All Questions
18,274
questions
3
votes
1
answer
287
views
Why will the Raptor not face the same turnaround issues as Space Shuttle engines?
The RS-25's notoriously slow, expensive turnaround was blamed on its complexity. The Raptor appears about as complex.
Both use regenerative cooling.
Both use preburners to drive turbopumps.
While the ...
- 2,553
5
votes
0
answers
216
views
Which (vintage?) CAD software is this in the Scott Manley video regarding The Titan Rocket
I was recently surprised by seeing a CAD software in the Scott Manley video that seems to be running on old computers in a command line like interface.
Which software is this? and is it still used by ...
- 2,901
0
votes
1
answer
93
views
How does SpaceX Raptor deliver a more benign turbine environment?
Raptor has been claimed to be able to deliver "long life ... and more benign turbine environments".
https://en.wikipedia.org/wiki/SpaceX_Raptor
The Raptor has hot oxygen flowing out of the ...
- 2,553
1
vote
0
answers
38
views
Using NASA Horizons with Celestrak Socrates's TLE CDMs?
Has anyone succeeded with getting a list of Collision Data Messages (CDMs) from nice sites like Celestrak in order to feed them into NASA Horizon's ephemeris computation service. These would include ...
- 321
1
vote
1
answer
123
views
Is it possible to generate a signal strong enough that it could be received on Alpha Centauri with today's technology?
Let's say we magically found out that there is an inhabited planet in the Alpha Centauri system and that the inhabitants there have the same level of technology that we do. Similarly, they know of our ...
- 113
0
votes
1
answer
107
views
Turbo code used in New Horizons - encoding coefficient?
I know that New Horizons uses turbo code with r=1/6 for space communication1, however I don’t know which is the encoding coefficient, because I din’t think it could be 6, it seems it high. Could you ...
- 9
-1
votes
2
answers
77
views
Higher density medium tube from sea level to space for travel
Is it theoretically possible to build a strong sealed tube from Earth's sea level all the way to Space, fill it with a medium (such as water) that has a higher density than humans. And then humans ...
- 107
3
votes
2
answers
222
views
SpaceX Falcon Reusable First Stage Innovations
What are the top five innovations that SpaceX was able to accomplish that allows the first stage to land vertically and be reused?
I am sure the Apollo program would have liked to reuse their first ...
- 151
4
votes
1
answer
135
views
What if Soyuz re-entered with orbital module attached?
Soyuz 5 and Soyuz TMA-11 survived reentry with an attached Service Module, which simply burned off. There have been no accidents where the Orbital Module has remained attached. What would be the ...
- 2,553
6
votes
2
answers
211
views
Is the crust of the Moon different on the near side and the far side?
If you assume that the origin of the Moon is due to an object hitting the Earth. The difference between far side and the near side of the Moon can be explained, if the 'chip' knocked off the Earth to ...
- 71
11
votes
2
answers
1k
views
Would we be able to tell if another civilisation built a Dyson sphere (or similar) around a distant star if we were looking for it?
A list of my thoughts/assumptions
we have a good understanding of how stars live and die, so a "healthy" star (I assume you would only build a Dyson sphere around a star that's going to ...
- 213
6
votes
1
answer
169
views
Sentinel-2C and frequency of acquisition
Sentinel-2C, the third Sentinel-2 satellite of the Copernicus program, is planned to be launched in 2024.
Currently, the Copernicus SENTINEL-2 mission "comprises a constellation of two polar-...
- 163
4
votes
3
answers
1k
views
Could Falcon 9 push the second stage a little longer after MECO and before separation?
When watching Starlink launches I noticed the MECO/stage separation usually occurs at about 2m30s with the speed of about 8000 km/h and altitude about 65 km. After the separation the first stage with ...
- 159
4
votes
0
answers
122
views
How was the external tank emptied in a TAL shuttle abort?
One of the numerous reasons RTLS was the least preferred choice is
For a safe separation, the ET must contain a maximum of 2% propellant remaining at Main Engine Cutoff (MECO).
How would TAL do away ...
- 365
3
votes
0
answers
55
views
What was the longest Rocketdyne F-1 full power test?
This number is relevant to the issue of F-1 reusability, as it determines how many flights are required before serious work needs to be done. That is because LOX/Kerosene engines have coking problems ...
- 2,553
1
vote
0
answers
58
views
How much did it cost to turnaround Rocketdyne F-1 test articles?
Despite being intended for an expendable vehicle, the F-1 was tested and rated for the equivalent of more than ten reflights.
How much did it cost to turnaround the test articles between the firings?
- 2,553
5
votes
0
answers
150
views
Glove in Phoenix Backshell?
