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6
votes
1answer
150 views

Why did the Vertical/Vehicle Assembly Building have four doors?

On this satellite image (credit: Google Maps) it is clear that only 3 out of four bays were ever used, since the 4th is not even connected to the crawlerway: (Yes, I made the screenshot deliberately ...
1
vote
1answer
75 views

Does a warped galaxy have any realistic implications for modern space travel?

A recent BBC news article with the title "Milky Way galaxy is warped and twisted, not flat" caught my attention. It goes on to say: Our results show that the Milky Way Galaxy is not flat. It is ...
0
votes
1answer
44 views

Any book overviews the ideas to reach/colonize/terraform Mars? [closed]

I'm recently looking for such a (popular) book(s), that would summarize the currently developed/planned/considered ideas. Zubrin's "Case for Mars" is a whole book just about one proposal (but of ...
0
votes
2answers
81 views

Warming Mars by increasing dust infall?

From this article: https://www.universetoday.com/142558/martian-clouds-might-start-with-meteor-trails-through-the-atmosphere/ It suggests that increasing high-level cirrus cloud would significantly ...
5
votes
1answer
93 views

How many different kinds of insulation film are wrapped around the Apollo Lunar Module?

In the image shown in the question Why is the Apollo LM landing gear covered with so much thermal isolation? (also shown below) it appears that the color of the film around the bottoms of the lander's ...
7
votes
1answer
358 views

Why is the Apollo LM landing gear covered with so much thermal insulation?

The Apollo LM landing gear – struts, footpads, shock absorbers and contact probes was completely covered with foils. There should be no temperature sensistive electronics within the landing gear, ...
5
votes
1answer
138 views

What criteria dictate solar panel design?

On space craft equipped with solar panels, those panels comes with various form factors and number. 2 straight rows (e.g. progress, rosetta,...) more straight rows (e.g. ATV, Juno,...) only one ...
15
votes
3answers
5k views

Is the EU really banning “toxic propellants” in 2020? How is that going to work?

This comment links to an archived presentation by Tesseract "The space transportation company offering revolutionary propulsion" says on slide 8: Timing is right Small satellite ...
5
votes
1answer
73 views

How to choose between Hermite and Chebyshev interpolation for spacecraft trajectory?

There's a related question, but it doesn't seem to apply to spacecraft trajectories. Suppose you want to send a non-thrusting spacecraft far from earth, and you have ground tracking of the spacecraft,...
1
vote
0answers
39 views

What was the procedure for Lunar Orbit Rendezvous? [duplicate]

I've read the following questions: Why was orbital rendezvous considered so controversial? Could an Apollo LM land uncrewed? How "hard" did Apollo 12 turn left just before it landed? And ...
-2
votes
2answers
177 views

Could NASA go back to the Moon? [closed]

Even after launching so many space missions, including the one which led Man to the Moon (Apollo 11, July 1969), NASA made several mistakes even in the space programs that followed. For e.g. Space ...
2
votes
1answer
83 views

Do the pipes used for RS-25 nozzle cooling channel have a constant section?

If I understand correctly from this question, The SSME's nozzle is made of pipes into which cool propellant circulate. The nozzle is larger at the end than near the combustion chamber. Thus, it must ...
1
vote
1answer
143 views

Is a Mars return mission by Starship possible without local propellant production, given the current specifications?

Let's imagine that Starship and Super Heavy were currently operational delivering the anticipated performance and reliably performing orbital refueling. As far as I know, Starship is capable of ...
4
votes
1answer
512 views

Why isn't LOX/UDMH used in staged combustion rockets now-a-days?

Liquid rockets usually use a propellant pair of fuel and oxidizer. I've seen some rockets from 1960's that used LOX/UDMH as propellant pair but why they are not used any more although it is mentioned ...
4
votes
1answer
176 views

What are those big valves on Soyuz control panel for?

What function do the two large, chunky red valves on the center of the Soyuz control panel have? They are located in the lower middle of this image, just above the Vizor periscope. I wish to know ...
6
votes
1answer
240 views

What is Tesseract's “secret sauce”? (green propellant)

TechCrunch's Tesseract makes spacecraft propulsion smaller, greener, stronger tells us to "ditch the hazmat suits" and https://www.tesseract.space/products-and-services lists the Lyra 22 (i.e. 22 ...
22
votes
2answers
5k views

Were there any unmanned expeditions to the moon that returned to Earth prior to Apollo?

