3
$\begingroup$

The question is restricted to payloads having described at least 2 orbits.

When watching launches, it appears that between launch and orbit insertion, the typical time interval is few minutes (perhaps between 8 and 30 minutes depending on the launcher). I imagine minimizing the time inside the atmosphere is important (while constraint by acceleration the payload can sustain and the time to perform the gravity turn).

If we define the launch time as... the launch time (beginning of launcher take off, before clearing the tower) and we consider the payload is in orbit as soon as it is released (end of launcher mission, possibly several seconds after reaching orbital velocity), what is the historical maximal time interval between launch and orbit? What is the minimal one?

$\endgroup$
  • $\begingroup$ Possibly sputnik for fastest. "Telemetry indicated that the strap-ons separated 116 seconds into the flight and the core stage engine shutdown 295.4 seconds into the flight." The final orbit was reached in 295.4 seconds. But I don't know if you're counting that (mostly because I don't fully know what you mean by "having described at least 2 orbits"). $\endgroup$ – Magic Octopus Urn Jul 23 at 13:10
  • $\begingroup$ @MagicOctopusUrn: "described 2 orbits" - orbited Earth at least twice. Gagarin wouldn't count because he completed only 1 orbit. Personally I'd put my money on one of the mini-launchers like Lambda 4s - or depending how you count the launch time, ATK Pegasus. Huge TWR, short time to reach circularization altitude. $\endgroup$ – SF. Jul 23 at 14:38
  • 1
    $\begingroup$ If you have a better formulation, don't hesitate to edit the question (and yes my intention was to exclude payload that didn't stay into orbit for more than one orbit, such as Gagarin) $\endgroup$ – Manu H Jul 23 at 14:52
  • 2
    $\begingroup$ Related: Is there a lower limit on time-to-orbit from launch? $\endgroup$ – Russell Borogove Jul 23 at 15:26
  • 1
    $\begingroup$ @MagicOctopusUrn "to trace or mark out; to give rise to a geometric structure" -- but "completed" is probably better for this Q. $\endgroup$ – Russell Borogove Jul 23 at 15:29
7
$\begingroup$

The fastest time to orbit I know of is the TRICOM 1R cubesat launch on SS-520-5. It reached LEO in 263.6 seconds -- and that's including a minute and a half of coast time between the first stage separation and second stage ignition! It's also the smallest orbital launcher. The payload wasn't released until 3 minutes later, however, which might disqualify it based on the wording of your question.

For crewed orbital launches, the Mercury-Atlas flights take the record. I think John Glenn's MA-6 flight at 5:01 was the winner but I haven't found a SECO time for MA-9.

For longest time to orbit, the answer is trickier. Some flight profiles, for example, the space shuttle, start by establishing an elliptical orbit with an in-atmosphere perigee, then coast for about half an orbit before circularizing at the apogee. The shuttle's main engines burned for 8 and a half minutes before cutoff, but the circularization burn would be about 35 minutes after liftoff. I don't know if any launchers do a direct-to-GTO ascent (without establishing a low Earth orbit) before circularizing at geosynchronous altitude, which would take many hours.

Some launchers with low-thrust upper stages (e.g. Ariane) take 15-20 minutes to reach LEO without a long coast phase.

$\endgroup$
  • $\begingroup$ I did hesitate to define the time of orbit insertion as when the payload reach orbital velocity, but it may be hard to find as orbital velocity vary with altitude. Payload release is easier to find just by watching a launch video (no need to access to the telemetry + compute the second at which the payload has reach orbital velocity at its current altitude) $\endgroup$ – Manu H Jul 23 at 14:48
  • 1
    $\begingroup$ After the launcher engines cut off, you’re either in orbit or you’re not (assuming the payload doesn’t complete orbital insertion on its own, which it doesn’t in most LEO cases), so that’s as good a milestone as any. $\endgroup$ – Russell Borogove Jul 23 at 15:09
  • $\begingroup$ @ManuH you can also compute Instantaneous Impact Point (IIP) -- when that point vanishes, you've reached orbit (for at least ~1 revolution) $\endgroup$ – costrom Oct 29 at 15:38

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.