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0answers
32 views

Landing legs problem with Falcon 9 Block 5 / Starlink 3 mission

Is this a late landing burn problem? it seems that the engine touch the OCISLY ground as the landing legs flex.
3
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0answers
27 views

Is there a rule of thumb for the mass of thermal protection systems?

A lot of discussions of SSTOs and the potential for making upper stages re-usable hinge on the fact that thermal protection systems for reentry from full orbital velocity are pretty heavy (and ...
4
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0answers
52 views

Whats the idea behind Axiom's space station's 3D shape and solar “tower”?

Along with Spaceflight Now's article Axiom wins NASA approval to attach commercial habitat to space station there's a file image of a hypothetical space station from Axiom. The bottom is reminiscent ...
2
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1answer
147 views

What does “MSR” represent in the context of this predicted satellite conjunction?

In a series of four tweets starting with this one (found in 2 satellites will narrowly avoid colliding at 32,800 mph over Pittsburgh on Wednesday) 1/ We are monitoring a close approach event ...
10
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1answer
1k views

How did two satellites end up in almost the same orbit except moving in opposite directions?

In a series of four tweets starting with this one (found in 2 satellites will narrowly avoid colliding at 32,800 mph over Pittsburgh on Wednesday) 1/ We are monitoring a close approach event ...
4
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1answer
99 views

Replacement strategies for defective Starlink satellites

I wonder what is the approach to replace let's say: 5 defective Starlink satellites, each one in a different orbit? I guess that it can't be done with just one launch as the krypton ion thrusters ...
2
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1answer
81 views

Where is http://thunder.msfc.nasa.gov/?

In the question Methods of lightning detection on Mars? I included an image of A lightning detector at the Kennedy Space Center in Florida: Source The Wikimedia's page cites http://thunder....
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0answers
25 views

Methods of lightning detection on Mars?

Teslarati's NASA’s next Mars rover will pave the way for humans includes the graphic below which is an artists conception of a dust storm on mars. It shows what looks like lightning or some kind of ...
2
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0answers
41 views

How much energy would be needed to liquify 1 gram of atmospheric oxygen on Mars?

I've been told I have no Moxie but I still need oxygen to live on Mars. I see that Mars' atmosphere is 0.14% oxygen and my sad moxiless self wants some. I want to make a low power refrigerator to ...
3
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1answer
57 views

Are Mars' atmospheric CO₂, O₂ and CO in equilibrium? Are sunlight or chemical reactions involved?

According to the NASA JPL video linked below the top five gases comprising the martian atmosphere include CO₂, O₂ and CO. Do the proportions reflect some chemical equilibrium? Are sunlight or chemical ...
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0answers
46 views

How many square meters of solar panel to power a MOXIE-like oxygen source per person?

If I wanted to live in a box on Mars to write my screenplay about living in a box on Mars, how many square meters of solar panels would I need to power a MOXIE-like CO2-to-O2 converter in order to ...
17
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2answers
3k views

What is the story behind specific impulse being expressed in seconds?

I've heard a couple of explanations but none of them quite make sense. One was that the German rocket engineers used metric and the American rocket engineers used the English system and seconds were ...
2
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2answers
111 views

How fast could a fully fueled Falcon 9 go to propellant depletion if started in a vacuum

I guess my question is related to somehow assembling and fueling a falcon 9 in LEO then launching it. I would say if all stages were fully fulled and the Merlins were all vacuum optimized. Situation ...
1
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0answers
78 views

Estimated 13.77 billion years is this age of observable universe or the entire universe? [closed]

Can we calculate the age of entire universe not just the observable part ? If any type of EMW will never reach earth how can we ever know ?
8
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2answers
474 views

As of January 2020, what is the single longest duration firing executed with a Raptor engine?

Can someone cut through the woo for me? As of January 2020, what is the single longest duration firing executed with a Raptor engine? Have any successfully run for full mission duration? Sourced ...
2
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0answers
45 views

Out of which alloys are the Common Core Booster and Common Booster Core propellent tanks manufactured?

All sources that I can find indicate that they are isogrid structural tanks manufactured of milled aluminum. However, I cannot find further detail about of which alloy specifically they are composed. ...
3
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2answers
183 views

What does Earth's J₂₂ moment look like?

Wikipedia's Geopotential model give's the form of the potential component linked to $J_2$ as $$u = J_2\frac{P^0_2(\sin \theta)}{r^3} = J_2\frac{1}{r^3}\frac{1}{2} \left(3 \sin^2\theta-1 \right) = ...
14
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2answers
4k views

What did the Apollo missions do with old LiOH canisters & the water they produced?

