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7 views

Long March 3C/E specification

From what I can see, it looks like the Long March 3C is pretty much a Long March 3B with two strap-on boosters instead of four. The Long March 3B/E is actually a Long March 3B with a bit higher ...
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1answer
18 views

rocket trajectory simulation in inertial frame, with drag

I created a rocket trajectory simulator and optimizer using the following equations of motion for a non-rotating frame of reference where v is velocity, gamma is flight path angle, h is altitude, r is ...
3
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1answer
68 views

Guidance vs. Navigation vs. Estimation

I'm still confused over what exactly falls under the scope of Navigation, Guidance, and Estimation systems. Say I have a bunch of IMUs and use them to determine my position and orientation and my ...
2
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1answer
42 views

Does Falcon 9 perform static fires before every launch?

Before launching every Falcon 9 rocket, is SpaceX performing a Wet Dress Rehearshal (WDR) and a static fire? If not before every launch then is it doing it before every first launch of a new booster? ...
2
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0answers
30 views

What specific device failed, causing engine #4 in the Core Stage Green Run to report a Failure Identification?

(See this Q&A for context if needed: What is a "Major Component Failure" referred to in news reports about the unsuccessful Space Launch System core stage test firing?) In the post-test ...
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0answers
47 views

Largest number of successful consecutive launches by rocket model?

Which rocket model has the largest number of successful consecutive missions? Active and inactive models. Falcon 9 just reached 77. Delta II reached 100. Is there any other model with a better ...
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0answers
23 views

What is the purpose of eccentric, parabolic and hyperbolic anomaly?

I am currently reading David Vallado's 'Fundamental of Astrodynamics and Applications' and I have this doubt on the 2nd chapter named 'Kepler's Equation and Kepler's Problems'. Although I understand ...
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0answers
51 views

The mission to Pluto? [closed]

Exactly 15 years ago an uncrewed NASA spacecraft by the Name of New Horizons blasted off on a 3 billion-mile journey to Pluto from Cape Canaveral Air Force Station at a speed 36,400 mph (16.26 km/s) ...
2
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0answers
48 views

How was an emergency landing site at Diego Garcia used during the Apollo program?

On the current Starlink mission as the 2nd stage passed over the Indian Ocean I heard mention of contact with a ground station at Diego Garcia. Checking that article I found the subsection Space ...
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0answers
29 views

Most energy efficient food production for sustainable human life support

Say you want to build a base on a place where conventional food deliveries from Earth would be very expensive. What will be the most energy efficient food that could feed humans in the long term (...
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0answers
16 views

spacecraft that can be used for microgravity missions [closed]

Can you name guided and uncrewed spacecraft that can be used for microgravity missions and experiments? Nowadays it`s rather popular and useful to use uncrewed guided space vehicles for particular ...
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0answers
20 views

Lightening As a source of energy [closed]

Is it possible to use lightning or thunder as a source of energy, with the help of dielectric breakdown and splitting. Sorry not based on space research but would appreciate the help
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2answers
79 views

Asteroid orbiting between Earth and Mars as ferry?

What if we moved a large asteroid to a highly elliptical orbit between Earth and Mars and then occupied it like we occupy the ISS? It'd be a slow trip to Mars, but if we're in no rush, we'd get free ...
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0answers
15 views

Are spacecraft star cameras ever used as scientific instruments for research?

There are quite a lot of spacecraft that have been up there a while and a lot of them have star cameras for attitude determination and for attitude control. Space telescopes (both heavenly and Earth-...
2
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1answer
82 views

Are Jool's moons' orbits stable? [closed]

The fictitious Kerbol system includes ...five planets: Moho, Eve, Kerbin, Duna and Jool; and two dwarf planets: Dres and Eeloo; orbit around it. Kerbol contains 99.97 % of the mass in the Kerbol ...
22
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1answer
4k views

Why don't lasers last long in space?

A news article reports that OSIRIS-REx was equipped with two lasers for the spacecraft to shoot off the rock and study the echo to facilitate its landing and sampling maneuver. ... Most lasers don't ...
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0answers
47 views

Why SN8 needed 12.5 km?

Is there a particular reason for chosing 12.5 km for the SN8 hop? Why 5 km for example is not good enough?
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1answer
64 views

Payload capacity of Electron rocket?

