1
the liftoff of [noun]
liftoff 是名词，常用 of 引出发射的运载工具。
The liftoff of the rocket was delayed by strong winds.
火箭的升空因强风而推迟。
升空；起飞；发射
先理解核心含义，再看它在真实句子里的用法。
升空；起飞；发射
the initial ascent of a rocket from its launching pad
The liftoff of the rocket was delayed by strong winds.
火箭的升空因强风而推迟。
火箭或飞机发射时离地的瞬间。
The point in the launch of a rocket or an aircraft where it leaves contact with the ground.
火箭从发射台初始升空
the initial ascent of a rocket from its launching pad
人或动物(如跳跃时)离地的瞬间。
The point at which a person or animal leaves the ground, as for example when jumping.
启动成功或行动的起点。
The point of launching into success or action.
Liftoff occurred exactly at 9:30 a.m., and the rocket rose into the sky.
火箭于上午9点30分准时升空，飞入天空。
The entire team held their breath during the liftoff of the new satellite.
整个团队在新卫星发射升空时都屏住了呼吸。
Mission control delayed the liftoff due to high winds.
任务控制中心因强风推迟了升空。
liftoff 是名词，常用 of 引出发射的运载工具。
The liftoff of the rocket was delayed by strong winds.
火箭的升空因强风而推迟。
at liftoff 表示“在升空时”，用作时间状语。
The cameras recorded the moment at liftoff.
摄像机记录了升空那一刻。
liftoff 后接 from 可表示发射地点。
Liftoff from the launch pad was right on time.
从发射台的升空准时进行。
Not this
The rocket will liftoff at 9 a.m.
Use this
The rocket will lift off at 9 a.m.
liftoff 是名词（火箭升空），而动词短语是分开写的 lift off，不能把名词形式直接当动词用。
Not this
Liftoff of rocket was successful.
Use this
The liftoff of the rocket was successful.
liftoff 是可数名词单数，前面需要限定词；汉语没有冠词，容易漏掉 the。
Focus on the distinctions below. Other candidates are kept compact until a reliable usage note is available.
预定发射
The scheduled liftoff was delayed by bad weather.
预定发射因天气恶劣而推迟。
发射时间
The liftoff time has been set for 9 a.m.
发射时间已定在上午9点。
发射程序
Engineers checked the liftoff sequence one last time.
工程师们最后一次检查了发射程序。
顺利升空
The rocket had a smooth liftoff from the launchpad.
火箭从发射台顺利升空。
发射前几分钟
The crew boarded the capsule minutes before liftoff.
机组人员在发射前几分钟进入太空舱。
升空！我们已经升空！
NASA launch commentator Jack King's famous call at the launch of Apollo 11 on July 16, 1969.
美国宇航局发射评论员杰克·金在1969年7月16日阿波罗11号发射时喊出的著名播报。
升空！哥伦比亚号航天飞机升空！
NASA commentator's historic call during the first launch of the Space Shuttle Columbia on April 12, 1981.
美国宇航局播音员在1981年4月12日哥伦比亚号航天飞机首次发射时的历史性播报。
Use liftoff naturally, then get feedback on meaning, tone, grammar, and phrasing.
Revisit a common error or keep this word in your review list.
把 liftoff 拆成 lift（举起）+ off（离开）：火箭被发射台“举起”后“离开”地面，就是升空。
语域：neutral 常见场景：航天/火箭发射、新闻报道、技术说明 liftoff 通常用于航天或火箭发射场景，指火箭离开发射台的初始上升动作，也见于新闻报道或技术说明中。日常口语中较少用，更常说 launch 或 takeoff。
在给定发音 /ˈlɪfˌtɔf/ 中，结尾 /tɔf/ 与 off、cough（美音）、toff、scoff 的 /ɔf/ 同韵。注意拼写近似的 lift /lɪft/ 和 toffee /ˈtɔfi/ 读音不同。
Dictionary facts from ECDICT, WIKTIONARY.