Apollo 8 orbited the moon, and obviously Apollo 11 landed. I'm wondering if there were any test missions to get unmanned ships to the moon and safely back to Earth? It seems like a big jump to ...
1
vote
1answer
112 views

Total delta-v expected from Lightsail-2's solar sail before end of mission, and why end it so soon?

While Bill Nye has recently gotten quite upset at us for some things (strong language for Bill Nye warning), in the video below he expresses heartfelt thanks to all members of the Planetary Society ...
3
votes
0answers
67 views

Was the kill-the-moon-bugs disinfectant the same as the kill-the-Earth-bugs disinfectant?

During the Apollo program, measures were taken to prevent Earth microbes from contaminating the moon, and to prevent hypothetical moon life from infecting the Earth. What were the disinfectants used ...
1
vote
0answers
36 views

What does it take to create a space startup in India? [closed]

I wish to create a space startup in my country. Does going to an existing space company(like ISRO) help me as a founder for my startup? Consider that I have enough investment and I am ready to take ...
4
votes
1answer
68 views

What will (or did) end of mission look like for the MarCo cubesats?

These two 6U's are the farthest cubsats from Earth. Are they still talking to us and being talked to? With loss of remaining propellant for momentum unloading needed for high-gain antenna pointing ...
4
votes
1answer
249 views

Which Voyager spacecraft “mutinied”, and what really happened?

The August 2017 BBC News Science in Action podcast The Algae that Changed the Earth includes other topics, including the following: In August and September 1977, Nasa's probes Voyager 2 and ...
5
votes
1answer
379 views

Are there any Earth observation-like spacecraft orbiting other planets or moons?

Earth has many observation satellites, with some having a resolution better than 1 meter. A consequence is that we can access high resolution images of almost every square meter of land (classified ...
9
votes
2answers
2k views

Microgravity indicators

As mentioned in the YouTube clip below and in the image, in the Soyuz craft hangs small toys or dolls as microgravity indicators. Is this really the purpose of the dolls being hung? Are people not ...
8
votes
7answers
3k views

Is it possible to get a spacecraft into earth orbit using Linear Eddy Current Braking on an orbital runway?

The "Space Runway" [I have slightly edited this to clarify some issues that have been raised] Luke Parrish mentioned an unusual and novel space launch method to me. The idea is to get a spacecraft ...
4
votes
1answer
109 views

Do space agencies (specifically NASA) face legal issues when flying scientific balloons?

I'm doing a project on scientific balloons, and I can't find anything on legal issues that the missions may face. My project consists of a hypothetical mission launching over Antarctica if that helps ...
23
votes
2answers
7k views

How did astronauts using rovers tell direction without compasses on the Moon? [duplicate]

I read that the astronauts who used Lunar rovers used heading indicators, which typically use compasses, for direction. How, on the Moon, did their equipment tell the direction of travel, presuming a ...
10
votes
2answers
468 views

Why was the LRV's speed gauge displaying metric units?

In the question Why did NASA use U.S customary units? it was basically stated in the answers that even when metric units were used "internally" (e.g. the AGC), the units presented to the astronauts ...
2
votes
0answers
90 views

Experiments during ascent

Has any astronaut or cosmonaut personally performed experiments, that could only be done by a human in flight, during the ascent phase of a flight. If so, what kind of experiment(s) did they perform?
3
votes
1answer
85 views

What kind of sensor can trigger launcher self-destruct?

Many questions here talk about the rational behind self-destruct systems and the implementation of the self destruction, but I cannot find specific information about the triggering of such system ...
4
votes
1answer
159 views

Why did NASA sent people to the Moon more than once? [duplicate]

Often, especially now with the 50th anniversary of the Apollo 11 mission, the question is asked: Why did we stop sending people to the moon. The answer is usually: because the USA had proved they ...
3
votes
1answer
77 views

Main issues space telescopes face when pointing in the same general direction as the Sun?

What are the main issues that space telescopes face when pointing at objects that are in the same general direction as the Sun? Why do they generally schedule their observing for objects in the ...
5
votes
1answer
177 views

Does the ISS yaw in orbit? And if so, why?

A NASA ISS reference guide (PDF; 37 MB) explains the use of reaction wheels -- Control Moment Gyroscopes (CMGs) -- to control the station's attitude/orientation. My understanding is the station is ...
26
votes
2answers
5k views

Why tantalum for the Hayabusa bullets?