I can only find the Electron capacity for LEO and SSO: 300 and 200 kg And for Venus: 15 kg (which links to here) But what is the capacity for GTO, Moon and Mars? LEO = Low Earht Orbit SSO = Sun-...
1
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1answer
30 views

Earth magnetic field vector in ECEF

I've this problem... I want to express the earth magnetic field vector in ECEF reference frame. As now I've just found some models for computing these values related to the earth magnetic field: D: ...
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1answer
77 views

How many solar system bodies have “knees” in their atmospheres?

Discussion lead to citing Why does Earth's atmospheric density have a big "knee" around 100 km? Is there a good analytical approximation? who's answer is "monatomic oxygen". ...
3
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1answer
88 views

Are westward launches more expensive than eastward launches?

Basic question for those who breathe rockets: The earth's rotation imparts to the rocket a free delta V of roughly 450 m/s if you launch straight eastward. If you launch westward instead, for a ...
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0answers
35 views

The most advanced private space company of the present time [closed]

Nowadays, the private space company really succeeded and manufactures pretty good technology and space vehicle. What do you think is the most advanced private space company ( except Space X ) at the ...
2
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1answer
31 views

How to retrieve MSL EDL trajectory using Javascript and webgeocalc API?

I found a "javascript gateway" to NASA SPICE data, the "webgeocalc" web api: https://wgc2.jpl.nasa.gov:8443/webgeocalc/example/perform-calculation.html It works both online and ...
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0answers
79 views

The fewest employees for an orbital rocket?

When these orbital rockets launched first to space, their companies had: SpaceX - 2008 - 525 employees Electron - 2018 - 200 employees Virgin Orbit - 2021 - 390 employees Astra - 2020 - 100 employees ...
4
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1answer
259 views

Has a rocket from a torpedo tube ever reached space?

Are submarine launches horizontal? is a general question and specifies by name two large ICBMs which are likely to need to be launched vertically. Since the large naval submarines usually come ready-...
4
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2answers
2k views

Are submarine launches horizontal?

Are the rockets launched from submarines in a horizontal or vertical position? I mean for the space launches like Volna and Shtil. This article says By reaching orbit, LauncherOne has become the first ...
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0answers
109 views

Why is the bottom of the SLS rocket covered with reflective silver “muffler” tape?

NASA.gov's First Artemis Rocket Stage Moved onto NASA Barge Ahead of Green Run contains a high resolution image of the rocket. The bottom end of the rocket's cylindrical shape is closed flat and ...
1
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1answer
58 views

How much easier is it, to explore space from a low orbit satellite, than from Earth?

Note: in this question I'm considering cost in both money and fuel terms, and looking for answers that consider both. So we know that using chemical rockets to reach the moon, or further into space, ...
2
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0answers
29 views

Meteoroid impact frequency in the size range of 1 mm or larger?

I wish to know the frequency of 1 mm diameter or larger meteoroids impacting the Earth's atmosphere each day. NASA's Asteroid Fast Facts (1) says "Every day, Earth is bombarded with more that ...
24
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1answer
3k views

What is a “Major Component Failure” referred to in news reports about the unsuccessful Space Launch System core stage test firing?

In reporting about the unsuccessful green run of the SLS core stage, Ars Technica mentions About 50 seconds into what was supposed to be an 8-minute test firing, the flight control center called out, ...
6
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1answer
203 views

Which RS-25s are on the Artemis 1 rocket?

The SLS core to be used for the Artemis 1 flight will use four RS-25 engines. These reusable engines were used on the Space Shuttle Orbiter previously. Is there a listing of which SSMEs are planned ...
1
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1answer
97 views

Why doesn't NASA just again build the Altair LM or a modified Apollo LM for the Artemis project?

The Altair lunar module was part of the wonderful Constellation program cancelled in 2010; just the Orion spacecraft has been retained which is to deliver a crew into lunar orbit. The new carrier ...
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0answers
60 views

Are there any space capable countries without ITAR laws?

In the US, the draconian ITAR laws prevent an open source space program from being founded, and make it incredibly difficult to found any aerospace company in general. Are there any countries that ...
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0answers
46 views

With a sufficiently diamagnetic material, is it possible to create thrust from a star to propel a spacecraft?

This is a showerthought after the NYtimes "tic tac" video that I've had for a while and am looking for a specific answer. Assuming a perfectly diamagnetic material exists, could an object ...
2
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0answers
46 views

What happens to ablative nozzles after a test fire?

