Skip to content
FastestThings

Vehicles

New Horizons

Earth-relative launch speed of about 36,400 mph on 19 January 2006. The launch-day releases say approximately 36,000 mph for the same departure.

Post on X (opens in a new tab)

Velocity

Published as 36,400 mph

Earth-relative speed after the Star 48B burn, 19 January 2006. NASA Science prints about 36,400 mph (58,536 km/h). Launch-day releases print approximately 36,000 mph.

OfficialNASA Science (opens source in a new tab)

In context

  • 1.5 laps of Earth an hourConstant · Earth's equator, 40,075 km (WGS 84)
  • London to New York in 6 minConstant · London to New York, 5,570 km great-circle
  • 55% of Earth's speed around the SunSourced · Earth, 29.8 km/s. NASA planetary fact sheet, mean orbital speed

Worked out from the sourced figure above, which stays the ranked number.

Mechanism

Why it's so fast

New Horizons is fast in a frame you have to name. A rocket does not need to breathe the air, and a spacecraft's big speeds come from burns and from falling in a gravity field.

  1. Say what the speed is relative to

    Speed relative to the Sun, to Earth, or to the air are different measurements. The entry keeps the frame in the conditions. Mixing them would invent a comparison.

  2. Gravity or a burn

    New Horizons gets its ranked speed from the burn or the fall the sources describe. This note does not add a delta-v the papers did not print.

Nearby on this list: Apollo 10.

Provenance

Every measurement

Claimed, measured and official figures side by side, each with its source. The ranked figure is marked.

  1. 16.27km/s36,400mphRanked figure

    Earth-relative speed after the Star 48B burn, 19 January 2006. NASA Science prints about 36,400 mph (58,536 km/h). Launch-day releases print approximately 36,000 mph.

    36,000 mph on the launch-day releases is the same departure, rounded. 58,536 km/h is the kilometre figure NASA Science prints beside 36,400 mph.

    Official
    NASA Science (opens source in a new tab)

Reference

Specs

Frame
Earth-relative launch
Date
19 January 2006
Speed
36,400 mph
Stage
Star 48B

Context

Background

NASA's New Horizons mission page says the Star 48B burn left the spacecraft at about 36,400 mph (58,536 km/h) relative to Earth, the highest launch velocity of a human-made object relative to Earth. The launch was 19 January 2006. That page is the rank. The stored unit is miles per hour.

The NASA press release and the Applied Physics Laboratory release, both dated the launch day, say approximately 36,000 mph. That is the same departure written as a round number, not a second burn. The 400 mph gap is the word approximately. A heliocentric cruise speed is a different frame and is not this row.

Spot a wrong number?

Every report is read by a person, and corrections are dated on the page.