I stumbled across this image which shows the Phoenix Lander being integrated into its backshell:
This is the only image "source" I was able to find: https://picryl.com/media/phoenix-mars-...
- 1,128
3
votes
0
answers
101
views
How do ablatively cooled rocket engines compare to regeneratively cooled ones, in terms of mass?
Assuming equivalent thrust and single continuous burn duration, is there a figure that roughly tells the difference in mass between these two engines cooling methods? This question focuses on first ...
- 3,966
14
votes
3
answers
3k
views
Could the Rocketdyne F-1 have been reused?
Assuming the engine is recovered on a platform at sea similar to SpaceX, could it be refurbished and reflown at a low cost? Would the coking, corrosion, and other problems be any worse than that in ...
- 2,553
10
votes
2
answers
1k
views
What's the motion of two connected satellites orbiting the Earth after their separation?
Let's consider the following problem (it's a job interview question): two satellites are orbiting the Earth in a circular orbit; they are rigidly linked by a tether which is always pointing in the ...
- 433
-3
votes
1
answer
114
views
At what point does an object lose 50% of escape velocity?
I find the kalman line an unsatisfactory definition of space. Instead, I will use 50% of escape velocity.
At what distance does this happen? If escape velocity is 11 km s and gravity is 9.81, I am ...
- 1
3
votes
0
answers
108
views
I am trying to create an inter-satellite network and run an inter-satellite routing protocols
I am trying to create a simulation of a network of cube sats connected to Earth station to provide me with internet. I want to run on these satellite a routing protocols can this be done using STK ...
- 31
3
votes
1
answer
275
views
Geofence - satellite contact time
I need to find the access/contact times for a satellite passing through a random geofence (polygon). Is there a python library or any code to integrate the geofence to the orbit of the satellite to ...
- 41
13
votes
1
answer
2k
views
How are those stunning space mission animations and images made?
I would like to understand which software/professionals are needed to produce the animations and images used to show how a space mission will be.
For example:
1 - Curiosity video:
...
- 163
2
votes
1
answer
34
views
Reducing degree of ICGEM's Gravity Field Models for orbit propagation
I would like to use one of the static gravity field models published at ICGEM for satellite orbit propagation. For example, EGM2008. Its degree is 2190. I would like to use only 360 (may be even less) ...
- 123
3
votes
2
answers
119
views
Which notes and/or books on mathematics, physics, 3D geometry preparatory to the study of orbital dynamics?
I have a master's degree in aerospace engineering and I'm preparing for job interviews for orbital mechanics/space flight dynamics engineer positions and I need material about maths, physics, 3D ...
- 433
3
votes
2
answers
308
views
What are these composite overwrapped pressure vessels on Super Heavy?
https://en.wikipedia.org/wiki/SpaceX_Super_Heavy
The oxygen tank has four chines attached. These protect the various COPVs on board, as well as providing lift during flight.
First I've heard of ...
- 2,553
2
votes
1
answer
122
views
How much does it cost to build terrestrial ground station capable of controlling satellites orbiting the moon?
I'm noobie in space exploration and I want to carry out market research to find out how much it costs to build a terrestrial groundstation to control satellite missions that are in lunar orbit.
Two ...
- 163
5
votes
2
answers
235
views
Can electrodynamic tether propulsion use the solar magnetic field?
Electrodynamic tethers have been proposed for satellite propulsion in the magnetic fields of Earth and the Gas Giant planets.
Is it realistic to consider using the Sun's magnetic field for ...
- 15.3k
8
votes
3
answers
3k
views
Why can't buoyancy of air be used to support a mega structure as an alternative to a space elevator?
The reason for asking this question stems from recent articles about large loss of strength of carbon nano tubes with even single atom movement, tested samples showing high vulnerability to space ...
- 99
2
votes
0
answers
143
views
Is the rocket exhaust plume at liftoff of a liquid fuled rocket cold? Can it condense? [duplicate]
I try to understand what the exhaust cloud on the ground from the start of Starship consists of.
Of course it was unusually mineral-rich, but I try to understand whether we saw much else, apart from ...
- 385
1
vote
1
answer
105
views
How do you calculate the characteristics of an orbit of an object launched from a mass driver?
What formula can I use to calculate the apoapsis of the orbit of an object launched from a mass driver on the moon at a given speed and angle to the surface (angle from horizontal)? The device will ...
- 21.2k
5
votes
1
answer
177
views
ARCA Aerospace has announced the EcoRocket Heavy, a wider-than-tall rocket. Has there ever been any other seriously proposed rockets wider than tall?
Is this the first seriously proposed/planned launch vehicle that is wider than it is tall?
https://www.arcaspace.com/ecorocket
- 932
4
votes
2
answers
206
views
How do Centrifugal Turbopumps work? How do you make one?
