# Jet boosters for rockets

**URL:** https://boards.straightdope.com/t/jet-boosters-for-rockets/112196
**Category:** Factual Questions
**Created:** [June 3, 2002, 5:25pm UTC](https://boards.straightdope.com/t/jet-boosters-for-rockets/112196 "2002-06-03T17:25:38Z")
**Posts on this page:** 10
**Page:** 1

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### Author: ![Enola\_Straight](https://avatars.discourse-cdn.com/v4/letter/e/dec6dc/32.png) [@Enola\_Straight](https://boards.straightdope.com/u/Enola_Straight)
#### Post date: [June 3, 2002, 5:25pm UTC](https://boards.straightdope.com/t/jet-boosters-for-rockets/112196/1 "2002-06-03T17:25:38Z")

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Why dosen’t NASA use jet boosters on rockets? I figure, a few  
disposable or reuseable turbo/ramjets (like that on the SR-72  
Blackbird) on the main stage…employed during the trans-atmospheric period of the launch would save the weight and internal volume of carrying your own oxygen.

Would the thrust to weight ratio be impractical?

Perhaps running an oxygen line directly to the jets’ combustion  
chambers?

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### Author: ![Whack-a-Mole](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/whack-a-mole/32/141_2.png) [@Whack-a-Mole](https://boards.straightdope.com/u/Whack-a-Mole)
#### Post date: [June 3, 2002, 7:44pm UTC](https://boards.straightdope.com/t/jet-boosters-for-rockets/112196/2 "2002-06-03T19:44:36Z")

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Jet engines are expensive. Even floating them back to earth under a parachute is likely to damage them. If they land in the sea salt water can’t be too good for them and dropping them onto the ground would likely cause all sorts of damage. Merely reparing them and tuning them up for another flight would likely be costly and not worth the effort. Solid rocket boosters are probably simpler to deal with in this fashion.

Additionally, for flat out thrust a jet can’t really compare to a rocket. A jet engine that would rival the thrust of the solid rockets on the shuttle would likely have to be huge and impractical.

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### Author: ![Kamandi](https://avatars.discourse-cdn.com/v4/letter/k/5daacb/32.png) [@Kamandi](https://boards.straightdope.com/u/Kamandi)
#### Post date: [June 3, 2002, 8:38pm UTC](https://boards.straightdope.com/t/jet-boosters-for-rockets/112196/3 "2002-06-03T20:38:44Z")

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Not to mention that the flight profile of a ballistic rocket makes using a jet impractical. Because a rocket accelerates continuously, the time that it spends in a useful speed range for a jet engine would be very short. It just wouldn’t be worth the effort.

However, [Orbital Science Corporation](http://www.orbital.com/LaunchVehicles/Pegasus/pegasus.htm) uses a jet aircraft (a Lockheed L-1011) as a “first stage” carrier for its Pegasus rocket. The rocket is carried underneath the aircraft and released at about 40,000 ft. It can put up to 1000 lb into low-Earth orbit.

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### Author: ![Kilt-wearin\_man](https://avatars.discourse-cdn.com/v4/letter/k/82dd89/32.png) [@Kilt-wearin\_man](https://boards.straightdope.com/u/Kilt-wearin_man)
#### Post date: [June 3, 2002, 9:35pm UTC](https://boards.straightdope.com/t/jet-boosters-for-rockets/112196/4 "2002-06-03T21:35:23Z")

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[nitpick] - it was probably a tpyo, but there is no “SR-72 Blackbird”. It’s the **SR-71**.

Ditto on jet engines not being nearly as powerful as rockets of comparable weight. There’s also the factor of the thousands of moving parts in a jet engine vs the minimal number of moving parts in a rocket engine. This is a big factor when your engine is all that keeps you from hitting the ground.

