Hot answers tagged

125 votes
Accepted

How much bigger could Earth be, before rockets wouldn't work?

Because linear increases in delta-v require exponential increases in mass, small changes to the assumptions you make about fuel tank structural mass and engine thrust-to-weight ratio start to make ...
user avatar
94 votes
Accepted

Is Starman in the Tesla Roadster a real human?

'Starman' is a mannequin (store dummy) wearing a real SpaceX developed space suit that was a qualification unit, used in designing the space suit for the Commercial Crew program. During the SpaceX ...
user avatar
  • 76.4k
66 votes

Why is the first launch of Falcon Heavy sending a car instead of something useful?

The very first start of a new rocket is a risky endeavour. Since the system is put to test for the very first time as a whole, all kind of things can go wrong and chances are that the rocket doesn't ...
user avatar
  • 12.2k
50 votes

Why is the first launch of Falcon Heavy sending a car instead of something useful?

Why not deliver something useful to the space station like a new living segment? Many, many reasons. A dummy payload is almost always used on the maiden flight of a new rocket. The risk of failure ...
user avatar
  • 62.8k
35 votes
Accepted

What's the largest single object payload ever lifted into space?

Depending on your definitions, the contenders seem to be the US Space Shuttle, Buran, Apollo 17, or Skylab. ...
user avatar
31 votes

Is Starman in the Tesla Roadster a real human?

I first need to know if starman is a real human or a robot. Starman is the name given to the mannequin/space suit occupying the driver's seat of the car. It is not human nor is it a robot. If he ...
user avatar
  • 1,093
29 votes

How much bigger could Earth be, before rockets wouldn't work?

First, let us look at the rocket equation: $$\Delta v=\ln \left(\frac{m_0}{m_f}\right)v_e$$ That tells how much a rocket can change its velocity (the $\Delta v$). The requirements for reaching a ...
user avatar
25 votes

How would a long pole be transported to space?

The ISS solar array masts are launched collapsed in canisters, and run through a deployer mechanism to erect them as a long straight object. I see no technical reason why a much longer mast couldn't ...
user avatar
25 votes

Is it possible to build a rocket with 2kg payload?

The SS-520-5 rocket from Japan is probably as close you can get with 4kg to orbit. Height: 9.54 meters Weight: 2600 kg Diameter: 52 cm
user avatar
  • 1,503
23 votes

How would a long pole be transported to space?

Long rigid structure can be transported as raw material for fabrication in space, in the same way that continuous rain gutters are made. In the pictures below, you can see a machine that creates the ...
user avatar
  • 331
21 votes
Accepted

How much mass could the Saturn V rockets have landed on the Moon if nothing was coming back?

According to Wikipedia, Saturn V could launch 48600 kg to translunar injection. From there, you need about 2410m/s of ∆v to soft-land on the moon. Let's take a little additional fuel for safety ...
user avatar
21 votes
Accepted

How can the 6.5 m primary mirror of the JWST fit inside the 5.4 m fairing of Ariane 5?

The JWST is made to fold up, to fit inside the standard fairing. You can sort of see this in your image, 3 mirror segments are visible (the hexagons in the middle), other segments are viewed side-on ...
user avatar
  • 121k
21 votes
Accepted

What was the outcome of the launch of ZUMA by SpaceX, to the best of the public's knowledge?

What is known: SpaceX issued a statement saying that the Falcon 9 performed as intended An object was seen with spinning plumes that is assumed to be a Falcon 9 upper stage post-thrust fuel dump. ...
user avatar
  • 118k
21 votes
Accepted

Can the Falcon Heavy handle deep space missions?

SpaceX published numbers on their website near the bottom of the page. I snapped an image to show here, since their formatting is prettier than I can do in Markdown. You can see that it can do ...
user avatar
  • 76.4k
21 votes
Accepted

What is the largest number of identical satellites launched together?

