Skip to main content

Questions tagged [mass]

Questions regarding the mass of spacecraft or other objects

Filter by
Sorted by
Tagged with
46 votes
1 answer
6k views

Why vent $CO_2$ and $H_2$ waste products to space on ISS?

In this answer, it's mentioned that waste $CO_2$ and $H_2$ from the Environmental Control and Life Support Systems (ECLSS) are vented into space from ISS. Are there no other uses for this material ...
Steve's user avatar
  • 1,174
26 votes
3 answers
6k views

What is the "mass" of a Lagrange point?

Of the five Lagrange points, L4 and L5, as stable points, can be orbited by asteroids, satellites, and any other useful or interesting object. Assuming two-body motion however, calculating orbits with ...
TheEnvironmentalist's user avatar
23 votes
2 answers
6k views

Is the mass of paint relevant in rocket design?

(Prompted by this answer): Do the designers of large rockets* (have to) take the mass of the exterior paint into account? If so, do we have examples of actual design changes/decisions based on this (...
user avatar
19 votes
3 answers
6k views

Did the Mars rovers actually confirm the gravity of Mars?

For years the theoretical calculated gravity of Mars has proliferated science texts and Internet documentation - but did the rover actually do a test to confirm the theoretical gravity is truly equal ...
Chris's user avatar
  • 301
19 votes
4 answers
6k views

Why can't we launch from space?

So this may be a stupid question but I was wondering why we couldn't launch from space. I know that most of the fuel that we spend is for escaping Earth gravity. Yet, if we have already done this with ...
bobthebuilder's user avatar
15 votes
6 answers
4k views

How do you weigh things in a micro-gravity environment?

Obviously a balance scale is not going to add value to the task in free-fall. Weight in space is more accurately described as mass, but the need to define it still exists. Regardless of if you're ...
James Jenkins's user avatar
15 votes
1 answer
677 views

How precisely do we know mass of the ISS?

Everyone knows that in space, every gram counts. Knowing how much mass an orbital object has is necessary for precise motion calculations. So how precisely do we know the mass of ISS? I'm sure we can ...
Euphoric's user avatar
  • 249
15 votes
6 answers
707 views

What limits miniaturization of space probes?

Another run of kerbal got me thinking about what, in reality, makes up the limit for small, but still useful space probes. The rationale should be obvious: The rocket equation does not hurt that ...
choeger's user avatar
  • 2,453
15 votes
1 answer
3k views

Where to find the best values for standard gravitational parameters of solar system bodies?

Where can I find the best values to use for standard gravitational parameters of solar system bodies for numerical simulation experiments? Here are two sets I've put together. The first set is from ...
uhoh's user avatar
  • 149k
14 votes
4 answers
3k views

Why are rocket mass on the launch pad and payload mass to LEO not strongly correlated?

What explains the relation between how much a launcher weights on the launch pad, and how much mass it can lift to orbit? I had expected that more payload requires more fuel to be launched and that a ...
LocalFluff's user avatar
14 votes
2 answers
2k views

Are there interstellar Lagrange points?

Is there for example some L1 like libration point where the Hill spheres of the Sun and of the Alpha+Beta Centauri meet? And are Lagrange points between stars inside of a binary system, like Alpha and ...
LocalFluff's user avatar
12 votes
2 answers
1k views

What savings allowed James Webb telescope to be lighter than Hubble?

Wikipedia states: The telescope has an expected mass about half of Hubble Space Telescope's, but its primary mirror (a 6.5 meter diameter gold-coated beryllium reflector) will have a collecting ...
SF.'s user avatar
  • 55k
11 votes
4 answers
4k views

How does the roll maneuver allow more mass to be lifted into orbit?

I read recently that the roll maneuver that rockets perform shortly after clearing the tower to become tilted serves a few purposes (Shuttle and Apollo Saturn V alike). I understand most of these ...
Patrick Van Rinsvelt's user avatar
11 votes
1 answer
4k views

How did the Space Shuttle maintain thrust/weight balance

As a seasoned KSP player, I am aware of how important it is during ascent to have center of thrust and center of mass perfectly aligned. If you don't, your rocket will deviate from its course and ...
choeger's user avatar
  • 2,453
10 votes
3 answers
3k views

What is the largest and/or heaviest object that could be sent to space?

What is the largest and/or heaviest object that could be sent to space? I know the space station is sent in pieces but I am looking with one launch.
Muze's user avatar
  • 1
9 votes
3 answers
3k views

How close would the Tesla Roadster with Starman have to get to Earth in order to become attracted and fall on Earth?

In 2091 the Tesla Roadster is said to maybe get closer to Earth than the Moon is. At Starman's current speed, would its location in 2091 be sufficient for the Earth to re-attract the Starman to let it ...
user avatar
9 votes
1 answer
435 views

Why have space stations become less volume-efficient despite technological progression?

