All Questions

1
vote
1answer
93 views

How do Saturn's rings affect the surface of the planet?

How do Saturn's rings affect the surface of the planet, and could a possible habitable exo-planet have a similar ring pattern to Saturn? Besides the probable increase of asteroids hitting the planet ...
1
vote
2answers
83 views

Estimating weight of New Shepard with NS-10 launch data

Looking at data from today's NS-10 launch, I estimated the acceleration early on in the flight between the 10 and 15 sec marks; from about 43 ft/s to 110 ft/s in 5 seconds, which gives roughly 13.4 ...
6
votes
1answer
147 views

Spacecraft Navigation

Reading fascinating things about New Horizon's journey in the Kuiper Belt, I asked myself the following question: how can one know the spacecraft's position and speed, and with which precision? Of ...
6
votes
2answers
1k views

What are SpaceX Starship/BFR proposed abort modes?

From the different renderings of Starship no escape systems can be seen. What will the different abort modes both during launch and landing be like? What happens for example if the first stage ...
2
votes
0answers
87 views

Would a space station be able to watch a world wide cataclysm and how long would the crew be able to survive for? [closed]

I know there is other questions with similar concerns about there being any protocols in pace if the crew of space station were to witness a world wide cataclysm and the survivability of the crew if ...
3
votes
1answer
124 views

Why does the exhaust plume apprear to be throbbing?

Here is a cropped video of the space shuttle exhaust. There appears to be some throbbing/oscillatory behaviour to the exhaust plume. It is often visible along with an intensity changes/fluctuation ...
28
votes
1answer
4k views

What are these membranes at the aft end of the Shuttle that get torn off during lift off?

The link to the Space Shuttle launch video. At 1:30 mark, three circular disks get torn away. It happens immediately after the engine ignition begins. Here is a cropped image of the Discovery after ...
1
vote
1answer
69 views

What are Longjian's “UV antennas” and “UV transciever” really?

The 15-Oct-2018 Planetary Society post Imaging the Earth from Lunar orbit shows an image of one of the Longjiang spacecraft (also known as DSLWP-B) where were carried with Chang'e-4 to the Moon and ...
1
vote
1answer
62 views

Selection crieteria for coolant media on spaceships

What is the Selection criteria for coolant media on spaceships? I have read that ammonia as well as water glycol have been used. These two have very diverse properties. So what makes both of them ...
0
votes
0answers
36 views

Can Voyager I be turned around? [duplicate]

This video discusses the looming death of the Voyager I. Is it possible for the craft to be reprogrammed, thus making its way back to earth?
2
votes
1answer
85 views

What licenses do you need to launch a rocket and put something into orbit? [duplicate]

Do you need a licence to build, and fly a rocket (mainly flying)? Can you build any type of rocket and fly it anywhere at any time? Are there regulations on what you can take to space?
1
vote
0answers
43 views

Calculating the height and width of a rocket for drag

While messing around with making a little rocket launch simulator, I seem to have hit a slight wall with finding the relevant information in order to calculate the width and height of the rocket for ...
1
vote
0answers
54 views

Why is the Hubble Space Telescope mass increasing? [duplicate]

According to this Youtube video I came to know that the mass of the Hubble space telescope has increased from the time of launch. What is making this mass increment? Are these the debris?
3
votes
1answer
109 views

How does launching suborbital payloads on New Shepard compare to sounding rockets?

Nine NASA payloads will be launched on the upcoming New Shepard mission (NS-10) into a suborbital trajectory. How does launching them on New Shepard compare to using traditional sounding rockets? Why ...
3
votes
1answer
103 views

ECI to LVLH conversion

I want to transform the position and velocity of two satellites from ECI mean of date mean of equinox to LVLH(Local Vertical Local Horizontal). The problem is that there is little documentation that I ...
3
votes
1answer
79 views

Where was the space station this morning?

Did the space station fly over North Carolina this morning (January 22, 2019) about 6:30am I live in Roxbro NC 27574. I spotted an unusual object in the sky about 140-150 degrees, toward the South ...
27
votes
1answer
4k views

What are the 'lights' inside Shuttle main engines at landing?

I have a night-landing photo of the Shuttle showing lights (I assume some type of glow-plug to burn off extraneous fuel). My understanding is that only the OMS engines burn to begin reentry. Can ...
3
votes
2answers
62 views

How to get an initial setting of the range gate for a Lunar Laser Ranging using a new Retro Reflector for the first time?

