All Questions

Filter by
Sorted by
Tagged with
21
votes
2answers
4k views

How does one throw a boomerang in space? Does it return?

From today's BBC's Japan developing wooden satellites to cut space junk: "We are very concerned with the fact that all the satellites which re-enter the Earth's atmosphere burn and create tiny ...
3
votes
0answers
40 views

Example of CubeSat Systems Architecture and Software Architecture

For a school project I'm required to research into the engineering methodology and process for a CubeSat. As such, I'm inquiring into if anyone has an example software and systems architecture for ...
1
vote
0answers
32 views

What percentage of the population can pass Virgin Galactic's training sessions for tourists to board a sub-orbital spaceflight?

I read on https://www.cnbc.com/2020/09/26/space-tourism-how-spacex-virgin-galactic-blue-origin-axiom-compete.html (mirror): Additionally, Virgin Galactic has said that passengers will spend three ...
1
vote
0answers
20 views

Falcon 9: SECO target altitude/speed?

Is there a typical target altitude and speed for SECO on a Falcon 9 CRS launch? SECO precedes orbital insertion but there are multiple orbital adjustments afterward, so I also wonder: does Dragon have ...
27
votes
2answers
2k views

Why does the Indian PSLV rocket have tiny boosters?

I have noticed that the Indian rocket PSLV has tiny strap-on boosters attached to it on the sides at the bottom. Why would these be used instead of just using a larger first stage? Why is there an ...
6
votes
1answer
120 views

Do astronauts on ISS notice Earth's seasons?

Has anyone stationed on the ISS for some months reported noticing the changing seasons on Earth in any way like people on the surface do, subconsciously without needing to look up numbers for anything?...
6
votes
1answer
92 views

Would 2 areostationary satellites around Mars, over opposite longitudes, allow constant communication with rovers?

I've heard that rovers on the surface of Mars can only communicate with and send data to orbiters for only 8 minutes at a time. Wouldn't two areostationary_orbit satellites orbiting opposite to each ...
6
votes
1answer
416 views

Is there an acronym for secondary engine startup? SESU?

We have acronyms for main engine cutoff (MECO) and secondary engine cutoff (SECO). Do we have an acronym for secondary engine startup---SESU maybe?
3
votes
1answer
48 views

NASA design handbooks and specifications

Does anybody know the designations, publication names, etc. for the design standards which NASA uses for space flight hardware? I’d like to add these resources into my engineering library.
3
votes
0answers
44 views

Can it be estimated when a first settlement near the equator would become more economical than one at the midlatitudes of Mars?

Choosing the right place on Mars for a settlement would be of course an important decision because once it's there it would take much time and money to move on to another, better location. Because the ...
9
votes
2answers
547 views

Falcon 9 TVC: Which engines participate in roll control?

Stage 1 of Falcon 9 uses its gimballed engines during launch to control roll, pitch, and yaw. Only the eight peripheral engines can be used for roll control since the center engine couldn't possibly ...
24
votes
4answers
3k views

Are SpaceX Falcon rocket boosters significantly cheaper to operate than traditional expendable boosters?

The title pretty much sums it all up. I remember somebody once remarked about the space shuttle program that “the space shuttle was originally designed to be a space truck. But the shuttle is to ...
3
votes
0answers
103 views

Why do spacecraft have seats?

Crewed spacecraft for travel to/from Earth, and much speculation for the SpaceX Starship, have seats with the astronauts upper body level in an eyeballs in orientation. This is because this is the ...
2
votes
1answer
78 views

How long do the ascent and the descent of Virgin Galactic's spacecraft take?

The VMS Eve mothership releases the VSS Unity spacecraft after ca. 48 minutes. The total duration is approximately 2 hours. As a result, the ascent time + the descent time that the Virgin Galactic's ...
4
votes
1answer
100 views

Is there an established name for the regions “above” or “below” the ecliptic plane in our Solar System?

In our Solar system, all of the planets orbit the Sun along a plane known as the ecliptic. If we extend the ecliptic plane into a sphere of the same radius centred around our Sun, is there any ...
4
votes
1answer
47 views

Does the volume of hydrazine propellant stored at 22 bar change?

I'm working on an extracurricular project and I'm trying to determine what volume of propellant tank I need to 12.14 kg of hydrazine propellant stored at 22 bar. I researched and found this pressure ...
13
votes
1answer
1k views

What is your name? What is your quest? What is the story behind Satellite 1963-38C?