If you compare the pressurized volume of all the space stations launched to their mass, their volume-efficiency (in this context volume divided by mass) seem to decrease over time. In chronological ...
SE - stop firing the good guys's user avatar
9 votes
1 answer
394 views

Does a persons weight affect their potential selection to be an astronaut?

Every extra bit of weight cost extra to send to orbit. Presumably it also impacts the possible payload. Assuming a generally healthy build, and otherwise physically able and fit person. In ...
James Jenkins's user avatar
9 votes
1 answer
634 views

How much extraneous mass did each of the Apollo missions carry?

By "extraneous mass" I am referring to any mass which had not as its primary purpose onboard or attached to the launch vehicle to contribute to the technical or scientific goals of each mission. For ...
user's user avatar
  • 7,330
8 votes
5 answers
2k views

Does trajectory of an object orbiting a planet depend on the object's mass? (With hypothetical Apollo example)

For example (hypothetically), if an Apollo crew of one of the lunar missions went on EVA just after Trans Earth Injection burn and carefully released a small bolt, or a plastic package from their food,...
Sergiy Lenzion's user avatar
8 votes
3 answers
1k views

What determines the orbital speed around a Lagrange point?

What value of M should I use to calculate the speed of a satellite orbiting a Lagrange point where there exists no mass?
LocalFluff's user avatar
8 votes
1 answer
4k views

Why is Curiosity so light compared to Opportunity?

Look at that: ...and now tell me how comes Opportunity weighs 530kg and Curiosity 900kg. It looks, like by volume, Curiosity is good 4x larger, if not more. Plus it contains heavyweight RTGs, its ...
SF.'s user avatar
  • 55k
8 votes
1 answer
525 views

Why is the Dragon small compared with the Falcon 9 LEO payload

According to wikipedia, the Falcon 9 1.0 had ca. 10t payload capacity to LEO. The Dragon has a 3.3t payload capacity to the ISS with a dry mass of 4.2t that leaves 2.5t unused lift capacity. Is this ...
choeger's user avatar
  • 2,453
8 votes
1 answer
176 views

What was known about 67P/C-G's mass before the arrival of Rosetta?

The determination of the mass of a celestial object is usually between hard and impossible unless one can observe something that orbits it. In the case of comet 67P/Churyumov–Gerasimenko, one of ...
E.P.'s user avatar
  • 1,254
8 votes
3 answers
373 views

Do larger less dense objects heat less while entering the atmophere?

When a space craft enters the atmosphere, it gets hot and heat shielding is needed. Do objects with more surface area and less density heat up less then heavier, smaller objects? Could an object with ...
Justintimeforfun's user avatar
8 votes
2 answers
768 views

Proportions of a reentering spacecraft as compared to fuel mass

Call this a thought experiment. Spacecraft to Earth orbit and beyond are traditionally launched by means of one or more rocket engines. The fundamental principle is that a rocket moves by expelling ...
Everyone's user avatar
  • 13.6k
7 votes
1 answer
303 views

Why will Starlink Gen2 be so big and heavy?

Apparently, the mass of a Gen2 Starlink satellite will be around 1 metric ton. It will also be too large to fit into a Falcon 9 fairing. Given that it's basically still a "flying router", ...
Peter - Reinstate Monica's user avatar
7 votes
1 answer
4k views

Total Mass of the ISS Solar Array

This document does a pretty decent job of detailing the ISS solar array. There's one part, however, that is sort of ambiguous and critical to an analysis I'm performing, and so I thought I might ask ...
Mephistopheles's user avatar
7 votes
0 answers
544 views

How much does JWST actually weigh?

I recently had to delete my answer to Why doesn't James Webb have a larger supply of thruster propellant? because @NgPh noted: As the last update, JWST weights 6200 Kg. jwst.nasa.gov/content/about/...
BrendanLuke15's user avatar
6 votes
2 answers
8k views

What is a typical satellite solar panel mass?

Does anyone know a reliable source to find the mass of solar panels on satellites (in particular GEO satellites)? I know they will vary but I am struggling to even find one data point let alone a ...
Jez Turner's user avatar
6 votes
3 answers
799 views

Could daily variations of weight on Earth really be 0.003%?

I've been reading about accelerometers. On earth, in a lecture demonstration, in a table-top experiment, they will generate a signal equal to the sum of the acceleration you'd like to measure plus the ...
uhoh's user avatar
  • 149k
6 votes
2 answers
2k views

What size payloads could we feasibly launch from the moon with a mass driver?

I've been wondering how large a payload could be launched & if it's viable to launch those payloads directly to the earth for splashdown & collection. Obviously the payload would need to be ...
Pelinore's user avatar
  • 712
6 votes
1 answer
2k views

What is the thickness of a rocket nozzle?

For a university project, I'm working on optimisation of a Falcon-9-like launch vehicle, and one element of that is varying expansion ratios of the engines. This will impact on the engine mass, but to ...
Talisker's user avatar
  • 352
6 votes
2 answers
411 views

How much will Europa Clipper weigh?