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### Author: ![racer72](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/racer72/32/3075_2.png) [@racer72](https://boards.straightdope.com/u/racer72)
#### Post date: [June 3, 2002, 10:43pm UTC](https://boards.straightdope.com/t/jet-boosters-for-rockets/112196/5 "2002-06-03T22:43:17Z")

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Many heavy aircraft used by the military such as tankers use rockets to assist the jet engines. It was one of these rockets that was part of the urban legend about the guy that strapped the JAT rocket to his Chevy and flew himself and the car into the side of a cliff.

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### Author: ![Whack-a-Mole](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/whack-a-mole/32/141_2.png) [@Whack-a-Mole](https://boards.straightdope.com/u/Whack-a-Mole)
#### Post date: [June 4, 2002, 12:16am UTC](https://boards.straightdope.com/t/jet-boosters-for-rockets/112196/6 "2002-06-04T00:16:31Z")

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> [@](#):
>
> \*Originally posted by racer72 \*  
> \*\*Many heavy aircraft used by the military such as tankers use rockets to assist the jet engines. \*\*

Yup…here’s a [picture of a C-130](http://www.fas.org/man/dod-101/sys/ac/c-130-jato.jpg) using one.

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### Author: ![Richard\_Pearse](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/richard_pearse/32/13144_2.png) [@Richard\_Pearse](https://boards.straightdope.com/u/Richard_Pearse)
#### Post date: [June 4, 2002, 12:32am UTC](https://boards.straightdope.com/t/jet-boosters-for-rockets/112196/7 "2002-06-04T00:32:22Z")

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Called a JATO not a JAT I believe (Jet Assisted Take-Off)

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### Author: ![Enola\_Straight](https://avatars.discourse-cdn.com/v4/letter/e/dec6dc/32.png) [@Enola\_Straight](https://boards.straightdope.com/u/Enola_Straight)
#### Post date: [June 4, 2002, 5:19am UTC](https://boards.straightdope.com/t/jet-boosters-for-rockets/112196/8 "2002-06-04T05:19:32Z")

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I heard about that myth. First read about it in Car and Driver…  
or is it Motor Trend?

Anyways…

A few years ago, the police out in the mid-west notices some  
wreckage at the base of a cliff. Seeing how flattened the sheetmetal was, they knew the impact was several hundred miles per hour, so they naturally assumed it was an aircraft.

Upon closer inspection, it turned out to be an Impala SS.

Apparently, some guy got one of these JATO bottles and attached  
it to his Hot-Rod, found a long straight stretch of road to ride,  
and let 'er rip.

Onlya bend in the road up ahead neccesitated decelleration…  
impossible until the fuel in the JATO is fully expended.

The poor sap burned out his brakes, still going 300+ MPH upon  
impact.

Or so the story goes.

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### Author: ![Kamandi](https://avatars.discourse-cdn.com/v4/letter/k/5daacb/32.png) [@Kamandi](https://boards.straightdope.com/u/Kamandi)
#### Post date: [June 4, 2002, 4:09pm UTC](https://boards.straightdope.com/t/jet-boosters-for-rockets/112196/9 "2002-06-04T16:09:26Z")

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Snopes says [it never happened](http://www.snopes2.com/autos/dream/jato.htm).

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### Author: ![Brave\_Sir\_Robin](https://avatars.discourse-cdn.com/v4/letter/b/a183cd/32.png) [@Brave\_Sir\_Robin](https://boards.straightdope.com/u/Brave_Sir_Robin)
#### Post date: [June 4, 2002, 5:43pm UTC](https://boards.straightdope.com/t/jet-boosters-for-rockets/112196/10 "2002-06-04T17:43:38Z")

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If this guy is on the level, there may be some truth behind the Rocket Car urban legend. The story he tells is much more believable than the urban legend, so I lend it at least a little bit of credence.

> **[Heard the One About the Rocket Car?](https://www.wired.com/2000/08/rocketcar/)**
>
> Hasn’t everyone? Now meet the guy who says he lit the fuse. Editor’s note: Wired found the following tale posted on the Web, originally at a site called cardhouse.com. According to its author, the story has garnered thousands of emails, some filled...
