radiation from the Sun is directed, with a few exceptions: First, inside a planetary ...
12 votes
Accepted

Influence of solar wind and radiation pressure on a sail

According to wikipedia, solar wind pressure at 1AU is about 1-6 nN/m2. Solar light pressure on the other hand is apparently 4.54-9.08 μN/m2. It therefore seems unlikely that solar wind pressure will ...
10 votes

How does the Parker Solar Probe's heat shield protect it from dust near the sun?

The heat shield (TPS) is not meant to protect the spacecraft from dust impacts. The statement is not quite accurate and (from a recent search) seems to have been removed from site. As an engineer on ...
8 votes

Is it possible to launch a satellite into orbit with a solar sail and a weather balloon using the magnetic poles?

The problem is that you have to go from low-speed regime in the atmosphere (the balloon), to a high-speed regime out of the atmosphere (~7000m/s). The low forces available from a solar sail don't ...
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7 votes

Comet at Mars L1

TL;DR: It wouldn't work, because you wouldn't be able to keep the comet at L1. The collinear Lagrangian points (L1, L2, and L3) are unstable; if a body were to be placed at one of these points, any ...
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7 votes

Is it possible to launch a satellite into orbit with a solar sail and a weather balloon using the magnetic poles?

You need 1000km of altitude to break even between air drag and light pressure of sunlight. Below that the solar sail acts as a parachute, dragging against the remains of the atmosphere. You must reach ...
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7 votes

Where is the Wind going? Where has it been? (Global Geospace Science spacecraft 1994-071A)

This is not an answer yet - just a collection of resources. Please feel free to write your own answer, using the image if you like: From the plots found at https://cdaweb.gsfc.nasa.gov/cgi-bin/...
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7 votes
Accepted

Where is the Wind going? Where has it been? (Global Geospace Science spacecraft 1994-071A)

Where has it been? The Wind spacecraft has been all over the near-Earth environment, as is shown below in the image: Figure 1. Orbital trajectories of the Wind spacecraft in the GSE XY plane from ...
6 votes

Is there any safety advantage/disadvantage to a particular attitude of a vessel in space?

Radiation As you have rightly noted, a long cylinder pointing end on to the radiation source (probably the sun, especially during periods of high activity), can be shielded by a smaller, and thus ...
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6 votes

How does Venus' thick atmosphere survive against the solar wind?

This looks like a good read if your really interested in the subject but the simple answer appears to be that the ionosphere of Venus is strong enough to sufficiently deflect the solar wind, without ...
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6 votes
Accepted

When do aircraft become solarcraft?

I think there are a few misconceptions to clarify here: Rotating bodies can generate lift. This is known as the Magnus effect. Lift is a hydrodynamical phenomenon: Differences in flow velocity above ...
6 votes
Accepted

Why didn't SpaceX see that geomagnetic storm coming? Was this a fluke or could this happen more frequently in the future? (R.I.P. 40 lost starlinks)

I think one possible reason that they didn’t see it coming was that the it was extreme ultraviolet photons that only took roughly 8 minutes to travel from the sun and to start heating the thermosphere....
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6 votes

Collecting suns cosmic rays

Technically, there is nothing preventing you from manipulating solar wind protons and electrons like any others. However: The solar wind is extremely sparse. Simple sunlight produces about 2000 times ...
5 votes
Accepted

Does solar wind have any influence on probes?

Of course it affects the probes, as the number and energy of the elementary particles increase as we get higher from the earth in general (even airplanes get higher dose of radiation than cars) and ...
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5 votes
Accepted

How can solar wind be supersonic?

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 ...
5 votes

Place a satellite at Sun-Mars L1 to shield Mars from Sun radiation

The very idea was proposed earlier this month at the Planetary Science Vision 2050 Workshop. The talk was titled: "A Future Mars Environment for Science and Exploration", J. Green, R. Bamford, et. ...
5 votes
Accepted

How much radiation shielding would be required for a habitat at Mercury–Sun L5?

You have to worry about the solar wind - the charged particles that are emitted by the Sun, and which are quite effectively shielded by the Earth's magnetic field. The magnetic field of Mercury is ...
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5 votes

Is the Heliosphere as elliptical as this graphic suggests?

..the heliosphere's longest span is at least 10 times as long as its shortest span Hundreds of times longer. The graphic fairly closely matches this peer-reviewed plot with actual numbers instead of ...
5 votes

Is the Heliosphere as elliptical as this graphic suggests?

Research from 2017 indicates that the image may not be realistic. Recent analysis of Voyager, IBEX (Interstellar Boundary Explorer) and, somewhat surprisingly, Cassini data, seems to indicate that ...
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4 votes

Could a spacecraft be propelled by the deflection of a very high number of charged particles?

What you are describing is basically a permutation of the basic concept of a magnetic sail. You need a much bigger sail to get useful thrust, but it can just be a loop of superconductor carrying a ...
4 votes

Would the Voyager probes go backwards affected by the strong interstellar wind beyond Heliosphere?

No. The interstellar medium is almost a vacuum, just like the heliosphere. In fact, this is a lower pressure than we've ever created on Earth, at 1-1000 atoms/cm3, so 1020 times lower than atmosperic ...
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4 votes

When do aircraft become solarcraft?

Some issues with this: Drag is dependent on cross-sectional area, and so is solar radiation pressure. This would mean that different spacecraft would have a different definition of space. We might ...
4 votes

Why exactly would "permanently shadowed polar lunar craters... have substantially higher levels of ³He than sunlit lunar surfaces?"

That is fairly obvious from the factoid you state yourself. In regions, of a celestial body, that are not shielded by an atmosphere and that are never lit by the sun, the temperatature can go down ...
4 votes

Are the JWST solar panels protected from solar flares?

Solar panels have been used on spacecraft since the late 1950s. Perhaps one of the longest running set of actively used solar panels is on the Wind, which just turned 27 years old on November 1, 2021....
3 votes

How can a solar storm be predicted?

Solar flares travel at about 2000 km/s. Radio travels at 300,000 km/s, so a spacecraft at L1 (1.5 million km out) like DISCOVR gives about 12 minutes of warning when the solar flare reaches it. ...
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3 votes

How can a solar storm be predicted?

You may be asking about a couple of different things here. 1 Events at the surface of the sun Events at the Sun itself may or may not head in the direction of the Earth, but this is step one of a ...
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