I realize that NASA will have to change Europa Clipper's loadout based on whether they are launching on the SLS 1b or the Atlas 5 backup, but does anyone know what those two mission masses will be, ...
ORcoder's user avatar
  • 1,033
6 votes
2 answers
257 views

What is the largest possible rocky body? [closed]

Suppose you start with a rocky sphere about 12,742 kilometers in diameter and continuously add more rocky material such that you don't smash this sphere to bits. What is the upper limit for this? ...
Frotz's user avatar
  • 161
6 votes
1 answer
1k views

Falcon 9: how much fuel is left on a booster after stage separation?

If the booster attempts either land or sea landing, how much fuel (RP-1 and LOX) is left in its tanks right after stage separation? Recently, I have heard numbers as high as 30% of its total tank ...
Everyday Astronaut's user avatar
5 votes
4 answers
3k views

With increased space exploration missions, are we affecting earth's mass?

This questions may seem naive, but, worth pondering: As humans keep sending more and more missions to space (outside earth's system), the earth is being affected in the following ways: Earth is ...
anurag's user avatar
  • 219
5 votes
3 answers
5k views

Common usage of "dry-mass"

Usually, I would consider the dry-mass the mass of a vehicle without any consumables, passengers, or cargo. This NASA article however describes the Apollo 11 Eagle as: The lunar module was a two-...
choeger's user avatar
  • 2,453
5 votes
2 answers
2k views

What happens to materials which burn up during reentry?

The common conception of satellite reentry is that they just burn up and are "gone". But the total mass must still be somewhere, right? What forms does it all end up as, and where?
Victor's user avatar
  • 51
5 votes
1 answer
265 views

Why are all possibly habitable exoplanets higher mass than Earth?

I have been writing a scifi book in which I wanted to include real stars and planets as locations. It was simple enough to find a chart on Wikipedia that lists possibly habitable exoplanets, but I ...
TitaniumTurtle's user avatar
5 votes
1 answer
466 views

How much mass does a gimbal mechanism add to a rocket?

After reading the question Did any rockets use differential throttling instead of gimbal? I wonder what the additional mass of a gimbal system is. How would the mass of a launch vehicle change if the ...
Everyday Astronaut's user avatar
5 votes
1 answer
247 views

How long would it take for air to completely leak from a spacecraft?

If a spacecraft of volume V was leaking air of density rho as a mass flow rate of m-dot can you calculate the time for all the air to leak out using (rho x V)/m-dot? rho would decrease and m-dot ...
Jez Turner's user avatar
5 votes
1 answer
147 views

square-cube law and thermal protection tiles (TPS)

Yesterday, I asked a question about the square-cube law and propellant tanks. Do larger rockets tend to have a better mass ratio due to the square cube law? I have a very similar question about ...
Krzysiek's user avatar
  • 153
4 votes
1 answer
2k views

What fraction of a liquid rocket launching from Mars to return to Earth would be fuel?

I've tried to get my head around this and have decided that, for the moment, I don't want to learn to solve logarithmic equations. Too much else going on. I was reading Mars Direct and got the ...
kim holder's user avatar
  • 21.4k
4 votes
3 answers
1k views

Data for Moons in the Solar System with Masses

I'm looking for a simple machine-readable table with basic parameters for all the known moons of the planets in the solar system. Stumbling around the internet, I can find plenty of sources like this ...
AlanSE's user avatar
  • 16.3k
4 votes
0 answers
123 views

Mass Breakdown of Apollo CSM by Subsystems? (also Cost Breakdown)

I am looking for a mass breakdown of the Apollo Command and Service Module by subsystems, like this Lunar Module's chart from the NASA publication After LM. I am particularly interested in how much of ...
mini earth's user avatar
4 votes
0 answers
90 views

How to estimate total CO2 emission per year due to rocket manufacture?

I'm working on a study on greenhouse gas emissions related to rockets. While I have the post-launch (atmospheric) emissions, I need data for emissions related to production. For example, according to ...
dxcfvgbh cfvgbhnj's user avatar
4 votes
0 answers
226 views

Is Earth's Moon gaining or losing mass?

The Earth gains mass from dust/meteors (and a tiny, tiny bit to increasing temperatures/energy), but loses mass from hydrogen/helium escaping and nuclear reactions. It's estimated to have a net loss ...
Nate Lowry's user avatar
3 votes
1 answer
908 views

Does the size of a satellite have an effect on orbit?

I understand that lighter satellites orbits decay faster. There is 2 satellites that weigh the same but 1 is huge and the other tiny in comparison. Would the size of the satellite make a difference on ...
Muze's user avatar
  • 1
3 votes
3 answers
1k views

Would orbital ring platforms affect the orbit of a planet?

If we built an orbiting platform of sufficient mass (let's say, made from harvested asteroids) that was anchored at both poles of the planet it surrounded, would such an addition to the planet's mass ...
Dan East's user avatar