88! PSLV-C37 launched 88 identical satellites into a sun-synchronous orbit. These satellites were for an imaging company called "Planet Labs". Technically the only ones that were identical were the ...
user avatar
20 votes

Payload capacity of a rocket

The short answer is: Tsiolkovsky rocket equation. You need some velocity to achieve some position (an orbit or a body) in space. Farther a position - more velocity. More velocity - more propellant ...
user avatar
18 votes
Accepted

Has any payload been as silly, as the Falcon Heavy's Tesla Roadster?

Update: February 24, 2018 The 'Disco Ball': Created by Rocket Lab founder and CEO Peter Beck, the Humanity Star is a geodesic sphere made from carbon fibre with 76 highly reflective panels. It spins ...
user avatar
  • 3,193
17 votes
Accepted

Why are there such large differences in launcher payloads to higher orbits (GEO, Lunar) compared to LEO?

The numbers on the Wikipedia page are a little messed up, so you can't do apples-to-apples comparisons. You'd need to go to the actual payload planner's guides to see what the performance is to what ...
user avatar
  • 57.4k
17 votes
Accepted

How would a long pole be transported to space?

Best way to do this could be to research, develop and send a "3D tube printer satellite" to low Earth orbit, and feed it with whatever material in liquid, powder or filament form, which will not ...
user avatar
  • 3,579
17 votes

Payload capacity of a rocket

It perhaps become clearer when stating what rockets do. They change velocity. In space terms, that's delta-v. A rocket stage can only change your velocity some limited amount. Different targets in ...
user avatar
16 votes
Accepted

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

Here's a Map to the Solar System. It details, roughly how much $\Delta v$ you need to get from one place to the next. You can take the rocket equation to quickly calculate your Fuel fraction for any ...
user avatar
16 votes

Why is the first launch of Falcon Heavy sending a car instead of something useful?

When SpaceX launched the Falcon 1, it took them 4 times to successfully orbit the Earth. The most similar rocket to Falcon Heavy, in terms of the number of engines, the N1, made 4 attempts to reach ...
user avatar
  • 118k
16 votes
Accepted

Where are all those blocks of steel and concrete now?

I have collected a list of orbital mass simulator launches and their fates: Antares A-ONE, mass simulator Orbit: approximately 150 by 160 miles (240 km x 260 km) with an inclination of 51.6 degrees ...
user avatar
  • 4,889
15 votes

What is simulated payload and why are they used?

Launching on a risky booster, is risky. You can define a risky booster as: First launch of a new booster. Return to flight after a failure. Booster with record of failure So you feeling lucky punk?...
user avatar
  • 76.4k
15 votes

Using large orbital launchers as sounding rockets. What are the opportunities and challenges?

Suborbital sounding rockets cost about 1/100 as much as an orbital launcher. Black Brant XII, one of the most advanced sounding rockets in use, can take 100-400kg payload into space for \$600K. For ...
user avatar
14 votes

What's the largest single object payload ever lifted into space?

Following the theme of "depending on your definitions" one could also consider the Polyus spacecraft launched in 1987. The mass of the spacecraft was 80 tonnes. Thoughts about definitions: slightly ...
user avatar
  • 8,848
14 votes

What is the largest number of identical satellites launched together?

480,000,000!† †Depending on how you define satellite. I think Project West Ford is the current record holder, with 480,000,000 individual satellites. Well technically 480,000,000 copper dipole ...
user avatar
13 votes

Was the Space Shuttle the most efficient orbital launcher, based on the launch/LEO mass ratio?

The shuttle was certainly one of the more mass-efficient orbital launchers, but it's a more complicated question than it might seem at first. The shuttle orbiter is ambiguously part of the launcher ...
user avatar
12 votes
Accepted

What is a "payload adapter"?

Payloads come in different shapes and sizes. To put them on a specific launch vehicle, you need to either design the payload to fit perfectly onto the rocket or you need some sort of adapter to mount ...
user avatar
  • 5,036
11 votes

What G-forces do different launchers cause?

It is necessary to have a look at LV manuals (see this meta post for the links to actual PDFs). For instance, Ariane 5 has the following longitudinal acceleration profile: Minotaur I: Roughness of ...
user avatar
  • 11.3k

Only top scored, non community-wiki answers of a minimum length are eligible