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6
votes
1answer
94 views

Was this Gemini “giant eye chart” ever performed?

This article from the May 14, 1965 issue of the Manned Spacecraft Center Roundup describes an "eye chart" experiment on an upcoming Gemini flight. Did this experiment end up happening in any manner? ...
4
votes
1answer
97 views

Space shuttle cabin atmosphere system

I see from looking at the space shuttle cabin air supply system that it provides O2 and N2 through a common manifold into a 14.7 psi regulator. What is not clear to me is where the cabin air goes, and ...
4
votes
1answer
101 views

How will Chandrayaan-2 reach a polar orbit?

This Wikipedia article says the the Chandrayaan-2 orbiter will be in a polar orbit above the moon. The orbiter will perform its mission for one year in a circularized lunar polar orbit of 100 × 100 ...
3
votes
1answer
239 views

How did skeptics of rocketry think rockets work?

About 50 years ago, the New York Times retracted an unsigned editorial from 1920, in which it was argued that rockets cannot work in vacuum. See this blog, or wikipedia. (alas, I was not able to ...
0
votes
0answers
62 views

Lunar contamination by tardigrades [duplicate]

According to this tweet the recent crash of Beresheet on the Moon could have spread tardigrades on the Moon surface. Isn't this a violation of the agreement on preventing contamination of outer ...
38
votes
4answers
9k views

During the Space Shuttle Columbia Disaster of 2003, Why Did The Flight Director Say, “Lock the doors.”?

Why does the NASA Flight Director say, "Lock the doors.", when realizing that disaster had struck for Space Shuttle Columbia, back in 2003? Does he mean lock the doors on the space shuttle that's ...
2
votes
0answers
50 views

Has one satellite's outgassing ever affected another satellite in the same fairing? Documented examples?

At about 01:31 in Scott Manley's new video RocketLab & Reusable Rockets - Plasma Knifes, Ballutes, Helicopters and... Elephants he says: This occurs during a ...
3
votes
1answer
122 views

Why send tardigrades to the moon if we have actively avoided contaminating other worlds? [duplicate]

In 2017, we sent Cassini crashing into Saturn to avoid contamination "The spacecraft will burn up and disintegrate like a meteor in the upper atmosphere of Saturn," Preston Dyches, of NASA's Jet ...
5
votes
2answers
92 views

When a coronal mass ejection (CME) hits a spacecraft, from which direction will the particles come?

I have long assumed that when a CME (aka solar mass ejection, SME) hits a spacecraft, its particles will be coming in a straight line from the Sun. I've learned recently that it isn't so direct, and ...
4
votes
1answer
64 views

What factors determine the altitude at which rocket exhaust plumes start blooming hugely?

The images below are from a much larger set of photos in Spaceflight Now's August 8, 2019 article Photos: Atlas 5 paints the sky with spectacular sunrise launch. They show several effects related to ...
1
vote
0answers
79 views

What would happen if one Ariane V SRB did not ignite properly? (there may be no lock-down mechanism)

The excellent answers to What are these circular spots on these Ariane V SRB nozzles? tend to indicate that unlike the IV, the Ariane V simply rests on two flat surfaces under the SRBs at launch time, ...
4
votes
0answers
48 views

What is the name of the animal vaccine created in space? (according to Robert Zubrin)

I'm reading "The Case for Space" and on pg 47 of the book, Zubrin mentions that some sort of animal vaccine was created thanks to research done in microgravity and in space. He goes on to say that ...
2
votes
1answer
163 views

Is contact with Pioneer 7 or 8 still possible?

Pioneer 6 to 9 are a series of scientific probes launched 1965-1968 that orbit the Sun at about 0.75 to 1.2 AU. Would it still be possible to contact Pioneer 7 or 8? This question asks a similar ...
7
votes
3answers
255 views

Why do all recent proposed lunar landers have payloads on top?

Every recently-proposed vacuum lander I've seen has its payload as far off the ground as possible. This necessitates cranes, ladders, and elevators to get things down. (Starship may be a partial ...
17
votes
3answers
5k views

Is it really ~648.69 km/s delta-v to “land” on the surface of the Sun?

According to the following diagram it would require ~648.69 km/s to do all of the intermediate transfers that would land you at or around the sun's surface at perigee. Is this a real number? How would ...
3
votes
2answers
110 views

How does a Hall effect ion thruster have a sea-level Isp of 800? Operates at 1 atmosphere?