Source see also the page On Possible Electric Phenomena in Solar Systems and Nebulae By Kristian Birkeland extracted from The Norwegian Aurora Polaris Expedition 1902-1903 (Book) Wikipedia's ...
1
vote
1answer
165 views

Are Virgin Galactic tourists asked to take a 6 to 8G centrifuge test to qualify, and if so, what's the point?

Regarding sub-orbital spaceflights with Virgin Galactic, claims that: Allegedly some travelers were asked to take a 6 to 8G centrifuge test to qualify Is that true, ...
0
votes
0answers
25 views

What's the slot region of Jupiter's electron radiation belt?

This is the slot region of the earth: https://www.sciencedirect.com/science/article/abs/pii/S0273117799005141
2
votes
0answers
70 views

Do the passengers in Virgin Galactic's VSS Unity spacecraft have a parachute or some other way to escape the spacecraft if needs be?

Do the passengers in Virgin Galactic's VSS Unity spacecraft have a parachute or some other way to escape the spacecraft if needs be? In the VSS Enterprise crash that occurred on October 31, 2014, the ...
2
votes
1answer
95 views

Do we have an effective way to dispose of space debris at LEO?

There are a lot of articles and news that companies have plans on how to get rid of space debris. But I never found a single proven and reliable method. Perhaps I was looking in the wrong place? Or ...
6
votes
1answer
93 views

Why is the Orbital Velocity after SECO of Crew Dragon with 27K km/h lower than of ISS?

Crew Dragon after SECO: Orbital Vfelocity at 27,000km/h at 200km altitude (roughly 9-10min after liftoff). ISS Orbital Velocity at ca. 28,000 km/h at 400km altitude.iss_altitude,iss speed However from ...
5
votes
0answers
103 views

How close a crewed spacecraft could orbit Jupiter?

How close could a crewed spacecraft orbit Jupiter? I read that Juno was as close as 5,000 km from Jupiter's top clouds, but I'm wondering about a spacecraft with humans inside (provided it's protected ...
2
votes
1answer
106 views

First Ham Radio contact from space; what frequency, what kind of antenna, and how did they route the coax out the window?

From Phys.org's Earthlings and astronauts chat away, via ham radio: NASA astronaut Doug Wheelock was just a few weeks into his six-month mission at the space station when feelings of isolation began ...
1
vote
1answer
64 views

Could we intentionally contaminate another celestial body with life to start producing oxygen?

My question is simple, could we "nuke" a planet with life to create an atmosphere over time? I was seeing a documentary about Jupiter's moon, Europa, and how it could have hydro thermal ...
19
votes
2answers
3k views

Why didn't NASA simulate the conditions leading to the 1202 alarm during Apollo 11?

If I understand it, the alarm during the first Lunar descent was due to the computer being overloaded by too much RADAR data. That sounds like something that they would have thought to simulate, but ...
1
vote
1answer
95 views

Liquid Nitrogen Diluted Rocket

Imagine a rocket that uses a mixture of liquid nitrogen and oxygen as the oxidiser. It is designed like an oxidiser-rich staged-combustion engine, however there is so much nitrogen in the mixture that ...
2
votes
1answer
64 views

GMAT: How to do a Hohmann transfer from a larger orbit to a smaller orbit

I've figured out how to do a Hohmann transfer to a larger orbit but can't seem to figure out how to do one back to a smaller orbit (e.g. GEO to random smaller orbit). Any advice would be amazing, ...
7
votes
1answer
96 views

Is there possible engine damage without launch platform on Mars return flight?

When a Starship has landed on Mars, there is not going to be any kind of prepared platform initially. (That may be a task for early crews to resolve). Is there the possibility that Starship, sitting ...
2
votes
0answers
72 views

Why shouldn't Chang'e 5's lander's propellant freeze?

We have just measured the shape of the crater that the returner landed on, which is part of the scientific data collection. Then the returner will [put on a] 'new warm coat' to prevent the remaining ...
9
votes
0answers
104 views

Does the SpaceX spacesuit address any of the criticisms of ACES raised by Columbia Crew Survival Investigation Report?

A brief history of what Shuttle crews wore for ascent and entry, from the Columbia Crew Survival Investigation Report: The shuttle was originally designed to be operated in a shirtsleeve (bare-hands) ...
26
votes
3answers
6k views

Why doesn't NASA release all the aerospace technology into public domain?

NASA is a publicly funded US governmental agency, yet it does not seem to release all the technology it develops into public domain for people being able to study it and learn from it. For instance, ...
11
votes
3answers
2k views

How come there are so few TNOs the Voyager probes and New Horizons can visit?

The region beyond Neptune is full of dozens, if not hundreds, of dwarf planets and possible dwarf planets. Why can't the interstellar probes visit some of them anyway, along their path? The only TNOs ...
3
votes
1answer
146 views

Why did Columbia disintegrate lower into the atmosphere, not during its peak heat phase?