From an answer to this question They were searching by aiming their laser at the moon and looking for reflections. But the system is set to only detect photons in a very narrow range of ...
1
vote
0answers
55 views

electromagnetics as a form of Gravity [closed]

Wondering if anyone has ideas about creating an electromagnetic field in the Floor of an exercise room combined with clothing that is laced with metal strands. the intensity could be adjusted to ...
7
votes
0answers
210 views

Why isn't stainless steel used for rocket engines?

Most people have probably heard by now that Elon is changing Starship to a complete stainless steel build. Anyways, it got me thinking, why isn't stainless steel ever used for rocket engines (nozzle, ...
4
votes
0answers
59 views

Hohmann transfer trajectory and “porkchop plot”

The “porkchop plot” for a spacecraft flying from Earth to Mars would show contours of equal characteristic energy against combinations of launch date and arrival date. Assuming the spacecraft has ...
18
votes
3answers
3k views

Could Hubble observe the night side of the Moon?

IIUC the Hubble space telescope cannot observe the Sun lit side of the Moon. And Hubble is never pointed closer than 90 degrees towards the Sun. But this still allows for observing the night side of ...
1
vote
0answers
33 views

How to get true anomaly using subsatellite point (latitude)?

I am working on an application which is using an orbit propagator. I have a satellite which sets its latitude using this orbit propagator. I want to change the latitude of the satellite by a new value,...
11
votes
1answer
226 views

Asteroid impact on the Moon: which effects cause the flash?

It is most likely that there was an impact on the Moon during yesterday's lunar eclipse. I am trying to get some more understanding of this so that I could maybe do a more detailed video on this ...
10
votes
3answers
999 views

How did Lunokhod 1 become “lost” in 1971; in what ways did astronomers “look for it” after that?

The Smithsonian Magazine article Lost Soviet Reflector Found on the Moon says: There are actually five retroreflectors on the Moon: three placed by Apollo astronauts and two that sit atop Soviet ...
4
votes
1answer
139 views

Is it possible to protect a Cubesat's electronics from 100g of acceleration?

I am currently researching the feasibility of setting up a coilgun that launches Cubesats for a paper. 1 cubesat per launch total payload mass <100kg.
3
votes
2answers
400 views

How much does a swing-by change the orbit of the planet?

A friend of mine told me that one Voyager swing-by moved the orbit of Jupiter a foot closer to the sun. I understand that Jupiter was slowed by the gravity assist, but I figured it would be minuscule ...
0
votes
1answer
57 views

Help with my tensor tension; how to derive and calculate this rigid body gravity gradient torque?

Tensors make me tense. Imagine a long thin rod in a circular orbit. The gravity gradient will produce a net torque on the rod whenever it is not oriented parallel, or perpendicular to the radius ...
1
vote
1answer
70 views

What psychiatric and psychological tests do people need to pass to become astronauts?

I am writing a short film about an astronaut during re-entry to earth. Part of the conflict I wrote is that the astronaut could not pass the mental tests required. Could anyone tell me any tests ...
4
votes
2answers
301 views

How would you move in low gravity without a suit?

Assuming your in a habitable environment, how would you move on a planet or moon with significantly less gravity without the encumbering EVA suit?
1
vote
1answer
63 views

Why did the S5.2/9D21 rocket engine engine have pyrocharges?

In a recent question, an answer showed a diagram of a Soviet S5.2/9D21 rocket engine. According to the diagram, there are four pyrocharges (3, 7, 24, and 27) in the engine. What is the purpose/...
4
votes
1answer
189 views

Who were the major manufacturers of the Apollo 11 rocket?

Organizing an exhibition around photographs from the 1969 launch and wanted to invite manufacturers.
2
votes
1answer
85 views

What are the limitations of monopropellant RCS thrusters in a re-useable spacecraft?

I understand the disadvantage of monopropellant is mainly dependent on the life of the catalyst. There is a possibility of catalyst failure due to it being subjected to catalytic poison and catalytic ...
1
vote
1answer
71 views

Was there once a semi-serious space-art project planning to use solar reflectors to put a spot of light on the crescent Moon?