The Hayabusa 2 probe is firing tantalum bullets at the asteroid Ryugu to knock off material that can be sampled. Why tantalum? That’s a pretty obscure element and I would assume rather rare. What ...
2
votes
2answers
94 views

How fast were the Lunar Command Module and Landing Module traveling around the Moon when they reconnected?

I can't find this information online and am wondering how fast each were going around the Moon when they reattached to one another after the moon landing.
8
votes
0answers
77 views

What is the current location of Link-built Apollo Mission Simulators?

There seems to be confusion about the final disposition of, and even the number of, Apollo Mission Simulators built by Link Flight Simulation Division. This question is not about any simulator built ...
14
votes
1answer
299 views

How were the pins for Saturn V controlled release tested?

I came across the following section of the Saturn V Flight Manual (pdf): The intriguing part is that they used 12 pins to actually bolt down the Saturn V to the launch pad and the combined engine ...
66
votes
1answer
15k views

Why did some Apollo missions carry a grenade launcher?

According to ALSEP Flight System Familiarization Manual, p. 2-166, some Apollo missions carried a grenade launcher and 4 grenades. What were these used for?
2
votes
1answer
78 views

Was there a measurable effect on gas concentration on the Moon during the Apollo missions?

Gas was released by the Apollo Lunar Modules during depressurization of the cabin in preparation to an EVA. Did this release of oxygen had a measurable effect despite the small amount of gas and the ...
3
votes
2answers
129 views

When calculating the future orbit of an artificial Earth satellite, is the Moon's gravity significant or insignificant?

Imagine a mathematician is plotting the future orbit of a satellite to be launched and put in orbit around the Earth. When they are making their calculation, is the moon so far away and the ...
22
votes
5answers
4k views

Why is the Apollo LEM ladder so far from the ground?

In an answer to this question, the following photo was posted: (source: NASA Apollo 11 Image Library) This made me recall that the first thing Armstrong did after climbing down the ladder to the ...
8
votes
1answer
2k views

Why would the Apollo Lunar Module pressure dump (to space?) valve have a bacterial filter?

This answer to Why did they bother closing the hatch on the LM while doing EVA? links to a transcript of Apollo 11 which contains the following (find it there by searching for "radiative"): 109:41:...
28
votes
5answers
5k views

Why were contact sensors put on three of the Lunar Module's four legs? Did they ever bend and stick out sideways?

In the video Brian Eno on Apollo starting at 08:37 there is Apollo-era movie footage of a lunar module taken from the command module as it prepares for descent ...
1
vote
1answer
41 views

Video standard used on Intelsat 1 (Early Bird)

I was watching a documentary on Intelsat 1 (also known as Early Bird) and some of the first live television sent over it. Was there any particular video format or modulation used, special for the ...
3
votes
1answer
116 views

What kind of camera was used to produce this Apollo-era footage of the Earth?

The question Reflected Earth is 1/3 the size of primary Earth in Apollo footage through spacecraft window; why? begins: In the video Brian Eno on Apollo at 08:20 ...
3
votes
1answer
77 views

Farthest distance to a solar system object that's been determined by spacecraft transponder?

Bouncing radar off of Venus' surface has yielded a rich body of data about the planet. Based on Venus' aphelion and Earth's perihelion, we know then that the answer is at least 38 million kilometers ...
2
votes
1answer
83 views

Farthest distance to a solar system object that's been measured by radar?

Bouncing radar off of Venus' surface has yielded a rich body of data about the planet. Based on Venus' aphelion and Earth's perihelion, we know then that the answer is at least 38 million kilometers ...
8
votes
1answer
501 views

Sea level static test of an upper stage possible?

As we know that for the upper stages of the rocket, we need high propulsion efficiency thereby high specific impulse. For that we employ a nozzle with higher expansion ratios. Now, if we conduct the ...
1
vote
0answers
44 views

Which space debris are used for science purpose?

I already know that some Apollo's space debris were used for seismic study of the Moon. Other debris may be used for scientific studies. By debris, I mean space objects that have no purpose or ...
2
votes
1answer
116 views

Who was the first person to shave in space?

A quick internet search shows that Apollo 11 astronauts shaved, but there were some Apollo missions earlier than that were also of similar week-like duration and the Soviet Union had astronauts in ...

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