I recently visited Wikipedia to look at centrifugal pumps and axial pumps. Centrifugal pumps are very interesting, and I was wondering how they work in more depth. I really don't understand how they ...
- 41
5
votes
0
answers
78
views
Does space have the same salvage laws as maritime law? [duplicate]
With the international space station being decommissioned within the decade and other abandoned satellites what are the rules on independently saving these objects?
- 357
7
votes
1
answer
1k
views
How do we define the aphelion of Earth?
After seeing this question, I was curious on how we define the aphelion of Earth. On a quick search it said that the aphelion is the point when Earth is the furthest way from the sun. However, all the ...
- 4,272
3
votes
1
answer
74
views
ROFI Temperature
Since hydrogen-fueled rockets usually require Radial Outward Firing Igniters (ROFI), what is the temperature of the sparks from this system? When seen at RS-25/RS-68 ignition, they don't melt but ...
- 129
30
votes
1
answer
6k
views
Is there someone continually monitoring the Voyager spacecraft?
I just finished watching The Farthest, a great documentary about the Voyager spacecraft, launched in 1977 and still operational today.
It got me wondering about those people shown in the documentary ...
- 453
1
vote
0
answers
78
views
Moving target during rendezvous
I am currently studying rendezvous and docking. I noticed the elliptic Hill equations only consider the acceleration of the target satellite due to its elliptic orbit (and fictitious forces in LVLH ...
- 45
5
votes
1
answer
266
views
Was the exhaust cloud at the Starship launch mostly pulverized launchpad?
The launch of Spacex Starship on April 20 2023 looked pretty normal on first sight, apart from some engines not running, and some concrete flying around.
The huge exhaust cloud looked normal, because ...
- 385
4
votes
0
answers
126
views
Why did LEM ascent stage swing during flight?
While watching Apollo 17 ascent footage, I've noticed that the camera is swinging quite a bit. It is definitely fixed to a window, so it means that the whole ascent stage is swinging back and forth ...
- 41
15
votes
2
answers
2k
views
How do the interferometers on the drag-free satellite LISA receive power without altering their geodesic trajectory?
LISA is a proposed space probe designed to measure gravitational waves. It aims to measure gravitational waves directly by using laser interferometry. It uses a drag-free satellite design to protect ...
- 15.3k
8
votes
1
answer
445
views
How are engines numbered on Starship and Super Heavy?
I was watching this video summarizing Elon Musk's recent remarks on the orbital test flight, and they mention specific engines. But unless a named engine shuts down and is shown on the small display ...
- 2,553
5
votes
1
answer
255
views
For Starship, using B9 and later, how will separation work if the Hydraulic Power Units are no longer needed for the TVC System?
On the SuperHeavy booster, the 33 engines break down into two sets, 20 outer engines that cannot relight (That equipment is actually on the pad itself) and cannot gimble.
The inner 13 consist of a ...
- 78.9k
2
votes
0
answers
41
views
Add small extra gps antenna on tracker installed inside aluminum tube [closed]
I would like to install a GPS tracker inside a scooter. Will the GPS signal will be lost if I install the tracker inside the vehicle?
Can I add a small extra antenna to fix outside the scooter?
- 21
2
votes
1
answer
225
views
Will this homopolar motor self rotate in a vacuum?
Is it convenient to ask about the motor from the link:
Roller Homopolar Motor
When it is on the table, the motor rotates freely, together with the attached conductor.
Will the upper motor in the ...
- 21
8
votes
2
answers
5k
views
If we had a video livestream of a clock being sent to Mars, what would we see?
If, you hypothetically started 2 clocks at exactly the same time, and placed one on Earth, and one on a rocket to Mars, and setup a video feed of both clocks, how would they compare as the 2nd clock ...
- 99
5
votes
1
answer
75
views
Can waterworld exoplanets have an ocean that's fresh or brackish by terrestrial standards?
The basic system is a terrestrial-type exoplanet in the liquid water zone around a star. The planet has a worldwide, liquid ocean with at most small islands above the surfaceMy question is what the ...
- 51
6
votes
2
answers
500
views
Does methalox fuel have a coking problem at all?
Methane was chosen for SpaceX Raptor because it has less coking problem that kerosene. But does it completely eliminate it? If not, how much less severe is it?
I googled 'thermal decomposition of ...
- 2,553
7
votes
1
answer
1k
views
Has depleted uranium been considered for radiation shielding in crewed spacecraft beyond LEO?
Does Depleted Uranium (DU) have a role in spacecraft shielding?
Crewed spacecraft require shielding to protect crew from hazards of space, particularly:
Micrometors. The chief defense is a Whipple ...
- 15.3k