# If rockets were fired at 30 degree angles instead of 90 degree ones, would they require less thrust to achieve orbit?

Relevance
• 4 weeks ago

The shortest distance between two points is a straight line.  If you want to get into outer space quickly, travel perpendicular to the Earth, and minimize the time Gravity has to try and pull you back.

• Jim
Lv 7
1 month ago

Not a direct answer!!!

If it had wings, a reduced thrust could allow it to fly up to a certain altitude, the rocket engine could continue the flight into space. So if MAX THRUST is limited, an angle could work. The X-15 was taken up like this.

• D g
Lv 7
1 month ago

The scientific people have calculated the energy required to achieve orbit is a certain amount... The angle chosen is to minimize travel time

Imagine the distance at 45 degs will be √2*orbital height so the rockets would be in atmosphere longer and thus have to fight friction longer

• Tom
Lv 7
1 month ago

They would have to be held up in a rack/ramp, Perhaps a very long one, until enough thrust developed to keep them off the ground.   Launching straight up  gets it up and gaining speed BEFORE it arches over at an angle anyway.------So why bother with a ramp?

• What do you think of the answers? You can sign in to give your opinion on the answer.
• 1 month ago

60 % More fuel would be needed

And that is an Engineering fact

So that is the reason Launches remain Vertical

It is the Shortest distance  in a straight line between Earth's Surface and Open Space

Did you know, the Saturn 5 used One Million Pounds of Force in just clearing the Ground

• 1 month ago

You don’t play KSP do you. Two words. Aerodynamic drag.

• 1 month ago

No, it would take more by reason of larger rocket to handle the more propellant needed for the longer time in the thicker atmosphere.

To "achieve" orbit is no easy task. Most of the consumed fuel is used for speed

then coast to orbital altitude, then there are burns needed for orbital insertion.

The smallest rocket to do such is Japan's SS-520-5 at a bit over 31 foot long,over a foot and a half diameter, and short of 2.5 tons.

• 1 month ago

Actually they are not launched on average at 90 degrees.  If you watch most of the trajectory you'll see that shortly after lift-off they roll over at less than perpendicular angle re the horizon.  In fact they do this because that allows them to take advantage of the initial velocity they have from the spin on the planet.  And...you are absolutely correct.  That does let them use less thrust to achieve the orbit.  Good catch.

• 1 month ago

Nope, more thrust because it is a longer distance, and therefore they would be fighting gravity for longer.

• 1 month ago

no. they would require more, usually

but it's not that simple. they blast almost straight up (with a small angle to the vertical) to get above the dense atmosphere where resistance is high, then curve over to gain horizontal speed needed for orbit. A lot of complicated calculations are done to get the most economical function of angle versus height.

Still have questions? Get answers by asking now.