Reading the question What are the effects of orbital reflectors and advertising on scientific observation and orbital debris? I am reminded of a story I read a while ago about an even in the past, ...
4
votes
0answers
78 views

What are the effects of orbital reflectors and advertising on scientific observation?

There's a couple of startups and initiatives which are proposing "space billboards" which have been getting a lot of bad press recently. Most of the proposals involve a bunch of cubesats with large ...
4
votes
0answers
66 views

Falcon 9 2nd stage pusher; how far does it continue to extend as it accelerates separation?

I've just watched Scott Manley's video SpaceX's Water Landing Reveals Rocket "Secrets" (or, What We Learned from CRS-16) (again) and he mentions the second stage "pusher" in the center of the view (...
3
votes
1answer
108 views

Help with Scott Manley's rigid body dynamics narration

I've just watched Scott Manley's video SpaceX's Water Landing Reveals Rocket "Secrets" (or, What We Learned from CRS-16) (again) and there's some rigid body dynamics in there where I'm not sure I am ...
3
votes
0answers
48 views

Cost of an earth observation cubesat satellite like Planet-s Doves?

With the Cubesat standard and more and more components being available off the shelf, this should really bring down the price of building a (simple) earth observation platform. I am curious how low a ...
13
votes
1answer
205 views

How will SpaceX Starship deploy its payload?

Most modern orbital launchers like the SpaceX Falcon9 have their payload at the front covered by a fairing which splits in half, ejecting the fairings and exposing the payload for deployment. With ...
1
vote
0answers
75 views

What is wrong with my orbit sim equations? How can I fix them?

Edit: Partial question: The object now moves in an ellipse like it's supposed to, but it orbits around a different point than I intend. How can I make it orbit around a particular object at a point? ...
1
vote
0answers
52 views

What causes these plume features on Delta IV Heavy?

Just catching up on the Jan 19th launch of NROL-71 on board the Delta IV Heavy and I noticed these very prominent features in the exhaust plumes, beginning around the time the centre core is throttled ...
3
votes
1answer
58 views

Luna artificial satellite eclipses

Have we been able to see the shadow on the Moon's surface of any artificial satellites that orbit the Moon?
-2
votes
2answers
113 views

Why didn’t the astronauts on the moon ever get out of breath? Even while running, or falling down?

My question is, even with the demand of learning how to walk and all the falls and and bumbling around of the astronauts, they never ran outta breath? Maybe in the newer missions they caught this and ...
6
votes
0answers
52 views

Does NASA still plan for the Mars Ascent Vehicle to burn wax from the surface to orbit?

The NASA news item From Pedicures to the Peregrine Rocket, Paraffin Wax Proves Its Worth says: The paraffin-based fuel also works under challenging environmental conditions, like the very low ...
0
votes
0answers
11 views

Has direct bandgap photoemission from III-V solar panels on spacecraft ever been detected or reported?

I thought I had asked this question before, but I can't find it now so I will ask here. I have asked a related question in Physics SE: Do III-V based photovoltaics “glow” (photo-luminesce) when ...
5
votes
1answer
77 views

Launch window for the Apollo Lunar Module?

If something would have gone wrong after a successful Moon landing requiring to ascent as soon as possible, what about the launch window for the lunar rendezvous maneuver? Could they ascent at any ...
20
votes
3answers
4k views

Why was the engine of the launch vehicle recently tested in Iran “not a very good missile engine”?

The NPR News item What's Iran Up To With Recent Rocket Launch Attempt? by NPR's Geoff Brumfiel, about a recent launch test in Iran includes the following: Earlier this week, Iran attempted to ...
18
votes
6answers
9k views

Why can't they just drop a solar winch down from a shuttle and have planes fly up and clip things on?

Why can't they just drop a solar winch down from a shuttle and have planes fly up and clip things on? I know of the idea to have a space lift but the cable necessary is too expensive. Why can't we ...
5
votes
3answers
287 views

Has any man-made satellite or space vehicle ever been hit by a natural meteoroid?

For precision I'm excluding artificial meteoroids and satellite debris (which is discussed in another question) of all kinds. I'm also considering collisions large enough to produce a noticeable ...
0
votes
0answers
29 views

Why does Delta IV have a programmed hold at T-4 minutes? [duplicate]

Why is this hold a planned part of the launch sequence? Can the delay at this point vary to allow for better launch conditions (eg weather, range obstruction)?

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