Astronatix's SPT-100 lists the following: Stechkin electric rocket engine. Used on Meteor and Gals satellites. In Production. 1.35 kW Hall thruster. Thrust variable 2 to 20 kgf. ...
1
vote
0answers
35 views

How does a “hybrid orbital raising system” based on R-4D (N2O4/MMH) + SPT-100 (Hall effect) work exactly? (Intelsat 38 & 39)

Astronatix's Intelsat 39 lists the two engines SPT-100 Stechkin 1.35 kW Hall thruster. R-4D Marquardt N2O4/MMH rocket engine. 490 N. Question: Why is this combination on Intelsat 39 called "hybrid" ...
9
votes
1answer
202 views

Did some Apollo astronauts actually carry a sandwich and bacon in their launch suit?

Normally I consider the Apollo Experience Reports as a reliable source, but the following claim is so bizarre that I'm asking if this claim can be verified by an independent source? THE APOLLO 14 ...
6
votes
1answer
116 views

Did the LEM ever rise above the orbit of the CSM at any time

We all know that the LEM descended from the CSM to the moon's surface and then rose back again to dock with it. But there are some videos that show the CSM floating in the foreground with the moon's ...
5
votes
1answer
124 views

What sounds did the Apollo astronauts hear during launch

I've looked through the Apollo Technical Debriefings 11, 12, 14-17, for descriptions of the sounds the astronauts heard during take off. Here is one example, from Apollo 15: *3.0 POWERED FLIGHT ...
4
votes
1answer
105 views

What happened to 2 of the 3 radiators on P6 on the ISS?

Source: nasa.gov; modified What happened to 2 of the 3 radiators on P6 (solar array) when P6 was moved from Z1 (the top) to its final position on the port side? Initially I thought 2 were removed ...
17
votes
3answers
6k views

Does the Voyager team use a wrapper (Fortran(77?) to Python) to transmit current commands?

I assume that the vast majority of the people who created the software for these missions are now retired (the "space pensioners" of the Voyager mission). Here's a very good summary of the current ...
18
votes
3answers
2k views

How do these cubesats' whip antennas work?

This answer has identified the three 1U cubesats shown in the question, and links to Engineers Rule's Maya-1: The Philippines’ First CubeSat along with the video Animation of MAYA-1, The Philippines' ...
3
votes
2answers
132 views

Stanley Kubrick used a NASA-inspired lens to film by candlelight in Barry Lyndon, but what did NASA use it for?

At 07:35 in the CinemaTyler video How Kubrick Achieved the Beautiful Cinematography of Barry Lyndon he says: As far back as 2001: A Space Odyssey, Kubrick and ...
2
votes
1answer
104 views

Saint Elmo's fire on the ISS? What are these green glowing balls of plasma on a solar panel? Dangerous?

This tweet says: Almost the entire population of Egypt lives within a few miles of the Nile. But my eye is on the green glowing balls on what looks like it might be a solar panel. Question: What ...
1
vote
1answer
212 views

Does this Soyuz vehicle burn coal or oil? What is its official name?

This tweet shows the image below and says: Soyuz rocket on its way to the launch pad (on a train of course). Question: Does this Soyuz vehicle (a train engine) burn coal or oil? Does it have an ...
1
vote
1answer
126 views

What cubesats are these, what flags are on them, and why? What's the background story?

This tweet includes the image below and says: Cubesats deploying from ISS. Question: What cubesats are these, what flags are on them, and why? What's the background story? Cropped, magnified and ...
10
votes
2answers
1k views

What are these circular spots on these Ariane V SRB nozzles?

This Space Shuttle Almanac tweet says: Pics 1-4 of todays @Arianespace #ArianeV VA249 launch carrying the #EDRSC & #Intelsat39 comsats from Kourou and includes the cool (hot) image below. ...
2
votes
1answer
236 views

Did SpektrRG make a “u-turn”, and how does this ground track remain a steady 6° above the equator?

This tweet The second (crucial) engine firing of the Block DM-03 stage in today's #SpektrRG launch to come in an hour, when the spacecraft almost completes its first orbit around the Earth. Here is ...
4
votes
2answers
104 views

Are second stage RUDs less common than first stage ones?

When I'm watching SpaceX launches, my biggest concern is to avoid a big boom. Specifically, an explosion that would threaten the astronauts who will eventually ride the Falcon 9. So around stage ...
2
votes
0answers
80 views

Why do these satellite antennas look so weird? (strangely shaped with little white dots…)

The NASA Spaceflight article Arianespace press onward with dual-passenger Ariane 5 launch shows a photo of Intelsat 39 during testing. The dish reflectors are strangely shaped: rather than being ...
49
votes
3answers
15k views

Did Apollo leave poop on the moon?

If you google the question, you will find an abundance of sources discussing the alleged fact that the Apollo missions left bags of fecal matter on the moon. A conversation on reddit got me looking ...
2
votes
1answer
33 views

Spacecrafts: NED frame to Orbit Frame or Body Frame Transformation

I calculate the geomagnetic field using IGRF model in Matlab. However, the output is in the NED coordinate frame and I want to tranform it into the Body frame. I've searched everywhere and I cannot ...
2
votes
1answer
112 views

How often does the ISS orbit over the same latitude and longtitude, at exactly the same time of day, as previously?

