What is (or was, if it's no longer in use) the system with lowest launch mass, capable of putting (any) payload in (or reaching) LEO? "How small" did we get with orbital flights?

(and yes, I realize economically that's a rather poor idea; still I'd like to know what was attempted.)


2 Answers 2


Juno 1 had a payload of 11 kg to LEO from a start mass of 29 t.

Diamant-A had a start weight of 18.4 t, payload 100 kg to LEO.

Black Arrow had a start weight of 18.1 t, payload 100 kg to LEO.

Vanguard, start weight of 10 t, payload 9 kg to LEO.

Lambda 4S had a start weight of 9.4 t, payload 26 kg to LEO.

Caleb was an air-launched missile theoretically capable of attaining orbit. Start weight of 1350 kg, payload 7 kg to LEO.

Project Pilot was an air-launched missile theoretically capable of attaining orbit. Start weight of 900 kg, payload 1 kg to LEO.

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    $\begingroup$ I arrived at my answer through several iterations, starting with Juno and Diamant. I left them in to give an idea of the playing field. $\endgroup$
    – Hobbes
    Jul 11, 2016 at 12:43
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    $\begingroup$ Thanks :) I wonder about thoughts of the pilot of the plane from which Calebs were launched, They had an uncanny tendency to explode on ignition, which would in this case probably mean "adjacent to the airplane". $\endgroup$
    – SF.
    Jul 11, 2016 at 13:02
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    $\begingroup$ It doesn't seem fair to neglect the mass of the plane for the air-launched rockets. That's like neglecting the mass of stage 1 for a multi-stage rocket. $\endgroup$ Jul 11, 2016 at 18:19
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    $\begingroup$ Are they sorted by cost? Which was cheapest of the alternatives listed? $\endgroup$ Jan 24, 2019 at 2:33
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    $\begingroup$ They are in the order in which I found them. Theyr'e also mostly really old projects (from the 1950s-1960s). No idea about the cost. $\endgroup$
    – Hobbes
    Jan 24, 2019 at 7:04

The smallest launch system (by total mass) that has actually put something in orbit is the SS-520 (first successful orbital launch 3 February 2018).

  • Start mass: 2,600 kg
  • Payload to LEO: 9 kg

Current design and future designs: Series size comparisons


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