We all love the Apollo 13 story, but the famous lithium hydroxide CO2 scrubber of that mission has made it hard for me to find information about its regular use. What happened to the old canisters ...
4
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1answer
244 views

What percent of fuel is consumed in powering the turbopumps? [closed]

The RD-170 consumes 5,300 lbs of fuel per second, including oxidizer. The turbopump produces 230,000 hp. If one assumes that roughly 1 lb of fuel is required to generate 1 lb of thrust (obviously this ...
3
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0answers
26 views

For the MSL (Curiosity) Mars atmosphere entry, how long was the Reaction Control System used in the atmosphere?

I understand that the Mars Scientific Laboratory used its Reaction Control System during its entry into the planet's atmosphere. How long had it been in Mars' atmosphere, during the "7 minutes of ...
5
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1answer
96 views

How are coatings like Vantablack and Aeroglaze Z306 used on spacecraft components? Exactly what functionalities do they provide?

Business Insider's SpaceX is launching 'dark satellites' to stop its Starlink project from wreaking havoc with astronomical research. Astronomers are skeptical. includes the following passage: "It'...
6
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0answers
97 views

What would a human rocket be like to launch a human off Mimas?

In a comment on Is there a self-rounding celestial body from which an Olympian could jump into space? @jpa made a modest proposal. What if we stacked a bunch of athletes on top of each other and ...
5
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1answer
137 views

Why does it take Spaceway 1 (satellite) two or three months to dump 73 kg of bipropellant?

I read on https://arstechnica.com/information-technology/2020/01/directv-races-to-decommission-broken-boeing-satellite-before-it-explodes/ (mirror): In the time available, DirecTV said "it will be ...
1
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0answers
15 views

Could the NOMAD instrument on the TGO detect methane at night with sufficient reflected sunlight or artificial light?

Nadir and Occultation for MArs Discovery (NOMAD) is a 3-channel spectrometer on board the ExoMars Trace Gas Orbiter (TGO). Both the solar occultation (SO), and the limb nadir and occultation (LNO) ...
5
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1answer
172 views

Does Dragon have any timeframes during launch where there is not a planned survivable abort mode?

The space shuttle had many scenarios with combinations of SSMEs or SRB failures where there was no planned survivable abort available because of a variety of factors (aerodynamics, energy, g forces, ...
5
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1answer
51 views

G forces on Mars Science Laboratory during parachute deployment?

The parachute for the MSL was "designed to survive deployment at Mach 2.2 in the Martian atmosphere, where it will generate up to 65,000 pounds of drag force." What was the G force the MSL ...
5
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2answers
99 views

Are there any close-up photos of the screens used in the MOCR2 from the Apollo era where text features can be distinguished?

The question is mostly about the fonts used in those screens. AFAIK, the images were slides superimposed with data generated by computers that was captured from CRTs by cameras and piped into the MOCR ...
2
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1answer
104 views

What are the lightning like flashes near the main parachute of Boeing's Starliner test?

Boeing released a highlights real of its test flight, and around 2:30 the main chutes deploy. When that happens, it appears as though is lightning like flashes around the main chute's cords. What is ...
19
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3answers
3k views

Why are we interested in visiting the giant planets' icy moons?

I have noticed lately that future missions by NASA and ESA are targeted towards the moons of Jupiter and Saturn. They mention that they might be a possibility of life; the icy moons they are focusing ...
1
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1answer
70 views

Building cubesat prototype using Rasberry Pi

We are doing a project in my university which is based on simple communication or GPS cubesat satellite (with only specific task not of so many functionalities), and we will be making a protoype for ...
3
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1answer
84 views

What fraction of Terminator Tape™'s drag comes from interaction with Earth's magnetic field as a function of altitude? Is it ever important?

This answer states that Terminator Tape™ uses the Earth's magnetic field to generate drag to shorten the deorbit time of a spacecraft in LEO. It links to https://sst-soa.arc.nasa.gov/12-passive-...
3
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1answer
135 views

Why is “Terminator Tape” electrically conductive?

A 230 foot long tape deployed from the satellite Prox-1 greatly reduced how long it took to deorbit. The tape was described as electrically conductive. Was that property intended to help the ...
3
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1answer
117 views

Could you carry around with you a rocket pack to get off Mimas?

