All Questions

9,989 questions
261 views

Regulations that prevent SpaceX from saying “no” if OneWeb asked them to launch their satellites?

The Forbes article With A Successful Launch, OneWeb Just Joined SpaceX And Others In The Satellite Internet Race says: This marks a turning point in a new generation of communications satellites, ...
99 views

Time to fall into the Sun from Mars orbit

If a body starts to fall freely from Mars orbit towards the Sun, then how can we calculate the time to touch the Sun' surface? I have tried the third equation of motion that says R=(1/2 dg)*dt^2. ...
2k views

Traveling through the asteriod belt?

The question What's the (particle) density of the asteroid belt? is about the density of objects in the asteroid belt. As a follow up related question and what I am interested in: When we send ...
155 views

Launching east from a mountain on the equator at midnight during a new moon; ranking of each contribution?

This answer is intriguing and I'm curious if it's correct, and especially which effects are most important. If you want to avoid gravity assists, the most fuel-efficient way out of the Solar System ...
3k views

What is the most fuel efficient way out of the Solar System?

I understand with current technology we can't just fly a straight line out of the solar system but which way out would need the least fuel? Currently to navigate the solar system it is a dance ...
151 views

Has any human had the capability of leaving the Solar System?

Inspired by Has any human ever had the choice to leave Earth permanently? and the answers and comments there, has any human had the capability of leaving the Solar System? I'm thinking of Apollo ...
229 views

What could go wrong if someone overpowered an ion engine?

The X-3 ion engine is the most powerful ion engine ever made, and puts out an astounding 5.4 N of force, using 103 kW. It's fuel is inert xenon gas, ionized and heated to a plasma. Now, what would ...
48 views

How do we manage the residual magnetic moment of magnetorquer with a ferromagnetic core?

I'm currently working on a control algorithm, specifically in detumbling, for a 3U cubesat. I'm using magnetorquers for actuation and magnetometers to receive feedback. If I have no current passing ...
2k views

Could an Apollo mission be possible if Moon would be Earth like?

I suspect that actual technology results in the apparently paradoxical situation that is easier to visit the moon rather than a comfortable planet able to sustain life. I am obviously supposing the ...
152 views

What type of propellant does Spacex plan to use in Starship for long duration missions?

For long duration missions such as ones to mars what type of propellant would be best suited?
128 views

How SpaceIL Beresheet gets to Moon from GTO?

GTO is an orbit which has its main axis in the plane of Earth's equator. Moon orbit has a different plane. This means until GTO main axis isn't on the intersection of equator and Moon orbit, you can't ...
137 views

Why did Voyager have to shunt unused electrical power and radiate as heat?

Reading about Voyager in The oldest computer (not) on Earth I saw the image below, where is shown a science instrument calibration panel and shunt radiator. According to the November 1980 NASA News ...
84 views

What's the lowest altitude that an ion engine has been used for a significant orbital maneuver?

I'm thinking about trying to calculate something for Where do ion propulsion's ions go? Do they remain in the solar system or shoot out into interstellar space? Excluding low altitude tests of ion ...
13k views

Has any human ever had the choice to leave Earth permanently?

Far beneath the ship / The world is mourning They don't realize / He's alive No one understands But Major Tom sees / "Now the light commands This is my home / I'm coming home." Peter ...
738 views

Why is that max-Q doesn't occur in transonic regime?

Is there any reason why the maximum dynamic pressure should not occur in the transonic regime. It is clear from this answer that the max-Q for various rockets occur outside the transonic region Do ...
25k views

A starship is travelling at 0.9c and collides with a small rock. Will it leave a clean hole through, or will more happen?

Say there is a football sized rock in the path of the ship. Will it create a football sized hole through the ship in the blink of an eye, or will more happen? The ship would be filled with metal, ...
125 views

Where do ion propulsion's ions go? Do they remain in the solar system or shoot out into interstellar space?

Writing this answer has got me thinking. You can estimate the exhaust velocity of an ion engine using $$\frac{v}{c} = \sqrt{\frac{2E}{m_0 c^2}}.$$ Choose $E=$ 100 keV and $m_0 c^2=$ 931 MeV times ...
32 views

What science data has been released from Chang'e 4?

Chang'e 4 was the first soft landing on the far side of the moon. What science data has been released from it? That is, in two parts: what science was done and of that, what data has been released to ...
63 views

Could Breakthrough Starshot proposed propulsion system be used in a regular size probe to accelerate it faster than any probe has been before?

Supposedly Breakthrough Starshot project wants to accelerate a capsule of the size of a mobile phone - according to one source - and of the size of the chip of a mobile phone - according to another ...
161 views

Are we changing Earth's rotation?

Can rockets launching change Earth's rotation, and can going into orbit do the same?
60 views

Mathematical approaches to analysis of terraforming

The process of terraforming has been discussed at length in this site. I am wondering if there has been any mathematical analysis of how terraforming would take place in credible scientific ...
117 views

All dressed up and no place to go; who will be Stratolauncher's aircraft-launched rocket?

According to the Verge's Stratolaunch is scaling back operations following the death of co-founder Paul Allen, development of planned rocket has been paused. Does that leave the Scaled Composites ...
141 views

How to slow a spinning spacecraft externally?

I came accross the is question What are the consequences to breaking the ISS? and wander how would a spacecraft be made to stop spinning from the outside? Scenarios might include (but are not limited ...
81 views

Would it be possible to reach Mars using the same fuel-saving method SpaceIL's Beresheet is using?