It appears that all spacecraft orbit within different parameters, dependant on altitude, and orientation to earths turn. The ISS synchronizes its orbit every 6 days(same latitude,same time of day) but ...
4
votes
2answers
374 views

Launch capabilities of GSLV Mark III

What are the parameters of determining the launch capabilities of a rocket? Also, How does ISRO's GSLV Mark III fare against rockets like N-1, Proton, R-7 etc?
2
votes
1answer
84 views

SpaceX rideshare missions: how many smallsats fit?

SpaceX has just announced their new smallsat rideshare program. Is it known how many satellites can be launched at once? Any estimates?
8
votes
1answer
1k views

Could an areostationary satellite help locate asteroids?

Could NASA put an artificial radar telescope satellite in geosyncronous orbit around Mars to help locate dangerous asteroids on a trajectory that would place them on a path to strike Earth?
10
votes
1answer
2k views

Has USSR/Russia launched humans on any rocket not derived from R-7?

The Soviet Union's first crewed launch, Vostok 1, was on a Vostok booster, derived from the R-7 ICBM and Sputnik satellite launcher with an additional stage added. The Soyuz boosters used today by ...
4
votes
3answers
847 views

How is foot-pounds of energy defined?

Tom Lodgson's classic textbook Orbital Mechanics: Theory and Applications frequently measures energy in foot-pounds, which I'd always thought to measure torque. The book doesn't define it. Is it the ...
6
votes
2answers
2k views

Why do rocket engines use nitrogen actuators to operate the fuel/oxidiser valves instead of electric servos?

Why do rocket engines use nitrogen actuators to operate the fuel/oxidiser valves instead of using electric servos?
1
vote
1answer
62 views

How do small, spin stabilized launchers follow a rhumb line?

This concise answer to What exactly is rhumb-line control in the context of a launch trajectory? explains the concept in the context of the SS-520 nanosatellite launch vehicle (which "doesn't exist"). ...
3
votes
1answer
379 views

What exactly is rhumb-line control in the context of a launch trajectory?

The conference paper SS-520 Nano satellite launcher and its flight result SSC18-IX-03 from the 32nd Annual AIAA/USU Conference on Small Satellites linked in this answer describes the use of rhumb-line ...
19
votes
1answer
3k views

How was the cosmonaut of the Soviet moon mission supposed to get back in the return vehicle?

In the Soviet Moon mission, for which the ill fated N-1 launcher was built, we know that the cosmonaut responsible for landing on the moon was to transfer from the equivalent of the command module to ...
1
vote
1answer
144 views

If there “won't be” rockets to launch individual cubesats, then why did JAXA build exactly that? (SS-520-xx)

The question Why isn't there a rocket to launch a single cubesat? has several good answers that explain why there isn't and/or will not likely be one, based mostly on commercial viability, consistent ...
7
votes
1answer
93 views

Can Dragonfly make it to one of Titan's Lakes?

Dragonfly is a drone set to land on Titan in the mid 2030s. As I've read, Saturn - and thus, Titan - won't be in the right orbital position at the time to allow for direct contact with the drone if it ...
-2
votes
0answers
31 views

Chandrayaan II - Sling Shot Maneuver [duplicate]

Given the huge swarm of artificial satellites swarming around earth, how could India's Lunar vehicle perform sling shot maneuver?
3
votes
1answer
117 views

How was sky crane (used on Mars Science Laboratory's Curiosity) tested?

This is sky crane: Mars has 1/3 of Earth's gravity, so how was sky crane tested on Earth? Did they even test it at all? Did they repeatedly do the math, and make sure everything works so that they ...
0
votes
3answers
65 views

When would the density Isp product be an important performance metric of a propellant?

The quote NASA is testing hydroxylammonium nitrate in space which is expected to perform 50% better than standard propellants and can be allowed to freeze (hydrazine must be kept liquid). LMP-103S ...
2
votes
1answer
103 views

Why would it be “less bad” for hydroxylammonium nitrate monopropellant to freeze than for hydrazine?

Answers to Is it bad if hydrazine freezes on a spacecraft? Is it always kept as liquid, or can it be safely allowed to freeze and then thawed when needed? explain that while the freezing of hydrazine ...
0
votes
1answer
67 views

Are these statements about “a first use of grid fins by China” simply wrong?

Ars Technica's Rocket Report: China discovers grid fins, NASA acknowledges Starship program says: China experiments with grid fins. The launch of a Long March 2C from Xichang last week included a ...

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