This question was inspired by the one here: Is there a self-rounding celestial body from which an Olympian could jump into space? regarding the, apparently shown infeasible, idea of jumping off what ...
4
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0answers
115 views

How will the huge SpaceX Starship be moved/ferried on long distances on the ground?

There are evidences that the current rocket by SpaceX, Falcon 9 booster can be ferried on long distances on the regular road network. Long distance road ferry movements seems to be necessary because ...
7
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1answer
168 views

How did the Curiosity rover on Mars manage to crack open a large area after drilling a hole?

The answer to this question has a link with this image, an animated GIF showing before and after views of a drill site on Mars. How did drilling at the site manage to disturb such a large area and ...
11
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3answers
1k views

Is the risk of explosion-induced damage to operational spacecraft in GEO actually reduced substantially by raising Spaceway-1 by 300 km?

Engadget: DirecTV satellite is at risk of explosion due to battery issues Space News: DirecTV fears explosion risk from satellite with damaged battery say that the spacecraft must move 300 km above ...
3
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1answer
66 views

How much more quickly does night come on Mars compared to Earth? Will it be easier to see Mercury there?

This answer to Visible sky features from Mars got me thinking. On Earth it takes a while for the sky to get dark after sunset, which makes looking for Mercury a challenge because it follows the Sun ...
1
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1answer
55 views

Government Bodies and Space Exploration [closed]

My question is rather a opinion based one. Why does Government Space Agencies (all) not run behind Reusable Launch Vehicles when they know slight hike in budget can significantly contribute to Cut ...
23
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4answers
6k views

Is there a self-rounding celestial body from which an Olympian could jump into space?

Is there a self-rounding object in our solar system whose mass is insufficient to prevent the highest jumping human from escaping its gravity?
3
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1answer
122 views

Visible sky features from Mars

For the purpose of this theoretical question, please assume the following criteria: The person will remain on the planet for at least a few years allowing for Mars to complete an orbit. The person ...
2
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1answer
41 views

Is it possible to update an existing TLE using new data?

I'm writing a simulation a space surveillance telescope. The population of satellites it observes is initialized using TLEs, and the telescope also is given these TLEs at the beginning of the night ...
16
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5answers
3k views

Non-orbital takeoff and landing?

I know it is a naive question, but somehow I couldn't find where it is answered here earlier. There have been a number of questions and answers detailing how spacecraft need to achieve high orbital ...
4
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1answer
74 views

Do Lagrange points still exist if there is significant radiation pressure on the third body from the first?

From this answer: To obtain the distance to L1, find the smallest value of $r$ such that $$\frac{M_2}{r_1^2} + \frac{M_1}{R^2} - \frac{r_1(M_1+M_2)}{R^3} - \frac{M_1}{(R-r_1)^2} = 0.$$ To ...
3
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1answer
144 views

What is the most massive object in the ISS whose position was altered by the circulating air?

In Leo S's comment to the question, Do astronauts develop the ability to regularly place an object at rest inside the ISS after extended periods in microgravity?, he said "forces due to circulation of ...
4
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1answer
131 views

Are there any images of Curiosity during the sky crane operations?

This answer has a nice video of Curiosity's descent to MARS. The images come from the Mars Descent Imager (MARDI), which is mounted on the underside of the rover. Was there any camera mounted on the ...
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0answers
45 views

Defining overshoot and undershoot boundary of entry corridor

I have been reading up on the mathematic of atmospheric entry. I have found different methods to theoretically calculate the corridor width but I don't understand how to define the overshoot and ...
5
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1answer
111 views

Will the Mars 2020 rover be able to record high-framerate video of its helicopter?

According to this answer, there have been no instances of video recorded from beyond lunar orbit. Mostly, this makes sense as rovers and spacecraft are served just as well with pictures and nothing ...
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0answers
87 views

What Safety procedures include while orbit insertion, etc? [closed]

1)When a body is launched aboard a Rocket what are the safety parameters after 100 Km (Karman Line). 2) How does payloads not gets damaged from the billions of micrometeoroids?
2
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1answer
128 views

How many “main” batteries does the ISS have? How many are still nickel-hydrogen?

CBS News's Third all-female spacewalk completes job of swapping out batteries says: NASA is in the process of replacing 48 older-generation nickel-hydrogen batteries in the station's solar power ...
3
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2answers
141 views

Spacecraft remaining at station-keeping with respect to the ISS

If any spacecraft has remained at station-keeping with respect to the ISS for 12 hours or more, how far from the station did the craft remain?

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