A few minutes before SpaceIL's Beresheet spacecraft was launched into space, Israeli prime minister Netanyahu congratulated SpaceIL and all those involved and said: "We are already waiting for you to ...
263 views

What prompted all of those private launch companies to get into the business?

It seems that, somewhere around the turn of the century, a bunch of private companies started gearing up for launching things into space when nobody (at least not private entrepreneurs) seemed very ...
191 views

What joints of Apollo 17 space suits did moon dust get into, making the astronauts arms difficult to move?

At about 02:45 the Curious Droid video Apollo, the Lunar Dust and NASA's Dirty Problem says: During Apollo 17, crew members Harrison “Jack” Schmitt and Gene ...
108 views

What are the consequences to breaking the ISS?

Suppose a relatively minor space faring government or a private company had permission to dock with the International space station. But then, due to their incompetence they caused a major problem. ...
64 views

Ellipse area section from foci

I am wondering how to calculate the area between the 2 red dots towards the bottom and in turn calculate the time elapsed between the right red dot and the green dot at apogee. I figure if I can find ...
87 views

Why didn’t the space shuttle external tank have pressure-relief vents?

During a space shuttle abort, it would have been vitally important not to allow the vehicle to droop below 265 kilofeet during powered flight, as excessive aerodynamic heating below 265 kft would have ...
126 views

Was Columbia’s CVR ever found?

Each of the space shuttles carried a cockpit voice recorder (CVR), similar to those required on commercial airliners, which recorded the crew’s conversations to aid in accident reconstruction should a ...
135 views

Why didn’t the space shuttle’s engine-out checklists include steps for attempting a relight?

Throughout much of a space shuttle ascent, even a single SSME failure would have left the mission’s intended orbit out of reach and forced some sort of abort; a two-SSME-out situation would have left ...
58 views

Will people living in Mars for several years be able to return to Earth without consequences?

Living without gravity has consequences for the bones and muscles. To counter that astronauts have to do exercise and lifting regularly when they go to the ISS. Now are there any plans to counter ...
90 views

Does Mars have a known “prevailing wind” direction?

Venus has a general retrograde wind direction, and a few days of measurements from the InSight lander so far suggest steady winds from the north-west, but are there any measurements that indicate Mars ...
120 views

How does SpaceX plan to obtain Oxygen in Mars?

In the ISS they obtain Oxygen from water through electrolysis. I guess this could be possible in Mars if they land near a large water source. NASA in the other hand, it's working for ways to obtain ...
128 views

How does InSight measure wind speed?

According to this answer the weather at the InSight lander can now be seen online at https://mars.nasa.gov/insight/weather/ This includes the wind speed and I believe the direction (if that's what ...
100 views
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What is the universal emblem that represents space exploration?

I am interested if there is an official emblem that represents space exploration worldwide? Are there any small pictures that everyone would recognize or associate to space exploration? I had more ...
1k views

How unreachable are Jupiter's moons from Mars with the technology developed for going to Mars?

Jupiter's moons in their closest point to Mars (when Jupiter is closest to the sun) are like 7 times the distance between Earth and Mars, and in a return journey they will farther away. Is there any ...
125 views

Terminology dispute: is an orbital flight still a ballistic flight?

We have a terminology dispute with a colleague: could a flight by elliptical orbit trajectory be called a ballistic flight as well or limits of the later is a parabolic trajectory of a suborbital ...
243 views

Cheapest rocket to go to space?

Have you ever heard of the old movie Salvage? The TV movie, “Salvage,” aired on January 20, 1979. The film begins with Harry successfully bidding for a vintage bi-plane and then reselling it in pieces ...
148 views

Is making gold mining in Mars profitable truly unlikely?

I was reading about Elon Musk believing space mining being unprofitable due to mining and transportation costs. Now I dont know about mining costs , but if Elon Musk says a person could go to Mars for ...
47 views

True Anomaly of Circular Orbit

How would you calculate the true anomaly of a circular orbit (e=0)? I'm trying to design an orbit for a mission on STK and so I'm not sure what the eccentric anomaly (in order to calculate true ...
73 views

When does reusable lower rocket stages become benificial?

Can lower stages of current rockets be replaced to reusable and more efficient boosters with parachutes? Would reusable rocket stages save money?
40 views

Would the destruction of Deimos have any lasting geological impact on Mars?

This question is inspired by events in the science fiction series: The Expanse. To summarize, Deimos is blown up in a retaliatory strike. One character laments about how she would feel if Earth's ...
34 views

How can we be certain that Ryugu is a remnant of the material that did not form planets?

Its mentioned here https://www.theguardian.com/science/2019/feb/22/japans-hayabusa-2-successfully-touches-down-on-ryugu-asteroid that Ryugu is a part of the Solar System material that did not get ...
41 views

NASA says Mars' soil has the nutrients for growing plants, how about the Moon?

Okey, that's not everything they said but I can't write everything in the title. NASA says Mars's soil has the nutrients for growing plants, though there may not be the right amount depending on where ...
49 views

Can small asteroids in the asteroid belt be detected on the fly and how much of a threat do they represent for a human manned space mission there?

Supposedly there are between 1.1 to 1.9 millions asteroids larger than 1 km in the asteroid belt. I assume there are many more , a lot of smaller ones, which cant be detected from here. According to ...
1k views

Will the duration of traveling to Ceres using the same tech developed for going to Mars be proportional to the distance to go to Mars or not?

I've read somewhere (I don't have right now the source and I don't know if it's trustworthy) that something that would take a significant amount of time for going to Mars would be the acceleration and ...
111 views

Can they isolate individual modules on the ISS?

In the event of a leak, in the cupola for example, can they isolate individual modules of the ISS?