For example RS-68 engine If you make a test fire of an ablative nozzle engine then the fire will consume the coating of that nozzle. That means you have to replace the coating or the entire nozzle. ...
2
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1answer
37 views

Will there be any additional benefits of reusability for the space tug?

We are now seeing certain advantages of the reusable use of different rocket stages. Decrease in price (perhaps not so much yet), increase in launch reliability, etc. Are there any other benefits of ...
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2answers
173 views

Why is the Orion spacecraft so big?

The Orion spacecraft which is to be used for the Artemis missions will be rated for 6 astronauts. Why so many? Given the "political" assignment is to put "a woman and another man to the ...
1
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2answers
80 views

Why does it cost more to get to L4/5 than C3=0?

I was looking at Delta-V budgets and noticed that it costs 4.1 km/s to get from LEO to L4/5, but just 3.2 km/s for LEO to geocentric C3 = 0 (escape velocity). I find that counter-intuitive. Why does ...
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4answers
4k views

Why is it so hard to build crewed rockets/spacecraft able to reach escape velocity?

Why are we still not going farther than to Low Earth Orbit? Orbital velocity is about 4.8 mi/s (7.7 km/s) and escape velocity is about 7 mi/s (11.2 km/s), about 45% faster. Why is it so hard to reach ...
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0answers
30 views

Moon Mission - Mars Mission

They can stay on the moon only around for 3 days because of the fuel but they need around 6 months to reach Mars. Now they are working on the Propellant depot project to be able to reach the moon and ...
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0answers
36 views

How long to flip over stage 1 of Falcon 9?

Curious how fast stage 1 flips over. 180 degrees is a lot of turning. At a rate of 5 deg/s, it would take 36 seconds to flip. This seems very long for the maneuver. A more modest duration of 10 s ...
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0answers
15 views

Is apsidal precession completely independent of the argument of periapsis?

Writing this comment got me thinking, which invariably leads to confusion in my case. @DavidHammen's answer to show that for Juno's near 90° polar orbit the major precession is apsidal; periapsis is ...
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0answers
50 views

fast moving object from one star to another [closed]

in the late 1990´s, when watching stars, I saw a very fast moving object, which moved from one "star" to another in a zigzag. We were 4 people watching the sky and nobody mentioned anything, ...
0
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1answer
47 views

Falcon 9 altitude and speed during reentry burn?

After MECO, stage 1 of Falcon 9 does up to three engine burns: a boostback burn followed by a reentry burn followed by a final landing burn. I'm interested here in the reentry burn. How high and how ...
2
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2answers
68 views

How big is an orbit of “X by Y miles”?

While reading the NASA overview of Apollo 11, says: Apollo 11 launched from Cape Kennedy on July 16, 1969, carrying Commander Neil Armstrong, Command Module Pilot Michael Collins and Lunar Module ...
4
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2answers
1k views

Rocket fuel cost to launch 1 kg to orbit

I have 2 questions about the cost of liquid rocket fuel to launch (anything) to LEO orbit. Let's assume we use fuels used in commercial spaceflight today (probably LOX+LH2 or LOX+RP-1 etc.). What is ...
3
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0answers
29 views

How to get MSL coordinates during EDL from SPICE kernel?

Upon trying to extract MSL position above surface by decoding a SPICE kernel, I am gettin this error: At epoch 3.9750216818313E+08 TDB (2012 AUG 06 05:16:08.183 TDB), there is insufficient ...
4
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0answers
83 views

What are the implications of North Korean black and white patterns on missiles?

Black and white patterns on rockets were originally intended as roll patterns. They helped as a visual back-up for acceleration sensors measuring the roll, as discussed in this previous question What ...
2
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0answers
44 views

How much lower is max q if launching from high altitude (i.e. mountain top)?

I looked at very simple max q formula: q=1/2 ρv^2 (https://en.wikipedia.org/wiki/Max_q). As air density is lower with altitude, the max q should be lower as well, and also should occur at higher ...
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0answers
20 views

Spacecrew member eligibility in future manned NASA space missions [duplicate]

What are the eligibility requirements to be part of future Spacecrew mission NASA programs? Age, Nationality, Medical Fitness, Educational qualifications, Work experience etc

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