Space Shuttle Columbia entered a period of peak heating at 46 mi (74 km) altitude. Before the contact got broken, the temperature on Columbia's wing leading-edges had sunk already (and the heat shield ...
4
votes
1answer
115 views

When our Moon is hiding Mars, is it possible to create a radio communication between Earth and Mars?

According to this link Mars is hiding behind the Moon ... It’s a twice-a-year occultation; like the eclipse When such situations happen, can we communicate with the Mars rovers, and in the future - ...
30
votes
3answers
4k views

Are all satellites of all planets in the same plane?

I'm aware of the fact that all planets are almost in the same plane as the Sun and the Earth(ecliptic) plane except Mercury and Pluto(which are more tilted). Are all satellites of all the planets also ...
10
votes
3answers
4k views

If there's a hole in Zvezda module, why didn't all the air onboard immediately escape into space?

The ISS is leaking through a hole in the Zvezda module that still hasn't been found. However, as with all pressurized chambers, shouldn't all air instantly run out through the hole into the vacuum of ...
19
votes
2answers
3k views

Why is unappetizing food brought along to space?

I read at some point about a Shuttle mission that ended up lasting longer than initially intended, and the crew had to eat more awful-tasting food for the last few days, because they had eaten through ...
0
votes
1answer
93 views

Does it count as orbital flight if one reentered the atmosphere due to its drag after about 1 revolution?

Imagine a spacecraft entered an orbit around the Earth whose perigee is low enough into the atmosphere so that it reenters and lands after a revolution, without having to perform a reentry burn. While ...
2
votes
3answers
184 views

Can liquid rocket engines have the same thrust as solid rocket engines?

Take the Vega rocket launcher for example. Its first three stages are solid rocket engines and burn at a relatively short time. If I were to change its first stage into a liquid rocket engine, can ...
2
votes
1answer
105 views

How redundant are Orion's power and data units (PDUs)? Doubly? Quadruply? If so, why?

In the news today: NASA to skip repair of Orion electronics unit NASA will fly Orion deep-space crew capsule ‘as is,’ despite failed component; The agency claims there is enough redundancy in the ...
1
vote
1answer
186 views

Why would it take so long (22 minutes!) to travel from Hong Kong to Singapore flying SpaceX?

In the SpaceX video Starship | Earth to Earth they show the flight time from Hong Kong to Singapore to be 22 minutes. What's taking so long? It's only 4 hours by airplane (and US $275!)
2
votes
0answers
19 views

When are close approaches of Helios 1 and 2 to the Earth? Any historical tracking data? Any reports in sky surveys?

This answer to ** notes that it's hard to get current data on the orbits of Helios-1 and Helios-2 and I couldn't find any in JPL's Horizons. They are shiny and in nice elliptical orbits between ...
8
votes
6answers
1k views

When has hydrogen peroxide been used in rocketry?

Peroxide is apparently a very good propellant, but I can't seem to find any instance of it being used. Has it ever been used and if not, why hasn't it? What's its downsides?
3
votes
1answer
140 views

Compressed Air Spaceship

Imagine a people who live within the debris ring of a planet. They make their homes on rocks that are only dozens of miles in diameter, so escape velocity is not a concern. They also do not need to ...
2
votes
2answers
112 views

Number of China orbital launches by year [duplicate]

I've also posted the numbers below as a temporary answer here but I don't know if they are right so I'll also ask this as a question. How many orbital launches did China make every year? I got some ...
2
votes
2answers
289 views

How did Argentina, Namibia, and Pakistan help China monitor and communicate with Chang'e 5?

At the end of The Hill's article Chinese official unveils future moon mission plans including possible lunar base it says: The most recent Chang'e 5 probe was assisted by the European Space Agency, ...
6
votes
2answers
709 views

How many burns does New Shepard have during a descent?

The Falcon 9 first stage is making two or three burns for descending: boostback burn (optional, depends on return to launch site vs ocean landing) entry burn landing burn But how many burns is the ...
3
votes
0answers
146 views

First time in orbit by USA state launched from? [closed]

Only five states and territories had launches that got into orbit: Florida, California, Virginia, Alaska and Marshall Islands But when is the first time a rocket launched from each of those that ...
2
votes
1answer
80 views

What is the LOX mass of a Starship and a Superheavy?

Starship's mass of propellant is 1.2 million kg, and Superheavy's is 3.4 million kg. How much of that is the liquid oxygen?

15 30 50 per page
1
3 4
5
6 7
293